A Cephalometric Assessment of Ideal Nasolabial Angle Range for South Indian Population

Background: Soft tissue diagnosis in orthodontics plays an important role in treatment planning and the mechanics involved. Evaluation of nasolabial angle is considered to be an essential in orthodontic diagnosis and treatment planning. In this study, we would like to assess the normal range of nasolabial angle in the South Indian population. As the people in South Indian may present craniofacial characteristics which differ from those of other races, whose cephalometric analysis are usually considered as the standard in routine orthodontic diagnosis and treatment planning. Further studies are therefore needed to ensure values of optimal range for an accurate diagnosis for this group. The purpose of this study is to establish norms for evaluation of nasolabial angle for the South Indian population. Materials and Methods: 102 lateral cephalometric radiographs (41 males and 61 females) were collected from Tamil Nadu, Pondicherry, Andhra Pradesh, and Karnataka. The average age ranged between 18 and 28 years. The radiographs are manually traced, and the nasolabial angle, lower border of the nose to the FH plane (N/ FH), and upper lip to the FH plane (L/FH) of these subjects were measured and after statistical analysis results were obtained. Results: The mean value of 99.76° with standard deviation (SD) ± 15.35° was established for the entire sample, no statistically significant difference was observed between male and female value, although males recorded a more obtuse nasolabial angle of 101.73° with SD ± 12.57 and the females who recorded 98° with SD ± 16.85. Conclusion: The mean nasolabial angle of 99.76° with SD ± 15.35° was observed in the South Indian population, the sexual difference was not observed. However, the values obtained in this study differ from the studies reported for Caucasian and other racial group, but it is accordance with the other Asian population.