Bilateral Sagittal Split Research Articles

79 Additional L-shaped miniplate osteosynthesis methods for early mandibular movement improvement in bilateral sagittal splitting ramus osteotomy

79 Additional L-shaped miniplate osteosynthesis methods for early mandibular movement improvement in bilateral sagittal splitting ramus osteotomy

Efficacy of the Coronoid Notch and Occlusal Plane As Predictable Landmarks for Determining the Medial Cut Height in Bilateral Sagittal Split Osteotomy: A Split-Mouth Observational Study.

This split-mouth observational study was conducted to assess the reliability and safety of using the coronoid notch and occlusal plane as landmarks to aid surgeons during bilateral sagittal split osteotomy(BSSO). Thirteen patients between the ages of 18 and 30 years, with class II and class III mandibular skeletal malocclusion requiring BSSO, were randomly selected and assigned to each of the study and control groups. A split-mouth study was chosen to conduct this research. Cone beam computed tomography (CBCT) imaging was conducted before the surgery to evaluate the anatomical structure, and three predefined points were marked at the superiormost point of the mandibular foramen, the inferiormost point of the mandibular foramen, and the deepest point of the sigmoid notch. A conventional sagittal split osteotomy was carried out in the control group. Preoperative values were obtained in the study group using the CBCT imaging technique by drawing an imaginary line from the inferiormost part of the mandibular foramen to the line corresponding to the occlusal plane that extended beyond the last molar. The lingual flap reflection was restricted to the internal oblique ridge. The posterior border of the mandible was not reflected. The measurements acquired via CBCT imaging were accurately transferred to the intraoperative surgical site using a vernier caliper. This facilitated the precise completion of the horizontal osteotomy, ascending ramus cuts, and vertical osteotomies. BSSO was performed, the mandibular setback or advancement was done with intermaxillary fixation, and the procedure was completed by rigid fixation. Types of lingual splits, types of lateral bone cut ends (LBCEs), any unfavorable split, and the time taken for the surgery (in minutes) were assessed. The surgery time in the control group (20.1538 ± 2.85325 min) was found to be higher than that in the study group (17.6154 ± 3.59487 min), with a p-value of 0.02. No significant differences were observed when assessing the presence of unfavorable splits in both groups (p = 0.500). Buccal LBCEs were the most prevalent, followed by inferior types. Type I lingual split was the most common in the study group (70%). This technique offers a dependable anatomical reference and significantly reduces surgical time for beginners. Additionally, the patterns of the lingual split were correlated with the types of lateral bone cut ends.

Positions of the Mandibular Foramen and Canal in Different Skeletal Classes and Implications for Bilateral Sagittal Split Osteotomy.

To evaluate the positions of the mandibular foramen (MF) and mandibular canal (MC) between different skeletal classes to highlight the implications for bilateral sagittal split osteotomy (BSSO). A cross-sectional study was performed using cone-beam computed tomography on 90 patients classified into classes I, II and III. Linear measurements were performed on multiplanar reconstructions as follows: from the MF to the edge of the mandibular ramus (1), to the mandibular notch (2), to the ramus width (3) and to the occlusal plane (4); and from the MC to the alveolar crest (A), to the lower border of the mandible (B) and to the mandibular buccal cortical bone (C). Mandibular thickness (D), width (E) and height (F) of the MC were measured. Intra-class correlation coefficient (ICC) checked the reliability. Two-way ANOVA and Tukey's test were used to compare measurements and classes. Linear measurements 2 presented a statistically significant difference between classes I and II. There was no statistically significant difference between the classes and measurements B, C, D, E and F. Linear measurements A were shorter in class III than in class II. Although most measurements suggest that the BSSO technique does not need to be modified for each skeletal class, measurements from the MF to the mandibular notch in class II and from the MC to the alveolar crest on distal of the second molars in class III could help surgeons to recognize critical regions.

