Experimental evidence suggests that altered muscular function can influence craniofacial morphology. The switch from a nasal to an oronasal breathing pattern includes functional adaptations that include an increase in total anterior face height and vertical development of the lower anterior face. While some animal studies have suggested predictable growth pat­terns may occur, studies in human subjects have been much more controversial. Therefore, individual variations in response should be expected from the alteration of a long face syndrome patient's breathing mode. [Reprinted from The Angle Orthodontist, Fall 1990, vol. 60, pages 167-176]


airway, lower anterior face height, long face syndrome