Influence of functional orthodontic therapy on body posture and postural control in children and adolescents with Class II malocclusion

BACKGROUND: Malocclusions in children and adolescents are not only associated with aesthetic and functional issues but may also influence body posture due to neurophysiological links between the temporomandibular system and the spinal column. This study aimed to evaluate how functional orthodontic treatment may affect mandibular function, upper body posture, and postural control in children with skeletal Angle Class II malocclusion, by comparing findings before and after treatment. METHODS: Thirty-nine children (18 f/ 21 m; median age 11.1 years, IQR 9.46–12.00 years) with skeletal Class II malocclusion were treated with a Balters bionator. Cephalometric data, occlusal parameters (overjet, overbite, transversal widths), axiographic measurements, as well as three-dimensional analyses of spinal and postural parameters were recorded both before and after therapy. RESULTS: Pre-post-skeletal changes: Orthodontic treatment led to significant skeletal improvements, including increased SNB° (p ≤ 0.001; 76.6° → 77.5°), reduced ANB° (p ≤ 0.001; 4.5° → 2.9°), and decreased overjet (6.0 mm → 4.0 mm). Pre-post-mandibular changes: Mandibular movement remained symmetrical, while mouth-opening deviations dropped significantly from 92 to 15% (p ≤ 0.001). Pre-post-postural control, pre-post-upper body posture: No clinically relevant changes were observed in postural control or upper body posture—e.g., increased trunk length (D: + 18.18 mm, S: + 22.63 mm; both p ≤ 0.001). Balance distribution remained physiological (forefoot-rearfoot approx. 37:63%), sway parameters stayed within normal limits Correlations: Significant correlations emerged between mandibular mobility (especially left laterotrusion) and various postural and balance parameters, with low to moderate effect sizes. No associations were found between model analysis and either axiographic or postural measures. DISCUSSION: This study underscores the functional stability of postural regulation in healthy children undergoing orthodontic treatment. Although significant improvements in dental and mandibular parameters were observed, neither postural control nor upper body posture exhibited clinically relevant changes. It should be noted that both posture and balance were already within physiological norms at baseline. In the absence of pre-existing postural dysfunctions, orthodontic interventions are unlikely to induce substantial postural changes.