Studies that used experimental or observational designs to investigate correlations between the stomatognathic system and body posture were eligible for inclusion. Case series and case reports were excluded. There were no restrictions on participants. Eligible studies had to be free of major biases in the statistical analysis and include groups with comparable characteristics at baseline. It appeared that two reviewers independently assessed studies for inclusion in the review.
Studies that met these criteria were predominately non-randomised controlled trials and non-controlled trials; there was one case-control study and a cross-sectional study. Studies recorded body posture under either static conditions (qualitative or quantitative posturographic parameters assessed by physical examination, postural platform, body photographs and rasterstereography) or dynamic conditions (Fukuda-Unterberger stepping test, analysis of gait rhythm and timing of posture recovery in response to external disturbances).
Most of the studies included asymptomatic patients with variable occlusal conditions, normal occlusion, unilateral crossbite or non-specified occlusal status; some studies included patients with functional disorders of the stomatognathic system or temporomandibular disorders. Most studies were in patients aged between 20 and 30 years; overall, the age range was wide (3.5 to 54 years, where reported). Interventions, where these existed, included use of intra-oral devices to change mandibular position, splints to modify masticatory muscle hypertonia, unilateral trigeminal anaesthesia, orthognathic surgery and external disturbance for challenging body equilibrium.