Oleh Andrukhov

Objective The present study investigated bone remodelling in the upper and lower incisor regions depending on the inclination pattern during the alignment phase of orthodontic treatment (OT). Materials and Methods This prospective clinical study included 71 patients undergoing OT without premolar extraction. Cone beam computed tomography scans were taken before and after the alignment phase and the changes in the inclination, alveolar bone height (ABH) and bone thickness (BT) at levels 2, 3, 4, 6, 8 and 9 mm starting from the cementoenamel junction (CEJ) were determined. Results Teeth were divided into ‘Retroinclination’ (lingual crown inclination <0°), ‘Proclination‐low’ (buccal crown inclination between 0° and 5°), or ‘Proclination‐high’ (buccal crown inclination >5°). The alignment phase of OT resulted in ABH loss. The highest ABH loss in the maxilla was observed on the buccal side in the ‘Proclination‐high’ and was 0.71 mm. ABH loss by 1.1 mm was observed in the mandible on the lingual side in the ‘Retroinclination’ group. The most significant changes in BT by up to 2 mm were observed at levels 6, 8 and 9 mm and these changes exhibited a moderate to strong correlation with the alterations in the inclination of individual incisors. At levels 2, 3 and 4 mm, the highest decrease in BT by up to 0.83 mm was observed on the palatal side of upper incisors in the ‘Proclination‐high’ group. Conclusion The direction and amount of tooth inclination partially determine changes in the bone parameters during the alignment phase.

Background: Fragile gingival tissue is a risk factor for the development of gingival recessions. Despite the fact that gingival recessions are more commonly seen around anterior mandibular teeth, previous research has predominantly concentrated on the gingival dimensions in the anterior maxilla. The objective was to systematically compare buccal gingival thicknesses between the upper and lower jaws in individuals with healthy gingival conditions in the aesthetic zone. Methods: A comprehensive search of three databases was carried out until October 2023. Gingival thickness differences between the maxilla and mandible were evaluated by calculating the mean differences along with the corresponding 95% confidence interval (CI). Subgroup analysis was conducted based on the measurement area, measurement method, and tooth category. Results: A total of seventeen studies were included in this systematic review. Eleven studies were included in the quantitative analysis. Quantitative analysis comparing gingival thickness around 2100 teeth in the anterior mandible to 2056 teeth in the anterior maxilla revealed a statistically significant thinner buccal gingiva in the mandible (mean difference: 0.16 mm; 95% CI [−0.24, −0.07]; p = 0.0003). Conclusions: The present systematic review revealed a more delicate buccal gingiva in the anterior mandible. However, further scientific validation is required due to the considerable heterogeneity in study design and the potential presence of confounding variables.