Human teeth as historical biomonitors of environmental and dietary lead: some lessons from isotopic studies of 19th and 20th century archival material.

The lead isotopic composition of various sections (crown, crown base, root) of teeth was determined in specimens collected from 19th century skulls preserved in museum collections and, upon extraction or exfoliation, from humans of known ages residing in Scotland in the 1990s. For most 20th century samples, calculation of accurate crown-complete or root-complete dates of tooth formation ranging from the 1920s to the 1990s enabled comparison of (206)Pb/(207)Pb ratios for teeth sections (crown base root) with corresponding decadally averaged data for archival herbarium Sphagnum moss samples. This showed that the teeth sections had been significantly influenced by incorporation of non-contemporaneous (more recent) lead subsequent to the time of tooth formation, most probably via continuous uptake by dentine. This finding confirmed that separation of enamel from dentine is necessary for the potential of teeth sections as historical biomonitors of environmental (and dietary) lead exposure at the time of tooth formation to be realised. Nevertheless, the mean 19th century value of 1.172+/-0.007 for the (206)Pb/(207)Pb ratio in teeth was very similar to the corresponding mean value of 1.173+/-0.004 for 19th century archival moss, although relative contributions from environmental sources - whether direct, by inhalation/ingestion of dust contaminated by local lead smelting ((206)Pb/(207)Pb~1.17) and coal combustion ((206)Pb/(207)Pb~1.18) emissions, or indirect, through ingestion of similarly contaminated food - and drinking/cooking water contaminated by lead pipes of local origin, cannot readily be determined. In the 20th century, however, the much lower values of the (206)Pb/(207)Pb ratio (range 1.100-1.166, mean 1.126+/-0.013, median 1.124) for the teeth collected from various age groups in the 1990s reflect the significant influence of imported Australian lead of lower (206)Pb/(207)Pb ratio (~1.04) and released to the environment most notably through car-exhaust emissions arising from the use of alkyl lead additives ((206)Pb/(207)Pb~1.06-1.09) in petrol in the U.K. from ca. 1930 until the end of the 20th century.

Evaluation of dental radiographic identification: an experimental study.

The object of this study was to assess the value of dental radiographs for the purposes of personal identification in the absence of tooth restorations. 198 periapical and bitewing radio graphs were taken of teeth contained in 22 dry skulls obtained from the skull collection of the Royal College of Surgeons of Edinburgh. Each selected view was taken three times: by a scientist, a dentist and a dental radiographer. Each operator independently positioned the films, selected the exposure times and positioned the cone of the X-ray machine. Three groups comprising forensic odontologists, dental vocational trainees and dental trainee hygienists attempted to match the randomly mixed radiographs into sets of three. Success rates for matching radio graphs ranged from 63.6 to 100%. The average for forensic odontologists was 93.3%, vocational trainees 85.2% and hygienists 89.7%. Where forensic odontologists had both formal training and experience, or extensive experience without formal training, the success rate was 100%. Where there was formal training but little experience the success rate was lower. Participants believed that root morphology and alignment had been the greatest aid to matching and not crown morphology. The depth of knowledge of the viewer correlated poorly with the number of correct results, although the forensic odontologists achieved the highest success rate. Formal training, although highly desirable, is no substitute for practical experience. Root morphology and alignment were cited most frequently as facilitating matching.

The skeletonized body: suicidal inhalation of motorbike exhaust.

An adolescent boy who was being treated for psychiatric illness went missing. The body was discovered a year later, and he appeared to have committed suicide by inhaling the exhaust fumes from his motorbike. This report highlights the procedure used for the identification of his skeletonized body and the unusual nature of the source of exhaust fumes.

Identification in the Lockerbie air disaster.

In the aftermath of the Lockerbie air disaster, identification of the victims (plane occupants and local residents) was established by two primary methods: odontology and dactylography. Scottish law requires corroboration of evidence of identity, so both primary methods were used whenever possible, with further evidence occasionally derived from the matching of physical characteristics, personal effects and details from past medical records. Of the 270 victims, 253 were positively identified. Of these, 209 were identified with the aid of odontology.

A common origin for dental porcelain derived from an accused's hand and the decreased victim of an assault.

A small, solid fragment removed from a wound on a hand of a murder suspect was submitted to electron microprobe analysis and found to have the properties of dental porcelain. A sample of porcelain removed from the dental bridge of the deceased had an essentially similar elemental profile. This investigation assisted the Court by providing valuable objective evidence of a physical contact between the accused and the victim.

Sarcoid-type reaction associated with retained roots: an unusual cyst-like lesion of the jaw.

