Fractal Analysis of Mandibular Trabecular Structure in Individuals with Different Vertical Dentofacial Skeletal Patterns

Abstract

Background: Different vertical dentofacial skeletal patterns may affect bone density of the temporomandibular joint (TMJ) and various mandibular structures. This study aimed to examine changes in mandibular trabecular structure in vertical dentofacial patterns using fractal analysis. Methods: Dental-skeletal Class I patients randomly selected from the university orthodontic clinic were allocated into 3 groups (low angle, normal angle and high angle) according to the SN-GoMe angle. Bone density of mandibular structures (corpus, angulus and condyle) were measured bilaterally on panoramic radiographs of the patients using fractal analysis. Results: Left condylar fractal dimension (FD) measurements differed significantly among the groups (p=.041). Compared to other groups, left condylar FD values were lower in the high angle group. Right and left mandibular angulus FD values were lower in the low angle group but the difference was non-significant (p>.05). Within-group comparisons showed a significant difference in FD values between right and left corpus in the low angle subjects (p=.047). Conclusion: Lower mandibular condylar FD values observed in high angle subjects may herald possible joint disorders. Low angle subjects exhibit lower FD values in the mandibular angulus. This may be related to degenerative changes in that region characterized by reduced bone density which results from increased muscle activity.