dental technician, or in some cases is performed by lay persons, including owners or trainers. Problems with dentition for horses in work can result in poor performance or behavioural issues, and must be ruled out as the cause of negative behaviours in horse. Most authorities recommend regular checks by a professional, normally six monthly or annually. Problems due to wear patterns The wear of the teeth can cause problems if it is uneven, with sharp points appearing, especially on the outer edge of the molars, the inner edge of the premolars and the posterior end of the last molars on the bottom jaw. Other specific conditions relating to wear include a "step mouth", where one molar or premolar grows longer than the others in that jaw, normally because the corresponding tooth in the opposite jaw is missing or broken, and therefore could not wear down its opposite, a "wave mouth", where at least two molars or premolars are higher than the others, so that, when viewed from the side, the grinding surfaces produce a wave-like pattern rather than a straight line, leading to periodontal disease and excessive wear of some of the teeth, and a "shear mouth" when the grinding surfaces of the molars or premolars are severely sloped on each individual tooth (so the inner side of the teeth are much higher or lower than the outer side of the teeth), severely affecting chewing. Horses may also experience an overbite/brachygnathism (parrot mouth), or an underbite/prognathism (sow mouth, monkey mouth). These may affect how the incisors wear. In severe cases, the horse's ability to graze may be affected. Horses also sometimes suffer from equine malocclusion where there is a misalignment between their upper and lower jaws. The curvature of the incisors may also vary from the normal, straight bite. The curvature may be dorsal or ventral . These curvatures may be the result of an incisor malocclusion (e.g. ventral=overbite/dorsal=underbite). The curvature may also be diagonal, stemming from a wear pattern, offset incisors, or pain in the cheek teeth (rather than the incisors), which causes the horse to chew in one direction over the other. Other dental problems Other common problems include abscessed, loose, infected, or cracked teeth, retained deciduous teeth, and plaque buildup. Wolf teeth may also cause problems, and are many times removed, as are retained caps. Prevention of dental problems To help prevent dental problems, it is recommended