Evaluation of pterygomaxillary anatomy using computed tomography: are there any structural variations in cleft patients?

Structural characteristics of the pterygomaxillary region in patients with cleft lip and palate (CLP) have not been fully investigated. This study aimed to evaluate the regional anatomy of the pterygomaxillary junction of patients with CLP using computed tomography.The pterygomaxillary structures of patients with unilateral or bilateral CLP were compared with those of a control group using axial computed tomography. The thickness and width of the pterygoid plate, the distance from the greater palatine foramen to the lateral pterygomaxillary junction, the lateral and medial pterygoid plate lengths, and the maxillary posterior transverse width were investigated with axial computed tomography just beneath the level of the inferior nasal concha and approximately 3 to 5 mm above the nasal floor. The difference between the cleft and noncleft sides or the right and left sides of each group and the measurement differences between the groups were statistically compared.The study group was composed of 14 patients with unilateral CLP and 6 with bilateral CLP, and the control group were 20 age- and gender-matched patients with skeletal Class III without CLP. Patients with unilateral CLP and those with bilateral CLP were statistically equivalent for all radiographic variables. In patients with CLP, the width of the pterygomaxillary region and the greater palatine foramen region were on average 1.5 to 1.8 mm larger than in control patients (P < .05). Lateral pterygoid plate length and maxillary posterior transverse width were similar in the 2 groups. However, the patients with CLP showed a 2.3-mm shorter medial pterygoid length (P < .05).Patients with CLP had larger and thicker pterygomaxillary dimensions, and the results imply that careful attention to pterygomaxillary anatomy is needed in patients with CLP undergoing Le Fort I surgery.