231. What is a cleft palate?It is a failure of the two halves of the roof of the mouth, or palatal shelves, to join in the midline and fuse. The cleft may involve the soft palate or both soft and hard palates.2. Explain the terms primary and secondary palate, and prepalatal and palatal structures.The incisive foramen, which is located behind the incisor teeth, is the site where the lateral maxillary bones meet the midline premaxilla. A cleft lip usually involves structures anterior to the incisive foramen, such as the alveolus, lip, and nasal tip cartilages, as well as the floor of the nose. These structures usually are referred to as the structures of the primary palate or prepalatal structures. They may be cleft unilaterally or bilaterally.The structures posterior to the incisive foramen, including the hard palate, soft palate, and uvula, usually are referred to as the secondary palate or palatal structures. Thus the incisive foramen separates the primary (prepalatal) and secondary (palatal) structures. What is the premaxilla?The premaxilla is the alveolar segment of the maxilla that includes the nasal spine and four incisor teeth. It is located centrally and anterior to the incisive foramen.

2016-12-24T18:13:07