Determining the anatomy of the descending palatine artery and pterygoid plates with computed tomography in Class III patients.

PURPOSE Understanding the anatomy of the pterygomaxillary junction region helps prevent blood loss in Le Fort I osteotomy. Here, we determined the location of the descending palatine artery and the structure of the pterygomaxillary region. PATIENTS AND METHODS The study group consisted of 82 Japanese patients with mandibular prognathism and asymmetry, with and without maxillary retrognathism or asymmetry. A total of 164 sides were measured and divided into right versus left, men versus women, and bimaxillary osteotomy (B) versus mandibular osteotomy (S). Lateral and frontal cephalograms and computed tomography (CT) were analysed for all patients. The relationship between the cephalometric measurements and the measurements of the descending palatine artery and pterygoid plate (PP) were assessed. RESULTS There were no significant correlations between measurements of cephalograms and those of the descending palatine artery and PPs. There were significant differences between right and left in lateral plate length (p=0.0014) and thickness of PP (p=0.0047). There were significant differences between men and women in right width of PP (p=0.0034), right thickness of PP (p=0.0063), left posterior length (p=0.0196), and left thickness of PP (p=0.0279). The B group had a shorter anterior length than the S group (right: p<0.0001, left: p=0.0027). CONCLUSION These results suggest that the location of the descending palatine artery and the morphology of the PPs were not significantly associated with any cephalometric measurements. CT examination is necessary to recognize the anatomy of pterygomaxillary region and the exact positions of descending palatine artery before Le Fort I osteotomy.