Elaboration of the measuring procedure facilitating precision assessment of the geometry of mandible anatomical model manufactured using additive methods

Abstract

This article presents a procedure for minimizing ATOS II Triple Scan system measurement errors during the verification of geometrical accuracy of the final lateral-mandibular condyle model. The process of manufacturing a template geometrically similar to that of lateral-mandibular condyle was performed on the five-axis machining centre 100 DMU MonoBlock. The next stage of the research was related to the implementation of the measurement system procedure on the template model, and the 12 anatomical models of the mandibular body-condyle were manufactured using five different additive methods. As a result of the comparison of anatomical models of the mandibular body-condyle designed in reverse engineering/computer-aided design systems and manufactured using additive methods, the average results of histograms and parameters determining the accuracy of geometry of 12 models were obtained. In the case of models manufactured using fused deposition modelling, PolyJet and selective laser sintering techniques, a unimodal distribution was observed in the same way as in the template model. The best results were obtained in the case of models manufactured using selective laser sintering techniques (standard deviation = 0.06 mm). In the case of fused deposition modelling and PolyJet, a similar value of standard deviation (about 0.07 mm) was observed, despite the fact that the layer thickness for PolyJet technology was 0.016 mm. In the case of melted and extruded modelling and ColorJet Printing technologies, there was a bimodal distribution. Through the implementation of own template and measurement method, it will be easier to estimate errors in the manufacturing of anatomical models of lateral-mandibular condyle part. As a result, medical models, surgical templates and implants will be manufactured more accurately and precisely, which will significantly reduce intraoperative complications during the surgical procedure in this area.