Examination of regressive features of third molars for the purpose of age assessment in the living by means of rescaled regression analyses

The main criterion of dental age assessment in living adolescents and young adults is the evaluation of third molars' mineralization. Concerning forensic age assessment after the completion of third molars' mineralization, apposition of secondary dentine and narrowing of the periodontal membrane as seen as decreasing radiolucent areas in the radiographs for mandibular third molars have already been described as regressive features. The present study examines the combination of both these features for the purpose of age assessment in regression analyses after rescaling the data to make it on the interval scale. To this end, a total of 1245 orthopantomograms was evaluated, taken from 606 females and 639 males in the age group of 15-40 years. The apposition of secondary dentine and narrowing of the periodontal membrane as seen as decreasing radiolucent areas in the radiographs were determined for the lower third molars. The correlation of the features with the chronological age was assessed by means of rescaled regression analyses. Furthermore, regression formulas for age assessment were established. The values of the standard error of estimate ranged between 3.55 and 4.52 years. In general, the rescaled regression of the examined features appears to be suited for forensic age assessment. A limitation of the present study is the comparatively low number of evaluable teeth in the examined age group. Due to an incomplete development or a lack of the mandibular third molars, only a mere half of the respective teeth could be included in the statistical analysis.

Mapping of an autosomal dominant gene for Dupuytren's contracture to chromosome 16q in a Swedish family

Mapping of an autosomal dominant gene for Dupuytren's contracture to chromosome 16q in a Swedish family.Dupuytren's contracture (DC) (OMIM 126900) is the most common connective tissue disease of mankind and has both heritable and sporadic forms. The inherited form is most frequently observed among the xanthochroi peoples of Northern Europe where its most common manifestations are thickening of the palmar fascia and contracture of the fingers. We ascertained a five-generation Swedish family in which DC is inherited in an autosomal dominant manner with high, but incomplete, penetrance by the end of the fifth decade. Blood was collected from all affected and informative unaffected family members for the performance of a genome-wide scan at a resolution of approximately 8 cM for all autosomes. Linkage was established to a single 6 cM region between markers D16S419 and D16S3032 on chromosome 16. A maximal two-point logarithm of odds (LOD) score of 3.18 was achieved at microsatellite marker D16S415 with four other markers in the region producing LODs of >1.5.