Prevalence and anatomic topography of mandibular tori: computed tomographic analysis.

PURPOSE: Mandibular tori are located above the mylohyoid ridge. These features are relatively common in most populations, but their prevalence varies with race. The purpose of this study was to identify the prevalence and features of mandibular tori in a Korean population using computed tomographic (CT) images. MATERIALS AND METHODS: The CT images of 726 patients were analyzed in this study. The presence or absence of a mandibular torus was identified on the CT images of each patient's quadrants and categorized according to gender and age. The most common location was also evaluated according to the corresponding teeth. The cortical thickness of each torus was evaluated using a 3-dimensional reconstruction software program. RESULTS: The prevalence of mandibular tori in the entire sample was 24.1%, and most cases were bilateral. Mandibular tori were observed more frequently in young adults, with the prevalence being inversely related to age. The most frequently observed location was the premolar region, and the mean cortical thickness was 6.9 mm. CONCLUSIONS: Mandibular tori seem to change with aging. The prevalence in the present sample composed of Koreans was 24.1%, and younger patients may be more likely to develop a mandibular torus. Most tori presented a medium size bilaterally in the lingual aspect of the premolar region, and all were composed of cortical bone.

Infant and juvenile growth in ancestral Pueblo Indians.

The present study examines patterns of infant and juvenile growth in a diachronic sample of ancestral Pueblo Indians (AD 1300-1680) from the American Southwest. An assessment of growth patterns is accompanied by an evaluation of pathological conditions often considered to be indicators of nutritional deficiencies and/or gastrointestinal infections. Growth patterns and the distribution of pathological conditions are interpreted relative to culturally relevant age categories defined by Puebloan rites of passage described in the ethnographic literature. A visual comparison of growth distance curves revealed that relative to a modern comparative group our sample of ancestral Pueblo infant and juveniles exhibited faltering growth beginning soon after birth to about 5 years of age. A comparison of curves describing growth relative to adult femoral length, however, indicated reduced growth occurring later, by around 2 years of age. Similar to previous studies, we observed a high proportion of nonsurvivors exhibiting porotic cranial lesions during the first 2 years of life. Contrary to expectations, infants and juveniles without evidence of porotic cranial lesions exhibited a higher degree of stunting. Our study is generally consistent with previous research reporting poor health and high mortality for ancestral Pueblo Indian infants and juveniles. Through use of a culturally relevant context defining childhood, we argue that the observed poor health and high mortality in our sample occur before the important transition from young to older child and the concomitant initial incorporation into tribal ritual organization.

Frequency variations of discrete cranial traits in major human populations. III. Hyperostotic variations.

Seven discrete cranial traits usually categorised as hyperostotic characters, the medial palatine canal, hypoglossal canal bridging, precondylar tubercle, condylus tertius, jugular foramen bridging, auditory exostosis, and mylohyoid bridging were investigated in 81 major human population samples from around the world. Significant asymmetric occurrences of the bilateral traits were detected in the medial palatine canal and jugular foramen bridging in several samples. Significant intertrait associations were found between some pairs of the traits, but not consistently across the large geographical samples. The auditory exostosis showed a predominant occurrence in males. With the exception of the auditory exostosis and mylohyoid bridging in a few samples, significant sex differences were slight. The frequency distributions of the traits (except for the auditory exostosis) showed some interregional clinality and intraregional discontinuity, suggesting that genetic drift could have contributed to the observed pattern of variation.