Relationship between anterior occlusion and frontal sinus size.

Objective: To determine the relationship between anterior occlusion and frontal sinus size.
Methods: The patient database at the Eastman Institute for Oral Health, University of Rochester, was searched for male patients older than 15 years and females older than 13 years of age. After applying inclusion and exclusion criteria, participants' photos and lateral cephalometric and posteroanterior radiographs were examined then classified into a control class I group (n = 20, 15.7 ± 2.7 years) and eight malocclusion groups (n = 136, 16.1 ± 2.1 years). The frontal sinus area on the lateral cephalometric radiograph and on the posteroanterior radiograph were measured and compared between groups.
Results: One-way analysis of variance demonstrated a significant difference among all nine groups (P = .0001). Pairwise comparison showed a significant difference between the class I group and all other malocclusion groups (P < .05) except the edge-to-edge group for both radiographs and except the bimaxillary protrusion group for the lateral cephalometric radiographs. Tukey's method was not able to demonstrate a significant difference among the subgroups of skeletal malocclusions (P > .05). Linear regression analyses with stepwise model selection demonstrated that anterior cranial base, mandibular plane angle, and upper incisor inclination commonly have a significant effect on frontal sinus size.
Conclusion: The frontal sinus size could be used as an indicator of harmonious anterior occlusion. There were no differences among the subgroups of each skeletal malocclusion. The anterior cranial base, facial height, and maxillary incisor inclination appear to have a significant effect on frontal sinus size.