A probable case of hypophosphatasia in St Bride's Lower Churchyard (1770-1849, London, UK).

OBJECTIVES: The objective of this study was to analyse an individual whose remains are characterised by early deciduous tooth loss and multi-focal lesions on the post-cranial skeleton. MATERIALS: Skeletal remains of an immature individual buried between 1770 and 1849 in London. METHODS: The remains were examined by visual macroscopic inspection, supplemented by radiographic examination of the mandible and maxillae. A differential diagnosis with possible conditions, frequent in this archaeological context, was conducted. A comprehensive examination of dental lesions was performed to investigate the aetiologies of deciduous tooth loss. RESULTS: The individual exhibited a mosaic of skeletal and dental pathological changes, including premature loss of deciduous dentition, premature eruption of permanent teeth generalised bone loss in both the mandible and maxilla; osteomyelitis of the left radius; osteolytic lesion on the body of the second lumbar vertebra, and marked expansions of the rib shafts due to sub-periosteal new bone formation. CONCLUSION: A differential diagnosis considered indicates that the pathological changes of the individual were most likely associated with a comorbidity involving hypophosphatasia and tuberculosis. SIGNIFICANCE: We present in this study several oral signs that could alert paleopathologists and bioarcheologists to systematically consider the potential of a condition that is rarely encountered in archaeological contexts. LIMITATIONS: Due to poor preservation, this study was confined to the analysis of a partial maxilla and mandible, a left radius shaft and the axial skeleton (rib heads and vertebrae) of the individual. SUGGESTIONS FOR FURTHER RESEARCH: Further radiographic, histological and genetic analyses would confirm the diagnosis.

Skeletal indicators of pathology in the context of early tooth loss in children: A systematic literature review.

OBJECTIVE: To provide an evidence-based resource for paleopathologists to consider multiple skeletal indicators of pathology associated with early tooth loss in children to aid in diagnosis. MATERIALS: Three databases (Cochrane Library, MedLine, and Scopus) were used for a review. METHODS: According to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) criteria, a systematic review guideline, 85 articles were selected. RESULTS: A total of 189 children had a syndrome or disease associated with early tooth loss. Our review, based on 25 diseases, lists the bone and dental lesions observable in archeological remains. CONCLUSIONS: Based on a review of the literature, a synthesis of 25 diseases and syndromes that may be associated with premature loss of permanent or deciduous teeth in children was developed for paleopathologists. It highlights the importance of a thorough dental examination by paleopathologists to further assess past health conditions. SIGNIFICANCE: This paper provides an extensive resource addressing early tooth loss in childhood to assist researchers with differential diagnosis. LIMITATIONS: The articles included in this review are case reports based on living populations. SUGGESTIONS FOR FURTHER RESEARCH: Further studies into diseases and their association with early tooth loss would complement this work, as would utilizing the differential diagnoses on archeological individuals to clarify its value and limitations.

How geographical origin and dietary habits interact with the shape of cortical mandibular sections? A geometric morphometrics study in an archaeological context.

OBJECTIVE: Mandibular shape is strongly influenced by biomechanics, particularly during dietary shifts that often occurred in past populations. The relationship is considered extremely complex as development of the mandible is a multifactorial process. Since cortical bone distribution is purportedly more biomechanically sensitive than external shape, comparison of its distribution in past populations can provide new input to understand this complex relationship. The present study examined the effects of geographical origin and dietary habits on the internal anatomy of the mandibular corpus and symphysis. DESIGN: A morphometric analysis was conducted on 72 mandibles from different populations, sampled by their geographical origin and subsistence strategies. Procrustes ANOVAs were performed to test the impact of section-plane location, geographical origin, and dietary habits on the groups' shapes. RESULTS: The specimens' geographical origin and dietary habits had a significant effect on the shapes of the sections (Generalized Goodall F-test, F = 3.2745, df = 6, 304: p < 0.001 and F = 3.7007, df = 4, 306: p < 0.001). CONCLUSION: Geographical origin and dietary habits influenced the shape of the mandibular sections in our sample. These relationships become more complex when analysed in isolated sections. Indeed, this study revealed that symphysis sections could be predominantly influenced by individual variables, whereas intermediate sections of the corpus could be predominantly influenced by populational variables. Future studies could focus on specific sections to better identify the specific "rules of dependence" in each cross-section.

Patterns and sexual dimorphism of non-syndromic hypodontia among a French orthodontic population.

OBJECTIVES: This retrospective study aimed to estimate the prevalence of non-syndromic congenitally missing teeth (CMT) and to explore the frequency of CMT patterns in a French orthodontic population. In addition, the study sought to assess sex-based differences in CMT patterns. DESIGN: Panoramic radiographs of 4569 orthodontic patients between 9 and 21 years-old performed over a 16-year period (2006-2022) were examined to identify non-syndromic tooth agenesis, excluding third molars. A chi-square test or a Fisher exact test were used to determine the difference in the prevalence of tooth agenesis between sex and between arches. RESULTS: Tooth agenesis was observed in 7.3% of the sample (7.9% for females and 6.6% for males). Approximately 86% of the included subjects presented 1 or 2 missing teeth. Single tooth agenesis was significantly more frequent in females than males (p = 0.002, χ2). In total, 23 of the 67 different patterns of CMT observed, were present more than once. 75.5% of male patients and 79.5% of female patients presented one or both missing lateral incisors or second premolars, rarely affected at the same time. This study showed no sex difference in the patterns of tooth agenesis. LIMITATIONS: This study has limitations due to its retrospective nature and our findings apply solely to an orthodontic population from a white ethnic background. CONCLUSIONS: Clinicians should be aware of this particular incisor/premolar phenotype regardless of biological sex. Issues associated with congenitally missing teeth can be managed more effectively with early teenage diagnosis.

