CHARACTERISTICS OF MAXILLOMANDIBULAR TRANSVERSAL DIMENSIONS IN DIFFERENT CLASSES OF MALOCCLUSION

Insufficient width of the upper jaw can lead to the formation of a unilateral or bilateral crossbite or dental compensation. Measurement methods using cone-beam computed tomography became considered the most reliable.The purpose of our article was to study the width of the upper and lower jaw using computed tomography scans in subjects with different Classes of malocclusion.Materials and methods. The research group included 66 non-growing subjects aged from 15 to 25 years. Female persons were 50 (75.8%), male – 16 (24.2%). All subjects were divided into 3 groups according to ANB angle: skeletal Class I group had ANB angle between 0° and 4° (n = 26 (39.4%), skeletal Class II group had ANB angle >4° (n = 34 (51.5%), and skeletal Class III group had ANB angle <0° (n = 6 (9.1%). The width of the upper and lower jaw was analyzed according to University of Pennsylvania Cone-Beam CT Analysis (Penn method) and Yonsei Analysis on cone-beam computed tomography scans.Results. In patients with the Сlass I the width of the upper jaw, measured by Penn method, slightly prevailed over the width of the lower jaw, but the difference was statistically insignificant (p>0.05). According to Yonsei method, maxilla transversal dimensions were slightly larger than mandibular width (p>0.05). In the Class II Group maxilla skeletal width was bigger than mandible width (p<0.05). The dental width did not differ significantly (p>0.05), indicating a compensatory lingual inclination of upper posterior teeth, and upright position of lower molars.In the Class III Group mandible transversal dimensions both in the area of the basal bone and in the area of teeth rotation center was bigger (p<0.05). The maxillomandibular width difference between dental points were less than between basal, which may indicate a compensatory lingual inclination of the lower posterior teeth.Conclusion. Comparison of the maxillomandibular difference, measured by basal and dental points, indicates dental compensation in the Class II – lingual inclination of posterior upper teeth, in Class III – lingual inclination of posterior lower teeth.