Pterygomaxillary junction: morphometric analysis and clinical aspect

The pterygomaxillary fissure is formed by the divergence of the maxilla from the pterygoid process of the sphenoid bone. It connects the infratemporal fossa with the pterygopalatine fossa. During the osteotomies this area couldn’t visualise and osteotomy is performed tactually. Osteotomy is performed by an osteotome or pterygoid chisel. Pterygomaxillary area is an important component of the orthognatic surgeries because during the Le Fort I osteotomies down fracture of maxilla are required. We studied 80 human dried skulls. We investigated the structure of the pterygomaxillary junction and differences between the right and left sides. The length and width of pterygomaxillary junction is measured in sagittal plane. Mean values and standard deviations are calculated and right and left sides are compared. The mean length, and width of the pterygomaxillary junction was 15.3 mm and 7.18 mm, respectively. There was no statistically significant difference between right and left sides of the skulls, but there was significant difference when the skulls compared with each other. The last step of the Le Fort I osteotomies is the separation of the maxilla from the pterygoid plates. For this process, the pterygomaxillary junction should be separated with curved osteotomes. By placing a finger inside the mouth and feeling the hamulus, the medial extent of the osteotome can be palpated to ensure the proper position. Once the osteotomies are completed, the down fracture is performed with digital pressure. Knowledge of the structure, mean values and distinctions of the pterygomaxillary junction is important to prevent possible complications during the orthognatic surgeries.