The Effect of Orthognathic Surgery on Temporomandibular Joint Function and Symptoms: What are the Risk Factors? A Longitudinal Analysis of 375 Patients

Bilateral sagittal split osteotomy with or without concomitant removal of third molars: a retrospective cohort study of related complications and bone healing

PURPOSE

To carry out a comparative evaluation of the intra- and postoperative complications, and bone healing, following bilateral sagittal split osteotomy (BSSO) with or without concomitant removal of third molars.

MATERIAL AND METHODS

A retrospective analysis was performed of two cohorts subjected to BSSO with the intraoperative removal of third molars (test group) versus the removal of third molars at least 6 months prior to BSSO (control group), comprising at least 1 year of clinical and radiographic follow-up. Partially or completely erupted third molars were extracted immediately before completing the osteotomy, whereas impacted third molars were removed after the osteotomy had been performed. Hardware reinforcement was performed in bimaxillary cases where concomitant molar extraction impeded placement of the retromolar bicortical screw of the hybrid technique.

RESULTS

A total of 80 surgical sites were included (40 in each group). Concomitant extraction of the molar represented a mean increase in surgery time of 3.7 min (p < 0.001). No additional complications occurred in the test group (p = 0.476). The gain in bone density was preserved in both groups (p = 0.002), and the increase was of the same magnitude in both (p = 0.342), despite the fact that the immediate and final postoperative bone densities were significantly higher in the control group (p = 0.020).

CONCLUSION

The results obtained support concomitant molar extraction with BSSO as a feasible option.

Effect of Orthognathic Surgery on Pre-existing Temporomandibular Disorders

The management of patients with pre-existing temporomandibular disorders (TMDs) undergoing orthognathic surgery remains a subject of ongoing debate. This study aimed to profile these individuals and evaluate the correlation between orthognathic surgery and alterations in TMD indicators and symptoms. We conducted a retrospective cohort investigation involving patients with skeletal malocclusion and established TMDs. Variables of interest encompassed the performance of orthognathic surgery, documented TMDs (including temporomandibular joint (TMJ) sounds, TMJ pain, muscle discomfort, and jaw locking), and patients' self-assessments of TMJ and muscle pain using a visual analog scale (VAS). The primary outcome measures focused on changes in TMD indicators and symptoms. Among the study cohort, 73.4% exhibited skeletal class III malocclusion, while 26.6% presented with skeletal class II malocclusion. Notably, patients classified as skeletal class III were significantly younger than their skeletal class II counterparts (mean age: 23.06±5.37 vs. 26.71±7.33; P=0.034). The most prevalent pre-existing TMD complaint was TMJ sounds (65.5%), followed by TMJ pain (39.1%), muscle discomfort (23.4%), and jaw locking (12.5%). Skeletal class II patients were more likely to experience TMJ sounds compared to skeletal class III patients (88.2% vs. 57.4%; P=0.022). Statistically significant improvements were observed in the VAS assessments among class III patients following surgery. A majority of patients with pre-existing TMDs seeking orthognathic surgery exhibited skeletal class III malocclusion and were younger than those with skeletal class II malocclusion. Importantly, orthognathic surgery was associated with positive changes in TMD indicators and symptoms in these patients.

Condylar Positional Changes in Skeletal Class II and Class III Malocclusions after Bimaxillary Orthognathic Surgery

Orthognathic surgery is indicated to modify the position of the maxillomandibular structure; changes in the mandibular position after osteotomy can be related to changes in the position of the mandibular condyle in the articular fossa. The aim of this study was to determine changes produced in the mandibular condyle 6 months after orthognathic surgery. A cross-sectional study was conducted that included subjects who had undergone bimaxillary orthognathic surgery to treat dentofacial deformity of Angle class II (group CII) or Angle class III (group CIII). Standardized images were taken using cone-beam computed tomography 21 days before surgery and 6 months after surgery; measurement scales were used to identify the condylar position and its relations with the anterior, superior, and posterior joint spaces. The results were analyzed using the Shapiro-Wilk and Student's t-tests, while considering a value of p < 0.05 as indicating a significant difference. Fifty-two joints from 26 patients, with an average age of 27.9 years (±10.81), were analyzed. All subjects in both group CII and group CIII showed a significant change in the anterior, superior, and posterior joint spaces. However, postoperative changes in the position of the condyle in the articular fossa were not significant in the anteroposterior analysis. We conclude that orthognathic surgery causes changes in the sagittal position of the mandibular condyle in subjects with mandibular retrognathism and prognathism.

Effect of the magnitude of condylar head displacement on the TMJ function in skeletal class II patients undergoing different degrees of mandibular advancement: A retrospective comparative study

PURPOSE

This study aimed to compare the condylar head displacement (CHD) after bilateral sagittal split ramus osteotomy (BSSO) between different degrees of mandibular advancement in skeletal class II patients and to evaluate whether the temporomandibular joint (TMJ) function would be affected.

PATIENTS AND METHODS

Fifty-nine patients (118 condyles) were included in this retrospective study and were divided into three groups based on the distance of mandibular advancement. The CHD in three directions, x (sagittal direction), y (coronal direction), and z (axial direction), was measured before operation (T0), immediately after operation (T1), and at least 6 months after operation (T2), and the TMJ function of patients was followed up and scored using the Helkimo index system. All the abovementioned data were statistically analyzed, and p < 0.05 was considered the statistical difference standard.

