Oral and Maxillofacial Surgery (OMFS) Board Practice Exam

DiGeorge syndrome is primarily associated with the failure of the development of the third and fourth pharyngeal pouches during embryonic development. These structures are critical as they contribute to the formation of key components of the immune system, particularly the thymus and certain cells of the parathyroid glands. When these pouches do not develop properly, it results in the characteristic features of DiGeorge syndrome, which include immune deficiencies due to thymic hypoplasia or aplasia, hypoparathyroidism, and various cardiac defects.

Furthermore, the implication of failures in the development of the first and second pharyngeal pouches, while important for other structures (such as the formation of certain parts of the middle ear and tonsils), is not directly linked to the features of DiGeorge syndrome. Rather, those failings lead to different developmental disorders. Similarly, failure limited only to the thymus would not encompass the full spectrum of DiGeorge syndrome, as parathyroid dysfunction and heart defects also play a significant role in the condition. The palatine tonsils, although significant in immune response, do not capture the broader implication of the syndrome’s manifestations orchestrated by the third and fourth pouches' development. This makes the choice reflecting the failure