An in vivo study to correlate the relationship of the extraoral and intraoral anatomical landmarks with the occlusal plane in dentulous subjects

Abstract

Background: The occlusal plane position is considered to be the primary link between esthetic and function. Aim: To evaluate the relationship between extraoral and intraoral soft tissue landmarks with the occlusal plane in dentulous subjects on both sides and to check for any variations. Study and Design: An in vivo study and 100 subjects with all healthy permanent teeth in normal arch and alignment were selected from Modern Dental College and Research Centre, Indore. Materials and Methods: Three custom made instruments (occlusal plane analyzer, buccinator groove relator, and level analyzer) were indigenously designed to check parallelism of the interpupillary line, ala-tragus line, buccinator groove with the occlusal plane. Relation of retromolar pad with the occlusal plane was checked with the metallic scale. Statistical Analysis: Chi-square test. Results: In 20.0% subjects, the occlusal plane was parallel to the interpupillary line. The posterior reference point for ala-tragus line was middle point on right side in 56% and left side in 58% subjects. Intraorally, right side 59% and left side 62% subjects had the occlusal plane at the same level as that of buccinator groove. Right side 48% and left side 45% subjects showed occlusal plane at the middle one-third of retromolar pad. Conclusion: The occlusal plane is not generally parallel to interpupillary line. The occlusal plane is parallel to the ala-tragus line with middle point of tragus as posterior reference point on right and left sides. Both sides, the buccinator groove and the middle one-third retromolar pad are coinciding with occlusal plane level.

Keywords

• Ala-tragus line
• buccinator groove
• Camper′s plane
• interpupillary line
• retromolar pad