Error rates in bite mark analysis in an in vivo animal model.

Recent judicial decisions have specified that one foundation of reliability of comparative forensic disciplines is description of both scientific approach used and calculation of error rates in determining the reliability of an expert opinion. Thirty volunteers were recruited for the analysis of dermal bite marks made using a previously established in vivo porcine-skin model. Ten participants were recruited from three separate groups: dentists with no experience in forensics, dentists with an interest in forensic odontology, and board-certified diplomates of the American Board of Forensic Odontology (ABFO). Examiner demographics and measures of experience in bite mark analysis were collected for each volunteer. Each participant received 18 completely documented, simulated in vivo porcine bite mark cases and three paired sets of human dental models. The paired maxillary and mandibular models were identified as suspect A, suspect B, and suspect C. Examiners were tasked to determine, using an analytic method of their own choosing, whether each bite mark of the 18 bite mark cases provided was attributable to any of the suspect dentitions provided. Their findings were recorded on a standardized recording form. The results of the study demonstrated that the group of inexperienced examiners often performed as well as the board-certified group, and both inexperienced and board-certified groups performed better than those with an interest in forensic odontology that had not yet received board certification. Incorrect suspect attributions (possible false inculpation) were most common among this intermediate group. Error rates were calculated for each of the three observer groups for each of the three suspect dentitions. This study demonstrates that error rates can be calculated using an animal model for human dermal bite marks, and although clinical experience is useful, other factors may be responsible for accuracy in bite mark analysis. Further, this study demonstrates that even under carefully controlled conditions, albeit in a forced-decision model, errors in interpretation occur even amongst the most experienced analysts.

Clinical and histopathological examination of experimental bite marks in-vivo.

Under rigorously controlled laboratory conditions, mechanically induced simulated human bite marks were made on pig skin to enable the clinical and histopatholgical study of experimental bite marks in-vivo. A series of bite marks were created on the abdomen and thorax of live anaesthetized juvenile pigs at specific times just prior to and after death. Following the release of the biting force clinical observations of antemortem wounds revealed slow diminishment of the bite indentations presumably due to dermal elastic recovery. Minutes after euthanasia of the animals, the indentations of the teeth from the postmortem bite marks faded rapidly. After the biting process the animals were placed on either the right or left side and this side was maintained until necropsy to examine for dependant and non-dependent side differences. All bite mark injuries located on the non-dependent side revealed specific pattern characteristics. However, on the dependent side whether the bite mark was antemortem or postmortem in areas of livor mortis, no clear pattern was visible. Histologically, the observations for each bite mark specimen were categorised by the presence or absence of extravasated red blood cells in the fatty or muscle layers. The histopathological findings correlate with the clinical observations of antemortem and postmortem bite marks located on the non-dependent side in regard to muscular erythema and extravasated red blood cells. It is clinically difficult to comment on temporal relationship of a bite mark in relation to time of death in areas affected by blood-pooling seen on the dependent side. In these situations, histopathological studies could be a reliable alternative to provide information regarding antemortem or postmortem injuries.

Porcine skin as an in-vivo model for ageing of human bite marks.

Porcine skin has been shown to have similar histological, physiological and immunological properties to human skin and has been suggested as a good analogue for medical and forensic research. This study was undertaken to examine the appearance of bite mark wounds inflicted at known time intervals before and after death. Under general anaesthesia, a series of bite marks were created on a pig's abdomen with a device designed to mechanically produce simulated human bite mark wounds. The pig skin model showed that bite mark characteristics are similar to those found on human skin. This study has provided information on the window of time showing clearly detailed bite marks occurring around the time of death. It also demonstrated that it is possible under certain conditions to determine that a bite mark was made before or after death in a porcine model. Under these experimental conditions, the results suggest that an in-vivo porcine skin model should be considered as a representative model for the study of human bite marks.

Nodular fasciitis in the oral cavity.

Rapidly growing soft-tissue lesions in the oral and maxillofacial region can represent a variety of diagnoses involving radically different treatment modalities. Accurate diagnosis is important to avoid unnecessary and often mutilating surgery. Nodular fasciitis is a rapidly proliferating fibroblastic lesion that presents as a tumour-like mass. Although up to 20% of cases occur in the head and neck region, lesions of the oral cavity are extremely rare. A case of oral nodular fasciitis is described, and a review of the literature is presented.

[Fibromyalgia in dentistry]]. / La fibromyalgie en médecine dentaire.

Fibromyalgia represents one of the most frequent musculoskeletal problems. This condition, associated with widespread pain, is characterized by a number of specific tender points, as well as symptoms such as tiredness, limb stiffness, depression and a lack of refreshing sleep. Patients suffering from fibromyalgia can also demonstrate the same clinical features as temporomandibular disorders or myofascial pain. Dentists should be aware that certain dental treatments will not be effective in patients suffering from temporal and masseter pain if fibromyalgia has been diagnosed.