Coronectomy of deeply impacted lower third molar : incidence of outcomes and complications after one year follow-up

Objectives: The purpose of present study was to assess the surgical management of impacted third molar with proximity to the inferior alveolar nerve and complications associated with coronectomy in a series of patients undergoing third molar surgery. Material and Methods: The position of the mandibular canal in relation to the mandibular third molar region and mandibular foramen in the front part of the mandible (i.e., third molar in close proximity to the inferior alveolar nerve [IAN] or not) was identified on panoramic radiographs of patients scheduled for third molar extraction. Results: Close proximity to the IAN was observed in 64 patients (35 females, 29 males) with an impacted mandibular third molar. Coronectomy was performed in these patients. The most common complication was tooth migration away from the mandibular canal (n = 14), followed by root exposure (n = 5). Re-operation to remove the root was performed in cases with periapical infection and root exposure. Conclusions: The results indicate that coronectomy can be considered a reasonable and safe treatment alternative for patients who demonstrate elevated risk for injury to the inferior alveolar nerve with removal of the third molars. Coronectomy did not increase the incidence of damage to the inferior alveolar nerve and would be safer than complete extraction in situations in which the root of the mandibular third molar overlaps or is in close proximity to the mandibular canal

Correcting for Non-adherence in a Randomized Study of Hip Protectors to Prevent Fractures

Between October 2002 and October 2004 the Hip Impact Protection Project (HIP PRO) cluster randomized 1042 nursing home residents to wear hip protectors on either the left or right hip; residents were followed for 676 person-years of observation. The intent-to-treat (ITT) incidence rate ratio, comparing protected to unprotected hips, was 1.23 (95% confidence limit (CL): 0.65, 2.34); overall adherence was 74%. When non-adherence is substantial an ITT analysis estimates the effectiveness of treatment in a mixed population comprised of both compliers and non-compliers and, therefore, under-estimates the etiologic effect of treatment to the extent that the study population is comprised of non-compliers. Because of the problems inherent to ITT analyses of studies with non-trivial amounts of non-adherence, there have been calls to supplement the ITT effect estimate with adherence corrected effect estimates. Three relatively new methods in the epidemiology literature correct for non-adherence in randomized studies, and provide unbiased effect estimates: marginal structural models (using inverse probability-of-censoring weights (IPCWs)), structural nested models, and instrumental variable analysis. We employed IPCWs to correct for non-adherence in the HIP PRO study under an assumption that we had measured and correctly modeled all important joint determinants of adherence and hip fracture, and obtained a hazard ratio of 0.55 (95% CL: 0.13, 2.40). Under a structural nested modeling approach, we employed a rank-preserving structural failure time model to identify the survival difference that would have been observed had all participants adhered to their assigned treatment. The factor by which time to a hip fracture was expanded under continuous exposure to hip protectors was 2.41 (95% CL: 0.31, 18.7), assuming a Weibull distribution for time to hip fracture. The estimated hazard ratio under constant exposure was 0.46 (95% CL: 0.07, 2.84). Using data from the HIP PRO study, we found apparent differences in results between the ITT analysis and analyses correcting for non-adherence. We do not take the adherence corrected results as a complete reversal of the prior analysis; rather, we see these results as supplementing the ITT analysis

Frailty modeling of semi-competing risks data

Master'sMASTER OF SCIENC

Biomechanics

Biomechanics is a vast discipline within the field of Biomedical Engineering. It explores the underlying mechanics of how biological and physiological systems move. It encompasses important clinical applications to address questions related to medicine using engineering mechanics principles. Biomechanics includes interdisciplinary concepts from engineers, physicians, therapists, biologists, physicists, and mathematicians. Through their collaborative efforts, biomechanics research is ever changing and expanding, explaining new mechanisms and principles for dynamic human systems. Biomechanics is used to describe how the human body moves, walks, and breathes, in addition to how it responds to injury and rehabilitation. Advanced biomechanical modeling methods, such as inverse dynamics, finite element analysis, and musculoskeletal modeling are used to simulate and investigate human situations in regard to movement and injury. Biomechanical technologies are progressing to answer contemporary medical questions. The future of biomechanics is dependent on interdisciplinary research efforts and the education of tomorrow’s scientists

JointCalc: A web-based personalised patient decision support tool for joint replacement

Background and purpose Health information systems (HIS) are expected to be effective and efficient in improving healthcare services, but empirical observation of HIS reveals that most perform poorly in terms of these metrics. Theoretical factors of HIS performance are widely studied, and solutions to mitigate poor performance have been proposed. In this paper we implement effective methods to eliminate some common drawbacks of HIS design and demonstrate the synergy between the methods. JointCalc, the first comprehensive patient-facing web-based decision support tool for joint replacement, is used as a case study for this purpose. Methods and results User-centred design and thorough end-user involvement are employed throughout the design and development of JointCalc. This is supported by modern software production paradigms, including continuous integration/continuous development, agile and service-oriented architecture. The adopted methods result in a user-approved application delivered well within the scope of project. Conclusion This work supports the claims of high potential efficiency of HIS. The methods identified are shown to be applicable in the production of an effective HIS whilst aiding development efficiency

Injury and Skeletal Biomechanics

This book covers many aspects of Injury and Skeletal Biomechanics. As the title represents, the aspects of force, motion, kinetics, kinematics, deformation, stress and strain are examined in a range of topics such as human muscles and skeleton, gait, injury and risk assessment under given situations. Topics range from image processing to articular cartilage biomechanical behavior, gait behavior under different scenarios, and training, to musculoskeletal and injury biomechanics modeling and risk assessment to motion preservation. This book, together with "Human Musculoskeletal Biomechanics", is available for free download to students and instructors who may find it suitable to develop new graduate level courses and undergraduate teaching in biomechanics