Effect of thumb sucking:
Localized anterior open bite.
Increase overjet.
Constricted maxilla
All of the above.
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.