Facial pattern analysis: critic review and collection of facial proportions in a brazilian sample using cone-beam computed tomography

Abstract

The classification of facial vertical patterns is a common practice among dentists of different specialties. It influences treatment planning and expected outcomes, but is usually carried out qualitatively. The aim of this study is to better understand vertical facial proportions, combining a critic review of the literature with the collection of data from 100 Brazilian adult sample in search of 3D quantitative parameters with the use of Cone-Beam Computed Tomography (CBCT) measurements. In Pubmed database, the following quoted phrases were used: "Facial pattern" AND "Facial Index" AND "Facial height Index" AND "Facial height" AND "Dolichofacial" AND "Brachyfacial" AND "Long-face syndrome" AND "Short-face syndrome" in a 25 years interval (1990-2015). Study selection was performed searching for crucial facial features, commonly used to determine the facial pattern of a patient. In CBCT exams, 100 patients had facial features measured and classified by the three most reliable methods. The literature on the field can be very confusing, as the methods, landmarks and averages differed considerably. Most of the facial features researched had different values when the literature was analyzed and compared to our data. This indicates that ethnic, age and gender variations play an important whole in facial pattern diagnostic and should be taken in account when using general cephalometric approaches on diagnosis. With a group sorting method, combining the ratios between the anterior Facial height and the width, the anterior vertical proportion and the gonial angle divergence, and with anatomical landmarks we successfully correlated the sample to the qualitative description, as shorter faced patients to larger bi-zygomatic distances and less divergent gonial angles and longer faced patients with narrower and more divergent faces.