Influence of vertical skeletal pattern on cortical and alveolar bone thickness and root spacing in the anterior maxilla assessed by cone beam computed tomography

Purpose

The aim of this study was to evaluate the dimensional properties of bone in the anterior maxilla in patients with different vertical skeletal patterns in order to ensure safe placement of temporary anchorage devices.

Materials and methods

Fifty-one CBCT images were divided into three equal groups according to vertical skeletal pattern, based on palatal plane to mandibular plane angle. Cortical bone thickness, alveolar bone thickness and interdental root distance were measured between the teeth in the anterior maxilla at 6 mm and 8 mm apical to the interdental cementoenamel junction.

Results

Cortical bone thickness was significantly different among vertical groups at some sites. Hyper-divergent subjects had thinner cortical bone than hypo-divergent and normo-divergent subjects. All three groups, in the anterior maxilla, cortical bone thickness tended to increase from between central incisors (U1–U1) to between lateral incisor and canine (U2–U3). Alveolar bone thickness was greatest between central and lateral incisors (U1–U2), and the thinnest alveolar bone was at U1–U1 area. Average interdental root distance ranged from 1.33 ± 0.48 mm to 3.43 ± 1.25 mm. The largest and smallest interdental root distances were at U1–U1 and U1–U2 sites, respectively.

Conclusion

Placement of TADs in hyper-divergent subjects should be performed with caution. The suitable site for TADs in the anterior maxilla was between the lateral incisor and canine in all vertical skeletal patterns.