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To investigate the behaviour of early loaded palatal implants when observed with resonance frequency analysis (RFA). Twenty patients (seven males and 13 females, mean age 26.4 years) received one palatal implant each (length: 4 mm, diameter: 3.3 mm; Orthosystem) for maximum orthodontic anchorage. The implants' stability was observed by RFA. Measurements were carried out at the time of surgery, after first orthodontic loading and subsequently once a week over a period of 12 weeks. Two palatal implants were lost. The other 18 remained stable. The average period from insertion to first loading was 6.7+/-0.8 days. The mean orthodontic force applied was 272.2+/-73.2 cN. The implant stability quotient (ISQ) value at the time of surgery averaged 69.4+/-3.9. The mean ISQ value 6.7 days after insertion was 69.8+/-3.6. Twelve weeks post-surgery the mean ISQ value was 69.8+/-3.5. A statistically significant decrease in stability was observed after 2 and 3 weeks post-surgery (P=0.005 and 0.04). The behaviour of early loaded palatal implants showed an initial decrease of the ISQ values. From 6 weeks post-surgery onward the ISQ values increased. Within the limitations of this study, the results suggest that the healing time of palatal implants reported in the literature (12 weeks) should be discussed. An orthodontic loading of palatal implants 6 weeks post-surgery with a force up to 400 cN seems to be justified. Yet further investigations are necessary to evaluate the behaviour of early loaded palatal implants considering observation periods of over 12 weeks.

The lack of significant overall effects apparent in this meta-analysis contradicts evidence-based statements on the advantages of self-ligating brackets over conventional ones regarding discomfort during initial orthodontic therapy, number of appointments, and total treatment time. Due to the limited number of studies included, further randomized controlled clinical trials are required to deliver more data and to substantiate evidence-based conclusions on differences between the two bracket types considering orthodontic pain, number of visits, treatment, and ligation times.

BackgroundTo evaluate the role of craniofacial shape in malocclusion by application of geometric morphometrics to a set of two-dimensional landmarks and semilandmarks obtained from lateral skull radiographs.MethodsCephalometric radiograph tracings of 88 untreated Caucasians (age range 7–39 years) were assigned to four groups according to their occlusion: neutrocclusion, distocclusion, mesiocclusion, and anterior open bite. The geometric morphometric shape analysis incorporated 66 landmarks and semilandmarks, which underwent generalized Procrustes analysis, between-groups principal component analysis, thin-plate spline deformation grid visualization, permutation tests, and receiver operating characteristic curves.ResultsThe position and shape of the mandible contributed to differences between the distocclusion and mesiocclusion groups, whereas the maxillary shape showed less variation. The growth-related shape alteration during adolescence was most pronounced in the mesiocclusion group and least pronounced in the neutrocclusion group. The open bite group was associated with an altered orientation of the mandibular body and the maxilla,  showed the most hyperdivergent maxillomandibular pattern but was not an own skeletal entity. Despite clear differences in mean shape across the four groups, the individual distribution of craniofacial shape overlapped between the groups without discrete clusters.ConclusionsCraniofacial shape was clearly associated with dental malocclusion and showed considerable variation. Geometric morphometrics was a powerful research tool but for diagnosing individual malocclusion standard cephalometric measurements including overjet and overbite were equally or more efficient than geometric morphometric descriptors.