Three dimensional condylar positional and morphological changes following mandibular reconstruction based on CBCT analysis: a prospective study

Abstract

Objective This study aimed to evaluate the condylar positional changes following mandibular reconstruction with preservation of the condylar head using Cone-Beam Computed Tomography (CBCT). Also, to assess joint space changes and the overall volumetric space compared to the preoperative status. Methodology This prospective study included 30 patients (60 joints) subjected to unilateral mandibular resection and reconstruction with preservation of the condylar head. The Helkimo index and preoperative (T1), two weeks postoperative (T2), and follow-up CBCTs (T3) after at least six months were gathered and processed to evaluate the condylar position and TMJ joint space using Anatomage Invivo 6. A student’s t-test and repeated-measures ANOVA statistics were used. A P value of less than 0.05 was considered statistically significant. Results Thirty patients (14 males, 16 females) with a mean age of 40.01 ± 12.7 years (a range of 18.1–62.9 years) were included. On the tumor side, there were significant variances in the vertical and mediolateral condylar positions between the three-time points (T1, T2, T3). Immediately after the operation, the condyles were significantly displaced in a downward direction at T2, which became larger after the last follow-up period (T3) (p = 0.007). The condylar positions at the anteroposterior direction were relatively stable without significant differences between the three times points (p = 0.915). On the non-tumor side, the condylar positions were relatively stable in the mediolateral and anteroposterior positions. In the tumor side, all of the TMJ spaces were significantly increased in size following the mandibular reconstructions (T2 and T3). However, on the non-tumor side, the anterior, posterior, and medial joint spaces were significantly changed postoperatively. Conclusion After mandibular reconstruction with condylar preservation, the condylar position and volumetric measurement immediately changed noticeably and continued to be a permanent change over time compared to relatively stable condyles on the non-tumor side. According to Helkimo index, patients become adapted to the postoperative changes without significant differences between the two sides.

Comparison of condylar position after free fibular flap mandibular reconstruction using computer-assisted and traditional techniques

“…Wei et al analyzed the CT images of 16 patients’ TMJs pre- and postoperatively and found that the ipsilateral condyles moved anteroinferiorly immediately after surgery and then moved anterosuperiorly thereafter [ 12 ]. Saddam et al examined the CBCT scans of 30 patients who underwent unilateral mandibular reconstruction to study their condylar positions and found that condylar position changed in a downward direction and became larger as time went on, whereas there were no significant differences in the anteroposterior direction [ 13 ]. In this study, the condylar position changed in the patients in both the 3D group and the traditional group after surgery.…”

Joint Space Analysis Using Cone-beam Computed Tomography Imaging in Patients Diagnosed with Temporomandibular Joint Osteoarthritis and Occlusal Changes

“…We also assessed the relationship between occlusal changes and mandibular condyle position using categorical variables (Table 3). The APP criteria used in this study were primarily used to assess the position of the mandibular condyle in relation to the skeleton [17] or changes in the position of the mandibular condyle after bimaxillary surgery [18,24]. Although condylar position may not be a determinant of TMJ pathophysiology [24,25], frequency analysis of condylar position over time may provide helpful information for clinicians diagnosing and treating TMJ OA.…”

“…Among the JS measurements, AJS and PJS were used to calculate information about the anteroposterior position (APP) of the mandibular condyle in the glenoid fossa. The APP is defined as the position obtained by dividing AJS by PJS (AJS/PJS ratio) and is considered a central condylar position when the calculated value is 1 (±0.09), a posterior condylar position when it is greater than 1, and an anterior condylar position when it is less than 1 [17,18].…”

Three-dimensional spatial analysis of temporomandibular joint in adolescent Class II division 1 malocclusion patients: comparison of Twin-Block and clear functional aligner

“…The sample size was calculated using the G* Power software (version 3.1; Universität Kiel). Considering α = 0.05, β = 0.2, t-test for matched pairs, and an effect size of 0.8 [20,21], the sample size was calculated as at least 15 patients per group.…”