Prevalence of class III malocclusion and crossbite among children and adolescents with craniomandibular dysfunction

Abstract

Numerous studies have been devoted to the causes of craniomandibular dysfunction (CMD). This investigation addressed the effect of class III malocclusion and crossbite on CMD based on a sample of 115 prepubertal and adolescent patients of both sexes. Although class III malocclusion only accounted for 12.2% of the total sample, thus, being the smallest group, the percentage of crossbite (71.4%) among these patients was disproportionately higher than among the other classes. Of the total sample, the prevalence of crossbite was 30.4%. We compared these findings to a large-scale (n=4727) study by Thilander et al. (2002), who reported a strikingly high percentage of class I patients compared to our findings (72.7% versus 27.8%) and a lower percentage of crossbite cases (8.0% versus 30.4%). In accordance with the "orthodontic risk child" concept by Grabowski et al. (2007) and Stahl et al. (2007), we conclude that class III malocclusion and crossbite are keys in the pathogenesis of CMD.

Patrón De Desgaste Oclusal Durante El Sueño en Adolescentes De 12 a 17 Años Según Clasificación De Angle

“…While the most prevalent upper and lower arch type in Class III was the ovoid (46.7% and 60%), the interdental relationship implies the presence of a varied occlusal wear pattern distribution depending on the intermaxillary relationship, which requires a broader sample and a more specific study on this classification, considering that no subject in the selected sample had anterior crossbite and only some had unilateral or bilateral posterior crossbite, which, according to the literature, can be associated with a high prevalence of signs and symptoms of TMD. 24,25 Moreover, Goldstein et al, in 1984, stated that there is a relationship between the position of the head and an unstable occlusion due to an upward and backward mandibular displacement, producing unnecessary muscular activity and altering the elastic properties of the jaw; this causes a retruded and elevated position, decreasing the physiological inocclusion space between the jaws, resulting in more posterior contacts that can behave as interferences in the case of crossbites. This finding can explain the higher frequency of GF + BCA (33.3%) and GF + BCP (26.7%) occlusal wear patterns in Class III subjects.…”