Do malocclusion and Helkimo Index ‡5 correlate with body posture? L. PERILLO*, B. FEMMINELLA † , D. FARRONATO ‡ , T. BACCETTI §¶ , L. CONTARDO** & G. PERINETTI** *Department of Orthodontics, 2nd University of Naples, Naples, † Department of Oral Sciences, University of Chieti, Chieti, ‡ Department of Oral Sciences, University of Milan, Milan, § Department of Orthodontics, University of Florence, Florence, Italy, ¶ Thomas M. Graber Visiting Scholar, Department of Orthodontics and Pediatric Dentistry, School of Dentistry, The University of Michigan, Ann Arbor, MI, USA and **Department of Biomedicine, University of Trieste, Trieste, Italy SUMMARY 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 per- formed 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 multi- variate level revealed that age and gender were mostly responsible for this. The only significant correlation that was seen was for the malocclu- sion + 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 maloc- clusal trait ⁄ Helkimo Index ‡5 (irrespective of the groups), only an increased overbite showed a statis- tically 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. KEYWORDS: malocclusion, Helkimo Index, posturog- raphy, body posture, Fukuda stepping test Accepted for publication 8 August 2010 Introduction Recently, a growing number of studies have focused on the potential impact of the stomatognathic system, which includes the mouth, the jaws and their closely associated structures, on whole-body posture, and vice versa (1, 2). In particular, potential effects on whole-body posture have been investigated for dental (3–6) and skeletal (7, 8) malocclusion, and for temporomandibular disorders (TMDs) (9–15). However, in spite of these previous studies, most of the information available to date remains inconclusive, and recent reviews have reported contrasting conclusions in favour of (1) and against (2, 16) clinically significant correlations. The few studies that have been specifically performed on dental malocclusion or TMDs have been hampered by the limited number of subjects included (5, 10) and by imbalances between the study groups (5, 9, 11, 15, 17). The other limitations of most of the previous studies have included incomplete sample descriptions, limited num- bers of parameters ⁄ conditions tested, and use of static recordings of body posture, as recently indicated by a ª 2010 Blackwell Publishing Ltd doi: 10.1111/j.1365-2842.2010.02156.x Journal of Oral Rehabilitation 2011 38; 242–252 Journal of Oral Rehabilitation