The present study aimed to evaluate the mandibular bone structure of patients with different malocclusions by using fractal dimension (FD) analysis on dental panoramic radiographic images.

Pre-treatment panoramic radiographic images of 103 patients were included in the study and divided into 3 groups as Class I (group 1: 0<ANB<5), Class II (group 2: ANB≥5), and Class III (group 3: ANB≤0) malocclusion. Five bilateral regions of interests (ROI) were selected: anterior (near the mandibular midline), premolar (between the premolars and away from the mental foramen), molar (between the molars and away from the mandibular canal), angulus (geometric centre of mandibular angle), and condylar regions (geometric centre of mandibular condyle) of the mandibular bone and mean values were recorded as the FD value of each ROI. The mean value of the five ROIs was recorded as the FD value of the patient's mandibular bone. FD values of different malocclusion groups were compared and the relationships between the age and sex parameters and FD values were evaluated.

FD values were lower in Class I sagittal skeletal pattern than Class II and III groups in anterior ROI FD, premolar ROI FD, angulus ROI FD, and mean FD values. There were differences between Class I and Class III skeletal patterns (P=0.023 for anterior ROI FD, P=0.016 for premolar ROI FD, P=0.034 for angulus ROI FD, and P=0.014 for mean FD). Class I and II malocclusions differed in anterior ROI FD (P=0.029) and also Classes II and III showed differences in angulus ROI FD (P=0.029).

Sagittal skeletal patterns may result in differences in the structure of the mandibular trabecular bone.