Journal articles: 'Molding segment'

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Vijaykumar, V., Lidhiya Alexander, and Pazhaniswamy Manivannan. "A Review on Nasoalveolar Molding." Journal of Scientific Dentistry 10, no. 2 (2020): 49–50. http://dx.doi.org/10.5005/jp-journals-10083-0922.

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ABSTRACT A common hereditary defect of the oral cavity with grave socioeconomic problem is cleft lip and palate. Although the defect varies in forms and severity, the individuals presented with glitches regarding functions and esthetics. Authors claim that nasoalveolar molding improves facial esthetics and function and has gained more attention. The objective of presurgical nasoalveolar molding comprises improving lip segment, inferior lateral alar cartilages, and alveolar cleft segments. Outcomes of presurgical nasoalveolar molding are promising and hence are encouraged immediately after birth and continued until further corrective surgery is planned. The rationale of presurgical nasoalveolar molding is approximation of the alveolar segments, wherein the surgeon has to perform gingivoperiosteoplasty followed by corrective lip surgery. How to cite this article: Manivannan P, Alexander L, Vijaykumar V. A Review on Nasoalveolar Molding. J Sci Dent 2020;10(2):49–50.

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Hu, Hai Ming, De Bao Yin, and Hui Li. "Forming Process of Segment-Narrow-Bars on the PCR Mold." Key Engineering Materials 561 (July 2013): 270–73. http://dx.doi.org/10.4028/www.scientific.net/kem.561.270.

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The narrow bars on tire mold segment are used for molding the sipes on the tread, Its size is small.Its shape and location is diverse and process is complex. This article, through processing feasibility analysis of the narrow bars, combined with production practice, conducted a systematic and detailed explanations on the process of molding the narrow bars in the precision casting method for molding segment.Through analyse a number of empirical conclusions about narrow bars’ forming process which have drawn, and has proved the practicality of these methods through practice.

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Saad, M. S., M. Fata, A. Farouk, A. M. A. Habib, M. Gad, M. B. Tayel, and M. K. Marei. "Early Progressive Maxillary Changes with Nasoalveolar Molding: Randomized Controlled Clinical Trial." JDR Clinical & Translational Research 5, no. 4 (December 20, 2019): 319–31. http://dx.doi.org/10.1177/2380084419887336.

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Objectives: Quantitative assessment of 3-dimensional progressive changes of the maxillary geometry in unilateral cleft lip palate (UCLP) with and without nasoalveolar molding (NAM). Methods: The study was designed as a prospective 2-arm randomized controlled clinical trial conducted in parallel. Forty infants with nonsyndromic UCLP were randomly assigned into a NAM-treated group (n = 20) and non–NAM treated group (n = 20). A total of 120 laser-scanned maxillary casts were collected and blindly analyzed via a modified algorithm at T0 (initial visit; baseline), T1 (after 3 wk; first interval), and T2 (after 6 wk; second interval). The main outcome measures were the amount and rate of cleft gap changes, the midline position, and the transverse, sagittal, and vertical growth through intervals. Results: More than 50% of the cleft gap (56.42%; P < 0.001) was reduced in the first 3 wk of alveolar molding (AM). The end point of the AM was obtained in 6 wk (86.25%; P < 0.001); then, the kinks of the greater segment were noticed. The AM effect decreased as far as posterior; the anterior arch width reduced slightly (1.23%; P < 0.001), while the middle and posterior arches increased slightly (P > 0.999 and P = 0.288, respectively). The posterior arch width was the least changing and was considered a baseline, while the anterior was the pivot of the segment rotation. Both groups showed different patterns of segment rotation and sagittal growth. The non–NAM treated group showed a slight increase in cleft gap length, arch width, and midline position. Conclusion: Based on this study, it was concluded that the NAM treatment is effective in minimizing cleft severity and realigning maxillary segments without the deterioration of the transverse and vertical arch growth. Near follow-up visits are recommended to monitor the rapid gap reduction within the first 3 wk. Further trials are recommended to compare the outcomes regarding the sagittal growth to reference values ( ClinicalTrials.gov NCT03029195). Knowledge Transfer Statement: The results of this study will help clinicians understand nasoalveolar molding biomechanics that may improve the treatment outcomes for patients with unilateral cleft lip and palate. The trial data can be a valuable guide to the qualitative and quantitative predictive virtual molding in computer aided design–simulated nasoalveolar molding therapy. The modified algorithm can be used by researchers to quantify the rate, the sequence, and the direction of the maxillary segments movement in unilateral cleft lip and palate.

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Chang, Chih-Yuan, and Wei-Ru Chen. "Influence of processing variables on quality of unsaturated polyester/E-glass fiber composites manufactured by double-bag progressive compression method." Advances in Mechanical Engineering 10, no. 9 (September 2018): 168781401879853. http://dx.doi.org/10.1177/1687814018798531.

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A hybrid process of articulated resin transfer molding and vacuum-assisted resin infusion, called double-bag progressive compression method, has been invented to fabricate composite parts. In double-bag progressive compression method, the secondary bag is divided into several segments. During resin infusion, the double bag is drawn upward by vacuum, and the initial flow resistance offered by the loose preform is low. Once the resin infusion is completed, the vacuum on the segmented bags is progressively released to ambient pressure, and the segmental compression is sequentially performed until unnecessary resin is completely removed. This research is to experimentally investigate the influence of double-bag progressive compression method processing parameters, including vacuum pressure in the cavity, number of segments, initiating time of the next compression, temperature of the heated air, initiating segment of the heated air, initial height of the mold cavity, and excess infused resin, on the mechanical property of the part. The design of experiments adopts Taguchi’s method. Results show that the double-bag progressive compression method significantly reduces total filling time and maximally increases the flexural modulus of the part by 17.81% as compared with the typical vacuum-assisted resin infusion. A preferable parameter condition is proposed by taking both the flexural modulus and the operation complexity into account.

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Cooper, Stuart L., and John A. Miller. "Chain Conformation in Elastomeric Multiblock Copolymers as Measured by Small-Angle Neutron Scattering." Rubber Chemistry and Technology 58, no. 5 (November 1, 1985): 899–912. http://dx.doi.org/10.5254/1.3536102.

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Abstract Small-angle neutron scattering has been shown to be an effective technique for investigating segment conformation in two-phase multiblock copolymer systems. By choosing the appropriate isotopic compositions, either segment can be investigated, as can the whole chain. The best approach to the experiment is to use a phase-contrast matched sample, one where no interphase scattering occurs. This allows the experiments to be carried out on a single sample, simplifying the experiment, and reducing the beam time requirements. Equations (2) and (3) describe the phase-contrast matched criterion. At room temperature, the polyether soft segments in the polyurethane elastomer-and in the polyether-polyester block copolymers are somewhat extended on the average relative to the bulk oligomer conformation. In the polyether-polyester with a lower hard-segment content, the soft segments are less extended than in the higher ester content material. A distribution of conformations occurs in these materials, with a majority of the soft segments being nearly in a random-coil conformation. A substantial number of segments are fairly taut, leading to an average conformation that is somewhat extended relative to the random coil conformation. The soft-segment radius of gyration in the polyurethane material initially decreases with increasing temperature. As the temperature rises, the retractive force on the taut soft segments increases, thus facilitating the extraction of hard segments from the amorphous hard phase into the soft phase. One would expect that the degree of phase separation would decrease with increasing temperature due to such a mechanism, and in fact this is borne out by small-angle x-ray scattering studies. Above 150°C, an upturn in the soft-segment radius of gyration is observed. Koberstein et al. propose a phase mixing transition around this temperature in polyurethane systems. Such a transition implies a greater compatibility between the hard and soft segment types at elevated temperatures. Thus, a swelling of the soft segments is seen due to favorable interactions with the hard segments located in the soft phase. A schematic diagram of the polyurethane microstructure and chain conformation is presented in Figure 9. The soft-segment radius of gyration in the polyether-polyester materials decreases smoothly with increasing temperature. This is primarily due to a decrease in the number of taut tie molecules present at elevated temperatures due to the rearrangement of the hard crystalline domains. In addition, relaxation of stresses introduced by molding these samples below the hard-segment crystalline melting temperature may contribute to the decrease in the soft-segment Rg.

