An experimental model of tool mark striations by a serrated blade in human soft tissues.

Tool mark analysis is a method of matching a weapon with the injury it caused. In a homicidal stabbing using a serrated knife, a stab wound that involves a cartilage may leave striations from the serration points on the blade edge. Assessing tissue striations is a means of identifying the weapon as having a serrated blade. This prospective study examines the possibility that similar striations may be produced in human soft tissues. Using tissues taken at the time of hospital-consented autopsies, stab wound tracks were assessed in a variety of human tissues (aorta, skin, liver, kidney, and cardiac and skeletal muscle). Stab wounds were produced postmortem with similar serrated and smooth-edged blades. The walls of the stab wounds were exposed, documented by photography and cast with dental impression material. Striations were identified by naked-eye examination in the skin and aorta. Photodocumentation of fresh tissue was best achieved in the aorta. Striations were not identified in wound tracks produced by the smooth-edged blade. Three blinded forensic pathologists were assessed for their ability to detect striations in photographs of wound tracks and had substantial interobserver agreement (κ = 0.76) identifying striations. This study demonstrates that tool mark striations can be present in some noncartilaginous human tissues.

Graduating grades and National Dental Examination results of foreign-trained and domestic dental students.

In this study, a comparison was made between the 1999-2009 graduates of the two-year structured program for foreign trained dentists at the Schulich School of Dentistry, University of Western Ontario, Canada, and the school's four-year program for domestic students. Both the students' final-year course grades and their results on the National Dental Examining Board (NDEB) written examination and objective structured clinical examination (OSCE) were compared. Differences of ≥ 10 percent in mean final-year grades and ≥ 5 percent for each component of the NDEB examination were considered academically meaningful for the purpose of this analysis. Although there were no academically meaningful and statistically significant differences in the mean overall final-year course grades between the two-year and four-year classes, there were differences in individual courses in prosthodontics, oral medicine, and practice administration. There were no differences (≥ 10 percent) in mean course grades since 2007. An academically meaningful difference in performance was observed on the NDEB written examination in three of the eleven years. There were no meaningful differences (≥ 5 percent) between the two groups in any year for the NDEB OSCE. The relevance and implications of these findings to both the two-year structured program and the newly introduced alternative pathway to certification are discussed.

Foreign-trained dentists' perceived knowledge and skills after graduation from a structured two-year program.

In this survey study, graduates of the University of Western Ontario program for foreign-trained dentists from 1999 to 2009 were asked for their perceptions of their knowledge and skill in fourteen clinical topic areas before they were admitted to the program and after graduation. Their ratings were made on a ten-point visual analog scale divided into three aptitude domains: competent, proficient, and master/expert. Definitions of each domain were provided. The majority of the respondents felt that their knowledge level improved at least one aptitude level in only four of the fourteen (29 percent) topic areas but that their skill level had increased at least one aptitude level in nine (64 percent) topic areas. Of note, clinical topics with content reflective of North American dental practice such as oral medicine and treatment planning, ethics, regulated dentistry, record keeping, and informed consent were the topic areas in which most respondents reported an improvement in both their knowledge and skill. It is suggested that programs evaluating or providing gap training for internationally trained dentists consider mandatory inclusion of these topics.

Periodontal health and systemic disorders.

Recent studies in periodontal medicine suggest a mild to moderate association between human periodontal disease and certain systemic disorders such as diabetes mellitus, pneumonia, heart disease and preterm birth. The latest evidence, presented at a symposium entitled Periodontal Health and Systemic Disorders, sponsored by the University of Western Ontario School of Dentistry, showed that indeed such an association is likely. New data suggest that this association is not indicated by traditional clinical signs of periodontal disease but rather by a cluster of host immune and inflammatory mediators. The coming era of periodontal medicine based upon molecular criteria will affect the future of periodontal diagnosis, treatment and professional practice.