Tongue thrust (also called reverse swallow or immature swallow) is a pseudo-pathological name of what is either considered a normal adaptive lip seal mechanism, whereby normal nasal breathing or normal swallowing can occur, or seen as an oral myofunctional disorder - a tongue muscle pattern that is perceived as clinically abnormal and in which the tongue protrudes anteriorly to seal otherwise incompetent lips. Tongue thrusting is only seen during speech, swallowing or eating, and in order to close otherwise incompetent lips on background of an almost ubiquitous small lower jaw and anterior open bite. The behaviour is apparent only during a normal awake state, and whilst the tongue (and rest of the body) is in normal resting tone. By descriptive inference, tongue thrusting is impossible during deep sleep, or non-tone phases; or in particular during non-conscious states. Nearly all infants exhibit a swallowing pattern involving forward tongue tip push as part of infant suckling behaviour . By six months of age most lose the forward extent of this push once paediatric incisal teeth erupt, and normal lip seal is automatically acquired as solid foods begin. There are thus two community and clinical professional views of the observation of tongue thrusting behaviour that persists past the neonatal period.