<prompt> Lip bumper is used for:Mouth breathingNail bitingFor lip biting hyperactive rnentalisAll of the above  <response>: Lip BumperLip bumper is an appliance that makes use of the tonicity of the lip. The lip trap and excessive lip activity can be helped with a lip bumper which prevents lip pressure on the lower incisor; their labial position gets normalised with tongue pressure. The lost arch length can also be gained with this method.Key Concept: The lip trap and excessive lip activity can be helped with a lip bumper which prevents lip pressure on the lower incisor.Reference: Orthodontics: Diagnosis and Management of Malocclusion andDentofacial Deformities 3rd ed Om P. Kharbanda pdf no 736 