This report describes the unusual findings following curettage of a large cyst-like lesion of the mandible in a 47-year-old woman. Histological examination of the lesional tissue revealed a sarcoid-type reaction, uncommon in the mandible, while further clinical and laboratory investigations failed to demonstrate underlying systemic disease.

A primary double molar tooth in a child with Russell-Silver syndrome.

The prevalence of double teeth in the primary dentition, for the British schoolchild, is 1.6%. Although primary double teeth in the anterior region of the mouth are not uncommon, double teeth in the primary molar region are rare. This case report describes the intra-oral findings, and in particular a case of a primary molar double tooth, in a young child who has Russel-Silver syndrome.

Multiple idiopathic root resorption. A case report and discussion of pathogenesis.

A rare case of multiple idiopathic root resorption (MIRR) involving 5 adjacent anterior and posterior teeth is presented and the pathogenesis discussed. The proposition is made that MIRR results from microbiologically-induced osteoclast activity facilitated by prior osteoblast activation.

Synovial chondromatosis of the temporomandibular joint.

A case report of synovial chondromatosis of the temporomandibular joint is presented in which the limitations of clinical findings, needle biopsy, standard radiography and computer assisted tomography were exposed and the importance of clinico-pathology consultation reaffirmed.

Understanding pathologists (an exercise in communication): 2. Understanding biopsy techniques.

For the best possible report to be made, it is necessary for the appropriate specimen to be taken and transported in the appropriate manner, and then correctly processed. In the second of a four-part series aiming to 'demystify' the subject of pathology, the author critically evaluates biopsy techniques. The next two articles in this series will look in some detail at the pathologist's report and special laboratory investigations.

Overview of dental treatment of patients with microstomia.

This paper provides an overview of the dental management of patients with microstomia. A brief review of its etiology is presented, along with advice on planning preventive and operative care.

Understanding pathologists (an exercise in communication): 1. Understanding pathology.

Pathology is a discipline that is often approached with some reserve by nonpathologists. In this four-part series the author aims to 'demystify' the subject. The objective of this first article is to improve understanding of the purposes, limitations and methodology of pathology. In essence the role of the diagnostic histopathologist is to help the clinician help the patient. If, in the request for help, the clinician states clearly why a histological examination is required and gives a relevant history, the pathologist finds it much easier to return a useful report. The subsequent three articles in this series will look in some detail at biopsy techniques, the pathologist's report and special laboratory investigations.

Central neurilemma of the mandible.

A rare case of symptomless central neurilemmoma of the mandible is reported. Post-operative recovery was uneventful and, in particular, post-surgical paraesthesia was followed by a return to normal sensation.

Alzheimer's disease.

Alzheimer's disease (AD) is a debilitating and progressive disease that can affect dental practice in a number of ways. Not only will increasing numbers of AD patients be treated by dentists in the future but the dentist and members of his family may also be unfortunate enough to become affected. In the United Kingdom, nearly 10% of the population over 65 years of age, and more than 20% of those over 80 years develop progressive deterioration of memory, resulting in a breakdown of intellectual capacity and personality. More than half of those are suffering from AD. The purpose of this review is to describe the aetiology and behavioural aspects of this distressing disease and to highlight some problems that the dentist may encounter when treating those patients.

Aluminium leaching and fluoride.

Aluminium leaching from cooking utensils is a source of dietary aluminium and there are differing reports in the literature concerning the effects of fluoride ions on aluminium leaching. This paper reports that aluminium leaching may be increased by around 5% when fluoride ion at 1 mg/litre is present. More dramatic increases in aluminium leaching occur if the fluoride ion concentration is increased to 20 mg/litre, but this would rarely, if ever, be found in a culinary situation. At fluoride ion concentrations likely to be encountered in cooking, the increased leaching due to fluoride is very small in relation to the effects of pH on aluminium leaching.

Recurrent meningioma of the head and neck--two case reports and a review of the literature.

Two very unusual cases of recurrent meningioma characterised by cheek swelling and proptosis of the eye are reported. Clinical and histological features are described and the literature reviewed.

Glomus tumor of the lip. A case report and immunohistochemical study.

A rare glomus tumor of the lip is reported and--with nineteen glomus tumors from other sites--examined immunohistochemically with both monoclonal and polyclonal antibodies. In every case, the glomus cells showed strong reactivity with antivimentin, and factor VIII-related antigen was consistently identified in the endothelial cells but not in the glomus cells. Antiblood group A antigen was located in endothelial cells in nine cases; of these nine, five also showed focal staining in glomus cells. In no case was there reactivity with antibodies to common leukocyte antigen or cytokeratin proteins. These results support the hypothesis of Tajima et al. that the glomus cell is transitional--between smooth muscle and vascular endothelium--being essentially a modified, smooth muscle cell with some endothelial cell properties.