Fully-customized distraction assembly for maxillofacial distraction osteogenesis: a novel device and its experimental accuracy verification.

BACKGROUND: A new distraction osteogenesis assembly system comprising a fully customized CAD/CAM-based fixation unit and ready-made distraction unit was developed. The aim of this study was to introduce our new distraction system and to evaluate its accuracy level in a sampled mandibular distraction osteogenesis. METHODS: Our system consists of a fully customized CAD/CAM-based fixation plate unit with two plates for each moving and anchoring part, and a ready-made distraction unit with attachment slots for fixation plates. The experimental distractions were performed on 3D-printed mandibles for one control and two experimental groups (N = 10 for each group). All groups had reference bars on the chin region and teeth to measure distraction accuracy. The control group had the classical ready-made distraction system, and experimental groups 1 and 2 were fitted with our new distraction assembly using a different distractor-positioning guide design. All distracted experimental mandibles were scanned by CT imaging, then superimposed on a 3D simulation to get their discrepancy levels. RESULTS: The measured 3D distances between the reference landmarks of the surgical simulations and the experimental surgeries for the three groups were significantly different (p < 0.0001) by statistical analysis. The errors were greater in the control group (with a total average of 19.18 ± 3.73 mm in 3D distance between the simulated and actual reference points) than those in the two experimental groups (with an average of 3.68 ± 1.41 mm for group 1 and 3.07 ± 1.39 mm for group 2). The customized distraction assembly with 3D-printed bone plate units in group 1 and 2, however, did not show any significant differences between simulated and actual distances (p > 0.999). CONCLUSION: Our newly-developed distraction assembly system with CAD/CAM plate for the distraction osteogenesis of the mandible produced a greater level of accuracy than that of a conventional distraction device. The system appears to address existing shortcomings of conventional distraction devices, including inaccuracy in vector-controlled movement of the system. However, it also needs to be further developed to address the requirements and anatomical characteristics of specific regions.

Effects of the Schroth exercise on idiopathic scoliosis: a meta-analysis.

INTRODUCTION: The purpose of this study was to examine the effects of the Schroth exercise on idiopathic scoliosis. The overall effect size was analyzed in 15 primary studies and a subgroup analysis of the standardized mean differences of effect sizes from 15 primary studies was also conducted. EVIDENCE ACQUISITION: We used PUBMED, MEDLINE, NDSL, EMBASE, and Web of Science. The key terms used in these searches were "Schroth," "scoliosis-specific exercise," "scoliosis," and "idiopathic scoliosis." EVIDENCE SYNTHESIS: Cobb's angle, asymmetry, angle of trunk rotation (ATR), strength of back extensor, strength of trunk flexor, quality of life (QOL), balance, chest expansion, and pulmonary function were coded as outcome measures for computing effect sizes. Potential moderating variables of the Schroth exercise included: 1) pre-intervention severity of the scoliosis; 2) duration; and 3) specific types of Schroth exercise. CONCLUSIONS: The overall effect size of the Schroth exercise is high (g=0.724). In addition, Schroth exercise may be more beneficial for scoliosis patients who have a 10 to 30° Cobb's angle than for those with a greater than 30° Cobb's angle. Patients should practice the exercise for at least one month to have a better effect. Thus, therapists should consider patients' initial curve status and exercise duration before prescribing the Schroth exercise program. Core muscle strength was most influenced, and structural deformity also changed after the Schroth exercise. In sum, the Schroth exercise is a recommended treatment method for scoliosis patients.