Concomitant Extraction of Wisdom Teeth with Bilateral Sagittal Split Osteotomy (BSSO): A Case Series

Aim: Aim:To investigate the incidence of postoperative complications (including pain, nerve damage, swelling and infection) associated with the concomit an textraction of wisdom teeth at the time of bilateral sagittal split osteotomy procedures. Materials and Methods: A retrospective evaluation of eight patients who underwent concomitant removal of their lower wisdom teeth (either fully erupted, partially or fully bone impacted) at the time of their surgical procedure (Bilateral sagittal split osteotomy with/without LeFort 1 procedure/genioplasty). All patients presented to the Oral and Maxillofacial Surgery Department at Case Western Reserve University. Postoperative complications (including pain, nerve dysfunction, swelling and infection) were examined at regular follow-up appointments after their surgical procedure. Results: A total of eight patients were examined for post operative complications. All patients confirmed the presence of mild pain/discomfort/swelling in the short-term postoperatively.

Pulsed electromagnetic fields (PEMF) as a valid tool in orthognathic surgery to reduce post-operative pain and swelling: a prospective study

PurposePEMF (pulsed electromagnetic fields) founds application in several medical fields to accelerate bone wounds healing and to reduce inflammation. The aim of our study was to evaluate the effectiveness of PEMF in reducing postoperative swelling and pain in patients undergoing orthognathic surgery.MethodsA prospective observational monocentric study was conducted on a sample of 30 patients undergone to orthognathic surgery in Maxillofacial Surgery Unit of University of Naples Federico II. The patients who followed these inclusion criteria were enrolled in the study: age ≥ 18 years, Class III malocclusion, Surgical procedure of Le Fort I osteotomy + Bilateral Sagittal Split Osteotomy (BSSO), Written informed consent. Patients were divided into two groups: Group SD) postoperative standard treatment with medical therapy and cryotherapy, Group SD + PEMF) postoperative standard therapy + PEMF. Each patient underwent a 3D facial scan, at one (1d) and four (4d) days after surgery to compare the swelling reduction. The pain score was assessed through VAS score and analgesics administration amount.ResultsIn SD + PEMF group, the facial volume reduction between 1d and 4d scan was on average 56.2 ml (6.23%), while in SD group, it was 23.6 ml (2.63%). The difference between the two groups was 3.6% (p = 0.0168). VAS pain values were significantly higher in SD group compared to SD + PEMF group in the second day after surgery (P = 0.021) and in the total 4 days (P = 0.008).ConclusionsOur data suggest that PEMF is valid tool to promote faster postoperative swelling and pain reduction in patients undergoing orthognathic surgery.

Evaluation of Intraoperative Inferior Alveolar Nerve Exposure During and Postoperative Neurosensory Disturbances after Bilateral Sagittal Split Osteotomy: A Prospective Cross-sectional Study in Iran

Introduction: Inferior Alveolar Nerve (IAN) exposure and neurosensory disturbances (NSDs) following bilateral sagittal split osteotomy (BSSO) of the mandible are paramount. We aimed to assess intraoperative IAN exposure during and NSDs after BSOO surgery using different clinical assessment methods in a prospective study in a local setting.
 Materials and methods: The present study was a prospective cross-sectional study. We monitored the nerve exposure status during the BSSO. Our time points were: before surgery, one day after, one month later, three months after and six months after the BSSO surgery. We performed two-point discrimination test, static light touch test and pinprick test on both mental regions of the cases.
 Results: We included seven women and eight men. The average age of the participants was 25.13 ± 3.27 years. The results of the two-point discrimination test showed the following: the day after the BSSO compared to before the surgery, the sensation is significantly impaired in both mental regions. In addition, it is noted that during our study, the two-point discrimination test results showed a gradient healing, though not reaching the point before the surgery (P>0.05). The results of the Pinprick test also showed a gradual resolution of the NSDs; however, a significant sensation difference remained between six months after the BSSO and before the surgery.
 Conclusion: The BSSO surgery significantly impairs the IAN sensation, causing intraoperative IAN exposure and postoperative NSDs for the patients. A gradient resolution of the NSDs was observed in all the cases, though; the sensation of the mental region did not reach the pre-surgical levels.

