Correlation Between the Posterior Mandibular Width and the Lingual Gap Caused by Symphyseal Fractures Using a Virtual Model

Abstract

The objective was to determine the dimensional impact, on the occlusal and articular level, of the gap produced in the lingual plate from symphyseal fractures, correlated with the dimensional change in the posterior mandibular width. We performed an observational experimental study based on 30 computed tomography scans of patients treated by the Maxillofacial Surgery Service, Hospital Clínico Mutual de Seguridad, Santiago, Chile, between 2012 and 2016. The inclusion criteria were jaws without evidence of fractures or pathology, with an absence of orthodontic appliances, and with complete dentition to the first mandibular molar.By use of Digital Dental Service 3-dimensional planning software (DDS-Pro; Digital Dental Service, London, UK), a vertical mandibular fracture was made, leaving lingual gaps of 1, 2, and 3mm, and the dimensional changes were recorded with regard to the posterior facial width. The mandibular height did not vary with regard to the lingual gap; the mandibular length was inversely proportional to the lingual gap; and the intermolar, intergonial, and intercondylar distances were directly proportional to increases in the lingual gap. The larger the lingual gap, the shorter the mandibular length and the larger the mandibular transverse dimensions. Special attention must be paid to the occlusal and articular level.