Effect of thumb sucking:

Clinical features of thumb sucking: Well localized Anterior open bite Secondary tongue thrusting(May develop). Increased overjet - Proclination of upper teeth, Retroclination of lower teeth Decreased overbite Maxillary constriction (greater maxillary arch depth & decreased maxillary width) -Posterior cross bite Mandible rotates downwards and backwards (vertical growth pattern) Hypotonic upper lip because of proclination of upper anteriors Hypertonic lower lip Hypertonic active mentalis activity causes Long face and convex profile.