Comparison of the Mesiodistal Angulations of Canine and Molar Teeth in Different Types of Orthodontic Malocclusions: A Retrospective Study

Abstract

(i) Objective: Changes in the mesiodistal axial angulations of teeth with orthodontic treatment have been a topic of interest in orthodontics for many years, although it has not been clarified enough yet. Therefore, this present study aimed to compare mesiodistal axial angulations of canine and first molar teeth by measuring from pre- and post-treatment panoramic radiographs in different types of orthodontic malocclusions. (ii) Materials and Methods: In the study, the mesiodistal axial angulation angles of the lower–upper canines (teeth numbered 13, 23, 33, and 43) and first molars (teeth numbered 16, 26, 36, and 46) were compared on panoramic radiographs taken pre- (T0) and post- (T1) orthodontic treatment of 353 patients: 237 female (mean age 14.74 ± 2.96) and 116 male (mean age 14.44 ± 2.50), who had not received any prior orthodontic treatment. The groups were formed according to pre-/post-treatment, gender, angle classification, skeletal classification, bilaterally first premolar extraction/non-extraction, and the use/non-use of miniscrews in the extraction cases. The mesiodistal angulations between the long axes of both the lower and upper canines and first molars and the interorbital plane were measured separately and recorded. The reliability analysis between the repeated measurements was evaluated using the intraclass correlation coefficient (ICC). For statistical analysis, a paired sample t-test and Wilcoxon test were used for the normally and non-normally distributed data, respectively. For the between-groups comparison, independent sample t-test and one-way ANOVA were used for normally distributed data, while the Mann–Whitney U and Kruskal–Wallis tests were used for non-normally distributed data. A value of p < 0.05 was considered statistically significant. (iii) Results: ICCs showed excellent reliability, ranging from 0.804 to 0.913 in other teeth, yet were good in tooth 43 (ICC = 0.712). Regardless of the groups, statistically significant differences were found between the T0 and T1 angulations for all teeth, except teeth 13 and 16. In all groups, the increase in the angulations of teeth 33 and 43 and the decrease in the angulations of teeth 36 and 46 (except skeletal class 3) were found to be statistically significant. The T0 and T1 angulation changes in the miniscrews in the used and non-used groups in extraction cases were similar to the differences found in all teeth, regardless of the groups. There was no significant difference between gender, skeletal classes, and angle classes in the amounts of change in the mesiodistal angulations. (iv) Conclusion: It was concluded that orthodontic treatment caused significant changes in the mesiodistal axial angulation of the canine and the first molar teeth. Furthermore, the fact that the angulations tended to increase in the lower canine teeth and decrease in the lower first molar teeth revealed the importance of tooth movement control, especially in orthodontic mechanics in the mandibula.

Investigation of the Mesiodistal Angulations of Maxillary Canines and Central Incisors for Missing Bilateral Maxillary Lateral Incisor

“…In the literature, it has been reported that panoramic radiographs can be used in the evaluation of root inclination and parallelism and in the evaluation of axial angulations with a reference plane, and that they have advantages such as causing less radiation and being inexpensive [27,32,33]. Therefore, in this study, the mesiodistal angulations of the maxillary canine and central incisors were measured according to the bicondylar reference line on panoramic radiographs.…”

“…Although there are studies investigating the relationship between the mesiodistal angulations of the maxillary lateral incisors and gender, different age groups, functional occlusal plane, and aesthetics [23,24], no study has been found investigating the mesiodistal angulations of the maxillary canine and central incisors in the MBMLIs. Moreover, when the literature is examined, although there are studies on the relationship of the mesiodistal angulations of various teeth with different facial growth patterns, different types of orthodontic malocclusion or third molars [25][26][27], the presented study represents research on the subject from a different aspect. In this context, the presented study is the first research that seeks answers to which method could be used for aesthetic and stable occlusal goals in the orthodontic treatment of MBMLI, based on the mesiodistal axial angulation changes that occur in the maxillary canine and central incisors.…”

Biomechanical Effects of Different Auxiliary–Aligner Designs on the Rotation of an Upper Canine: A Finite Element Analysis of a Specific Patient

“…The accuracy of the rotation movement was significantly reduced for rotations greater than 15 • (19%) [12]. Additionally, another study investigating the mesiodistal angulation of canines with fixed orthodontic treatment revealed the importance of movement control of the lower canines, especially in orthodontic mechanics in the mandible, due to the increase in the mesiodistal angulation of the lower canines in all malocclusion groups [13].…”

Evaluation of Trabecular Changes Using Fractal Analysis After Orthodontic Treatment for Congenital Maxillary Lateral Incisor Missing with Space Opening and Closure Methods

“…In addition to the clinical examination, radiographic evaluation is also necessary to select the treatment procedure that will provide the most effective and optimal dentofacial outcome for the patient. For this purpose, radiographic diagnostic tools, such as dental panoramic radiographs (DPRs), are frequently used routinely in addition to the clinical examination (13)(14)(15).…”