Three-Dimensional Evaluation Of The Temporomandibular Joint After Using Facemask Appliance; A Clinical Prospective Study.

Aim of the study: This study was conducted to evaluate the three dimensional changes in the TMJ after the maxillary protraction using face mask therapy. Material and Methods:Eighteen growing patients (ages ranged from 8-11 years) were included in the current study.All patients manifested features of skeletal class III due to maxillary deficiency.A Petit-type facemask was used for all patients and was attached intraorally to a fixed labiolingual appliance through extraoral elastics .A cone-beam CT scan had been applied for each patient before the start of the treatment and after 10 months.The three-dimensional (3D) temporomandibular joint measurements included: 1) anterior fossa line inclination, 2) posterior fossa line inclination, 3) anterior joint space, 4)posterior joint space,5) medial joint space, and 6) superior joint space.Results : Regarding Anterior Joint space : measurements after using a facemask appliance were significantly higher than before (as P<0.05) ,while regarding Posterior and superior Joint spaces: measurements after using a facemask appliance were significantly lower than before (as P<0.05) Conclusion: Facemask therapy for maxillary protraction in management of skeletal class III produced: 1-Decrease in both posterior and superior joint spaces ,while increase in the anterior joint spaces.2-Bone remodeling in the glenoid fossa causes upward and backward displacement of the condyle.