CEPHALOMETRIC EVALUATION OF IDEAL POSITION OF MAXILLARY INCISOR RELATIVE TO UPPER LIP THICKNESS

Abstract

Objective :

To cephalometrically evaluate the maxillary central incisor position relative to upper-lip thickness and to determine the most esthetic incisor position in skeletal class I, II and III patterns.

Study design:

Cross-sectional Analytical study.

Place and duration of study:

Department of Orthodontics, Armed Forces Institute of Dentistry (AFID), CMH Rawalpindi from June 2024-November 2024.

Methodology:

Standardised profile photographs of 120 patients with skeletal class I, II and III patterns were obtained and cropped from suborbital point to below soft tissue point B. Corresponding lateral cephalograms were traced to measure upper incisor to Na-B line distance and upper-lip thickness. Photographs were categorised by gender, skeletal pattern, lip thickness and incisor position; then evaluated by 90 raters (30 lay persons, 30 dentists and 30 orthodontists) to determine the most esthetic incisor position for varying upper lip thickness in all skeletal patterns. Data analysis was done with Chi-square and Fisher's exact tests (p < 0.05).

Results:

The mean upper incisor to Na-B distance was 4.25 ± 0.76 mm and mean thickness of upper lip was 13.12 ± 2.19 mm. For thin upper lip, a normal incisor position in class I and II was preferred. For thick upper lip, both normal and increased incisor position was preferred in class III.

Conclusion:

Incisor position interpreted with upper lip thickness affects profile esthetics. This study offers initial population-specific norms to guide esthetic orthodontic treatment planning.