Growth of maxilla in the vertical direction is due to:

 # Growth of maxilla in the vertical direction is due to:

A. Growth of alveolus

B. Growth of sutures

C. Growth of cranial base

D. Growth of synchondrosis

The correct answer is B. Growth of sutures

Vertical growth of the maxilla occurs primarily through inferior displacement facilitated by bone apposition and remodeling at the circum-maxillary sutures (e.g., fronto-maxillary, zygomatico-maxillary, and spheno-maxillary sutures), allowing the maxilla to elongate downward while adapting to surrounding structures like the expanding nasal septum and orbital contents. This mechanism accounts for the majority of vertical maxillary development from infancy through adolescence, with contributions from alveolar apposition around erupting teeth but not as the primary driver. Cranial base growth (via synchondroses) contributes indirectly by providing anteroposterior expansion that influences displacement, but sutural growth is the direct enabler of vertical changes, as supported by classic orthodontic principles (e.g., Enlow's remodeling concepts and Björk's implant studies showing downward vector at ~51° to the cranial base).