Objective To evaluate bone availability at the infrazygomatic crest for extra‐alveolar bone miniscrew insertion in subjects with different vertical and sagittal skeletal patterns. Setting and sample population Measurements of the infrazygomatic crest were performed on multislice computed tomography scans from 58 adults with different skeletal patterns. Materials and methods Infrazygomatic crest bone depth was measured at 4, 5 and 6 mm from the cementoenamel junction (CEJ) of the maxillary first molar at three different angles (60°, 70° and 80°) in the first molar occlusal plane. The sagittal and vertical skeletal patterns were determined. Analysis of variance followed by Tukey's post hoc test was used (P ≤ .05). Results Bone depth was greater near the CEJ (8.7 ± 3.1 mm) and lower in the apical area (5.8 ± 2.7 mm). In Class II subjects, considering 6 mm from the CEJ, there was a significantly lower depth at the 80° angle (5.4 ± 2.5 mm) than at 60° (8.6 ± 3.5 mm; P = .007). In mesofacial subjects, considering 5 and 6 mm from the CEJ, bone depth was lower at 80° (5.7 ± 3.2 mm and 5.3 ± 2.5 mm) than at 60° considering 4 mm from the CEJ (P ≤ .019). Conclusion Bone availability was lower at the apical level, especially in Class II and mesofacial subjects. Therefore, when the planned insertion site is located in the apical direction, it is recommended to choose shorter miniscrews (2.0 x 12mm) and a smaller insertion angle (60°) and/or to plan a miniscrew bone insertion deep enough to allow bicortical fixation.

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The purpose of this study was to investigate the relationship between the alveolar bone and gingival dimensions in the maxillary anterior teeth. Cone-beam computed tomography images of 160 maxillary anterior teeth were evaluated. The Bone (BT) and Gingival Thickness (GT) and distances between Cemento-Enamel Junction (CEJ) and alveolar Bone Crest (CEJ-BC) and Cemento-Enamel Junction and Gingival Margin (CEJ-GM) were measured on the labial surface at the cervical third of the tooth root. Pearson correlation test or partial correlation was used. BT was significantly and positively associated with CEJ-GM in lateral incisors (p=0.04). The correlation between CEJBC and CEJ-GM was negative and statistically significant for incisors and canines (p≤0.01). The correlation between CEJ-BC and GT was positive and statistically significant for central incisors and canines (p≤0.01). Greater bone thickness was associated with higher gingival margin level at the lateral incisor, but not with bone crest level. Lower bone crest level was associated with greater gingival thickness at the central incisor and canines, and with lower gingival margin level at all the anterior maxillary teeth. The planning of orthodontic, periodontal, and restorative treatments should consider these dimensions of marginal periodontal tissue are interrelated and their relationship vary by tooth type.

Objective: The present study aimed to investigate the relationship between tooth inclination and gingival and bone dimensions in maxillary anterior teeth. Methods: This cross-sectional study included cone-beam computed tomography (CBCT) images of 160 maxillary anterior teeth (30 individuals). Tooth inclination, gingival and bone thickness, and distances from cementoenamel junction to alveolar bone crest and gingival margin were measured in the labial surface. The correlations were analyzed using Pearson and partial correlation tests (p≤0.05). Results: In the central incisors, tooth inclination was positively and significantly related to apical bone thickness (R = 0.34, p= 0.001). In the canines, tooth inclination was negatively and significantly related to cervical bone thickness (R = - 0.34, p= 0.01) and positively associated to apical bone thickness (R = 0.36, p= 0.01) and to gingival margin-cementoenamel junction distance (R = 0.31, p= 0.03). In the lateral incisors, tooth inclination was not associated with gingival or bone dimensions. Conclusions: In the central incisors, the greater the labial tooth inclination, the greater is the apical bone thickness. In the canines, the greater the labial tooth inclination, the smallest is the cervical bone thickness, the greater is the apical bone thickness, and the greater is the gingival margin. Gingival and bone dimensions should be assessed when planning orthodontic treatment involving buccal movement of central incisors and canines.