Abstract:Aim: The purpose of this study was to systematically review the literature on survival rates of palatal implants, Onplants®, miniplates and mini screws. Material and Methods:An electronic MEDLINE search supplemented by manual searching was conducted to identify randomized clinical trials, prospective and retrospective cohort studies on palatal implants, Onplants®, miniplates and miniscrews with a mean follow-up time of at least 12 weeks and of at least 10 units per modality having been examined clinically at a follow-up visit. Assessment of studies and data abstraction was performed independently by two reviewers. Reported failures of used devices were analyzed using random-effects Poisson regression models to obtain summary estimates and 95% confidence intervals of failure and survival proportions. Results:The search up to January 2009 provided 390 titles and 71 abstracts with full-text analysis of 34 articles, resulting in 27 studies that met the inclusion criteria. In meta-analysis, the failure rate for Onplants® was 17.2% (95% confidence interval: 5.9% -35.8%), for palatal implants 10.5% (95% CI: 6.1% -18.1%), for miniscrews 16.4% (95% CI: 13.4% -20.1%) and 7.3% for miniplates (95% CI: 5.4% -9.9%). Miniplates and palatal implants, representing torque resisting temporary anchorage devices, when grouped together, showed a 1.92 fold (95% CI: 1.06 -2.78) lower clinical failure rate than miniscrews. Conclusions:Based on the available evidence in the literature, palatal implants and miniplates showed comparable survival rates of ≥90% over a period of at least 12 weeks, and yielded superior survival than miniscrews. Palatal implants and miniplates for temporary anchorage provide reliable absolute orthodontic anchorage. If the intended orthodontic treatment would require multiple miniscrew placement to provide adequate anchorage, the reliability of such systems is questionable. For patients who are undergoing extensive orthodontic treatment, force vectors may need to be varied or roots of the teeth to be moved may need to slide past the anchors. In this context, palatal implants or miniplates should be the TADs of choice.3

Aim: The aim of this randomized‐controlled clinical study was to examine stability changes of palatal implants with chemically modified sandblasted/acid‐etched (modSLA) titanium surface compared with a standard SLA surface, during the early stages of bone healing. Materials and methods: Forty adult volunteers were recruited and randomly assigned to the test group (modSLA surface) and to the control group (SLA surface). The test and control implants had the same microscopic and macroscopic topography, but differed in surface chemistry. To document implant stability changes resonance frequency analysis (RFA) was performed at implant insertion, at 7, 14, 21, 28, 35, 42, 49, 56, 70 and 84 days thereafter. RFA values were expressed as an implant stability quotient (ISQ). Results: Immediately after implant installation, the ISQ values for both surfaces tested were not significantly different and yielded mean values of 73.8±5 for the control and 72.7±3.9 for the test surface. In the first 2 weeks after implant installation, both groups showed only small changes and thereafter a decreasing trend in the mean ISQ levels. In the test group, after 28 days a tendency towards increasing ISQ values was observed and 42 days after surgery the ISQ values corresponded to those after implant insertion. For the SLA‐control group, the trend changed after 35 days and yielded ISQ values corresponding to the baseline after 63 days. After 12 weeks of observation, the test surface yielded significantly higher stability values of 77.8±1.9 compared with the control implants of 74.5±3.9, respectively. Conclusion: The results support the potential for chemical modification of the SLA surface to positively influence the biologic process of osseointegration and to decrease the healing time.

Abstract:Aim:The purpose of this prospective cohort study was to assess the survival and success rates of palatal implants. Material and Methods:Seventy patients (56 female, 14 male; age 25-6 ±10-8 years) receiving Orthosystem® (Straumann, Basel AG, Switzerland) palatal implants from March 1999 to November 2006 were included. The indication was established according to the required anchorage for orthodontic therapy. All implants were placed in a mid-sagital, median or paramedian palatal location by the same surgeon. They were orthodontically loaded after a healing period of 8-16 weeks (Mean: 12.8 weeks). Results and Discussion:Of the initially 70 consecutively admitted patients, two implants in two patients were not primary stable after installation and had to be removed. Of the 70 initially installed palatal implants, 67 implants or 95.7 % osseointegrated successfully and were loaded actively and/or passively for approximately 19 months. Only 1 implant of the 67 osseointegrated implants lost its stability under orthodontic loading. By the time of re-evaluation, 20 palatal implants were still used for orthodontic therapy, while 46 implants had been removed after completed orthodontic therapy. By only analyzing those, the success rate of the initially installed implants was 92 %. Conclusions:Orthodontic palatal implants with a rough surface are predictable and highly reliable devices for a multitude of maxillary orthodontic treatment options. The survival and success rates for palatal orthodontic implants are comparable to dental implants installed for dental prostheses.

Abstract:Aim:The purpose of this prospective cohort study was to assess the survival and success rates of palatal implants. Material and Methods:Seventy patients (56 female, 14 male; age 25-6 ±10-8 years) receiving Orthosystem® (Straumann, Basel AG, Switzerland) palatal implants from March 1999 to November 2006 were included. The indication was established according to the required anchorage for orthodontic therapy. All implants were placed in a mid-sagital, median or paramedian palatal location by the same surgeon. They were orthodontically loaded after a healing period of 8-16 weeks (Mean: 12.8 weeks). Results and Discussion:Of the initially 70 consecutively admitted patients, two implants in two patients were not primary stable after installation and had to be removed. Of the 70 initially installed palatal implants, 67 implants or 95.7 % osseointegrated successfully and were loaded actively and/or passively for approximately 19 months. Only 1 implant of the 67 osseointegrated implants lost its stability under orthodontic loading. By the time of re-evaluation, 20 palatal implants were still used for orthodontic therapy, while 46 implants had been removed after completed orthodontic therapy. By only analyzing those, the success rate of the initially installed implants was 92 %. Conclusions:Orthodontic palatal implants with a rough surface are predictable and highly reliable devices for a multitude of maxillary orthodontic treatment options. The survival and success rates for palatal orthodontic implants are comparable to dental implants installed for dental prostheses.

The pitchfork analysis has gained increasing acceptance among researchers and clinicians to evaluate the effects of orthodontic treatment that can be measured on lateral cephalometric radiographs. It is primarily used in Class II cases to distinguish between the skeletal and dental effects of such treatments. The aim of this study was to conduct an objective evaluation of the pitchfork analysis by comparing cephalometric data obtained by that method with those using the more conventional and established method of Björk. The pitchfork analysis consistently provided an overestimation of the skeletal effects and an under-estimation of the dental changes. These results indicate that the pitchfork analysis is not sufficiently sensitive to distinguish between the skeletal and dental effects of orthodontic treatment.