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 34 men and 37 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 = 0.009), nasal (Cm-Sn/N-Prn, P = 0.012) and vertical nasal (N-Prn/Tv, P = 0.029). Other nine angles showed statistically insignificant gender differences (P > 0.05). 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.