Fractal analysis of the mandibular ramus in class II and III patients undergoing orthognathic surgery: retrospective study trough cone-beam computed tomography.

Introduction: One of the challenges of orthognathic surgery (OS) is maintaining condylar position during osteosynthesis. It is believed that the post-surgical condylar position is related to postoperative morphological changes in the temporomandibular joint (TMJ), as well as surgical stability.

Objective: The aim of this study is to perform fractal analysis of the mandibular ramus in class II and class III patients undergoing OS, analyzing cone beam computed tomography (CBCT) images one month before surgery (T0), one month after surgery (T1), and six to eight months after surgery (T2).

Materials and methods: Fractal analysis was performed on coronal and sagittal reconstructions. Regions of interest (ROIs) were selected for each patient and evaluated region. The ROIs underwent a processing method described by White & Rudolph in 1999. After processing, fractal analysis calculation was performed using the box-counting method by the "Fractal Box Count" function of the ImageJ software.

Results: When examining the different periods (T0, T1, and T2) among class II and class III patients, no statistically significant differences were identified (p > 0.05). This finding suggests stability in the fractal characteristics of the analyzed region, regardless of skeletal class.

Conclusion: OS for correction of Class II and Class III malocclusions did not demonstrate a significant impact on the microstructure of the mandibular ramus over time.