Assessment of tooth and gingival display in maxillary anterior teeth and premolars relative to gingival and interdental smile lines

Background: Gingival tissue circumforaneous to the maxillary anterior teeth has been known to play a crucial role in smile esthetics. Reports in the literature suggest that both tooth and gingival display in the premolar areas are relevant for a beautiful smile. The present study examines the amount of tooth and gingiva exhibited in relation to the gingival smile line (GSL) and the interdental smile line (ISL). Materials and methods: The study population comprised 120 periodontally healthy patients within an age range of 20 to 40 years who were equally divided into two groups based on gender. The gingival zenith position (GZP), gingival zenith level (GZL), presence or absence of interdental papillae, GSL, and ISL were determined for the maxillary anterior teeth up to the second premolars. Results: The mean GZL for the second premolars was found to be highest, followed by that for the first premolars and the lateral incisors. The GZL for female patients was slightly higher than that for males. The difference between the GZL for the first and second premolars in both the males and females was statistically significant (P 0.0001). The majority of participants – 36 (60%) of the males and 33 (55%) of the females – displayed first premolars, whereas both the premolars were visible in 18 (30%) males and 22 (36%) of the females. Conclusions: Within the smile corridor, the majority of participants exhibited tooth and gingival display in the maxillary anterior teeth and premolar region. The GZL was greatest for the second premolars and smallest for the lateral incisors, indicating a considerable amount of gingival tissue display during smile for both GSL and ISL.