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

Abstract

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.

Volumetric changes in temporomandibular joint space following trans-oral vertical ramus osteotomy in patients with mandibular prognathism: a one-year follow-up study

“…On the other hand, there were studies that reported no change in joint space or a decrease in posterior joint space compared to pre-surgery levels. 20 , 21 These studies targeted patients undergoing SSO, introducing potential variations from our study.…”

Highlights of orthognathic surgery in class II patients: a systematic review

“…Orthognathic surgery is indicated to modify the position of the maxillomandibular structure, which may cause changes in the sagittal position of the mandibular condyle in individuals with retrognathism and mandibular prognathism. In the context of orthognathic surgery, anterior open bite (AOB) is an easily recognized malocclusion and presents only aesthetic and functional problems [1,2]. Its etiology is multifactorial, including heredity, oral habits, unfavorable growth patterns, and enlarged lymphatic tissue along with mouth breathing and oral functional matrices.…”

“…In this context, open bite treatment involves preventive treatments, eliminating harmful habits, and correcting the posture of soft tissues through the use of palatal bars or orthopedic devices, including corrective mechanics, extractions, elastics, alignment, and leveling, headgear, and orthognathic surgeries [1,2]. The literature is controversial regarding definitions, etiology, and forms of treatment [4][5][6][7].…”

“…The positioning of the tongue is generally overlooked by dentists, however, it is an important factor to be considered, as tongue posture is one of the most important factors that allow the development of AOB [1]. To achieve stability, there must be good occlusion after carrying out the open bite correction treatment, so the orthodontist must aim for excellent occlusion, with simultaneous contacts bilaterally, in total harmony with the centric relationship, with the presence of disocclusion of the posterior teeth during excursive movements of the mandible [2,3].…”