| Aim: To compare the facial morphologies of a Mexican American population in Texas to a Houstonian Caucasian population using 3D imaging to determine whether there are significant facial morphological differences between the two groups and consequently determine if orthodontic treatment modalities should be modified to serve each population.;Materials and Methods: 3D images were acquired via a commercially available stereo-photogrammetric camera capture system, 3dMDface(TM). Using the 3dMDface(TM) system, 84 Mexican American subjects were photographed at diverse locations through out Houston. For the Houstonian Caucasian population the data from a previous study of 100 subject was used. All of the participants from both population groups were between 18-30 years of age, had no apparent facial anomalies. All facial images were overlaid and superimposed. A complex mathematical algorithm was performed to generate a composite facial average (one male and one female) for each subgroup (MEX-M: Mexican American males, MEX-F: Mexican American females, HOU-M: Houstonian Caucasian males and HOU-F: Houstonian Caucasian females). The computer generated facial averages. These were then superimposed based on a previously validated superimposition method. The facial differences were evaluated both quantitatively and qualitatively for differences.;Results: Distinct facial differences were evident among the subgroups evaluated. These areas included the nasal tip, the periorbital area, the malar process, the labial region, the forehead, and the chin. With respect to the comparison of the Mexican American and Houstonian Caucasian male shells (MEX-M vs HOU-M), the Mexican American male shell only demonstrated a 22.74 % similarity in the signed histogram and had an average distance of 1.15 mm in the absolute histogram. Looking at specific regions, the Houstonian Caucasian males showed narrower faces, more prominence in the pogonion, nasal tip, and frontal area. The Mexican American males exhibited wider malar regions and ala of the nose and more prominence on the periorbital area as wells as upper lip area. The female specific subgroup comparison (MEX-F vs HOU-F) had the highest percentage of similarity, 37.71%. The average distance for the MEX-F vs HOU-F group in the absolute comparison was 0.77 mm. When looking at specific areas of difference, the Houstonian Caucasian females showed more prominence in the midline region specifically more prominence in pogonion, nasal and malar areas. The Mexican American females exhibited wider faces, prominent perioral region in particular upper and lower lips and prominent perio-orbital area. Overall the results show that the Mexican American population have a more convex profile with pronounced lips than the Houstonian Caucasian population studied.;Conclusions: The average adult Mexican American face and Houstonian Caucasian face possess distinct differences that may lead to an individualized orthodontic treatment plan for each ethnic group. |
