Three-dimensional assessment of facial bone cavities in Class I occlusion with normodivergent skeletal pattern.

Introduction: The aims of our study are to measure the volume of the facial cavities based on a three-dimensional tomodensitometric acquisition in normodivergent, skeletal and dental Class I subjects; to quantify volumetric normality and generate an individual normality concept of these cavities.

Material and methods: The study was performed on a sample of 60 subjects equally divided between both genders. Based on the X, Y, Z coordinates of the anatomic landmarks and structural contours selected on the native slices and with the help of the GammaCepha software, we were able to compute the volume of the different cavities.

Results: The ratio of the different volumes compared to the total volume is 20.9% for males, 19.1% for females in maxillary sinuses ; 13.4% for males, 14.7% for females in orbital cavities; 29.7% for males, 30.2% for females in ethmoido-nasal cavity and 36% for males, 36% for females in oral cavity.

Conclusion: This new method of calculating volumes of the different facial cavities is an original approach to three-dimensional biometrics. To our knowledge, the criteria of normality chosen in this study, which have not been defined until present, have allowed us to establish standards of volumetric facial cavities. This will allow identifying individuals in comparison to a normal volume reference, and define an individual balance regarding facial volumes.