The palatine fibromucosa is not the same throughout the various regions of the palatine vault and its role differs in maxillary growth. On can in fact distinguish: --the fibromucosa of the "palatine lamellae", thin and smooth, which occupies only the median and posterior portion of the vault, opposite the nasal fossae. Its importance derives from the fact that it covers the medio-palatine and palatino-vomerian suture complex, which has an essential role in transverse, vertical and also sagital maxillary growth; --the palatine maxillary fibromucosa, thick and striated, which surrounds the above as far as the gingiva. It plays a major role in transverse and vertical maxillary growth. In fact, it would appear that it possesses autonomous growth potential; --the "gingival" fibromucosa, smooth, which is located at the alveolar level (from the palatine maxillary to the gingivo-dental border) and is involved in the structure of the latter. A good understanding of the anatomical and physiological aspects of these three fibromucosae has a therapeutic relevance, in particular, in subjects suffering from congenital velo-palatine defects (isolated or associated with a labio-maxillary defect).