Surgical Management of Laterognathia with Bilateral Sagittal Split Osteotomy: A Serial Case Report

Introduction: Laterognathia is characterized by the mandibular deviation to one of the sides affected which often caused by unilateral overgrowth of the mandible and age-related adaptive remodeling changes in the temporomandibular joint (TMJ) that affected masticatory function and aesthetics. The aim of this serial case report is to discuss the surgical management for laterognathia with bilateral sagittal split osteotomy (BSSO) on a clinical case of asymmetrical dentofacial deformity due to an excessive mandibular unilateral laterognathia. Case Report: This case report contains two cases of mandibular laterognathia. Both of our patients underwent a corrective procedure with bilateral sagittal split ramus osteotomy (BSSO) that performed mandibular setback and rotation. Post-operative follow-up showed the patient was in good condition and no complications were noted. Conclusion: The mandibular setback and rotation procedure can be performed with a bilateral sagittal split ramus osteotomy (BSSO). Significant improvement of laterognathia in occlusion, masticatory function, and facial appearance was achieved by surgical management with BSSO procedure. Keywords: laterognathia, bilateral sagittal split osteotomy, mandibular setback.

Parallel Osteotome Technique: New Approach to Reduce Neurosensory Disturbances following Bilateral Sagittal Split Osteotomy.

The purpose of this study was to determine clinically whether the parallel osteotome technique (POST) reduces the incidence of neurosensory disturbances (NSDs) following bilateral sagittal split osteotomy (BSSO), and to corroborate the findings with finite element analysis. The authors conducted a quasiexperimental study of 30 patients requiring BSSO. The sample was divided into two groups: a control group who underwent the conventional osteotomy technique and an experimental group who underwent POST osteotomy. A finite element analysis simulation of the two techniques was also generated for computational analysis. The primary outcome was clinical comparison of subjective and objective measures for NSDs; the secondary outcome was a comparison of stress, strain, and deformation. The osteotomy technique was the exposure studied. Data were analyzed for differences in proportions and means. Thirty patients (12 female and 18 male patients; age range, 18 to 28 years; mean age, 21.6 years) were recruited for the study, providing 60 sides as a sample. The experimental group had significantly lower subjective scores for NSD at the 3-month ( P = 0.03) and 6-month follow-ups ( P = 0.025). Objective testing revealed a lower incidence of NSDs for the experimental group during postoperative months 3 ( P = 0.07), 6 ( P = 0.007), and 12 ( P = 0.17). The computational analysis also revealed significantly lower stress ( P = 0.007), strain ( P = 0.009), and deformation ( P = 0.04) on the inferior alveolar nerve with the POST osteotomy. The incidence of NSDs following BSSO is lower with the POST osteotomy. This technique also induced significantly lower deformational forces on the inferior alveolar nerve when compared with the conventional osteotomy.

Bilateral Sagittal Split Osteotomy with Mandibular Setback - A Case Report

Bilateral Sagittal Split Osteotomy with Mandibular Setback - A Case Report

Long-term Skeletal Stability of Mandibular Surgery with Bilateral Sagittal Split Ramus Osteotomy—Advancement Versus Setback: A Systematic Review and Meta-analysis

