Orientation of the occlusal plane in a Class I adult population.

OBJECTIVE To primarily evaluate whether Delaire's ideal occlusal plane is present in Class I occlusal relationship adults. STUDY DESIGN Pretreatment lateral cephalometric radiographs from 30 orthodontically untreated Caucasian Class I malocclusion adults were obtained. The occlusal, mandibular, and maxillary planes were traced and compared with the ideal occlusal, mandibular, and maxillary planes according to Delaire. RESULTS The average occlusal plane was 3.5° below the ideal plane. This divergence was more pronounced in males, and in patients presenting with a hypodivergent skeletal pattern. The maxillary plane displayed on average less than 0.5° of divergence to the ideal. The average mandibular plane showed a divergence of 3.3° below the ideal. CONCLUSIONS When aiming to obtain an ideal orientation of the occlusal plane postoperatively, one must keep in mind that in Class I occlusal relationship adults without any dentofacial disharmony, the occlusal plane is rarely coincident with the ideal plane.