Volumetric mandibular change after angle ostectomy and outer cortex grinding.

[BACKGROUND] Mandibular angle ostectomy is one of the most common surgical procedures for facial contouring in Asian women. However, some patients complain about mandibular angle hypertrophy recurrence after surgery. The present study evaluated volumetric change of the mandible after angle ostectomy and outer cortex grinding.

[METHODS] Twenty-four patients who underwent bilateral mandibular angle ostectomy and outer cortex grinding from 2013 to 2016 were enrolled. Three-dimensional computed tomography data were used to evaluate the preoperative, immediate postoperative, and long-term follow-up (≥12 months) volume of the mandible. The volumetric change between different groups was analyzed.

[RESULTS] The results of software measurements showed that the preoperative mandible volume was significantly larger than immediate and long-term postoperative volumes (P = 0.000), and there was no significant difference between immediate and long-term postoperative mandibular volume (P > 0.05). Mean bone regeneration at long-term follow-up was 1.42% ± 3.84% for those who underwent mandibular angle ostectomy with outer cortex grinding alone and 1.69% ± 2.45% on the left and 2.59% ± 3.61% on the right sides of patients who underwent this procedure along with advancement genioplasty.

[CONCLUSION] Mandibular angle ostectomy can effectively change the facial contour to achieve a more oval-shaped face favored by most Asians. Postoperative bone remodeling is mostly regenerated, although bone absorption did occur. However, the mean bone volume did not reach preoperative levels, and the difference between preoperative and long-term postoperative bone volume at follow-up (≥12 months) was significant.