Is the distribution of cortical bone in the mandibular corpus and symphysis linked to loading environment in modern humans? A systematic review.

OBJECTIVE: The human mandible is a unique bone with specific external and internal morphological characteristics, influenced by a complex and challenging loading environment. Mandibular cortical thickness distribution in cross-sections is reported to be related to facial divergence patterns, cultural and dietary habits and more generally, specific loading environment. This review hypothesises that a process of environmental mechanical sensitivity is involved in the distribution of cortical bone in the mandibular corpus and symphysis in modern humans, and that loading regimes can influence this distribution pattern. Based on a review of the recent literature, this study aims to answer the following question: "Is the distribution of cortical bone in the mandibular corpus and symphysis linked to the loading environment in modern humans?" DESIGN: A systematic review was undertaken using the PubMed/Medline, Scopus and Cochrane Library databases for publications from 1984 to 2022 investigating the relationship between cortical bone distribution in the mandibular corpus and the loading environment. A subgroup meta-analysis was performed to determine the overall effect of facial divergence on cortical thickness. RESULTS: From a total of 2791 studies, 20 fulfilled the inclusion criteria. The meta-analyses were performed in eight studies using a randomised model, finding a significant overall effect of facial divergence on cortical thickness in posterior areas of the mandible (p < 0.01). CONCLUSIONS: Within the limitations of this review, specific loading regimes and their consequent variables (diet, culture, facial divergence) were linked to cortical thickness distribution. Sex was found to be unrelated to cortical thickness pattern.

Prevalence of taurodontism: meta-analysis in recent humans and evolutionary perspectives.

Taurodontism is a continuous anatomical variation of permanent and primary posterior teeth represented by an enlargement of the pulp cavity. A high prevalence of the trait is reported in Homo neanderthalensis remains. Exploring and refining epidemiology of taurodontism in actual populations could strengthen the hypothesis of a selective advantage for a high attrition diet (as heavy tooth wear in Homo sapiens evolution changed little until recently) or favour pleiotropic or genetic drift effects to explain the high frequency of the trait in Neandertal remains. Prevalence ranges between 0.1% and 48% in the literature. The aim of the present study is to assess the prevalence of taurodontism in recent populations by means of meta-analysis, that is, is the prevalence of taurodontism lower or higher in modern human living populations, where the selective advantages of high attrition diet are still expected? From 90 potentially eligible studies, 15 were included in the meta-analysis. Only cross-sectional studies were reported, and 14,771 participants were included. The meta-analyses were performed with a random model, calculating a weighted-mean prevalence of 11.8%. Gender was found to be unrelated to the prevalence of taurodontism (OR = 0.84 (95% CI 0.67-1.05), p > 0.05). Taurodontism occurs in approximately 11.8% of the living population. This result questions the status of taurodontism as a "typical trait" in Homo neanderthalensis and allows a possible common evolutionary mechanism in Homo sapiens and Homo neanderthalensis for the trait. Further studies should include more accurate and standardized methods to assess the condition.

Prevalence of talon cusp: Systematic literature review, meta-analysis and new scoring system.

OBJECTIVES: Talon cusp is a developmental anomaly consisting of a vertical ridge or cusp projecting labially or lingually from an anterior permanent or primary tooth. A range of prevalence between 0.06 % and 40.8 % has been reported in the literature. Although many epidemiological studies have been conducted, no synthesis of these data has been performed to date. The aim of this paper was to determine the prevalence of talon cusp and to investigate the link between sex and talon cusp. SOURCE: A systematic search was undertaken using the PubMed/Medline, Embase and Cochrane Library electronic databases for publications from 1981 to 2020 investigating the prevalence of talon cusp and the link between talon cusp and sex. STUDY SELECTION: Three reviewers selected the studies independently, extracted the data in accordance with the PRISMA statement, and assessed the risk of bias via the GRADE & Cochrane approaches. RESULTS: From 39 potentially eligible studies, 9 were selected for full text analysis and 8 were included in the meta-analysis, representing 35,224 participants. The meta-analyses were performed with a random model, calculating a weighted-mean prevalence (at least one talon cusp per individual) of 1.67 %. Sex and talon cusp were not statistically significantly associated in our study (OR = 1.10; 95 % CI [0.82-1.47]; p > 0.05). DISCUSSION: We report the first prevalence of talon cusp provided by meta-analysis in a non-syndromic sample. A non-statistically significant association between sex and talon cusp is relevant in terms of genetic etiology. In order to improve the homogeneity and accuracy of the results of further studies, we propose a new universal scoring system for talon cusp. CLINICAL SIGNIFICANCE: Talon cusp is a developmental anomaly with various clinical implications. Therapeutics may vary from simple monitoring to extraction of the supporting tooth. This condition occurs in approximately 1.67 % of the population.