scholarly journals Disk Position and Temporomandibular Joint Structure Associated with Mandibular Setback in Mandibular Asymmetry Patients

2009 ◽  
Vol 79 (3) ◽  
pp. 521-527 ◽  
Author(s):  
Masayoshi Kawakami ◽  
Kazuhiko Yamamoto ◽  
Tomohiro Inoue ◽  
Atsuhisa Kajihara ◽  
Masaki Fujimoto ◽  
...  

Abstract Objective: To determine the changes in articular disk position and the temporomandibular joint (TMJ) structure in patients who had an asymmetric setback of the mandible performed by a bilateral sagittal split ramus osteotomy with manual positioning of the condyle. Materials and Methods: Twenty-two patients with skeletal Class III malocclusion being treated at Nara Medical University Hospital were evaluated using clinical examination and pre- and postoperative magnetic resonance images of their TMJs. Results: Changes in articular disk position after asymmetric setback surgery were not statistically significant, although a tendency of anterior displacement in the fossa was noted. The anterior and posterior joint spaces did not show significant changes, whereas the condyle head of the deviated or contralateral side tended to be positioned downward. Conclusion: The asymmetric setback of the mandible with intraoperative manual positioning of the condyle does not significantly change the disk position in the fossa.

2011 ◽  
Vol 81 (4) ◽  
pp. 624-631 ◽  
Author(s):  
Hyung-Joo Choi ◽  
Tae-Woo Kim ◽  
Sug-Joon Ahn ◽  
Shin-Jae Lee ◽  
Richard E. Donatelli

2021 ◽  
Vol 11 (14) ◽  
pp. 6439
Author(s):  
Ewa Zawiślak ◽  
Szymon Przywitowski ◽  
Anna Olejnik ◽  
Hanna Gerber ◽  
Paweł Golusiński ◽  
...  

The analysis aims at assessing the current trends in orthognathic surgery. The retrospective study covered a group of 124 patients with skeletal malocclusion treated by one team of maxillofacial surgeons at the University Hospital in Zielona Góra, Poland. Various variables were analysed, including demographic characteristics of the group, type of deformity, type of osteotomy used, order in which osteotomy was performed and duration of types of surgery. The mean age of the patients was 28 (ranging from 17 to 48, SD = 7). The group included a slightly bigger number of females (59.7%), with the dominant skeletal Class III (64.5%), and asymmetries were found in 21.8% of cases. Types of osteotomy performed during surgeries were divided as follows: LeFort I, segmental LeFort I, BSSO, BSSO with genioplasty, LeFort I with BSSO, LeFort I with BSSO and genioplasty, segmental LeFort I with BSSO, isolated genioplasty. Bimaxillary surgeries with and without genioplasty constituted the largest group of orthognathic surgeries (49.1%), and a slightly smaller percentage were one jaw surgeries (46.7%). A statistically significant correlation was found between the type of surgery and the skeletal class. In patients with skeletal Class III, bimaxillary surgeries were performed significantly more often than in patients with skeletal Class II (57.5% vs. 20.0%; p = 0.0002). The most common type of osteotomy in all surgeries was bilateral osteotomy of the mandible modo Obwegeser–Epker in combination with Le Fort I maxillary osteotomy (42.7%). The order of osteotomies in bimaxillary surgeries was mandible first in 61.3% of cases. The longest surgery was bimaxillary osteotomy with genioplasty (mean = 265 min), and the shortest surgery was isolated genioplasty (mean = 96 min). The results of the analysis show a significant differentiation between the needs of orthognathic surgery and the types of corrective osteotomy applied to the facial skeleton.


2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Chun-Ming Chen ◽  
Han-Jen Hsu ◽  
Ping-Ho Chen ◽  
Shih-Wei Liang ◽  
I-Ling Lin ◽  
...  

Purpose. This study investigated the relationship between the shortest buccal bone marrow of the ramus and skeletal patterns. Materials and Methods. Using cone-beam computed tomography data (specifically, the A point-nasion-B point (ANB) angle), we divided patients into three groups as follows: skeletal class I ( 0 ° < ANB < 4 ° ), class II (ANB: ≥4°), and class III (ANB: ≤0°). Sixteen vertical sections in the coronal plane were taken starting from slice 0 (original intact mandibular canal) anteriorly at 2 mm intervals to slice 15 (30 mm). The thickness of the mandible (M) and shortest buccal bone marrow (SBM) were measured. The data of SBM were divided into two groups ( SBM ≥ 1   mm and SBM < 1   mm ). For each skeletal pattern, an SBM   value < 1   mm was considered to indicate a high possibility of postoperative nerve paresthesia and bad split. Results. The three skeletal pattern groups also did not significantly differ in their M values for all sections. The mean SBM values of class III (0.91–2.11 mm) at 6–16 mm anterior to the mandibular foramen were significantly smaller than those of class II (1.53–3.17 mm). Comparing the occurrence ratio of SBM < 1   mm , the highest and lowest probabilities in class III (55% and 21.7%, respectively) were significantly larger at 6–20 mm anterior to the mandibular foramen than those in class II (28.3% and 5%, respectively). Conclusion. Class III had a significantly shorter SBM distance and higher SBM occurrence probability than class II at the mandibular ramus region, implying that class III participants are more likely than class II participants to have nerve paresthesia and bad split after sagittal split ramus osteotomy.


