Littérature scientifique sur le sujet « Circummaxillary suture »

INTRODUCTION: With the advent of cone beam computed tomography (CBCT), it is now possible to quantitatively evaluate the effects of rapid maxillary expansion (RME) on the entire maxillary complex in growing patients. OBJECTIVE: The purpose of this study is to use three-dimensional images to evaluate the displacement that occurs at the circummaxillary sutures (frontonasal, zygomaticomaxillary, intermaxillary, midpalatal, and transpalatal sutures) following rapid maxillary expansion in growing children. METHODS: The CBCT scans of 25 consecutively treated RME patients (10 male, 15 female) with mean age of 12.3 ± 2.6 years, were examined before expansion and immediately following the last activation of the expansion appliance. RESULTS: Statistically significant (P < 0.05) amounts of separation were found for the displacement of the bones of the frontonasal suture, the intermaxillary suture, the zygomaticomaxillary sutures, and the midpalatal suture. The change in angulation of the maxillary first molars due to RME was also statistically significant. There was no statistically significant displacement of the transpalatal suture. CONCLUSIONS: Rapid maxillary expansion results in significant displacement of the bones of circummaxillary sutures in growing children.

ABSTRACTObjective:To evaluate the evidence on three-dimensional immediate effects of rapid maxillary expansion (RME) treatment on growing patients as assessed by computed tomography/cone beam computed tomography (CT/CBCT) imaging.Materials and Methods:The published literature was searched through the PubMed, Embase, and Cochrane Library electronic databases from January 1966 to December 2012. The inclusion criteria consisted of randomized controlled trials, prospective controlled studies, and prospective case-series. Two reviewers extracted the data independently and assessed the quality of the studies.Results:The search strategy resulted in 73 abstracts or full-text articles, of which 10 met the inclusion criteria. When treating posterior crossbites with a RME device, the existing evidence points out that the midpalatal suture opening is around 20%–50% of the total screw expansion. There seems to be no consistent evidence on whether the midpalatal sutural opening is parallel or triangular. The effect on the nasal cavity dimensions after RME seems to be apparent and indicates an enlargement between 17% and 33% of the total screw expansion. Circummaxillary sutures, particularly the zygomaticomaxillary and frontomaxillary sutures and also spheno-occipital synchondrosis, appear to be affected by the maxillary expansion. Overall, however, the changes were small and the evidence not conclusive.Conclusions:CT imaging proved to be a useful tool for assessment of treatment effects in all three dimensions. The majority of the articles were judged to be of low quality, and therefore, no evidence-based conclusions could to be drawn from these studies.

Aims The aim of this study is to evaluate the effects of the chincup appliance used in the treatment of Class III malocclusions, not only on the mandible or temporomandibular joint (TMJ) but also on all the craniofacial structures. Materials and Methods Chincup simulation was performed on a three-dimensional finite element (FE) model. 1000 g (500 g per side) force was applied in the direction of chin-condyle head. Nonlinear FE analysis was used as the numerical analysis method. Results By the application of chincup, stresses were distributed not only on TMJ or mandible but also on the circummaxillary sutures and other craniofacial structures. Conclusions Clinical changes obtained by chincup treatment in Class III malocclusions are not limited by only mandible. It was seen that also further structures were affected.

Aims The aim of this study was to evaluate the biomechanical effects on the craniofacial complex of skeletal anchorage and dental anchorage during face mask therapy. Subjects and Methods Two nonlinear finite element (FE) simulations were performed using a three-dimensional FE model. Face mask therapy with dental anchorage in the upper canines and face mask therapy with skeletal anchorage in the piriform apertures of the maxilla were simulated. In both simulations, the magnitude of the applied force was 750 g per side, and the force direction was 30° forward and downward relative to the occlusal plane. Results The circummaxillary sutures showed greater and more uniform stresses in the skeletal anchorage model than the dental anchorage model. This is the result of the more parallel forward movement of the maxilla in the skeletal anchorage model. Conclusions In Class III malocclusions with maxillary deficiency, for improved effects on the maxilla, choosing skeletal anchorage may be more effective in face mask therapies

