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Objectives: The purpose of this study was to evaluate whether there is a relationship between the alignment or misalignment of the marginal ridges of posterior teeth and the degree of resorption of interproximal alveolar bone. Material and Methods: Intraoral scans and bitewing radiographs were performed on 50 subjects. The bitewing radiographs were analyzed using the VixWinTM Platinum software, measuring the distance between the cementitious junction and the alveolar ridge at the interproximal level for 32 sites for each patient, defined as bitewing scores. The digital models have been oriented in the three dimensions using the Rhinoceros 3D and the linear distance between two contiguous marginal ridges was measured for each interproximal space. To estimate the entity of the correlation, a separate linear regression was performed on the bitewing score for each mouth quadrant. Using the t-test the significance of each estimated coefficient was determinate (P < 0.05). Results: In the general comparison including all the analyzed elements, the independent variables are partially correlated with each other. Apparently, the relationship between independent and dependent variables appears to be insignificant. Comparing groups of teeth, however, there seems to be a statistically significant correlation (P < 0.05) between canine and lower first premolar in the XZ and YZ planes and between lower first and second molars in the three dimensions. Conclusion: There seems to be a poor correlation at a general level between periodontal conditions of the alveolar bone and the degree of alignment of the marginal ridges.

Using a single bone-borne maxillary appliance with twofold mechanics, that is, rapid palatal expander and nonfrictional distalizing appliance (Pendulum) is a valuable option to treat young-adult patients with poor compliance. In this particular case, the same appliance was used to disinclude 2.3, eliminating reaction forces on the arch. Therefore, the first expansive phase was followed by the distalizing phase. After enough space was obtained for the recovery of tooth 2.3, a triple-looped titanium-molybdenum alloy (TMA) spring was used to perform canine orthodontic traction. The core concept is that digital planning and optimal positioning of two palatal mini-screws can ensure a bicortical anchorage which, in turn, enabled to tolerate the different orthodontic phases. As a matter of fact, a tooth-bone-borne anchorage was followed by a pure bone-borne anchorage with no lost of stability.