Mathematical assessment of foetal facial skeleton development

The goal of the study was to analyse statistically the survey of measurable parameters distinguishing human facial skeleton as well to construct mathematical model describing foetal facial skeleton selected features. The material consisted of 112 foetuses (44 females – 39.29% and 76 males – 60.71%) in the CRL: 83-245 mm, aged 4-7 months of foetal life. The whole of the examined material originated from the collection of the Department of Normal Anatomy, Medical University of Wrocław. The study methods included: preparation, anthropological method, image acquisition with the use of digital camera as well as statistical methods. Symmetry and sexual dimorphism were evaluated. The following parameters were observed: head circumference – HC, bi parietal diameter – BPD, body mass, mandibular angle – Ang1, mental angle– Ang 2, mandibular body length – Lb, mandibular ramification length – Lra, mandibular body width – Wb, mandibular body width at the mandibular angle height – Wang, mandibular body width at the mandibular ramus height – Wra, coronoid process width – Wcp, mandibular condyle width – Wcon, mandibular height in medial line – A1, nasolabial groove height – A2, frontal bone height – A3, the distance between orbital edge and mandibular body – A4, nose length – A5, facial skeleton width on maxilla alveolar process level – S1, facial skeleton width on nasal cavity level – S2, facial skeleton width on orbital level – S3, facial skeleton height – W1. Female foetuses were significantly older than the male ones and asymmetry was not observed. Female foetuses facial skeletons (4-6 month) are characteristic for mandible body Lb increased length, smaller mandibular angle Ang1 as well as the increase of Wang width and W1 height. The remaining parameters do not differ significantly in male foetuses. The growth rate of analysed parameters describing facial skeleton morphology was the biggest in 4 and 5 months. Logarithmic model seems to be the best to describe bone structures sizes dependence on foetal age.