Evaluation of Changes in the Pharyngeal Airway Space as a Sequele to Mandibular Advancement Surgery: A Cephalometric Study.

PURPOSE: To evaluate effect of mandibular advancement on pharyngeal airway space using lateral cephalogram. MATERIALS AND METHODS: Twenty patients who were diagnosed with class II skeletal malocclusion and underwent surgical intervention for the correction of their dentofacial deformity following orthodontic treatment were included. The soft tissue changes in the pharyngeal space were brought about by the surgical intervention, and the changes that had occurred in increasing the airway were evaluated by using cephalogram. RESULTS: The results of this study showed that following mandibular advancement surgery, the pharyngeal airway space increased along with an increase in the length and thickness of the uvula with a reduction in the angulation. All the changes remained stable in the late postoperative phase. CONCLUSION: Patients who underwent mandibular advancement showed a significant increase in the pharyngeal airway space and that remained stable during the evaluation period. As a consequence, mandibular advancement seems to be the most stable surgical movement in relation to airway dimensional gains.

Dynamic Stability Assessment of the Temporomandibular Joint as a Sequela of Open Reduction and Internal Fixation of Unilateral Condylar Fracture.

PURPOSE: Dynamic stability of the temporomandibular joint (TMJ) is the characteristic of the joint to achieve normal function by harmonious, balanced, synchronized interactions of the various functional subunits of the stomatognathic system. The aim of this study was to evaluate changes in the mechanics and dynamics of the TMJ during recovery from surgical treatment of an isolated condylar fracture. PATIENTS AND METHODS: This is a prospective cohort study involving 30 patients who underwent open reduction and internal fixation for an isolated unilateral condylar fracture and were clinically asymptomatic at 6 months after surgery. The dynamics of the TMJ were assessed by bite-force analysis, both static and dynamic, to assess masticatory efficiency. Surface electromyography was recorded to assess changes in muscle dynamics. Joint vibration analysis was performed to evaluate the internal functioning of the TMJ. All the assessments were carried out bilaterally to allow comparison of the injured and uninjured joints, and the data were analyzed with the paired t test and independent-samples t test. Statistical significance was considered at P < .05. RESULTS: The study included 18 male and 12 female patients aged between 20 and 40 years. Bite-force analyses showed significantly higher bite forces on the uninjured side at 6 months after surgery. Similarly, surface electromyography analysis showed increased muscle activity on the affected side pointing toward some compensatory hyperactivity in the masticatory muscles. Joint vibration analysis showed that there was increased friction during function in both the injured and uninjured joints. CONCLUSIONS: The observations in this study suggest that residual imbalances are present in the TMJ at 6 months after open reduction and internal fixation of condylar fractures. Therefore, long-term studies are required to establish a complete timeline of adaptive changes occurring in the TMJ after condylar fractures, especially in comparison with other treatment modalities.

Mandibular Third Molar Position Influencing the Condylar and Angular Fracture Patterns.

PURPOSE: The aim of this study was to assess the influence of position of mandibular 3rd molar on angle and condylar fractures. MATERIALS AND METHODS: Panoramic radiographs were used to determine the mandibular fracture patterns based on the presence or absence of the third molar. RESULTS: Of the 64 patients with mandibular fractures, condyle and angle fractures were found to be 67 and 33 % respectively. The greatest percentage (75 %) of condylar fractures were associated with erupted third molar teeth, and 25 % had impacted teeth. Subcondylar region was found to be the most common site that predisposes to fracture. Moderate force lead to condylar fracture when third molar is erupted or absent and mild force showed angle fracture when third molar is impacted. Increased incidence of angle fracture was observed when tooth is in mesioangular and distoangular position. CONCLUSION: Impacted mandibular 3rd molar leads to an increased risk of angle fracture and decreased risk of condylar fracture especially when they are more deeply seated.

Soft tissue changes and its stability as a sequlae to mandibular advancement.

PURPOSE OF THE STUDY: To predict the changes and evaluate the stability that occurs in the soft tissues following the skeletal movement subsequent to surgical advancement of the mandible through bilateral sagittal split osteotomy and to provide the patient reliable information with regard to esthetic changes that can be expected following the treatment. MATERIALS AND METHODS: Twenty adult patients diagnosed with skeletal class II malocclusion and underwent bilateral sagittal split osteotomy for mandibular advancement by a mean of 8 mm using rigid fixation were included in the study. Soft tissue changes brought about by the surgical procedure and their stability over a period of time were evaluated prospectively using 12 linear (4 vertical and 8 horizontal) and 4 angular measurements on profile cephalograms which were taken preoperatively after the pre-surgical orthodontics (T1) and postoperatively with duration of 1 month (T2) and 6 months (T3) respectively. RESULTS: It was observed that compared to the linear measurements, the angular measurements showed significant changes. The improvement in the esthetic outcome is a direct reflection of the angular changes whereas the linear changes played a contributing role. Following mandibular advancement surgery the profiles of the patients was perceived to have improved with reduction in the facial convexity, an increase in the lower facial height, decrease in the depth of the mentolabial sulcus and improvement in the lip competency with lengthening, straightening and thinning of the lower lip. CONCLUSION: The soft tissue response and its stability depends on the stability of the surgical procedure itself, postsurgical growth and remodeling of the hard tissues and soft tissue changes as a result of maturation and aging.