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Spengler, Adam L., Carmen Chavarria, John F. Teichgraeber, Jaime Gateno, and James J. Xia. "Presurgical Nasoalveolar Molding Therapy for the Treatment of Bilateral Cleft Lip and Palate: A Preliminary Study." Cleft Palate-Craniofacial Journal 43, no. 3 (May 2006): 321–28. http://dx.doi.org/10.1597/05-093.1.

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Objective To evaluate the outcome of presurgical nasoalveolar molding therapy in the treatment of patients with bilateral cleft lip and palate. Design A prospective study with blinded measurements. Setting The Cleft and Craniofacial Clinic at the University of Texas at Houston Medical School, Houston, Texas. Patients Eight patients with bilateral cleft lip and palate, treated between 2002 and 2004. Interventions The starting age for presurgical nasoalveolar molding therapy was 34.9 days and the average length of the therapy was 212.5 days. Main Outcome Measures Measurements of intraoral and extraoral casts were performed, and statistical analyses were used to compare the differences between measurements before and after therapy. Results Intraoral measurements demonstrated that there was a statistically significant reduction of the premaxillary protrusion and deviation. There was also a significant reduction in the width of the larger cleft. Extraoral measurements revealed that there was a significant increase in the bi-alar width and in the columellar length and width. Moreover, there was a significant improvement in columellar deviation. Finally, the nostril heights of both sides were increased. Conclusion The authors have quantitatively shown that presurgical nasoalveolar molding therapy has significant advantages in the treatment of bilateral cleft lip and palate patients. It improves the nasal asymmetry and deficient nasal tip projection associated with bilateral cleft lip and palate. It also forces the protruded premaxillary segment into alignment with the dental alveolar segments, improving the shape of the maxillary arch. As a result, the changes associated with presurgical nasoalveolar molding therapy help decrease the complexity of subsequent surgeries.

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Birkar, Smita, Joey Mead, and Carol Barry. "INJECTION MOLDING OF THERMOPLASTIC ELASTOMERS FOR MICROSTRUCTURED SUBSTRATES." Rubber Chemistry and Technology 87, no. 4 (December 1, 2014): 629–46. http://dx.doi.org/10.5254/rct.14.86924.

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ABSTRACT Microstructured surfaces injection molded from thermoplastic elastomers have emerging applications as superhydrobic surfaces and patterned adhesives, but there is a limited understanding of the factors affecting replication with these materials. This work investigates the interactions of the tooling aspect ratio and feature orientation (negative and positive tooling) and thermoplastic elastomer hard segment content on microfeature replication. Electroformed nickel tooling having positive and negative features with different geometries and aspect ratios of 0.02:1 to 2:1 were molded from three copolyester thermoplastic elastomers with similar chemistry and different hardness values. The tooling and part features were characterized for feature depth and height as well as feature definition using scanning electron microscopy and optical profilometry. Results were correlated with elastomer properties.

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Suri, Sunjay, and Bryan D. Tompson. "A Modified Muscle-Activated Maxillary Orthopedic Appliance for Presurgical Nasoalveolar Molding in Infants with Unilateral Cleft Lip and Palate." Cleft Palate-Craniofacial Journal 41, no. 3 (May 2004): 225–29. http://dx.doi.org/10.1597/02-141.1.

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Objective The purpose of this article is to describe a modified appliance and treatment approach for presurgical nasoalveolar molding in infants with unilateral cleft lip and palate. Methods This approach uses a plate held in with outriggers, which prevents the cleft-widening effect of the tongue, helps with tongue tip placement, and utilizes the functional movements of the facial musculature to guide and relocate the major segment medially to its normal position. Nasal molding is undertaken after most of the lateromedial correction of the alveolar position. Conclusions This technique helps to improve alveolar position, nasal septum alignment, nasal symmetry, and nasal tip projection prior to lip repair.

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Vura, Nandagopal, Rajasekhar Gaddipati, Yudhistar Palla, and Pranay Kumar. "An Intraoral Appliance to Retract the Protrusive Premaxilla in Bilateral Cleft Lip Patients Presenting Late for Primary Lip Repair." Cleft Palate-Craniofacial Journal 55, no. 4 (January 23, 2018): 622–25. http://dx.doi.org/10.1177/1055665617732783.

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The protruding and deviated premaxilla in bilateral complete cleft lip and palate (BCL/P) patients causes a perplexing problem in achieving a tension-free primary lip closure. An innovative noninvasive active intraoral Fixed Pre-Surgical Cleft Orthopedic (FPSCO) appliance is presented that has enabled to successfully reposition the premaxillary segment to a more favorable position prior to the surgical repair in 4 BCL/P patients, who reported late for treatment with a mean age of 18 ± 3 months. All the patients had at least 1 deciduous tooth erupted in 3 cleft segments, 1 premaxilla (PM), and 2 lateral maxillary (LM) segments. This innovative approach is a noninvasive method of getting the cleft segments closer prior to chelioplasty, where conventional presurgical nasoalveolar molding (PNAM) is not possible, which needs to be done early in life as it requires circulating maternal estrogen levels to achieve results preferably possible in patients younger than 3 to 6 months. Bonding to erupted teeth with glass ionomer cement was implemented to secure the appliance. Nickel-titanium (Ni-Ti) closed-coil springs were used that delivered continuous forces of 150 g/5 oz per side to retract the premaxillary segment. The mean active period of treatment time was 3.5 ± 1.6 months and the retention period was 1.2 ± 0.6 months, following which cheiloplasty was performed.

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Bauer, Franz Xaver, Markus Schönberger, Johannes Gattinger, Markus Eblenkamp, Erich Wintermantel, Andrea Rau, Florian Dieter Güll, Klaus-Dietrich Wolff, and Denys J. Loeffelbein. "RapidNAM: generative manufacturing approach of nasoalveolar molding devices for presurgical cleft lip and palate treatment." Biomedical Engineering / Biomedizinische Technik 62, no. 4 (August 28, 2017): 407–14. http://dx.doi.org/10.1515/bmt-2016-0035.

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AbstractNasoalveolar molding (NAM) is an accepted treatment strategy in presurgical cleft therapy. The major drawbacks of the treatment listed in the literature relate to the time of the treatment and the coordination of the required interdisciplinary team of therapists, parents, and patients. To overcome these limitations, we present the automated RapidNAM concept that facilitates the design and manufacturing process of NAM devices, and that allows the virtual modification and subsequent manufacture of the devices in advance, with a growth prediction factor adapted to the patient’s natural growth. The RapidNAM concept involves (i) the prediction of three trajectories that envelope the fragmented alveolar segments with the goal to mimic a harmonic arch, (ii) the extrusion from the larger toward the smaller alveolar segment along the envelope curves toward the harmonic upper alveolar arch, and (iii) the generation of the NAM device with a ventilation hole, fixation pin, and fixation points for the nasal stents. A feasibility study for a vector-based approach was successfully conducted for unilateral and bilateral cleft lip and palate (CLP) patients. A comparison of the modified target models with the reference target models showed similar results. For further improvement, the number of landmarks used to modify the models was increased by a curve-based approach.

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Ryan, Anthony J., Todd B. Bergstromcu, Wayne R. Willkomm, and Christopher W. Macosko. "Thermal, mechanical, and fracture properties of copolyureas formed by reaction injection molding: Effects of hard segment structure." Journal of Applied Polymer Science 42, no. 4 (February 20, 1991): 1023–39. http://dx.doi.org/10.1002/app.1991.070420416.

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Yoo, Do-Jae, Ki-Chan Kim, Young-Hoon Kwak, Min-Seok Jang, Job Ha, Jae-Cheon Doh, Chang-Bae Lee, and Young-Do Kweon. "Molded Underfill (MUF) Technology Development for SiP Module with Fine Flip Chip." International Symposium on Microelectronics 2010, no. 1 (January 1, 2010): 000204–11. http://dx.doi.org/10.4071/isom-2010-tp2-paper2.

