Vestibular crown relief measurement in normal occlusion arches

Resumen

Masticatory system function is related , among other aspects,  to occlusal configuration characteristics. Through the years, different occlusion concepts have been described until reaching the functional occlusion concepts that we nowadays use. Common characteristics of ideal or normal occlusion have been established. Nevertheless, in our days, several authors agree upon the concept that  occlusal characteristics are specific to each individual. The aim of this study was to determine vestibular crown characteristics of both arches  by means of  dental crown rotation measurements . The study was conducted in a specific Mexican population   not subjected to orthodontic treatment and considered normal. Dental crown rotation was measured in 110 models.  Use was made of an appliance and an attachment which allowed measurement of dental surfaces with the aid of a laser beam. Results show a similar pattern in left and right side  rotations of a same region (upper and lower jaw). All  average rotations of lower teeth measured between -1º and 1º. Average rotation of upper jaw teeth ranged from -2º to 8.5º. In both upper and lower regions, central, lateral and canine teeth presented a negative average rotation; premolars and molars presented a positive average rotation. Upper and lower molars presented greater standard deviation.  This study reached the conclusion that, due to variations observed in crown rotation, it is not appropriate to standardize its values to conduct orthodontic treatments. It is more convenient to use  appliances  individually tailored for each patient.