![]() ![]() Inadequate growth of the palatine shelves leaves a central defect, in either or both of the hard and soft palates, which communicates between the oral and nasal cavities. At the midline, they fuse with each other and with the nasal septum, and undergo intramembranous ossification, except in their caudal part, which becomes the soft palate. The normal hard palate is formed, except for a small rostral contribution from the frontonasal process, and by the bilateral ingrowth of the lateral palatine shelves from the maxillary processes. ) is often associated with primary cleft palate. Secondary cleft palate (cleft palate, palatoschisis) ( Fig. The defect arises from incomplete fusion of the frontonasal process with the maxillary processes. They may be unilateral or bilateral and superficial or extend into the nostril. Primary cleft palate (harelip, cheiloschisis) includes developmental anomalies of the upper lips rostral to the nasal septum, columella, and premaxilla. A defect extending from a cleft lip to the eye results from failure of fusion of the maxillary and frontonasal processes, which may be a superficial defect with failure of closure of the nasolacrimal duct. ![]() This results from failure of fusion of the lateral portions of the maxillary and mandibular processes. The most common is a complete cleft from one angle of the mouth to the ear of that side. They are variously located, and not all are obviously related to normal lines of fusion. This may leave facial fissures, cleft lip (harelip, cheiloschisis) and unilateral or bilateral primary cleft palate involving the area rostral to the incisive papilla.įacial clefts may involve the skin only, or the deeper tissues as well. A common failure of fusion is that of the maxillary processes to the frontonasal process. These are usually expressed in the newborn in the form of clefts resulting from failures of integrated growth and fusion of these processes. The complexity and duration of this development may lead to a great variety of aberrations. ![]() The development of normal face, jaws, and the oral cavity requires the integration of many embryonic processes, most importantly the frontonasal, maxillary, and mandibular processes. Congenital anomalies may occur as heritable conditions or be the result of nongenetic factors, including toxicity and infectious agents. ![]()
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