Shedding deciduous teeth can be a source of oral irritation in horses that are 2–5 years old. Deciduous teeth in horses are referred to as "caps", and can become loosened, displaced, or fractured, leading to problems with mastication and biting. Abnormal eruption of permanent teeth is commonly a sequela of mandibular or maxillary trauma—eg, incisor avulsion fractures in cattle and horses in which the developing dental bud of the permanent tooth is damaged by the fracture itself or by the repair process. In horses, delayed eruption or impaction of cheek teeth is a common cause of periapical infection. Medial displacement of the third cheek tooth is another form of abnormal eruption due to overcrowding.