Cephalometric Analysis of Modifications of the Mandible Due to Reduction Mandibuloplasty in Patients With Prominent Mandibular Angle

Cephalometry has been used to measure hard and soft facial tissues as well as to conduct the ostectomy to determine the characteristics of the prominent mandibular angles (PMA). The changes produced on the mandibles by reduction mandibuloplasty are not known. The objective of the present study was to identify by cephalometric analysis the anatomical changes of the mandibles that occur in patients with PMA after reduction mandibuloplasty. Forty-two patients with PMA were submitted to cephalometric analysis before, 1 week and 6 months after surgery to evaluate the changes of the mandibles produced by reduction mandibuloplasty. Cephalometry was standardized to obtain descriptive measurements of the dimensions of the mandibles. The modifications of the mandibles due to reduction mandibuloplasty showed a significant change obtained by cephalometry. At 1 week after surgery, the average distance between the gonions decreased 17.70 +/- 8.46 mm, the average length of the mandibular ramus reduced 5.84 +/- 3.26 mm, the average mandibular body length increased 4.61 +/- 2.74 mm, the average gonial angle increased 14.78 +/- 6.658, the average mandibular plane angle increased 10.29 +/- 3.828. At 6 months postoperatively, the first 3 linear measurements increased 3.68 +/- 2.91, 1.66 +/- 2.51, and 2.10 +/- 2.37mm respectively; however, the last 2 angular measurements reduced 2.86 +/- 3.028 and 1.77 +/- 2.628 respectively. The results demonstrated that reduction mandibuloplasty can modificate mandibular contouring three-dimensionally. The data of 6 months postoperatively compare to those of the beauty people reported in the literature, there were statistically differences between the linear measurements, but no statistically differences between the angular measurements. Despite bone regeneration result in linear or angular measurements change, postoperative angular shape was predominantly maintained, and the preoperative angular prominence did not recur.