Study of twenty non-metric dental crown traits using ASUDAS system in NCR (India) population

Abstract

Background The non-metric dental crown traits (NDCT) can vary within and between the geo-populations. These play a critical role in the ethnicity determination and help in identification of an individual. A commonly used system for scoring these dental traits is “Arizona State University Dental Anthropology System” (ASUDAS). Aim and objectives Our study aims to evaluate the frequency trend of twenty NDCT traits in the India, National Capital Region population using ASUDAS, and check for any significant sexual dimorphism for each trait. Methods The maxillary and mandibular dental casts from 200 patients (100 males+100 females, age 18–30 years) reporting to the dental OPD of a Government dental college were evaluated. Twenty dental crown traits were scored as per ASUDAS protocol in each dental cast by three investigators independently. NDCTs were tabulated and the chi-square test was performed for calculation of the P value. Results The results showed that the trait cusp number (83%) and lingual cusp variation (79%) were the two most frequent NDCTs and Y groove pattern (13%) and premolar accessory cusp-4 (12.5%) were the two least frequent traits observed. Shoveling of the upper lateral incisor (P=0.007), tuberculum dentale (P=0.049), mesial ridge (lingual) (P=0.034), and hypocone absence (P=0.001) were found to show statistically significant sexual dimorphism (P < 0.05). Although grade-wise expression of shoveling in upper lateral had statistically significant sexual dimorphism and the frequency of higher expression grades was found more in females, overall dichotomy of expression was not significant. Similarly, although an expression of grade-wise tuberculum dentale, mesial ridge (lingual) and hypocone absence had statistically significant sexual dimorphism, an overall dichotomy of expression was not significant. Conclusion The current study shows certain NDCTs like cusp number and lingual cusp variation have a significant association with the NCR population. Sexual dimorphism was not significant; hence, future studies should be planned on a large sample with sex pooled data for each precise location and ethnicity in all the regions of India. This can be further correlated with different facial forms and dental occlusal patterns, for correlation with abnormalities in jaws and teeth.

Maxillary first premolar shape (and not size) as an indicator of sexual dimorphism: A 2D geomorphometric study

“…Their research revealed that males and females had slightly larger proportions of premolar accessory cusps in first and second premolars, respectively. 3 These patterns show the shape of the premolars and are independent of tooth size. The present study explores the change in the shape of the premolars using landmark based morphometric evaluation.…”

“…However tooth are less influenced by hormones (Oettlé et al, 2009). In a study byGuatelli-Steinberg et al (2008) on seven different populations, they found no significant association of sex hormone concentrations post-birth and tooth patterning 3. However,Ribeiro D et al (2013) have demonstrated a significant role of intrauterine testosterone levels in dental development and size 4.…”