Malnutrition Has No Effect on the Timing of Human Tooth Formation

The effect of nutrition on the timing of human tooth formation is poorly understood. Delays and advancements in dental maturation have all been reported as well as no effect. We investigated the effect of severe malnutrition on the timing of human tooth formation in a large representative sample of North Sudanese children. The sample (1102 males, 1013 females) consisted of stratified randomly selected healthy individuals in Khartoum, Sudan, aged 2-22 years using a cross-sectional design following the STROBE statement. Nutritional status was defined using WHO criteria of height and weight. Body mass index Z-scores and height for age Z-scores of ≤-2 (cut-off) were used to identify the malnourished group (N = 474) while the normal was defined by Z-scores of ≥0 (N = 799). Clinical and radiographic examination of individuals, with known ages of birth was performed including height and weight measurements. Mandibular left permanent teeth were assessed using eight crown and seven root established tooth formation stages. Mean age at entry and mean age within tooth stages were calculated for each available tooth stage in each group and compared using a t-test. Results show the mean age at entry and mean age within tooth stages were not significantly different between groups affected by severe malnutrition and normal children (p>0.05). This remarkable finding was evident across the span of dental development. We demonstrate that there is little measurable effect of sustained malnutrition on the average timing of tooth formation. This noteworthy finding supports the notion that teeth have substantial biological stability and are insulated from extreme nutritional conditions compared to other maturing body systems

Incidence of Stylohyoid Ligament Calcification and Its Length in an Iranian Adult Population

Introduction: Elongation and calcification of the stylohyoid ligament complex may be correlated with eagle’s syndrome which could cause facial pain or dysphasia. The aim of this study was to investigate the prevalence of stylohyoid ligament complex elongation in Iranian adults. Methods: Panoramic radiographs of 504 patients older than 20 years referring to the dental school were selected from 2003 to 2008. The stylohyoid ligament complexes were measured from the cranial base up to the osseous tip of each process. Mineralization of the complex of more than 25 mm in length on the radiograph was considered to be abnormal. The lengths of the areas of mineralization were recorded. Results: This abnormality was seen in both sexes. A calcified complex was found in 135 of the 504 patients. Of the total, 26.8% were longer than 25mm and so were abnormal. They included 20.4% bilateral cases and the average length was 21.7±7.65mm. Ten patients (2%) of the abnormalities were longer than 40mm in each age group. The mean length of a mineralized stylohyoid ligament complex in patients in the 60-79 years age group was 23.13mm. Conclusion: The results suggest that anatomical variant of the stylohyoid ligament complex is frequent in Iranian population and present in both sexes with equal distribution