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In this study, we developed the Molded Underfill (MUF) technology for system in package (SiP) module with fine pitch flip chip in RF application, in which two flip chips, LC filter, and additional passive components are integrated side-by-side. This study covered not only MUF reliability performance but also MUF design study focused on the void free methodology to minimize void between flip chip bumps in the SiP module. The investigation comprises several aspects: A design study that present a printed circuit board (PCB) and epoxy molding Compound (EMC) selection approach, air vent design of cavity vacuum molding, and void formation mechanism by mold flow simulation and DOE(Design of Experiment) of several SIP module layouts. The test vehicle used for this study of MUF by vacuum transfer molding shown as SiP module (8.2×7.7×1.13mm) which was sawn from 52.70×68.70×0.75mm mold area of 118.5*75.5*0.38 substrate. One segment mold inside (52.70× 68.70×0.75mm) had 35ea SiP modules (7X5 unit array). In addition, one SiP module included one Flip chip RF/BB IC(6.51×5.81×0.41mm) which had 339ea bumps and 95um Bump height, one Flip chip RF switch (0.705×0.705× 0.33mm) which had 4 bumps and 85um bump height, 1.6×0.8×0.6mm size of LC filter, and total 25ea passives. In the end, SAT result of void, moisture sensitivity test, thermal cycle test and pressure cooker test had also been carried out for reliability evaluation. The test result shows that the optimized SiP module with fine flip pitch has a good reliability performance.

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Dai, Jinyue, Na Teng, Xiaobin Shen, Yuan Liu, Lijun Cao, Jin Zhu, and Xiaoqing Liu. "Synthesis of Biobased Benzoxazines Suitable for Vacuum-Assisted Resin Transfer Molding Process via Introduction of Soft Silicon Segment." Industrial & Engineering Chemistry Research 57, no. 8 (February 19, 2018): 3091–102. http://dx.doi.org/10.1021/acs.iecr.7b04716.

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Nalla, Ajit R., Michael Fuqua, James Glancey, and Benoit Lelievre. "A multi-segment injection line and real-time adaptive, model-based controller for vacuum assisted resin transfer molding." Composites Part A: Applied Science and Manufacturing 38, no. 3 (March 2007): 1058–69. http://dx.doi.org/10.1016/j.compositesa.2006.06.021.

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Mohammed, Shammas, Rama Krishna Alla, Achut Devarhubli, and SK Shakeel. "Changes in Vertical Dimension of Complete Dentures due to Rebasing with Different Techniques." World Journal of Dentistry 4, no. 2 (2013): 96–99. http://dx.doi.org/10.5005/jp-journals-10015-1211.

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ABSTRACT Dental literature is devoid of information in respect of altered incisal pin relation due to compression molding in a single denture. It is to be reckoned that in rebasing technique, the entire segment of teeth remain fixed through a matrix of set polymethylmethacrylate that binds all the teeth. Thus, the artificial teeth do not remain as individual but act as a single unified unit of all the teeth. In view of lack of information in change in vertical dimension due to rebasing procedures and with the aim of determining the method of rebasing that result in minimal changes in occlusal discrepancy, the study was undertaken to evaluate the changes in vertical dimension of occlusion after rebasing using two different methods. How to cite this article Mohammed S, Alla RK, Devarhubli A, Shakeel SK. Changes in Vertical Dimension of Complete Dentures due to Rebasing with Different Techniques. World J Dent 2013;4(2):96-99.

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Chae, MyoungSu, Eric Ouyang, JaeHan Chung, DokOk Yu, SeonMo Gu, Gwang Kim, and Billy Ahn. "Simulation and Experiment of Molded Underfill Voids." International Symposium on Microelectronics 2012, no. 1 (January 1, 2012): 000359–65. http://dx.doi.org/10.4071/isom-2012-tp33.

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The molded underfill (MUF) has become one of the trends in the IC packaging industry due to its simplification of assembly process steps and the saving of the cost. However, for the fine pitch flip chip bumping array, the void generation is one serious issue causing the short of the electrical connections and the cracking of the bumps. In this paper, the main focus is to predict the void generation and to compare with the experimental data. The early stage FEM numerical simulation not only can predict the risk of voids but also provide the best economic approach without the need to spend trial and error budget. A multiple segments substrate strip, with totally 64 packages populated on it, is used in the experiment. The manufacturing process parameters are programmed and recorded for comparison. The filling, packing, and curing of molding compound are carefully chosen in order to compare their effects. After the assembly process, each package is scanned with C-SAM inspection to check if the voids appear. For FEM numerical simulation, only one segment of the substrate strip, with totally 16 packages, is modeled to save computational resources and time. However, all the bumps, on each of the package, are modeled in order to check how the flow field is affected by the packages. In conclusion, we have obtained good match of experimental vs. simulation data. The prediction of voiding location is very close to each other.

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Roh, Hyun-gyoo, Sunghoon Kim, Jungmin Lee, and Jongshin Park. "Effect of Low-Temperature Pyrolysis on the Properties of Jute Fiber-Reinforced Acetylated Softwood Kraft Lignin-Based Thermoplastic Polyurethane." Polymers 10, no. 12 (December 3, 2018): 1338. http://dx.doi.org/10.3390/polym10121338.

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Short jute fiber-reinforced acetylated lignin-based thermoplastic polyurethane (JF reinforced ASKLTPU) was prepared and characterized as a short-fiber-reinforced elastomer with carbon-neutrality and biodegradability. The acetylated softwood kraft lignin-based thermoplastic polyurethane (ASKLTPU) was prepared with polyethylene glycol (PEG) as a soft segment. Short jute fiber was modified using low-temperature pyrolysis up to the temperatures of 200, 250, and 300 °C in order to remove non-cellulosic compounds of jute fibers for enhancing interfacial bonding and reducing hydrophilicity with the ASKLTPU matrix. JF-reinforced ASKLTPUs with fiber content from 5 to 30 wt % were prepared using a melt mixing method followed by hot-press molding at 160 °C. The JF-reinforced ASKLTPUs were characterized for their mechanical properties, dynamic mechanical properties, thermal transition behavior, thermal stability, water absorption, and fungal degradability. The increased interfacial bonding between JF and ASKLTPU using low-temperature pyrolysis was observed using scanning electron microscopy (SEM) and also proved via interfacial shear strength measured using a single-fiber pull-out test. The mechanical properties, thermal properties, and water absorption aspects of JF-reinforced ASKLTPU were affected by increased interfacial bonding and reduced hydrophilicity from low-temperature pyrolysis. In the case of the degradation test, the PEG component of ASKLPTU matrix highly affects degradation and deterioration.

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Kim, Peter Chanwoo, Yong Don Kim, and Dae Hwan Park. "Occipitofrontal Switching for Simultaneous Correction of Synostotic Frontal and Occipital Plagiocephaly: A Novel Surgical Technique." Craniomaxillofacial Trauma & Reconstruction 3, no. 3 (September 2010): 161–66. http://dx.doi.org/10.1055/s-0030-1263081.

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Plagiocephaly has traditionally been corrected by unilateral or bilateral frontal bone advancement or rotation using bone-molding forceps and distraction devices. Complete symmetrical correction of deformed frontal bones is considered almost impossible because the curvature of each frontal bone varies. We evaluated the feasibility of measuring the optimal curvature of frontal and occipital bones using a plaster skull model and applying these measurements to “switch” them for simultaneous correction of frontal and occipital plagiocephaly. A 2-year-old girl suffering from unifrontal flattening visited our clinic. Unilateral coronal synostosis was observed. The 3-D rapid prototype model and skull replica method using thin paper clay were used for preplanned virtual surgery. The triangular bone was harvested from the contralateral bulging side of the occipital bone (“occipitofrontal switching”) for the best optimal curvature in the affected frontal bone. Another triangular bone was harvested from the ipsilateral flattened side of the frontal bone, and bones were switched with each other. Further bending of the frontal or occipital segment was not necessary for optimal curvature. Symmetrical correction was made by switching the triangular bone of the frontal area with that of the contralateral occipital area. Revision has not been necessary, and infection was not observed at 1-year follow-up. Our novel technique of preplanning surgery using a 3-D plaster model for simultaneous correction of frontal and occipital plagiocephaly is effective and time-saving.

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Abdulrauf, Badr M. I. "The nasal cantilever technique in children undergoing primary cleft lip surgery: novel concepts and review." Innovative Surgical Sciences 5, no. 1-2 (September 7, 2020): 53–62. http://dx.doi.org/10.1515/iss-2020-0016.

