over bites & under bites

Jaw Defects: Jaw defects are present in almost all breeds of sheep and many breeds of goats. These conditions are associated with failure of the lower incisor teeth to properly meet the dental pad. A jaw is undershot if the incisor teeth extend forward past the dental pad; it is overshot if the teeth hit in back of the dental pad (this condition is known as parrot mouth). Cull animals (sire and dam) with either of these genetic defects.

Underbite (undershot, reverse scissors bite, prognathism): In this condition, the lower jaw is longer than the upper jaw. If the upper and lower jaw meet each other edge to edge, the bite is referred to as an even or level bite. If the lamb or kid has either an overbite or an underbite, it will not be able to properly nurse, get enough nutrition, eat from the creep feeder, or graze.

Overbite (overshot, parrot mouth, overjet, mandibular brachygnathism): With this condition, the lower jaw is abnormally short. In the newborn, there is a gap between the dental pad and the lower incisors when the mouth is closed. Some animals that are born with an overbite might self-correct if the bite is no larger than the head of a wooden match. In most breeds of sheep and goats, the bites are “set” by the time the newborn is a few months old. An overshot bite will rarely improve after the animal reaches maturity.