Morphometric Analysis of the Frontal Sinus in Skeletal Class III

Purpose Anthropometric studies have shown a correlation between the origin and development of the frontal sinus, with the evolution of the masticatory apparatus and development of the symphysis and, consequently, the length of the jawbone. The purpose of this work was to conduct a morphometric evaluation of the frontal sinus, to highlight a potential correlation between the sinus size and third-class skeletal pattern, analysed on a sample of growing patients. Materials and Methods Twenty subjects with third-class skeletal malocclusion were selected and 20 with first-class skeletal malocclusion were considered as the control group. The sample was selected from ‘AAOF Craniofacial Growth Legacy Collection’. For each subject, all the x-rays collected from early childhood to adulthood were analysed and digitally traced, using the software Webceph. Furthermore, for each x-ray, the morphometric analysis of the frontal sinus was performed using the ImageJ software, examining the following parameters: height, width, perimeter and area. Results The statistical analysis showed that subjects in III skeletal class have higher average dimensional values than those in class I. The value of the width of frontal sinus has the greatest association. This difference appears to become significantly relevant in the circumpuberal period when the spurt of mandibular growth has not yet occurred. Conclusion Based on the results, the width of frontal sinus could be an indicator of skeletal class III. Further investigations will be necessary to decide whether to use the frontal sinus size as a prognostic value of class III severity.