Introduction of a three-dimensional anthropometry of the viscerocranium. Part I: measurement of craniofacial development and establishment of standard values and growth functions.

BACKGROUND AND OBJECTIVE: The analysis of lateral cephalograms is based on many vague landmarks that vary intra- and inter-individually. Exposure to radiation and high-quality equipment are essential, while identical object positioning is almost impossible. Anthropometry as presented in the literature is time consuming and cannot reproduce cranial three-dimensionality. Poor landmark definitions and resilience of the soft tissue foster systematic measurement errors. We used few easily detectable and accessible landmarks that are closely related to underlying bone. The distances measured were visualized three-dimensionally. MATERIAL AND METHODS: Measurements from 540 volunteers were reconstructed. Reliability was assessed through repeated measurements. Corresponding distances were measured in lateral cephalograms taken the same day. RESULTS: The age- and sex-related mean values and 95%-percentiles were visualized as growth functions. The intra-individual relative error in anthropometry was 3.7%, in roentgenocephalometry 0.9%. The inter-individual error was 5.8% for anthropometry and 3.6% for roentgenocephalometry. CONCLUSION: Applied anthropometry as described in the paper is reliable and valid for measuring craniofacial growth, arriving at a diagnosis and 'monitoring' treatment results. The relative measurement error in anthropometry appear to be smaller than the systematic magnification and distortion found in lateral cephalograms.