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AbstractBackgroundNasal deformity associated with cleft lip deformity is a challenging issue, encompassing controversies, theories, and a diversity of techniques. Historically, esthetic outcomes have ranged from being below expectations to barely acceptable.MethodBased on the concept that the nasal cartilaginous framework in clefts is similar to that of a collapsing pyramid, a novel suspension technique has been described. The entire cartilaginous structure is lifted from the infratip segment with a loop suture and is secured in a cantilever fashion onto the periosteum overlying the nasal bone. This part of the operation is performed in a semiclosed manner. The technique is applied during primary surgery in bilateral and unilateral nasal cleft lip deformities, with changes in the orientation of the cantilever loop suture. Studies conducted by Masters S. Tajima, H. McComb, H. Thomson, D. Fisher, and J. Mulliken, which are most relevant to this article, have been reviewed and discussed throughout.ResultsThe technique was first applied over 10 years ago. A case series of nine children whose parents consented to the developing technique is presented with follow-up ranging from months to years, along with technical descriptions and illustrative drawings. None of these cases had preoperative orthopedic correction, molding, or postoperative nostril splints. The esthetic outcome was optimal enough; none of the cases requested a secondary correction.ConclusionThe nasal cantilever technique is a novel concept in cleft nasal deformity, which can be used in conjunction with an appropriate lip technique, per the surgeon’s discretion. Other than a learning curve, we believe that it provides a solid correction by securing the cartilaginous structures after they have been mobilized to a stable base, the nasion.

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Bhagat, Rohan, Meghna Vandekar, Nikhilesh R. Vaid, Jae Hyun Park, and Yoon-Ah Kook. "A Staged Expansion Screw Protocol to Retract the Premaxilla In BCLP Infants with Delayed Nasoalveolar Molding." Journal of Clinical Pediatric Dentistry 45, no. 2 (April 1, 2021): 123–28. http://dx.doi.org/10.17796/1053-4625-45.2.9.

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Currently, the treatment protocol for cleft palate at several centers around the world involves primary lip repair around 3-4 months of age, using presurgical nasoalveolar molding, which is done soon after birth. Unfortunately, in cases where treatment is delayed, the potential for repositioning the nasoalveolar apparatus is severely limited. The purpose of this paper is to illustrate a novel use of an expansion screw appliance to aid in the faster and more efficient active molding of the premaxillary and lateral maxillary segments in infants for whom the start of PNAM therapy is delayed, without the side effects commonly seen with pin-retained active molding appliances.

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Wang, Jian, Jiong Peng, Jin Nan Chen, and Jing Li. "Numerical Optimization of the Parison Thickness of Oil Drum in Extrusion Blow Molding." Advanced Materials Research 881-883 (January 2014): 1455–59. http://dx.doi.org/10.4028/www.scientific.net/amr.881-883.1455.

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The optimization parison thickness can reduce the oil drum weight and meet the requirement of the minimum thickness. The profile thickness of the extruded parison can be optimized by simulation. Under different blowing pressures, extrusion blow molding non-isothermal process of the high density polyethylene oil drum with a handle was simulated by using Polyflow. The initial parison was respectively divided into 11, 51, 101 and infinite segments. After seven optimizations, the oil drum wall thickness was equal or larger than 2 mm. An appropriate inflation pressure of 0.6 MPa was obtained. The results show that the production efficiency increases with the inflation pressure increasing. With the parison segments increasing, the oil drum thickness distribution inflated from the optimized parison is more uniform and approaches to the required thickness. The oil drum mass is decreased with the segments increasing. It is necessary that the non-uniform thickness parison was produced by injection molding.

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Doruk, Cenk, and Banu Kiliç. "Extraoral Nasal Molding in a Newborn with Unilateral Cleft Lip and Palate: A Case Report." Cleft Palate-Craniofacial Journal 42, no. 6 (November 2005): 699–702. http://dx.doi.org/10.1597/04-134r.1.

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Objective The purpose of this case report is to introduce an extraoral nasal molding appliance (ENMA) and treatment approach for presurgical nasoalveolar molding in newborns with unilateral cleft lip and palate. Methods A 15-day-old girl presented with complete unilateral cleft lip and palate. A circumferential headband supported the actual nasoalveolar molding device, which consisted of a nasal stent made from a 0.8-mm stainless steel helical spring. The spring was activated at 2-week intervals. Discussion The shape of the cartilaginous septum, alar cartilage tip, medial and lateral crus and alveolar segments were molded to resemble the normal shape of these structures. ENMA can be helpful in any patient with unilateral cleft lip and palate because it is easy to fabricate, practical to activate, and comfortable to wear and use.

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Kuang, Tangqing, Qiang Feng, Tian Liu, Luohao Zhong, Yanqing Wang, and Hesheng Liu. "Numerical Simulation on the Penetration Behavior of the Projectile during the Water Injection Stage of Water-Projectile-Assisted Injection Molding Process." Advances in Polymer Technology 2020 (March 28, 2020): 1–15. http://dx.doi.org/10.1155/2020/6861216.

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Water-projectile-assisted injection molding (W-PAIM) is a novel molding process for plastic pipes with complicated shape. It utilizes high-pressure water as a power to push a solid projectile to penetrate through the melt to form a hollow space. In order to investigate the penetration behavior of the projectile during the water injection stage of W-PAIM process, numerical simulation of the water injection stage of a W-PAIM pipe with straight and curved segments was carried out. A turbulent flow for the driving water was considered in the motion equation, and the dynamic mesh technology was used to deal with the moving solid projectile. The simulation results, including RWT and the flow fields, were compared with those of water-assisted injection molding (WAIM) pipe with the same outer dimensions. It was found that the residual wall thickness (RWT) of the W-PAIM pipe is much thinner than that of the WAIM pipe. The projectile has a crucial influence on the RWT. The pressure fields of W-PAIM and WAIM are very similar in both straight and curved segments. The velocity field and strain rate field near the penetration front in W-PAIM are quite different from those in WAIM due to the drag flow caused by the projectile penetration.

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Sabarinath, VP, Vasant Radhakrishnan, PV Hazarey, and Ravindran Sreeja. "Alternative Approaches to Managing the Cleft Alveolus." Journal of Clinical Pediatric Dentistry 38, no. 1 (September 1, 2013): 89–93. http://dx.doi.org/10.17796/jcpd.38.1.n152280p45mj53m2.

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The cleft alveolus component of the oral cleft deformity is addressed with a separate surgical stage. Several host and operator related factors affect the surgical outcome. When factors that increase the likelihood of secondary alveolar bone graft failure are identified, alterative methods like dentoalveolar distraction (DAD) may be employed. In infants, molding of the alveolar segments is possible and when a synergistic surgical approach is used, the possibility of successful alveolar cleft repair is increased. The authors present two case reports wherein the use of nasoalveolar molding (NAM) and DAD helped to tackle the alveolar cleft deformity.

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Abraham, G. A., P. M. Frontini, and T. R. Cuadrado. "Molding of biomedical segmented polyurethane delamination events and stretching behavior." Journal of Applied Polymer Science 69, no. 11 (September 12, 1998): 2159–67. http://dx.doi.org/10.1002/(sici)1097-4628(19980912)69:11<2159::aid-app7>3.0.co;2-f.

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Shanbhag, Gajanan, Swapnil Pandey, Nirali Mehta, Yogesh Kini, and Ashwini Kini. "A Virtual Noninvasive Way of Constructing a Nasoalveolar Molding Plate for Cleft Babies, Using Intraoral Scanners, CAD, and Prosthetic Milling." Cleft Palate-Craniofacial Journal 57, no. 2 (November 7, 2019): 263–66. http://dx.doi.org/10.1177/1055665619886476.

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Presurgical nasoalveolar molding (PNAM) is a key step in the early management of cleft babies. It involves making an impression of the alveolar segments and the lip elements, after which an appliance is fabricated and activated to achieve optimal alveolar and nasal positions for a superior surgical result. These appliances are fabricated and activated in babies as young as 10 days, and the molding is ideally carried on till the baby is ready for the primary lip repair. This article outlines in detail a digital method of fabricating the PNAM appliance using a combination of intraoral scans, computer-assisted digital software, and computer-assisted machining, facilitated by milling machines. This process obviates impression making and the subsequent laboratory procedures.

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Pereira, AlbertoRocha, Nuno Montezuma, Luis Oliveira, Miguel Magalhães, and José Rosa. "Immediate Reconstruction of Large Full-Thickness Segmental Anterior Maxillary Defect with Bone Transport." Craniomaxillofacial Trauma & Reconstruction 9, no. 4 (December 2016): 305–12. http://dx.doi.org/10.1055/s-0036-1592094.

