Digital measurements of 120 mandibular angles to determine the ideal fibula wedge osteotomy to re-create the mandibular angle for microvascular reconstruction.

PURPOSE

Mandibular reconstruction continues to be a challenge, even for the seasoned reconstructive surgeon. The present study sought to determine the normal anatomic mandibular angle and to establish a predictable angle of resection for the fibula bone cut to re-create the neomandibular body-ascending ramus angle.

MATERIALS AND METHODS

A total of 30 random male and female panoramic radiographs were selected from our database. The selection criteria included age older than 21 years and a full or near total complement of teeth. The exclusion criteria were an edentulous mandible or maxilla, a history of trauma or maxillary or mandibular pathologic features, and age younger than 21 years. A total of 120 total measurements were performed. The angle measured was determined from a line coinciding with the posterior border of the ramus and the lower mandibular border. The measurements were taken from each side and from each gender group. The institutional review board of our institution approved the present study.

RESULTS

The mean female mandibular right angle was 122.62°, and the left was 124.59° (average, 123.61°). The mean male mandibular right angle was 122.66°, and the left was 124.2° (average, 123.43°). The mean and median values were very similar. A statistically significant difference was identified between the left and right sides but not between the genders. Given this information, one can calculate a wedge cut in the fibula of about 56° to re-create the mean mandibular angle.

CONCLUSIONS

This information can be used to make predictable fibula wedge closing osteotomies to re-create the normal mandibular ascending ramus body angle in a low-cost manner with the aid of an autoclavable metal wedge of 56°. This method would obviate the need for costly prefabricated guides.