ABSTRACT Objectives To investigate the relationship between circummaxillary sutures and miniscrew-assisted rapid palatal expansion (MARPE) success in adult male patients and to evaluate the correlation between the width of the sutures and the maxilla expansion ratio. Materials and Methods This retrospective study comprised 40 adult male patients treated with MARPE divided into a separation group (N = 20, mean age, 21.9 years) consisting of subjects with midpalatal suture opening and a nonseparation group (N = 20, mean age, 21.7 years) consisting of subjects with no midpalatal suture opening. Cone-beam computed tomography images were obtained before MARPE expansion for both groups and after expansion for the separation group. Vertical and horizontal skeletal relationships, palate length, and widths of 10 circummaxillary sutures before expansion were compared. The correlation between maxilla expansion ratio (jackscrew expansion to maxillary expansion ratio) and circummaxillary suture widths was also analyzed in the separation group. Results There were no significant differences in age, vertical and horizontal skeletal relationships, and palate length between the two groups. Zygomaticomaxillary, pterygomaxillary, midpalatal, and transverse palatine sutures showed significantly greater width in the separation group (P &lt; .05). The zygomaticomaxillary suture showed the greatest difference (Δ = 0.36 mm) between the groups. The zygomaticomaxillary and pterygomaxillary sutures showed significant positive correlation with the maxilla expansion ratio (P &lt; .01). Conclusions In adult male patients, greater circummaxillary suture widths before MARPE expansion, especially zygomaticomaxillary and pterygomaxillary sutures, resulted in a better chance of successful suture separation and more maxillary expansion.

Objective: To evaluate patency of circummaxillary sutures in children with Apert, Crouzon, and Pfeiffer Syndromes and to compare it to a nonsyndromic matched control group. Design: Case–control study. Setting: Tertiary care public hospital. Materials and Methods: Thirty-eight computed tomography (CT) scans of patients affected by syndromic craniofacial synostosis (13 patients with Apert syndrome, 20 patients with Crouzon syndrome, and 5 patients with Pfeiffer syndrome), average age 5 ± 2.8 years, range 1.9 to 12 years, were compared to age- and sex-matched control CTs of 38 nonsyndromic children. Computed tomography scans of the study group had to be performed prior to any midfacial surgery. Main Outcome Measures: Midpalatal suture, zygomaticomaxillary sutures, and pterigomaxillary sutures were evaluated and scored. Results: The syndromic group showed a significant earlier ossification of all sutures compared to the nonsyndromic group. Significant differences were already present in early childhood and continued through adolescence. Conclusions: Based on the differences in terms of maxillary sutural ossification identified, midfacial hypoplasia does not seem to be only secondary to premature cranial base ossification, but also to primary synostosis of facial sutures, thus providing new insights into the pathogenesis of midface deficiency in children with craniofacial-synostosis. Care should be taken when planning any maxillary orthopedics, such as expansion or maxillary protraction, given the high frequency of early fusion of circummaxillary sutures.

Introduction: The tongue exerts its force during swallowing, while it rests behind the crib. Magnitude of forces tongue exerts through tongue crib at various sutures, its implication in various grades of maxillary hypoplasia in Class III malocclusion is not provided in literature. The rationale of this study is to investigate stress distributions in the sutures of craniofacial region produced by forces applied by tongue through tongue crib in comparison with facemask therapy in Class III malocclusion with maxillary hypoplasia in maxillary protraction. Objectives: The rationale of this study was to compare forces generated by tongue through tongue crib and facemask therapy in Class III malocclusion with maxillary hypoplasia in child of pubertal age group. Methodology: Finite element model of skull would be generated and simulation of tongue crib and facemask therapy would be done and stresses would be studied at various sutures. Quantitative analysis is done by elucidating values of finite element analysis. Expected Results: The forces produced by tongue on circummaxillary sutures in skeletal Class III malocclusion with maxillary hypoplasia using tongue crib with that of facemask therapy would be substantial. Conclusion: Stress distribution produced by protraction forces exerted by tongue through tongue crib in comparison with facemask therapy in Class III malocclusion with maxillary hypoplasia would be studied through finite element analysis to promote growth in maxilla.

