Posture is the strategy adopted by the neuromuscular and skeletal systems in response to gravity and acceleration, allowing the body to perform both static and dynamic motor functions.

To maintain physiological posture, three main parameters should be respected:

ECONOMY: minimum energy expenditure and minimal tonic-phasic activity.
STATIC-DYNAMIC BALANCE: maximum stability.
COMFORT: minimum stress on bone, ligament and fascial structures.

When these three components are altered, the body develops compensatory adaptations that may exceed its ability to maintain balance. As a result, mobility may decrease and defensive, less efficient postural patterns may develop. [Busquet] This can lead to asymmetric posture or a compensatory postural system.

A well-balanced individual generally presents Class I occlusion with orthognathic maxillomandibular relationships and an anteroposteriorly centred posture, with the centre of gravity at the level of the atlas-axis complex.

In patients with prognathism, posture may tend to shift anteriorly, while in patients with retrognathism it may tend to shift posteriorly.

In pathological conditions, the tongue may be unable to correctly perform its role in shaping the dental arches. By altering its posture, it may adapt to available vertical, anterior or lateral spaces, changing its shape and position.

The close interdependence between the different structures of the body means that a structural or functional alteration in one area may contribute to imbalances affecting other areas, through both ascending and descending mechanisms. [Bibby RE, Bondi M, Bourdiol RJ, Bricot B, Gagey PM, Guaglio G, Planas P, Rocabado M, Sauchand E, Solow B, Stefanelli G].