Inheritance of Class III Soft Tissue Facial Features from Parents to Offsprings Using Photogrammetric Analysis Technique.

Objective: The present study was undertaken to analyze the facial features in class III patients by measuring the facial frontal (linear) parameters and profile (angular) parameters and correlate them with parents to determine the inheritance of facial features.

Methods: The sample consisted of 40 class III patients aged between 9 and 18 years based on skeletal ANB angle (less than 0 degrees) and Angle's class III classification. Frontal and profile photographs of the subjects and parents were taken in a standardized position according to ABO guidelines. The photographs were analyzed using custom-made software for measuring various frontal (linear) and profile (angular) parameters to check for the degree of resemblance of facial features with parents by determining mean value, standard deviation and by applying Student's t-test. The level of significance was set at 5% (p < 0.05).

Results: The common facial frontal (linear) parameters in sons and daughters which showed close mean inheritance (p < 0.005) with father were: 1. Al-Me/Ex-Al(R), 2. Al-Me/Ex-Al (L), 3. Al-Me/Ch-Me(R), 4. Al-Me/Ch-Me (L), 5. Ch-Me/Al-Ch(R), and 6. Ch-Me/Al-Ch(L). The common facial profile (angular) parameters in sons and daughters which showed close mean inheritance (p < 0.005) with mother were: 1. nasolabial angle (Cm-Sn-Ls), 2. nasofacial angle (G-Pog/N-Nd), 3. total convexity except nose (G-Sn-Pog), 4. upper lip projection angle (N-Pog/N-Ls), 5. lower lip projection angle (N-Pog/N-Li), and 6. Sn-Po-Gn. The only linear parameter which showed close mean inheritance with mother in both sons and daughters was: 1. ChR-ChL/AIR-AIL (p = 0.0001).

Conclusions: Facial frontal (linear) parameters showed close inheritance with father in sons and daughters, while profile (angular) parameters showed close inheritance with mother in sons and daughters. The linear vertical parameters have more inheritance in daughters than sons, while angular parameters have more inheritance in sons as compared to daughters. Overall, facial inheritance from father is more dominant in class III sons and daughters. Conclusions: The results of this study simplify the orthodontic treatment planning in subjects having class III malocclusion in terms of predicting the course of facial growth from parents. Such prediction can guide in forecasting the treatment outcome in complex malocclusion like class III. The results of this study revealed various parameters which are less heritable, having lesser genetic component, and mostly influenced by environment which can be modified through orthodontics and Dentofacial Orthopedics, thereby having lesser chances of relapse. The results of this study can also be utilized in the field of plastic surgery and forensic science. How to cite this article: Arshad F, Prashanth CS, ShashiKumar HC, et al. Inheritance of Class III Soft Tissue Facial Features from Parents to Offsprings Using Photogrammetric Analysis Technique. J Contemp Dent Pract 2024;25(12):1162-1171.