Soft-tissue wits appraisal: a novel measurement of the maxillo-mandibular discrepancies

Aim: maxillo-mandibular sagittal discrepancies are a relevant factor in orthodontic diagnosis and for the evaluation of facial proportions. The aim of the study is to identify and test a novel method of measurement for the maxilla-mandibular discrepancy based on soft tissue landmarks and the soft tissue Wits appraisal. In addition, it is also aimed at overcoming the flaws in established traditional measurements, based only on skeletal criteria, increasing the diagnostic precision. Methods: the sample included 300 subjects (162 males and 138 females) with an age range of 6 to 50 years old (divided also in 6 age groups). Inclusion criteria were: Caucasian ethnicity, skeletal and dental malocclusion class I, II and III. Exclusion criteria were facial asymmetry, cross-bite, need for surgical treatment, absence of molars and premolars, past or present orthodontic treatment and alterations in bone metabolism. For each patient a CBCT and facial scan were requested for a cephalometric evaluation. From all cephalometric analysis Wits appraisal and soft tissue Wits appraisal (by measuring the linear distance between the projections of point A’ and B’ on the occlusal plane) were examined. Results: a significant correlation was found between the two appraisals in all age groups, with no gender differences. Conclusions: the soft tissue wits appraisal proved to be a simple and reproducible measurement for the diagnosis, including aesthetical diagnosis, of the maxilla-mandibular sagittal relationship.