Angular Photogrammetric Analysis of the Soft Tissue Facial Profile of Iranian Young Adults

Background The evaluation of the soft tissue facial profile is essential to achieve facial harmony in orthodontic diagnosis and treatment planning. Objectives This study aimed to develop soft tissue angular photogrammetric norms for a sample of Iranian population. Patients and Methods Standardized profile photographic records were taken from ۳۴ men and ۳۷ women. Twelve measurements were analyzed on each photograph by AutoCad software. For statistical evaluation a Student’s t-test was used and the reliability of the method was assessed by using Intra-class Correlation Coefficient (ICC) within a four week interval. Results Three of the angles showed sexual differences: nasofrontal (G-N-Prn, P = ۰.۰۰۹), nasal (Cm-Sn/N-Prn, P = ۰.۰۱۲) and vertical nasal (N-Prn/Tv, P = ۰.۰۲۹). Other nine angles showed statistically insignificant gender differences (P > ۰.۰۵). Two of the angles that suggested gender differences were wider in females: nasofrontal and nasal angle while the third angle was wider in males. Other angles such as nasolabial (Cm-Sn-Ls), mentolabial (Li-Sm-Pg), nasal dorsum (N-Mn-Prn) and angle of the total convexity (G-Prn-Pg) were also found wider in females. The inferior third was larger than the middle third. Mentolabial angle (Li-Sm-Pg), which had the highest standard deviation, showed the greatest variability. Conclusions The results showed gender dimorphism in three of the measurements: the nasofrontal, the nasal and the vertical nasal angles. Another significant finding was the large variability for the mentolabial angle. The result of this measurement should be assessed with caution.

Keywords:

Angular Photogrammetry , Orthodontics , Facial Profile , Soft Tissue Analysis