Fractal analysis of mandibular bony healing after orthognathic surgery

Abstract

Objectives: We evaluated the radiographic changes to the operational sites after orthognathic surgery by using fractal analysis.

Study design: Panoramic radiographs from 35 patients who underwent orthognathic surgery on the mandible without any complications during the osseous healing process were selected. The radiographs taken before the operation (stage 0) and 1 or 2 days (stage 1), 1 month (stage 2), 6 months (stage 3), and 12 months (stage 4) after the operation were digitized at 600 dpi with 256 gray levels. The fractal dimension was calculated by means of a tile-counting method in the region of interest centered on the operational site and was statistically analyzed according to its stages.

Results: The fractal dimension was decreased immediately after the operation and increased gradually according to the time lapse (P <.05). The fractal dimension in the region of interest 12 months postoperatively was similar to that preoperatively.

Conclusion: This result suggests that fractal dimension can be used to evaluate the bony healing process after orthognathic surgery.