This study examined the changes in the positions of the condylar head of mandible before and after sagittal splitting ramus osteotomy surgery performed by applying the photographic subtraction method to Cephalometric laminagraph.
Materials and Methods: This examination was carried out in twelve patients (two males and ten females, ranged 14 to 27 years old) who were diagnosed as having severe class III skeletal pattern and underwent sagittal splitting ramus osteotomy. Cephalometric laminagraphs taken before and after surgery were used for photographic subtraction. Changes in positions of the condylar head after surgery, were examined with respect to direction of rotation, degrees of vertical movement and horizontal movement.
Results: rotation of condyle was observed in seven cases, two cases showed forward rotation (+) on one side only, two cases showed backward rotation (-) of the condyle on one side only, and three cases showed forward rotation (+) of the condyle on both sides. Vertical and horizontal movement were observed in all the cases: vertical change of the condyle on both sides in two cases, on one side in the other ten, horizontal change of the condyle on both sides in seven cases, and on one side in the other five.
Discussion: Applying photographic subtraction to cephalometric laminagraphy was clinically useful for observing not only the small changes in the mandibular condyle but also the overall changes in the surgical position of the mandible.