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Maxillary segmental defects are a reconstructive challenge particularly when the anterior arch is involved. Missing bone, mucosa, and teeth should be replaced; fistulae closure should be guaranteed by bone and mucosa continuity; stable functional occlusion should be achieved; and facial aesthetics restored. These defects resulting from tumor excisions, if left untreated, will cause additional problems related to interposed scar and collapse of lip and nose. Immediate reconstruction should avoid these problems and should be considered when safe tumor-free margins are obtained. This study describes the treatment of such a defect resulting from a myxoma excision, with trifocal distraction requiring only one additional surgery. Internal distractors were fixed bilaterally for transport of two segmental discs created by inverted L osteotomies at the same surgical time of tumor excision. A second surgery was performed after central contact between transport discs was achieved, for device removal and creation of a dynamic system to regenerate molding and compression-focus development. This was accomplished by internal fixation of one side and central fixation of a full-open distractor to act as compression device when reversely activated. Central perfect adaptation between transported segments and good-quality attached mucosa lining the alveolar crest were determinant to obtain a stable functional and aesthetic result.

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Mathew, Abin, Sunil Muddaiah, Jayanth B. Subrahmanya, Sanju Somaiah, Balakrishna Shetty, and Goutham Reddy. "Presurgical Nasoalveolar Molding in a 4-day-old Infant with Unilateral Cleft Lip, Alveolus, and Palate Deformity." APOS Trends in Orthodontics 8 (December 1, 2018): 225–29. http://dx.doi.org/10.4103/apos.apos_128_17.

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Introduction A four day old male infant was referred to our department. Infant’s mother complained of an opening over lip and difficulty in feeding and desires to get it corrected. On clinical examination patient showed complete unilateral cleft lip, alveolus and palate deformity towards the left side. Methods On the initial visit, lip taping using 1/4inch 3M Steri-strip was applied and instructions were given to parents about lip taping, and advised to continue lip taping for 2 weeks. Initial impressions were taken to fabricate the Presurgical nasoalveolar molding appliance. Intraoral molding plate was made to approximate the maxillary segments. Nasal stent was added to correct the nose deformity. Presurgical impressions were made. Results Under this pre surgical treatment, the cleft alveolus reduced in size from 13mm to 3mm at the alveolar ridge and palate, respectively. The nasal wing was lifted considerably. Conclusion Pre-surgical nasoalveolar moulding helped to reduce the cleft gap, improve the arch form, approximate lip segments and distinctly improve the morphology of the nose by correcting flattened nasal wings. This aforementioned correction not only enabled better aesthetic results after surgery but also reduced tissues tension and scar formation post-surgery.

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Hopmann, Ch, M. Schmitz, and H. Dornebusch. "Development of a Segmented Temperature Control for Targeted Solidification in Injection Molding." International Polymer Processing 33, no. 2 (May 27, 2018): 206–16. http://dx.doi.org/10.3139/217.3452.

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Bauer, Franz X., Dominik Gau, Florian Guell, Markus Eblenkamp, and Denys J. Loeffelbein. "Automated detection of alveolar arches for nasoalveolar molding in cleft lip and palate treatment." Current Directions in Biomedical Engineering 2, no. 1 (September 1, 2016): 701–5. http://dx.doi.org/10.1515/cdbme-2016-0152.

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AbstractNasoalveolar moulding (NAM) has become a widely accepted and evidence-based treatment strategy for newborns with cleft lip and palate (CLP), attempting to reduce the cleft gap and to form an appropriately shaped alveolar arch by an intraoral patient-specific NAM plate and to erect the usually flattened nostrils towards a natural nose wing occurrence. The generation of such an appropriately shaped NAM plate requires, besides 3d information of the patient’s initially cleft lip and palate, an estimated target model of the maxilla. Previous studies showed the applicability of curve-based approaches to describe the maxilla during early infancy. We have developed an automated algorithm implemented with the programming language Python, describing the alveolar arch by an approximated ellipse. Therefore, the digitalized data sets of human maxillae were aligned to a global coordinate system with a total least square method and subsequently analyzed with the curvature-based algebraic point set surfaces (APSS) algorithm. The gathered information of height ratio and curvature allows the detection of points on the alveolar segments and therewith the fit of an ellipse describing the human maxilla. In 84.5% of 193 maxilla impressions of healthy newborns the fitted ellipses described the course of the maxilla within defined margins. Applying the algorithm to 38 newborns suffering from unilateral cleft lip and palate in 76.3% the fitted ellipses bridge the CLP alveolar segments, so that a harmonic alveolar arch can be deduced. Describing the alveolar arch by one or multiple ellipses allows (i) to automatically measure the dimensions of the maxilla, (ii) to derive a growth model during early infancy, (iii) to derive a healthy harmonic arch from CLP alveolar segments and (iv) to automatically generate a basic NAM device on the basis of the virtually modified maxilla.

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Ma, Tao. "A Study on Moulding Technology of Starch-Based Totally-Biodegradable Plastic Products." Advanced Materials Research 726-731 (August 2013): 622–28. http://dx.doi.org/10.4028/www.scientific.net/amr.726-731.622.

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Based on monofactorial comparison experiment, the following two excellent technological formations was derived for the production of starch-based totally-biodegradable tray via extruding, pelleting, slicing, and sucking molding: The first formulation: 40% of starch, 12.5% of DOP, 5% of EVA, 15% of polyvinyl alcohol, 20% of talc power and calcium carbonate, and 7.5% of other materials. The material temperature in high-speed kneader was about 90°C, rotation velocity was 600 r/min, kneading duration was 5~10 minutes, diameter of screw stem of extruder was 90 mm, ratio of length versus diameter of screw stem (L/D) was 44, rotation velocity of the screws stem was 40~50 r/min. Temperature in four segments of extruder were 145°C, 155 °C, 150°C, and 160°C respectively, and temperature in extruder head was 170 °C; the material rod extruded was set while passing a cold water bath, and then was cut to pellets whose size was 3 mm×3 mm; the latter was transformed into slices and subject to sucking molding after predrying; temperature of sucking molding was 180~190°C, and sucking molding duration was 15~20 seconds. The second formulation: 60% of starch, 15% of DOP, 5% of PHB, 15% of polyvinyl alcohol, and 5% of other materials. All technological parameters were the same with that for the first formulation. According to the test result of Chinese institute of plastic processing, the biodegradation ratio of the tray made through the above treatment 1 and 2 in 30 days amounted to 54.2% and 70.6% respectively, which showed that a satisfied biodegradation effect was realized.

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Santiago, Pedro E., Barry H. Grayson, Court B. Cutting, Mark P. Gianoutsos, Lawrence E. Brecht, and Soon Man Kwon. "Reduced Need for Alveolar Bone Grafting by Presurgical Orthopedics and Primary Gingivoperiosteoplasty." Cleft Palate-Craniofacial Journal 35, no. 1 (January 1998): 77–80. http://dx.doi.org/10.1597/1545-1569_1998_035_0077_rnfabg_2.3.co_2.

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Objective The purpose of this study was to evaluate if narrowing and approximation of the alveolar cleft through presurgical alveolar molding followed by gingivoperiosteoplasty (GPP) at the time of lip repair reduces the need for a bone-grafting procedure. Design This was a retrospective blind study of patients with unilateral or bilateral alveolar clefts who underwent presurgical infant alveolar molding and GPP by a single surgeon. Alveolar bone formation was assessed prior to the eruption of the maxillary lateral incisor or canine by clinical examination, panoramic and periapical radiographs, and/or a dental CT scan. The criterion for bone grafting was inadequate bone stock to permit the eruption and maintenance of the permanent dentition. Setting This study was performed at the Institute of Reconstructive Plastic Surgery by the members of the Cleft Palate Team. Patients All patients with unilateral (n = 16) or bilateral (n = 2) alveolar clefts who underwent presurgical infant alveolar molding and GPP by a single surgeon from 1985 to 1988 were studied. The control population consisted of all alveolar cleft patients (n = 14) who did not undergo alveolar modeling or GPP during the same time period. Interventions Presurgical alveolar modeling was performed with an intraoral acrylic molding plate. This plate was modified on a weekly basis to align the alveolar segments and close the alveolar gap. The surgical intervention consisted of a modified Millard GPP. Main outcome Measures The primary study outcome measure was the elimination of the need for a secondary bone graft in patients who underwent presurgical alveolar molding and GPP. Results Of the 20 sites in the 18 patients who underwent GPP, 12 sites did not require an alveolar bone graft. Of the 8 sites requiring a bone graft, 4 presented minimal bony defects. All 14 patients in the control group required bone grafts. Conclusions In this series of 20 alveolar cleft sites treated with presurgical orthopedics and GPP, 60% did not need a secondary alveolar bone graft in the mixed dentition.