Objectives The aim of this study was to evaluate and compare the long-term skeletal stability of mandibular advancement and mandibular setback achieved with bilateral sagittal split ramus osteotomy (BSSRO) procedure in adult patients with a minimum follow-up of at least 1 year. Methods A literature search was systematically performed according to PRISMA guidelines from four databases without limitation till 15 June 2021. Available literature was assessed for long-term skeletal stability as horizontal/vertical changes at cephalometric point B following conventional mandibular surgery (BSSRO) with rigid internal fixation. The quality of selected articles was assessed using Newcastle–Ottawa scale and the meta-analysis was carried out with Q statistic method, I-squared statistics, and fixed-effect model to estimate the pooled mean and Begg–Mazumdar bias indicator. Results A total of five studies (three pertaining to mandibular advancement and two setback groups) were included for comparative evaluation of relapse. The mean horizontal relapse was 7.85% pertaining to mandibular advancement (4.2–7.06 mm) as compared to 27% pertaining to mandibular setback (7.18–10.26 mm). The meta-analysis of four included studies (two in each group) revealed significant differences in long-term skeletal stability of mandibular advancement and setback (pooled proportion = 20.10; 95% confidence interval = 2.48–39.57). Conclusion Mandibular setback can be expected to relapse by 21.7–32.3% (mean 27%) as compared to mandibular advancement accounting for a relapse of 2.1–15.4% (mean 7.85%) in adult patients. Hence, mandibular advancement is a relatively stable procedure in the long term. PROSPERO registration number: CRD42021261466

Changes of Temporomandibular Joint Morphology and Symptoms in Class II Malocclusion Patients With Bilateral Sagittal Split Ramous Osteotomy.

This study included 46 patients with class II malocclusion ranging in age from 19 to 39 years old treated with bilateral sagittal split ramous osteotomy (BSSRO). Left and right temporomandibular joints (TMJs) of each subject were evaluated independently with cone-beam computed tomography (CBCT) before operation (T1), 1 week after operation (T2), and 1 year after operation (T3) and assessed the effects of orthognathic surgery (OGS) on the temporomandibular joint disease (TMD) symptoms. Temporomandibular joint morphology evaluation included condylar volume, condylar area, cortical bone thickness, depth of the mandibular fossa, fossa thickness, joint nodule angle, joint space, and condyle-fossa relationship, which were calculated by using the Mimics software and 3-matic software. Data were statistically analyzed with SPSS software (P <0.05 means statistically significant). In our study, bilateral TMJs have no difference in T3. Bilateral sagittal split ramous osteotomy had no significant effect on the articular fossa. The condyle volume and surface area decreased from T1 to T3, but the cortical thickness of the bone did not change significantly. More anterior condyle positions in T1 and more posterior in T3.21 patients had at least 1 sign or symptom of TMD in T1 and 27 patients in T3. Four patients who were asymptomatic in T1 developed pain after surgery, 10 developed noises, 12 showed limited mouth opening, and 8 had abnormal opening patterns. It is concluded that more condylar posterior position after BSSRO and the reduction of condyle may be related to the enlargement of anterior space. The number of patients with joint symptoms increased postoperative, and the impact of BSSRO on TMD may be negative.

Risk factors for postoperative facial swelling at 1 week after bimaxillary orthognathic surgery in Class III patients

ObjectiveTo quantify facial swelling at 1 week after Le Fort I osteotomy and bilateral sagittal splitting ramus osteotomy in Class III patients and to identify factors contributing to the swelling based on clinical, morphologic, and surgical variables. Study DesignData from 63 patients were examined in this single-center, retrospective study. Facial swelling was quantitatively measured by superimposing computed tomography data taken in the supine position at 1 week and 1 year postoperatively and extracting the area of maximum intersurface distance. Age, sex, body mass index, thickness of subcutaneous tissue, and of masseter muscle, maxillary length (A-VRP), mandibular length (B-VRP), and posterior maxillary height (U6-HRP), surgical movement (ΔA-VRP, ΔB-VRP, ΔU6-HRP), drainage method, and usage of facial bandages were examined. Multiple regression analysis was performed using the above factors. ResultsThe median swelling at 1 week postoperatively was 8.35 IQR (5.99–11.47) mm. Multiple regression analysis revealed three factors that were significantly associated with facial swelling: Use of postoperative facial bandages (P=0.03), masseter muscle thickness (P=0.03), and ΔB-VRP (P=0.04). ConclusionAbsence of a facial bandage, thin masseter muscle, and large horizontal mandibular movement are risk factors for facial swelling at 1 week postoperatively.

