Objectives: The objective of the present systematic review was to test the hypothesis of no difference in transverse skeletal and dental arch expansion and relapse after segmental Le Fort I osteotomy versus surgically assisted rapid maxillary expansion.
Material and Methods: A MEDLINE (PubMed), Embase and Cochrane library search in combination with a hand-search of relevant journals was conducted by including human studies published in English from January 1, 2000 to June 1, 2016.
Results: The search provided 130 titles and four studies fulfilled the inclusion criteria. All the included studies were characterized by high risk of bias and meta-analysis was not possible due to considerable variation. Both treatment modalities significantly increase the transverse maxillary skeletal and dental arch width. The transverse dental arch expansion and relapse seems to be substantial higher with tooth-borne surgically assisted rapid maxillary expansion compared to segmental Le Fort I osteotomy. The ratio of dental to skeletal relapse was significantly higher in the posterior maxilla with tooth-borne surgically assisted rapid maxillary expansion. Moreover, a parallel opening without segment tilting was observed after segmental Le Fort I osteotomy.
Conclusions: Maxillary transverse deficiency in adults can be treated successfully with both treatment modalities, although surgically assisted rapid maxillary expansion seems more effective when large transverse maxillary skeletal and dental arch expansion is required. However, considering the methodological limitations of the included studies, long-term randomized studies assessing transverse skeletal and dental expansion and relapse with the two treatment modalities are needed before definite conclusions can be provided.
Objectives: The objective of this study is to develop a Ti fibre knit block without sintering, and to evaluate its deformability and new bone formation in vivo.
Material and Methods: A Ti fibre with a diameter of 150 μm was knitted to fabricate a Ti mesh tube. The mesh tube was compressed in a metal mould to fabricate porous Ti fibre knit blocks with three different porosities of 88%, 69%, and 50%. The elastic modulus and deformability were evaluated using a compression test. The knit block was implanted into bone defects of a rabbit’s hind limb, and new bone formation was evaluated using micro computed tomography (micro-CT) analysis and histological analysis.
Results: The knit blocks with 88% porosity showed excellent deformability, indicating potential appropriateness for bone defect filling. Although the porosities of the knit block were different, they indicated similar elastic modulus smaller than 1 GPa. The elastic modulus after deformation increased linearly as the applied compression stress increased. The micro-CT analysis indicated that in the block with 50% porosity new bone filled nearly all of the pore volume four weeks after implantation. In contrast, in the block with 88% porosity, new bone filled less than half of the pore volume even 12 weeks after implantation. The histological analysis also indicated new bone formation in the block.
Conclusions: The titanium fibre knit block with high porosity is potentially appropriate for bone defect filling, indicating good bone ingrowth after porosity reduction with applied compression.
Objectives: Osteonecrosis of the jaws is a side effect associated with the use of bisphosphonates. Using histologic analysis, this study aimed to evaluate the influence of microbial colonies in the development of osteonecrosis in the jaws of rats subjected to nitrogenous and non-nitrogenous bisphosphonates, undergoing surgical procedures.
Material and Methods: Thirty-four rats (Rattus norvegicus, Wistar strain) were allocated randomly into three groups: 12 animals treated with zoledronic acid; 12 animals treated with clodronate; and 10 animals treated with saline. Sixty days after the start of treatment, the animals underwent three extractions of the upper right molars. After 120 days of drug administration, the rats were killed. Histologic analysis was performed on specimens stained with hematoxylin and eosin by the technique of manual counting points using Image-Pro Plus software on images of the right hemimaxilla.
Results: Osteonecrosis was induced in the test groups. There was no statistically significant association between the presence of microbial colonies and the presence of non-vital bone (Kruskal-Wallis, P > 0.05).
Conclusions: Use of zoledronic acid was associated with non-vital bone and the results suggested that the presence of microbial colonies does not lead to osteonecrosis.
Objectives: In this study is investigated if bundling of two scanners leads to better accuracy in recording faces than a standard face-scanning device.
Material and Methods: In a group of 28 volunteers, two test specimens were attached to their faces: one on their forehead and one turned 90° on their cheek. Each volunteer was scanned by FaceScan3D® and two bundled Artec EVA® scanners. The scans were aligned to a three-dimensional model of the test specimen, and the mean error was recorded. Length, width and angles between the test specimen’s planes were compared.
Results: The mean deviation is significantly lower for the cheek test specimen in alignment (P < 0.001), length and width (P < 0.001) but not for the forehead test specimen in alignment and length and width (P > 0.05) using FaceScan3D®. The aberration from the original angle between two sides of the test specimen is significantly lower measured with Artec EVA® for the angle between the front and the bottom plane of both test specimens (P < 0.01). Besides the angle between the right plane and the bottom plane as well as the top plane of the test specimen mounted to the cheek, the deviation of the angle between the other side planes to each other is significantly lower (P > 0.05) scanned with Artec EVA®.
Conclusions: Compared to FaceScan3D®, two bundled Artec EVA® scanners provide different accuracies depending on the location of the measured parameters. The accuracy measured for both scanners is inside the range found in the literature.
Objectives: The aim of the present study was to investigate the incidence of deformation and fracture of twisted file adaptive nickel-titanium instruments after repeated clinical use and to identify and check whether the three instruments within the small/medium sequence showed similar or different visible signs of metal fatigue.
Material and Methods: One-hundred twenty twisted file adaptive (TFA) packs were collected after clinically used to prepare three molars and were inspected for deformations and fracture.
Results: The overall incidence of deformation was 22.2%, which was not evenly distributed within the instruments: 15% for small/medium (SM)1 (n = 18), 38.33% for SM2 (n = 46) and 13.33% for the SM3 instruments (n = 16). The defect rate of SM2 instruments was statistically higher than the other two (P < 0.001). The fracture rate was 0.83% (n = 3), being two SM2 instruments and one SM3.
Conclusions: It was observed a very low defect rate after clinical use of twisted file adaptive rotary instruments. The untwisting of flutes was significantly more frequent than fracture, which might act as prevention for breakage. The results highlight the fact that clinicians should be aware that instruments within a sequence might be differently subjected to intracanal stress.
