Evaluation of PRE-surgery and postoperative alveolar bone levels in orthognatic surgery patients

Aim: Evaluation of preoperative and postoperative changes in alveolar bone levels with CBCT supported by cephalometric images in cases with skeletal class II and III anomalies treated with different surgical methods using three-dimensional examination Material and Method: A total of 64 CBCT measurements were made on T1 before the operation and T2 at least 6 months after the operation. To examine changes in alveolar bone level, 28 measurements were made using alveolar bone levels and reference points determined on teeth. In addition to these, 2 cephalometric measurements were used as incisor angle.21 patients in class III maxillary advancement mandibular set-back, 6 patients in class III single jaw operated patients, 3 patients maxillary advancement, 3 patients mandibular set-back, 5 patients class II single jaw advancement patients; operation method, cephalometric analyses made in the preoperative and postoperative period, also to be taken into account, it is aimed to be compared on tomography and to examine it retrospectively. For statistical evaluation, the normal distribution of data was tested with the Shaphiro-wilk test. Mann Whitney U test was used to compare non-normally distributed measurements in 2 groups, and Kruskal Wallis and Dunn multiple comparison tests were used to compare more than 2 groups. The Willcoxon test was used to evaluate changes in measurements before and after surgery. Results: When the preoperative and postoperative groups were compared, there was a statistically significant difference at p<0.05 level in the Upper Anterior Bone Level, Upper Palatinal Bone Thickness, Lower Anterior Bone Level, Upper Trifurcation Buccal, Upper Distobuccal Root Middle Buccal, Lower Bifurcation Buccal, Lower Distal Root Middle Buccal value. A statistically significant difference was observed in the Cemento Enamel Junction Width value in the comparison between the sexes. When the correlations between age and differences were examined, no statistically significant parameter was found in any value, but when the correlation between Class II and Class III anomalies was examined, it was found that Lower Anterior Bone Thickness, AABL/Root and ALBL/Root values were statistically associated with more alveolar bone loss in class III patients. Conclusion: Orthognathic surgery causes alveolar bone loss in the patient. In order to minimize the side effects of the operation on the patient's periodontal tissues, oral hygiene, amount of forces applied, and intermaxillary fixation methods should be carefully evaluated. Key words: Orthognathic Surgery, Cephalometry, Alveolar Bone Loss