Evaluation of the lower face enlargement following mandibular osteotomy: Bilateral sagittal split osteotomy (BSSO) vs supra basilar sagittal Split Osteotomy (SBSSO)

IntroductionThe current most common technique for mandibular split is the sagittal split osteotomy described by Obwegeser and modified by Dalpont and Epker. Several studies have shown a lower face enlargement while employing these techniques. The supra-basilar sagittal split osteotomy described in 2017 seems to be an interesting alternative as mandibular angles remain in continuity with the internal valve. The aim of this study was to evaluate lower face enlargement by comparing two techniques: sagittal split osteotomy and supra-basilar sagittal split. Materials and MethodsCephalograms were analyzed before and after surgery. Bigonial distances (BGD) were measured in frontal cephalograms, ramus length and distances between upper and lower incisors on lateral cephalogram. Control of those measures was also performed by measuring the Nasion-Anterior Clinoid distance and intercanthal distance to assess the comparability and error rate. Finally, a comparison of cephalograms before and after surgery to assess bigonial enlargement, ramus elongation and advancement was performed. ResultsOut of the 69 patients, 18 had a Bilateral Sagittal Split (BSSO) and 52 had a Supra-Basilar Sagittal Split (SBSSO). The error rate and patients’ characteristics were the same in the two groups. A statistically significant widening of the bigonial distance with the BSSO in comparison with the SBSSO was found (BGD difference: 5.82 mm (BSSO) vs - 1.47 mm (SBSSO), p < 0,001). A greater ramus elongation with the SBSSO was found (ramus elongation: 1.12 mm (BSSO) vs 5.1 mm (SBSSO)). This study has shown that the supra-basilar sagittal split is an interesting way to avoid the widening of the mandibular angles.

Evaluation and Comparison of Cervical Spine Posture in Class II Division I Patients Treated with Twin Block Appliances, Forsus Appliances, and Bilateral Sagittal Split Osteotomy: A Cephalometric Study.

It has been speculated that a change in cervical spine posture occurs due to forward repositioning of the mandible. Therefore, this study aimed to evaluate and compare the cervical spine posture in Class II division one patient treated with three different treatment modalities. A retrospective cohort study was conducted using pre and post-treatment lateral cephalograms of Class II Division one patients who have undergone orthodontic therapy using twin block appliance, Forsus, and bilateral sagittal split osteotomy (BSSO). This study included a total of 57 subjects comprising 19 subjects in each group. Seven cervical, three sagittal, and one vertical parameters were compared within and between each group. The data were tested using the Dependent t-test, One-way analysis of variance, and Tukey's post hoc test. A significant difference existed between the pre- and post-treatment angular measurements within the three groups showing a change in the cervical spine posture with forward positioning of the mandible. A comparison of mean changes in angular measurements between the three groups showed a significant difference in SNA, SNB, ANB, and odontoid process tangent-cervical vertebral tangent (OPT-CVT), indicating a change in the cervical posture. OPT-CVT angle predicts a change in cervical spine posture after treatment with a significant difference in the Twin Block group (P = 0.029) compared to Forsus and BSSO groups. Thus, the twin block group results in a more upright craniocervical posture than the other two treatment groups.

Does the Posterior Bending Osteotomy in Bilateral Sagittal Split Osteotomy Affect the Condyle Position in Asymmetric Patients?