2020 ◽  
Vol 54 (2) ◽  
pp. 150-156
Author(s):  
Sanjeev Verma

VG, 25-year-old male, presented with c/c of forwardly placed lower jaw and history of unsatisfactory previous orthodontic treatment. Extraorally, the patient had asymmetrical face and concave profile, competent lips, positive lip step, and chin deviated toward left side by 2 mm. Intraorally, the patient had Angle’s class III type 3 malocclusion with an overjet of (–1) mm, overbite of 0%, and cross-bite wrt 12, 21. The patient was skeletal class III due to macrognathic and prognathic mandible with hypodivergent growth pattern, and proclined upper and retroclined lower incisors. The patient was managed orthosurgically with bimaxillary surgery (maxillary advancement 3 mm + mandibular setback 7 mm) after presurgical decompensation. The case report discusses in detail the diagnosis and comprehensive management of the skeletal class III case.


2017 ◽  
Vol 87 (4) ◽  
pp. 526-533 ◽  
Author(s):  
Xi Wen ◽  
Xiyu Wang ◽  
Shuqi Qin ◽  
Lorenzo Franchi ◽  
Yan Gu

ABSTRACT Objective: To compare the three-dimensional (3D) morphology of the upper airway in skeletal Class III patients with and without mandibular asymmetry and to investigate the possible underlying correlations between the morphology of the upper airway and mandibular deviation. Materials and Methods: Cone-beam computed tomography images of 54 subjects with skeletal Class III malocclusion (ANB angle ≤ 0.4°, Wits ≤ −5.5°) were taken and 3D upper airway models were reconstructed using Dolphin 3D software. According to the distance (d) from symphysis menti to the sagittal plane, all subjects were divided into a symmetry group (d ≤ 2 mm) and an asymmetry group (d ≥ 4 mm). Based on the severity of mandibular deviation, the asymmetry group was divided into subgroup I (4 mm ≤d &lt;10 mm) and subgroup II (d ≥ 10 mm). Cross-sectional linear distances, areas, and volumetric variables of the upper airway were measured in the 3D airway model. Results: Width of the inferior limit of the glossopharynx (P3W), cross-sectional area of the anterior limit of the nasal airway (P5S), and height of the glossopharynx (GPH) in the asymmetry group were significantly larger than in the symmetry group. As for subjects with severe mandibular deviation in subgroup II (d ≥ 10 mm), volume of the glossopharynx (GPV), total volume of the pharynx (TPV), length of the inferior limit of the velopharynx (P2L), and ratio of length to width of the inferior limit of the velopharynx (P2L/P2W) showed significantly negative correlations with mandibular deviation (r &gt; 0.7, P &lt; .05). Conclusions: In Class III subjects with severe mandibular asymmetry, the pharyngeal airway showed a tendency toward constriction and presented a more elliptical shape as mandibular deviation became more severe (P &lt; .01).


2014 ◽  
Vol 8 (1) ◽  
pp. 43-48
Author(s):  
Dai Juan and Feng Xue

In this report we describe a combined orthodontic and surgical treatment for a 14-year-old boy with severe skeletal class III deformity and dental problem. His upper posterior primary teeth in the left side were over-retained and 6 maxillary teeth (bilateral central incisors and canines, left first and second premolars) were impacted, together with 5 supernumerary teeth in both arches. The treatment protocol involved extraction of all the supernumerary and deciduous teeth, surgical exposure and orthodontic traction of the impacted teeth, a bimaxillary orthognathic approach including Lefort I osteotomy. Bilateral sagittal split ramus osteotomy (BSSRO) and genioplasty was performed to correct skeletal problem. After treatment, all of the impacted teeth were brought to proper alignment in the maxillary arch. A satisfied profile and good posterior occlusion was achieved. Treatment mechanics and consideration during different stages are discussed.


2017 ◽  
Vol 30 (3) ◽  
pp. 224
Author(s):  
Nuno Durão ◽  
José Amarante

Introduction: Prognathism is a common skeletal facial abnormality, associated with class III malocclusion, often with repercussions in quality of life. In addition to orthodontic treatment, sagittal split ramus osteotomy is the most common technique for its correction, and segment osteosynthesis is an important element of the post-surgical outcome.Materials and Methods: A search for relevant literature was conducted in the PubMed/MEDLINE database and in other relevant sources.Results: The stability of different fixation methods, their repercussions on inferior alveolar nerve lesions, and the type of material are among the most researched subjects.Discussion: Recent research about the type of osteosynthesis applied in the sagittal split ramus osteotomy for mandibular setback is discussed.Conclusion: Miniplates appear to be the better option for fixation of sagittal split osteotomy for mandibular setback. Bioabsorbable osteosynthesis may be an acceptable alternative to titanium.


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