European Journal of Molecular & Clinical Medicine

Purpose of the study : This study aimed to determine the height at which both the lateral
and medial cortical bone layers of mandibular ramus merge, using a reference point on the
anterior margin of the mandibular ramus and comparing with lingula as another
reference point, using cone beam computed tomography, thus establishing an effective
method of determining the level of the horizontal cut of sagittal split osteotomy.
Material and Methods: The mandibular ramus of 15 patients were analysed on a three
dimensional (3D) model constructed using Cone Beam Computed Tomography. Starting at
reference point (A), a line was marked from the anterior border of the ramus of mandible
till the posterior border on lateral surface. On three vertical section of the ramus (1/3rd
and 2/3rd and lingula), the level at which both lingual and buccal cortices meet were
determined- A1 and A2 and L respectively.
The results of the study showed that mean height of fusion of medial and lateral cortices at
1/3rd and 2/3rd and lingula were 8.96mm, 4.62mm and 11.00mm respectively.
Conclusion:The point A is a safe and easy to locate anatomic reference point to establish
the level of horizontal cut in sagittal split ramus osteotomy (SSRO).