To measure and compare changes in postoperative condylar position following bilateral sagittal split osteotomy in patients with asymmetry treated using a posterior bending osteotomy (PBO) and conventional methods (shaving of premature contacts). Participants were randomized to either the PBO or conventional group. The inclusion criteria were the need for bilateral sagittal split osteotomy or bimaxillary asymmetric surgery (menton deviation >4mm). The primary outcome variable was changes in the condylar position in the axial, coronal, and sagittal planes 6months after surgery, whereas the secondary outcome variable was changes in temporomandibular joint symptoms. Covariates included surgery type, deformity type, age, and sex. Categorical and numerical variables were analyzed using Fisher exact χ2 test and 2-way analysis of covariance. The study sample comprised 42 patients with a mean age of 23.3years; 57.5% were women. The alteration in the coronal condyle angle was 0.8⁰ ± 0.86⁰ in the PBO and 2.72⁰ ± 0.81⁰ in the conventional group. The differences in the condylar position in the coronal plane were not statistically significant (P=.129). The alteration in the axial condyle angle was 2.31⁰ ± 1.74⁰ in the PBO group and 5.65⁰±1.65⁰ in the conventional group. The alteration in the sagittal plane was 0.44⁰ ± 1.52⁰ in PBO and 0.47⁰ ± 1.44⁰ in the conventional group. Alterations in axial (P=.194) and sagittal (P=.976) condylar positions were insignificant. In the conventional group, statistically significant differences were found in the axial (P=.002) and coronal (P=.002) planes, and the condyle turned inward in both planes. There were no statistically significant differences between the groups or within the groups in the sagittal plane (P>0,5). In PBO and conventional groups, joint noise examination revealed positive results in 11 and 6 patients preoperatively and 1 and 2 patients postoperatively, respectively. A statistically significant decrease in joint noise was detected in the PBO group (P=0,04). The maximum mouth opening without pain was 5.95±1.47 in the PBO group and 7.91±1.39 in the conventional group, respectively. The alteration was not statistically significant between the groups but was significant within the groups (P<.001). PBO effectively prevents premature contact between mandibular segments in facial asymmetry.

Assessment of Mandibular Canal Using Cone-Beam Computed Tomography (CBCT) and Its Relevance in Post-Operative Neurosensory Disturbances Following Bilateral Sagittal Split Osteotomy Setback.

Damage to the inferior alveolar nerve (IAN) during bilateral sagittal split osteotomy (BSSO) causesneurosensory disturbances (NSD) of the lower lip and chin. The study aims to investigate the pre-operative position and course of the mandibular canal using cone-beam computed tomography (CBCT) and orthopantomogram (OPG) and compare if there is any difference in NSD following the BSSO setback procedure. This is an observational study. This study was conducted in the Department of Oral and Maxillofacial Surgery, Mar Baselios Dental College, Kothamangalam, from November 2017 to October 2019. Thirty patients undergoing BSSO setbacks are selected based on the inclusion and exclusion criteria and randomly grouped into two groups - group A (15) andstudy group B (15). OPG was done for both groups as it was required during surgical orthodontic evaluation and preoperative assessment of the mandibular canal was done using CBCT in group B. Neurosensory assessment was done in all the patients and compared the results. NSD were reported in all the patients on the first postoperative day. The correlation between subjective and objective evaluation showed absolute coincidence but nearly all the patients returned to their presurgical situation within six months in group B and one year in group A who had NSD problems. From the study, it can be concluded that a CBCT scan is a useful and reliable modality in the pre-operative evaluation of the mandibular canal in patients undergoing BSSO setback procedures, which helps to improve the patient's post-operative care and quality of life.

Association between Bilateral Sagittal Split Osteotomy Setback and Autorotation of the Mandible

Introduction: The study aimed to evaluate the autorotation for Class III malocclusions after the bilateral sagittal split osteotomy (BSSO) setback procedure . Methodology: This retrospective study includes lateral cephalograms of eight males and three females total of 11 patients who had undergone BSSO, without any other additional surgeries. The Frankfurt-Horizontal (F-H) plane was used as a reference and manual superimposition was done. Considering stable mandibular landmarks, reference line perpendicular (RLp) and reference line (RL) were drawn as x and y coordinates, respectively. Pre- and postsurgical statistics were used to compare using paired t-test where P &lt; 0.05 was set for statistical significance. Results: Superimposed tracings showed no significant difference in pre- and postsurgical treatments. There was no statistically significant amount of autorotation after the BSSO setback procedure (P = 0.714). Conclusion: Hence, BSSO setback surgery will not cause any significant amount of autorotation of the mandible. If autorotation is required it must be incorporated into treatment planning.