Introduction The aim of the present study is to evaluate the skeletal modifications induced by maxillary expansion supported by palatal micro-implants and localized osteotomies produced with minimally invasive surgical technique in young-adult and adult patients. In the present investigation, osteotomies had a lower extension than the ones used in conventional surgically assisted rapid palatal expansion (SARPE), to adopt a minimally invasive surgical technique that can be performed with greater comfort for the patient and less post-operative sequelae. More in detail, the localized osteotomies were executed only in the anterior part of the midpalatal suture and bilaterally at the basis of the zygomatic process of the maxilla without involvement of the piriform rim. These areas represent a great resistance to the lateral maxillary movement. Furthermore, they are of simple surgical access and don’t present important arterial plexuses. Patients requiring micro-implant supported maxillary expansion and/or SARPE routinely undergo a pre-treatment cone-beam computed tomography (CBCT) of the skull, to plan the surgical operation and, one month after treatment a secondary CBCT for a surgical and orthodontic control. CBCT is a low radiation tomography, extensively used in maxillofacial surgery and in dentistry. For the implementation of this study, that aims at evaluating the efficacy of micro-implant-supported maxillary expansion in combination with localized osteotomies, only radiologic exams that are anyway needed for the planning and post-treatment evaluation were used. Aim The aim of the present study is to evaluate the advantages introduced in the treatment of maxillary constriction by the therapy with micro-implant supported Maxillary Skeletal Expander (MSE) and localized osteotomies in young-adult and adult patients. The main objective is to evaluate the efficacy of the technique, by measuring the movement of skeletal landmarks in the midface, particularly on the maxillary and zygomatic bones, and on the lateral wall of the nose, by comparing the pre-treatment and post-treatment CBCT. For this particular technique, a new methodology for digital planning of position of MSE and miniscrews on patient CBCT was developed. Furthermore, incorporation of 2 additional miniscrews to the original MSE design, which conventionally features only 4 miniscrews, was developed with the aid of computer aided design – computer aided manufactured (CAD-CAM) technology. Methods The study presented the following steps: ▪ Development of a digital planning methodology for positioning the miniscrews and MSE appliance on pre-treatment CBCT ▪ Development of a CAD-CAM methodology for incorporating 2 additional miniscrews to the original MSE design with 4 miniscrews ▪ Selection of patients with age above 17 years, without congenital craniofacial syndromes, who require intervention of maxillary skeletal expansion ▪ Acquisition of initial CBCT with 17 x 13.5 cm field of view (FOV) ▪ Intervention of maxillary expansion supported by palatal micro-implants and localized osteotomies executed with minimally invasive surgical technique ▪ One month after treatment, acquisition of post-treatment CBCT with 17 x 13.5 cm FOV ▪ Analysis of skeletal modifications in the midface (maxillary bone, sphenoid bone, zygomatic arch, nasal cavity, etc.), by comparing the pre- and post- treatment CBCT with a 3D software (OnDemand software by Cybermed) Results The new methodology allowed the digital planning of MSE and miniscrews positioning on patients’ CBCTs, and the incorporation of two additional miniscrews to the original MSE design through CAD-CAM technology. In the clinical trial, a total of four patients had an average age of 27.6 years (range 22.1 – 39.9 years). MSE appliance was activated by an average of 6.0 mm and generated a parallel split of the midpalatal suture of 3.4 mm, 3.0 mm and 3.6 mm at anterior nasal spine (ANS), nasopalatine foramen (NPF) and posterior nasal spine (PNS), respectively. Skeletal modifications were found in all CBCT sections evaluated in the study (axial palatal, upper nasal, coronal zygomatic, axial zygomatic), indicating that all midfacial bones are affected by maxillary expansion with MSE and localized osteotomies. Particularly, skeletal changes were noticed also in CBCT sections above the lateral maxillary osteotomies (LMOs), in the maxilla, zygomatic bone, zygomatic arches, and nasal cavity. In the upper nasal section (UNS) the maxilla was laterally displaced by 2.4 mm and 0.9 mm, at its anterior and posterior extremities, respectively. The frontozygomatic angle (FZA) increased by 1.9° (average of right and left side), while the lower interzygomatic distance increased by 2.9 mm, indicating a rotation of the zygomatic bone in a lateral direction. The zygomatic arch was affected by bone bending phenomena and was deflected in an outward direction, with increase in the anterior intermaxillary distance by 1.7 mm and in the posterior inter-zygomatic distance by 1.6 mm. The nasal width (NW) parameter increased by 2.9 mm with treatment: this anatomical finding is the basis for a potential improvement in nasal breathing for patients suffering from increased nasal airway resistance. The cited modifications in skeletal structures above lateral maxillary osteotomies (LMOs) are most likely due to the fact that LMOs didn’t involve the piriform rim of the maxilla, and this point needs further investigations. Regarding dentoalveolar modifications, the inter-molar distance increased by 7.4 mm, and molars underwent a small dentoalveolar tipping in a buccal direction by 1.1° (average of right and left side), as evidenced by the change in molar basal bone angle (MBBA). No intra-operatory hemorrhage nor post-operatory bleeding was reported in treated patients, probably due to the lack of pterygopalatine suture surgical disjunction. A limitation of the study is its small sample size, represented by 4 patients. A larger number of patients is required to confirm the above results.