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Zhang, Meili, and Yong Xin. "Molecular Mechanism Research into the Replication Capability of Nanostructures Based on Rapid Heat Cycle Molding." Applied Sciences 9, no. 8 (April 24, 2019): 1683. http://dx.doi.org/10.3390/app9081683.

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Aimed at the molding of polymer nanostructure parts, the interface model between long- and short-chain polycarbonates (PC) and nickel mold inserts was established by the molecular dynamics method. The molecular mechanism of the replication capability of polymer nanostructure part molding was discussed by analyzing the migration and diffusion of the molecular chain, concentration profile, filling morphology evolution, interface binding energy, and filling rate of conventional injection molding (CIM) and rapid heat cycle molding (RHCM). The results show that nanostructures are filled mainly during the packing stage. A short-chain PC system has a low glass transition temperature (Tg) and viscosity, good fluidity, and a high filling rate, so the replication capability of its nanostructures is good. A long-chain PC system has a fast cooling rate in CIM, its molecular chain motion is blocked, the filling rate is low, and the interface binding energy is small, and so its nanostructures have poor replication capability. However, the high temperature at the nanostructures can be maintained for a long time in RHCM, which promotes Brownian motion in the molecular chains. Under the action of packing pressure, molecular chains can overcome entanglement barriers and viscous resistance. Thus, the polymer concentration profile and filling rate increase with increasing packing pressure, which can produce more van der Waals energy. Furthermore, the evolution process of polymer filling morphology is realized by the Brownian motion of chain segments under packing pressure; that is, the diffusion motion of the molecular chain along the direction of a tube composed of other chains around it. With the increase of temperature or pressure, the migration and diffusion of the molecular chain can be promoted; thus, the replication capability of nanostructure parts for mold cavities can be enhanced.

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Song, J. H., J. R. G. Evans, M. J. Edirisinghe, and E. H. Twizell. "Optimization of heating schedules in pyrolytic binder removal from ceramic moldings." Journal of Materials Research 15, no. 2 (February 2000): 449–57. http://dx.doi.org/10.1557/jmr.2000.0068.

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A model that finds the maximum permissible heating rate for pyrolysis of ceramic moldings is extended to produce multi-segment temperature–time profiles to minimize the binder removal time. The degradation of the polymer and the diffusion of degradation products in solution to the free surface in a cylinder containing 50 vol% alumina and polyalphamethylstyrene is considered. The theory has previously been validated experimentally for fixed heating rates for cylindrical and flat plate geometries and for overpressure debinding. The extended model, presented here, calculates the vapor pressure of monomer over solution and modifies the heating rate to keep this just below ambient pressure. In this way, the temperature follows the maximum allowable rate at each stage to prevent boiling and hence the incidence of defects.

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Luo, Ning, De-Ning Wang, and Sheng-Kang Ying. "Phase separation in segmented poly(urethane urea) copolymers during reaction injection molding (RIM) polymerization." Journal of Polymer Science Part B: Polymer Physics 35, no. 6 (April 30, 1997): 865–73. http://dx.doi.org/10.1002/(sici)1099-0488(19970430)35:6<865::aid-polb1>3.0.co;2-h.

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Liu, Wei Hong, and Hai Bo Liu. "Strategy and Application of Modeling and NC Machining for Rotary Parts of Complex Curved Surface." Applied Mechanics and Materials 184-185 (June 2012): 477–81. http://dx.doi.org/10.4028/www.scientific.net/amm.184-185.477.

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Aimed at the difficulty of rotary parts of complex curved surface in modeling and NC machining, making full use of advanced modern molding technology of Solidworks and powerful NC machining skill of Mastercam, the paper introduced a strategy , segmented milling that a true part was step to step machined by end mill not ball mill on 3 Axes NC milling machine but 4 Axes during rough machining. According to the method, it can raise the operation rate and shorten production cycle.

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Chen, Kun Nan, and Wen Der Ueng. "Determination of the Optimal Locations for Injection Molding Gates with Higher Order Response Surface Approximations." Applied Mechanics and Materials 479-480 (December 2013): 126–30. http://dx.doi.org/10.4028/www.scientific.net/amm.479-480.126.

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This paper proposed a gate location optimization scheme to minimize the maximum injection pressure in plastic injection molding. The method utilized a series of higher order response surface approximations (RSA) to model the maximum injection pressure distribution with respect to gate locations, and the global minimum of these response surface models were subsequently sought by a global optimization method based on a multi-start sequential quadratic programming technique. The design points for RSA were evaluated by the finite element method. After a sequence of repetitions of RSA and optimization, the converged minimizer would represent the optimal gate location. A rectangular plate with two segments of different thicknesses was selected to demonstrate the effectiveness of the procedure. The variation of the thicknesses causes the optimal gate location to deviate from the center and induce multiple valleys in the maximum injection pressure distribution, which is ideal for the application of the higher order RSA and a global searching technique.

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Yap, Yan Lin, Jane Lim, Wei Chen Ong, Matthew Yeo, Hanjing Lee, and Thiam Chye Lim. "Stabilization of Mobile Mandibular Segments in Mandibular Reconstruction: Use of Spanning Reconstruction Plate." Craniomaxillofacial Trauma & Reconstruction 5, no. 3 (September 2012): 123–26. http://dx.doi.org/10.1055/s-0032-1313354.

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The fibular free flap is the gold standard for mandibular reconstruction. Accurate 3-dimensional contouring and precise alignment of the fibula is critical for reestablishing native occlusion and facial symmetry. Following segmental mandibulectomy, the remaining mandibular fragments become freely mobile. Various stabilization methods including external fixation, intermaxillary fixation, and preplating with reconstruction plate have been used. We describe a modification to the preplating technique. After wide resection of buccal squamous cell carcinoma, our patient had an 11-cm mandibular defect from the angle of the left mandible to the right midparasymphyseal region. A single 2.0-mm Unilock® (Synthes, Singapore) plate was used to span the defect. This was placed on the vestibular aspect of the superior border of the mandibular remnants before resection. Segmental mandibulectomy was then performed with the plate removed. The spanning plate was then reattached to provide rigid fixation. The fibular bone was contoured with a single osteotomy and reattached. The conventional technique involves molding of the plate at the inferior border of the mandible. This is time-consuming and not possible in patients with distorted mandibular contour. It is also difficult to fit the osteotomized fibula to the contoured plate. In comparison, the superiorly positioned spanning plate achieve rigid fixation of the mandible while leaving the defect completely free and unhampered by hardware, allowing space for planning osteotomies and easier fixation of the neomandible. Using this modified technique, we are able to recreate the original mandibular profile with ease.

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Mesquita, Rafael Agnelli, and Reinhold S. E. Schneider. "Tool Steel Quality And Surface Finishing of Plastic Molds." Exacta 8, no. 3 (February 16, 2011): 307–18. http://dx.doi.org/10.5585/exacta.v8i3.2442.

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Plastic industry is today in a constant growth, demanding several products from other segments, which includes the plastic molds, mainly used in the injection molding process. Considering all the requirements of plastic molds, the surface finishing is of special interest, as the injected plastic part is able to reproduce any details (and also defects) from the mold surface. Therefore, several aspects on mold finishing are important, mainly related to manufacturing conditions – machining, grinding, polishing and texturing, and also related to the tool steel quality, in relation to microstructure homogeneity and non-metallic inclusions (cleanliness). The present paper is then focused on this interrelationship between steel quality and manufacturing process, which are both related to the final quality of plastic mold surfaces. Examples are discussed in terms of surface finishing of plastic molds and the properties or the microstructure of mold steels.

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Mesquita, Rafael Agnelli, and Reinhold S. E. Schneider. "Tool Steel Quality And Surface Finishing of Plastic Molds DOI: 10.5585/exacta.v8i3.2442." Exacta 8, no. 3 (February 16, 2011): 307–18. http://dx.doi.org/10.5585/exactaep.v8i3.2442.