Redundancy of the Visual Identification of Lingula in the Bilateral Sagittal Split Ramal Osteotomy Procedure of the Mandible.

The bilateral sagittal split ramus osteotomy (BSSRO) is the technique in vogue which is used for correction of a range of mandibular corpus deformity involving the dentoalveolar segment. The surgical technique has been subjected to a variety of modifications ever since its inception in the 1950s. One of the operative objectives which has been advocated sacrosanct has been the visual identification of lingula during the exposure of the medial aspect of the ramus. BSSRO was successfully carried out in 45 cases operated over a period of eight years for correction of different kinds of skeletal mandibular deformity. The medial subperiosteal dissection did not involve a visual identification of the lingula. In our experience, the visual identification of the lingula is not essential to carry out a safe BSSRO procedure.

Case Report: Delayed onset of severe acute facial swelling following bimaxillary osteotomy surgery

This case report will discuss a 20-year-old male who presented to the Accident and Emergency (A&amp;E) department at a district general hospital (DGH) with severe bilateral submandibular facial swelling four days following bimaxillary osteotomy surgery to correct his mandibular prognathism and maxillary retrognathism.The patient had previously undergone both bilateral sagittal split (BSSO) and LeFort 1 osteotomy surgery for the correction of a severe class 3 skeletal discrepancy following orthodontic treatment. The osteotomy was stabilised with titanium fixation plates. Following the surgical treatment, the patient received a regime of co-amoxiclav antibiotic prophylaxis and dexamethasone to combat post-operative inflammation. After an uneventful surgery and a single night in hospital post-operative inpatient stay, the patient was discharged with oral antibiotics and chlorhexidine mouth rinse along with their regular inhalers for his medical history including mild well controlled asthma.Four days following the surgery, the patient presented to A&amp;E complaining of sudden onset severe dysphagia, trismus, and bilateral submandibular and submental facial swelling, only noticed on waking. This case report will discuss the indications of a bimaxillary osteotomy as well as the management and treatment of post-operative complications following this surgery.

The Clinical and Radiographic Changes of Temporomandibular Joint (TMJ) Following Mandibular Set Back Surgery by Bilateral Sagittal Split Osteotomy (BSSO).

BackgroundBilateral Sagittal Split Osteotomy (BSSO) is one of the treatment options for Class III maxillary deficiency which may affect the condylar position and the patient’s occlusion. We aimed to evaluate the clinical and radiographic changes of temporomandibular joint (TMJ) following mandibular set back surgery by BSSO.MethodsIn this retrospective study, All Class III patients, aged between 18-30 years old who underwent bimaxillary orthognathic surgery in the Oral and Maxillofacial Surgery Ward of Ghaem Hospital, Mashhad, Iran from January 2018- January 2020 were enrolled. Radiographic changes of joint space, condylar position and clinical changes for maximal mouth opening and joint sound were examined before and 6 months after surgery. Data were analyzed by SPSS16 software and the significance level of the data was set at P-value < 0.05.ResultsTwenty-five patients were recruited. The axial angle of the left and right condyle and condylar inclination on both sides reduced but this reduction was not statistically significant. While the anterior joint space was reduced and posterior joint space was increased in both sides, the changes on the right side were only significant (P = 0.039). In clinical examinations maximum mouth opening, lateral and protrusive movements were also decreased but this reduction was not statistically significant.ConclusionThe mandibular set back with BSSO surgery in class III skeletal patients had no significant effect on the position of the condyle in the glenoid fossa as well as clinical symptoms.