What are the Pterygomaxillary Fracture Patterns in Cleft Orthognathic Surgery?

Background: Patients with cleft lip and palate (CLP) often exhibit unique anatomical variations in the pterygoid plates, which can influence fracture patterns at the pterygomaxillary junction (PMJ) during Le Fort I osteotomy. These differences may increase the risk of unfavorable fractures, complicating surgery and recovery.

Purpose: The study purpose was to measure the association between the osteotomy level with the PMJ fracture patterns in CLP patients undergoing Le Fort I osteotomy.

Study design, setting, and sample: This retrospective cohort study included 100 patients with CLP, representing 200 tomographic views of the right and left pterygomaxillary regions. Preoperative tomographic scans were analyzed to measure morphometric features of the pterygomaxillary suture in the axial and sagittal planes.

Predictor variable: The primary predictor was osteotomy level: at the level or above of the PMJ.

Main outcome variable: The main outcome was the pterygomaxillary fracture pattern, categorized as favorable or unfavorable.

Covariates: The covariates included age, sex, side of the mandible, pterygomaxillary suture thickness, pterygomaxillary suture width, distance between the greater palatine canal and the pterygoid suture, length of the medial plate, length of the lateral plate, insertion of the pterygomaxillary suture in the posterior part of the maxilla, and the length and height of the tuber.

Analysis: Statistical analyses included t-tests for mean differences (P < .05) and χ² tests for associations. Relative risk was calculated for osteotomy levels to assess the significance of associations with fracture patterns.

Results: The study comprised 100 participants (47 men, 53 women), with a mean age of 23 years (SD = 2.31). In total, 110 (55%) fractures were classified as favorable. The frequency of unfavorable fractures was significantly higher when the osteotomy was performed above the PMJ (P < .005). The relative risk for unfavorable fractures was 23.06 on the right side (95% confidence interval = [5.94, 89.53], P < .001) and 65.00 on the left side (95% confidence interval = [9.30, 454.52], P < .001).

Conclusion: The study findings suggest that in cleft surgery the osteotomy should be performed at the level of the PMJ to reduce the risk of inadvertent pterygomaxillary fractures.