RESULT

During the BSSO surgery, the condyle was predominantly displaced in a lateral, posterior, and superior direction whenever in T1 and T2, even though the degree of CHD was different. Regarding the amount of CHD, the large advancement group was higher than the other two groups in T1 and T2 (p＜0.01). The Helkimo index scores of the three groups were evaluated, and there was no significant statistical difference between the Ai and Di index of the three groups.

CONCLUSION

In our center, CHD occurred in lateral, posterior, and superior directions following mandibular advancement in skeletal class II patients, with a positive correlation between the CHD and the mandibular advancement; however, the TMJ function of the three groups did not show significant differences.

Early Outcomes and Risk Factors in Orthognathic Surgery for Mandibular and Maxillary Hypo- and Hyperplasia: A 13-Year Analysis of a Multi-Institutional Database

BACKGROUND

Orthognathic surgery (OS) is a frequently performed procedure for the correction of dentofacial deformities and malocclusion. Research on OS is mostly limited to single-surgeon experience or single-institutional reports. We, therefore, retrospectively analyzed a multi-institutional database to investigate outcomes of OS and identify risk factors for peri- and postoperative complications.

METHODS

We reviewed the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database (2008-2020) to identify patients who underwent OS for mandibular and maxillary hypo- and hyperplasia. The postoperative outcomes of interest included 30-day surgical and medical complications, reoperation, readmission, and mortality. We also evaluated risk factors for complications.

RESULTS

The study population included 674 patients, 48% of whom underwent single jaw surgery, 40% double jaw surgery, and 5.5% triple jaw surgery. The average age was 29 ± 11 years, with an equal gender distribution (females: n = 336; 50%, males: n = 338; 50%). Adverse events were relatively rare, with a total of 29 (4.3%) complications reported. The most common surgical complication was superficial incisional infection (n = 14; 2.1%). While the multivariable analysis revealed isolated single lower jaw surgery (p = 0.03) to be independently associated with surgical complication occurrence, it also identified an association between the outpatient setting and the frequency of surgical complications (p = 0.03) and readmissions (p = 0.02). In addition, Asian ethnicity was identified as a risk factor for bleeding (p = 0.003) and readmission (p = 0.0009).

CONCLUSION

Based on the information recorded by the ACS-NSQIP database, our analysis underscored the positive (short-term) safety profile of OS. We found OS of the mandible to be associated with higher complication rates. The calculated risk role of OS in the outpatient setting warrants further investigation. A significant correlation between Asian OS patients and postoperative adverse events was found. Implementation of these novel risk factors into the surgical workflow may help facial surgeons refine their patient selection and improve patient outcomes. Future studies are needed to investigate the causal relationships of the observed statistical correlations.

Examination of factors affecting condylar bone changes following surgical-orthodontic treatment

OBJECTIVE

To identify factors affecting condylar bone changes following surgical-orthodontic treatment.

METHODS

A total of 200 patients with dentofacial deformities were classified into skeletal Classes I, II, and skeletal Class III groups consisting of 61 and 139 subjects, respectively. Temporomandibular joints (TMJs) were evaluated using clinical findings and computed tomography images before treatment, immediately before surgery, and 6 months after surgery.

RESULTS

Condylar bone changes occurred at a significantly higher rate after surgery in both groups. Factors related to condylar bone changes following surgical-orthodontic treatment included skeletal Class I or II, disc displacement, and condylar bone changes before treatment. There were three cases with condylar bone changes after surgery that were diagnosed with condylar resorption and skeletal Class II and anterior disc displacement before surgery.

CONCLUSION

Condylar resorption could occur when the load on the condyle increases after orthognathic surgery and exceeds the permissible limit.

The Influence of the COVID-19 Pandemic on the Stress Levels and Occurrence of Stomatoghnatic System Disorders (SSDs) among Physiotherapy Students in Poland

Background: This study is a quantitative analysis examining the impact of the COVID-19 pandemic on the occurrence of stress and stomatognathic system disorders (SSDs) among students of physiotherapy. Objective: To assess stress severity, strategies of coping with stress and the presence of type D personality among physiotherapy students including those with symptoms of stomatognathic system disorders. Material and Methods: The research was conducted from October to December 2020 on a sample of 188 students of physiotherapy. The data were collected using a survey form related to the occurrence of SS disorders symptoms and standardized psychological questionnaires, such as the Perceived Stress Scale (PSS)-10, Mini-Cope, and the type-D Scale (DS14), developed for the purpose of this study. Results: Women experiencing at least one of the SS disorder-related symptoms were characterized by a significantly higher level of stress and a type D personality (p < 0.05). Among men, these differences were not statistically significant (p > 0.05). On the basis of the strategies of coping with stress, i.e., positive self-reevaluation, discharging and blaming oneself, and taking psychoactive substances, it is possible to predict the intensity of stress during the pandemic in the group of the examined students. Among the reported symptoms of SS, headache was a significant predictor of stress, which was accompanied by an increase in the intensity of stress by nearly 0.2 measurement points. Students with higher levels of stress showed more symptoms of type D personality, and those with more severe symptoms of SS showed higher levels of stress. Conclusions: People prone to stress and having type D personality traits should be assessed for the presence of SS disorders.