Cleidocranial dysplasia (CCD) is an autosomal-dominant malformation syndrome affecting bones and teeth. The most common skeletal and dental abnormalities in affected individuals are hypoplastic/aplastic clavicles, open fontanelles, short stature, retention of primary teeth, delayed eruption of permanent teeth, supernumerary teeth, and multiple impacted teeth. Treatment of CCD requires a multidisciplinary approach that may include dental corrections, orthognathic surgery and cranioplasty along with management of any complications of CCD. Early diagnosis of this condition enables application of the treatment strategy that provides the best quality of life to such patients. Notably, Runx2 gene mutations have been identified in CCD patients. Therefore, further elucidation of the molecular mechanism of supernumerary teeth formation related to Runx2 mutations may improve understanding of dental development in CCD. The insights into CCD pathogenesis may assist in the development of new treatments for CCD.

This study used resonance frequency (RF) analysis to assess miniscrew implant (MSI) stability during wound healing in a sample of 68 patients (41 women, 27 men; mean age, 27.7 years). The 104 MSIs included 66 placements in the buccal shelf (BS; 2.0 × 12 mm) and 38 placements in interradicular (IR; 1.5 × 8 mm) sites. Thirteen (12.5%) of the MSIs failed. A new RF detection device was used to measure RF at baseline (T0) and at 3 (T1), 6 (T2), 9 (T3), 12 (T4), and 15 (T5) weeks after placement. A linear mixed-effects model was fitted to change in RF values. As compared with the BS group, the IR group had significantly lower RF values on the right side from T0 through T4 and on the left side from T0 through T2. Insertion site and time of visit were significantly associated with RF value. The effects of time of visit significantly differed between the BS and IR sites. Starting from T0, the MSIs placed at both sites had significantly lower RF values at all intervals, except for T0-T1. Future studies should examine how the present clinical protocols can optimize timing of MSI loading to maximize the success rate.

The aim of the present study is to use a 3D finite element analysis to investigate and compare the transverse displacement and stress distribution between stainless steel miniscrews and titanium alloy miniscrews used for monocortical and bicortical anchorage during miniscrew-assisted rapid maxillary expansions. Skull models were constructed to depict expansion after and before midpalatal suture opening at varying miniscrew insertion depths in four clinical scenarios: monocortical, monocortical deepening, bicortical, and bicortical deepening. Finite element analyses of miniscrew properties, including transverse displacement and von Mises stress distribution, were performed for each clinical scenario. Peri-implant stress was lesser in both bicortical anchorage models compared to both monocortical models. Transverse displacement in the coronal and axial planes was also greater and more parallel in both bicortical models compared to both monocortical models. Transverse displacement and peri-implant stress did not significantly differ between monocortical and monocortical deepening models or between bicortical and bicortical deepening models. From a biomechanical perspective, the bicortical deepening miniscrew anchorage is preferable to monocortical and monocortical deepening anchorage, because bicortical anchorage induces less stress on the peri-implant bone. Consequently, bicortical deepening anchorage should be considered the preferred option in challenging clinical scenarios in which strong anchorage is required for maxillary skeletal expansion.