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 degrees 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 degrees of divergence to the ideal. The average mandibular plane showed a divergence of 3.3 degrees 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.