Age- and sex-related growth patterns of the craniofacial complex in European children aged 3-6 years.

BACKGROUND: Craniofacial growth changes in young children are not yet completely understood. Up-to-date references for craniofacial measurements are crucial for clinical assessment of orthodontic anomalies, craniofacial abnormalities and subsequent planning of interventions. AIM: To provide normal reference data and to identify growth patterns for craniofacial dimensions of European boys and girls aged 3-6 years. SUBJECTS AND METHODS: Using standard anthropometric methodology, body weight, body height and 23 craniofacial measurements were acquired for a cross-sectional sample of 681 healthy children (362 boys and 319 girls) aged 3-6 years from Germany, Italy and Lithuania. Descriptive statistics, correlation coefficients, percentage annual changes and percentage growth rates were used to analyse the dataset. RESULTS: Between the ages of 3-6 years, craniofacial measurements showed age- and sex-related patterns independent from patterns observed for body weight and body height. Sex-related differences were observed in the majority of craniofacial measurements. In both sexes, face heights and face depths showed the strongest correlation with age. Growth patterns differed by craniofacial measurement and can be summarised into eight distinct age- and sex-related patterns. CONCLUSION: This study provided reference data and identified sex- and age-related growth patterns of the craniofacial complex of young European children, which may be used for detailed assessment of normal growth in paediatrics, maxillofacial reconstructive surgery and possibly for forensic age assessment.

Extraction and amplification of nuclear and mitochondrial DNA from ancient and artificially aged bones.

An experimental design is presented that simulates an accelerated process of DNA degradation in human bone tissues and thus provides a possibility for a systematic investigation of factors hampering DNA extraction and amplification. Equal sized slices of human femoral bones were incubated in 90 degrees C water for 2 h up to 30 days. DNA was extracted and subjected to a human specific Duplex polymerase chain reaction (PCR) and also to a Multiplex short tandem repeat (STR) PCR. Additionally 24 ancient bones representing different age periods were investigated in the same way. The results were compared to those from the artificially aged samples. After just 12 h of incubation, DNA is totally degraded, but still fully typable. After 36 h no reproducible amplification of DNA is possible. Using Multiplex PCR the DNA from artificially aged bones shows the typical STR pattern for ancient samples suggesting that the in vitro approach provides a useful and comparable method to elucidate the DNA degradation process in bones.