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Plastic industry is today in a constant growth, demanding several products from other segments, which includes the plastic molds, mainly used in the injection molding process. Considering all the requirements of plastic molds, the surface finishing is of special interest, as the injected plastic part is able to reproduce any details (and also defects) from the mold surface. Therefore, several aspects on mold finishing are important, mainly related to manufacturing conditions – machining, grinding, polishing and texturing, and also related to the tool steel quality, in relation to microstructure homogeneity and non-metallic inclusions (cleanliness). The present paper is then focused on this interrelationship between steel quality and manufacturing process, which are both related to the final quality of plastic mold surfaces. Examples are discussed in terms of surface finishing of plastic molds and the properties or the microstructure of mold steels.

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Baek, Seung-Hak, and Woo-Sung Son. "Difference in alveolar molding effect and growth in the cleft segments: 3-dimensional analysis of unilateral cleft lip and palate patients." Oral Surgery, Oral Medicine, Oral Pathology, Oral Radiology, and Endodontology 102, no. 2 (August 2006): 160–68. http://dx.doi.org/10.1016/j.tripleo.2005.09.009.

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Oliveira, Nathália Viegas de, Gabriel Antônio Anjos Tou, Raquel Souto Silva, Sérgio Edriane Rezende, Henrique Pretti, and Soraia Macari. "The First-Year Follow-Up of a Cleft Lip and Palate Patient Treated With Nasoalveolar Molding (NAM)." Brazilian Dental Journal 31, no. 2 (April 2020): 190–96. http://dx.doi.org/10.1590/0103-6440202003040.

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Abstract The objectives of pre-surgical orthopedics are to allow surgical repair with minimal tension of the involved tissues and less restriction to the craniofacial growth. The aim of this study was to evaluate the benefits of nasoalveolar model (NAM) as a pre-operative therapy in a patient with bilateral cleft lip and palate followed by labioplasty and palatoplasty. A 15-day-old patient underwent orthopedic treatment with NAM. After pre-operative treatment, retraction of the pre-maxilla was observed with reduction of the fissure. Due to the successful effects of NAM treatment the patient had a one-step surgery for lip correction. Six months later, due to lip pressure the fissure was further decreased. After six months, the patient underwent palatoplasty. Both surgeries contributed to the remaining closure of the fissure, which were reduced by half compared to the end of pre-operative treatment. The uses of NAM as a pre-operative treatment approached the alveolar segments, centralized the pre-maxilla, decreased the cleft palate resulting in a marked improvement of the arch and provide superior surgical results. In addition, it allows the primary repair of the patient’s lip with asymmetric bilateral fissure in only one-step surgery; in consequence, it will reduce treatment morbidity and decrease cost of treatment.

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Koya, Shafees, Sandeep Shetty, Akhter Husain, and Mustafa Khader. "Presurgical Nasoalveolar Molding Therapy Using Figueroa's NAM Technique in Unilateral Cleft Lip and Palate Patients: A Preliminary Study." Journal of Clinical Pediatric Dentistry 40, no. 5 (June 1, 2016): 410–16. http://dx.doi.org/10.17796/1053-4628-40.5.410.

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Objective: The objective of the study was to evaluate the results of nasoalveolar molding (NAM) in the treatment of patients with unilateral cleft lip and palate using a modified technique in a South Indian population. Study design: The design was a prospective study with blinded measurements. The sample constituted 10 complete unilateral cleft lip and palate (UCLP) patients who underwent NAM therapy by the same operator. Direct extra and intra oral anthropometric measurements were done using a digital vernier caliper before and after NAM therapy. A photographic evaluation was also done to rate the nasal deformity post NAM therapy. The differences between measurements were statistically analyzed using paired t tests. Results: The extra oral measurements revealed a statistically significant increase in bi-alar width, columellar length and width. The intraoral measurements demonstrated a statistically significant reduction in anterior alveolar cleft width. There was also a significant increase in arch width and greater and lesser segments length. All cases were rated as improved by the surgeons in photographic analysis. Conclusion: The study has quantitatively shown that the modified NAM therapy improved nasal asymmetry by columellar lengthening and effectively molded the maxillary alveolar arch.

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Wang, V. W., C. A. Hieber, and K. K. Wang. "Dynamic Simulation and Graphics for the Injection Molding of Three-Dimensional Thin Parts." Journal of Polymer Engineering 7, no. 1 (January 1, 1986): 21–46. http://dx.doi.org/10.1515/polyeng-1986-0104.

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Summary A numerical formulation is presented for simulating the injection-molding filling of thin cavities, together with the delivery system, in three dimensions. The modelling is based on generalized Hele-Shaw flow for an inelastic, non-Newtonian fluid under non-isothermal conditions, which has been previously shown to be satisfactory for simulating the polymer melt flow in the cavities. A hybrid numerical scheme is employed in which the injection-molded part is described by two-dimensional triangular elements, provided that the cavity thickness is relatively thin, and the gapwise and time derivatives are expressed in terms of finite differences. The elements are flat, but can have any orientation in 3-D space to approximate the surfaces of the molded part. A triangular element is further divided into three sub-areas by joining the centroid of the element to the mid-point of its three edges. The control volume associated with any vertex node is then defined as the sum of all such sub-areas containing that node multiplied by each respective thickness. The numerical calculation of the flow field (or the pressure field) is based on the conservation of mass in each control volume which, at any given instant, can be either empty, partially filled, or totally filled with polymer melt. The melt-front location is defined by the partially filled control volumes which are allowed to advance in the calculation such that one partially filled control volume gets filled during each properly chosen time step with all of its adjacent empty control volumes then becoming new melt-front control volumes. The pressure and temperature are calculated at each time step, with the resulting pressure field determining the flow direction which, in turn, determines which partially-filled control volume should get filled during the following time step. One-dimensional flow segments, such as circular or non-circular tubes, can also be employed to represent the delivery system. This one-dimensional flow is coupled with the cavity filling in order to form a complete simulation of the mold filling. Comparisons with experiment have been made for a rectangular cavity with three inserts. The results show good agreement in terms of pressure traces and weldline locations. Another complex 3-D injection molded part has also been modelled to demonstrate the capability of the analysis.

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Fisher, Daniel C., Ethan A. Shirley, Christopher D. Whalen, Zachary T. Calamari, Adam N. Rountrey, Alexei N. Tikhonov, Bernard Buigues, Frédéric Lacombat, Semyon Grigoriev, and Piotr A. Lazarev. "X-ray computed tomography of two mammoth calf mummies." Journal of Paleontology 88, no. 4 (July 2014): 664–75. http://dx.doi.org/10.1666/13-092.

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Two female woolly mammoth neonates from permafrost in the Siberian Arctic are the most complete mammoth specimens known. Lyuba, found on the Yamal Peninsula, and Khroma, from northernmost Yakutia, died at ages of approximately one and two months, respectively. Both specimens were CT-scanned, yielding detailed information on the stage of development of their dentition and skeleton and insight into conditions associated with death. Both mammoths died after aspirating mud. Khroma's body was frozen soon after death, leaving her tissues in excellent condition, whereas Lyuba's body underwent postmortem changes that resulted in authigenic formation of nodules of the mineral vivianite associated with her cranium and within diaphyses of long bones. CT data provide the only comprehensive approach to mapping vivianite distribution. Three-dimensional modeling and measurement of segmented long bones permits comparison between these individuals and with previously recovered specimens. CT scans of long bones and foot bones show developmental features such as density gradients that reveal ossification centers. The braincase of Khroma was segmented to show the approximate morphology of the brain; its volume is slightly less (∼2,300 cm3) than that of neonate elephants (∼2,500 cm3). Lyuba's premaxillae are more gracile than those of Khroma, possibly a result of temporal and/or geographic variation but probably also reflective of their age difference. Segmentation of CT data and 3-D modeling software were used to produce models of teeth that were too complex for traditional molding and casting techniques.

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Grigora, Maria-Eirini, Zoi Terzopoulou, Konstantinos Tsongas, Panagiotis Klonos, Nikolaos Kalafatakis, Dimitrios N. Bikiaris, Apostolos Kyritsis, and Dimitrios Tzetzis. "Influence of Reactive Chain Extension on the Properties of 3D Printed Poly(Lactic Acid) Constructs." Polymers 13, no. 9 (April 23, 2021): 1381. http://dx.doi.org/10.3390/polym13091381.

