Evaluating the Accuracy of Ascending Ramus Geometry Using Cone-Beam Computed Tomography for Bilateral Sagittal Split Osteotomy's Horizontal Osteotomy.

INTRODUCTION

An accurate identification of anatomic structures is crucial for planning orthognathic osteotomies. Identification of anatomic landmarks on cephalograms was carried out; however, its application in 3D imaging remains limited. This study assesses the accuracy of using the geometry of ramus on cone-beam computed tomography (CBCT) to locate the horizontal medial osteotomy (MHO).

MATERIAL AND

METHODS

Forty rami from 14 fresh cadaveric head and necks were subjected to CBCT analysis before performing surgery. The MHO was identified in coronal CBCT views. Measurements were obtained in different CBCT views: sagittal, coronal, and axial views.

RESULTS

The mean distance from the proposed horizontal medial osteotomy or cut (HC) to the mandibular foramen (MF) (HC/MF) is 5.2±2.1 mm, which confirms that all the HC are located above the MF. Notably, there were reported differences between the right and left sides of the jaw in the same cadavers, concerning the vertical dimensions and location of Lingula (Li) and MF; there were statistically significant differences in relation to co-variables ( P <0.05).

CONCLUSIONS

Using the ascending ramus geometry functions as a guide while performing the medial horizontal cut by avoiding excessive medial dissection to locate the lingula and thereafter avoiding accidental postoperative nerve disturbance. The study outcome would contribute to the development or amelioration of present machine learning algorithms that are highly effective in supporting surgical planning for dento-maxillofacial deformities.