Whether there are correlations between the stomatognathic system and body posture remains controversial. Here, we have investigated whether malocclusal traits and having a Helkimo Index ≥ 5 show detectable correlations with body-posture alterations in children and young adults. A total of 1178 11- to 19-year-old subjects were divided into four groups: (i) controls; (ii) malocclusion; (iii) Helkimo Index ≥ 5 and (iv) malocclusion + Helkimo Index ≥ 5. Dental occlusion assessment included the following: overbite, overjet, posterior crossbite, scissorbite, mandibular crowding and dental class. Subsequently, body-posture assessments were performed through static analyses of body inclination and trunk asymmetry, and according to the dynamic Fukuda stepping test. Univariate and multivariate statistical analyses were performed. Although at the univariate level both the trunk asymmetry and Fukuda stepping test showed significant differences among the groups, the multivariate level revealed that age and gender were mostly responsible for this. The only significant correlation that was seen was for the malocclusion + Helkimo Index ≥ 5 group: these subjects had a positive (worse) trunk asymmetry and a negative (better) Fukuda stepping test performance. At the further multivariate analyses of each single malocclusal trait ⁄Helkimo Index ≥ 5 (irrespective of the groups), only an increased overbite showed a statistically significant association with a slightly better Fukuda stepping test performance. Given the small number of significant associations seen and their limited entities, this study does not support the existence of clinically relevant correlations for malocclusal traits and Helkimo Index ≥ 5 with body posture in children and young adults.