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Fused deposition modeling (FDM) is currently the most popular 3D printing method, where thermoplastic polymers are predominantly used. Among them, the biobased poly(lactic acid) (PLA) governs the FDM filament market, with demand higher than supply, since not all grades of PLA are suitable for FDM filament production. In this work, the effect of a food grade chain extender (Joncryl ADR® 4400) on the physicochemical properties and printability of PLA marketed for injection molding was examined. All samples were characterized in terms of their mechanical and thermal properties. The microstructure of the filaments and 3D-printed fractured surfaces following tensile testing were examined with optical and scanning electron microscopy, respectively. Molecular weight and complex viscosity increased, while the melt flow index decreased after the incorporation of Joncryl, which resulted in filaments of improved quality and 3D-printed constructs with enhanced mechanical properties. Dielectric spectroscopy revealed that the bulk properties of PLA with respect to molecular mobility, both local and segmental, were, interestingly, not affected by the modifier. Indirectly, this may suggest that the major effects of the extender are on chain length, without inducing chain branching, at least not to a significant extent.

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Fang, Zhengwu, Wenqiang Jiang, Yiqin He, Dongfang Ma, Yike Liu, Shuping Wang, Yingxin Zhang, and Junliang Yin. "Genome-Wide Identification, Structure Characterization, and Expression Profiling of Dof Transcription Factor Gene Family in Wheat (Triticum aestivum L.)." Agronomy 10, no. 2 (February 19, 2020): 294. http://dx.doi.org/10.3390/agronomy10020294.

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DNA binding with one finger (Dof) proteins are plant-specific transcription factors with crucial roles in plant growth and stress response. Even so, little is known about them in wheat. In this study, 108 wheat Dof (TaDof) genes across 21 chromosomes were detected. Although variable in sequence length, molecular weight, and isoelectric point, all TaDof proteins contained conserved zinc-finger structures and were phylogenetically divided into 7 sub-groups. Exon/intron and motif analyses suggested that TaDof structures and conserved motifs were similar within sub-groups but diverse among sub-groups. Many segmental duplications were identified and Ka/Ks and inter-species synthetic analyses indicated that polyploidization was main reason for increased number of TaDofs. Prediction and experimental confirmation revealed that TaDofs functioned as transcription factors in the nucleus. Expression pattern profiling showed that TaDofs specifically affected growth and development, and biotic and abiotic stress responses. Wheat miRNAs and cis-regulator were predicted as essential players in molding TaDofs expression patterns. qRT-PCR analysis revealed that TaDofs were induced by salt and drought stresses. Customized annotation revealed that TaDofs were widely involved in phytohormone response, defense, growth and development, and metabolism. Our study provided a comprehensive understanding to wheat TaDofs.

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Spauwen, Paul H. M., Widanto Hardjowasito, Jan Boersma, and Benny S. Latief. "Dental Cast Study of Adult Patients with Untreated Unilateral Cleft Lip or Cleft Lip and Palate in Indonesia Compared with Surgically Treated Patients in the Netherlands." Cleft Palate-Craniofacial Journal 30, no. 3 (May 1993): 313–19. http://dx.doi.org/10.1597/1545-1569_1993_030_0313_dcsoap_2.3.co_2.

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To determine differences in maxillary and dentoalveolar relationships between untreated and treated patients having unilateral clefts of the lip and alveolus (UCLA) or lip and palate (UCLP), dental cast assessments were done on 70 untreated adult indonesian patients (UCLA-I, UCLP-I) and 67 Dutch patients, surgically treated in infancy (UCLA-D, UCLP-D). The indonesian group consisted of 44 UCLA-I and 26 UCLP-I patients, and the Dutch group of 24 UCLA-D and 43 UCLP-D patients. In the UCLA-I patients, deformities occurred in that part of the dentoalveolar complex that surrounds the cleft. Lip repair in the UCLA-D group more frequently caused deformities in the incisor and buccal areas on the cleft side. In the UCLP-I patients, deformities were present in the incisor and cuspid areas on the cleft side. The buccal segments showed collapse both on the cleft and noncIeft sides. Lip and palate repair in the UCLP-D group caused significantly more deformities in the incisor, cuspid, and buccal areas up to the level of the first molars, both on the cleft and noncleft sides. Surgical treatment seems to cause maxillary and dentoalveolar deformities up to the first molars more frequently, but these are not as pronounced as one would expect: following the practiced surgical regimen, the deformities were usually mild. Negative effects of surgical intervention seem to be antagonized by the restored integrity of the lip and palate leading to orientation of maxillary parts and correction of tongue position, which in turn has a molding effect on the maxilla and mandible.

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Abd El-Ghafour, Mohamed, Mamdouh A. Aboulhassan, Mona M. Salah Fayed, Amr Ragab El-Beialy, Faten Hussein Kamel Eid, Seif El-Din Hegab, Mahmoud El-Gendi, and Dawlat Emara. "Effectiveness of a Novel 3D-Printed Nasoalveolar Molding Appliance (D-NAM) on Improving the Maxillary Arch Dimensions in Unilateral Cleft Lip and Palate Infants: A Randomized Controlled Trial." Cleft Palate-Craniofacial Journal 57, no. 12 (September 10, 2020): 1370–81. http://dx.doi.org/10.1177/1055665620954321.

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Objective: The aim of the current study was to introduce and measure the effectiveness of a new 3D-printed nasoalveolar molding (D-NAM) appliance on improving the maxillary arch dimensions (MADs) in infants with unilateral complete cleft lip and palate (UCLP) before surgical lip repair. Design: A prospective, balanced, randomized, parallel groups, single-blinded, controlled trial. Setting: All the steps of the current study were carried in the Department of Orthodontics, Cairo University in Egypt. Participants: Thirty-four, nonsyndromic infants with UCLP. Interventions: The eligible infants were randomly assigned into either no-treatment (control) or to the new D-NAM groups. In D-NAM group, the maxillary models were 3D scanned into virtual models onto which segmentation and alveolar segments approximation were performed. Approximation movements were divided into 3 models representing 3 activation steps. On each of these models, virtual appliance construction was performed followed by 3D printing of the appliance. Nasal stent was added manually to the appliances of the second and third steps. Horizontal tapes were applied to infants in the D-NAM group only. Main Outcomes Measures: A Blinded assessors carried all the MADs measurements virtually on digital models collected at the beginning (T1) and after (T2) treatment. Results: Clinically and/or statistically significant improvements in all the measured MADs were recorded in D-NAM group at T2 before surgical lip repair in comparison to control group. Conclusions: The introduced D-NAM/3D-printed appliance is a simple and efficient technique to improve the MADs in infants with UCLP before surgical lip repair.

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Wang, Changchun, Bo Kou, Zusheng Hang, Xuejuan Zhao, Tianxuan Lu, Ziqi Wu, and Jin-Peng Zhang. "Tunable shape recovery progress of thermoplastic polyurethane by solvents." Pigment & Resin Technology 47, no. 1 (January 2, 2018): 7–13. http://dx.doi.org/10.1108/prt-03-2017-0021.

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Purpose This study aims to present that the chemo-responsive shape recovery of thermoplastic polyurethane (TPU) is tunable by solvents with different solubility parameters, and it is generic for chemo-responsive shape-memory polymer and its composites. Design/methodology/approach Two kinds of commercial TPU samples with different thicknesses were prepared by panel vulcanizer and injection molding (an industrial manner) to investigate their chemo-responsive shape memory properties in acetic ether and acetone. Findings Results showed that all of TPU films with different thicknesses can fully recover their original shapes weather they recover in acetic ether or acetone. But the recovery time of TPU films in acetone is greatly reduced, especially for the twisting samples. The residual strains of recovery TPU samples after extension reduce obviously. Research limitations/implications The great decrement of recovery time is related to two factors. One is due to the bigger solubility parameter of acetone with higher dipole moment compared with those of acetic ether, and the other is the remained internal stress of TPU films after preparation. The internal stress is identified to have an effect on the shape-memory properties by comparing the recovery process of samples with/without annealing. The reduced residual strains of recovery TPU samples after extension is due to the increasing mobility of polymer segments after molecules of acetic ether penetrates into the polymeric chains. Originality/value This is a universal strategy to control the recovery process of shape-memory materials or composites. The underlying mechanism is generic and should be applicable to chemo-responsive shape-memory polymers or their composites.

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Journal articles on the topic 'Molding segment'

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