Velopharyngeal nomenclature: incompetence, inadequacy, insufficiency, and dysfunction.

Different usages of the terms velopharyngeal incompetence, velopharyngeal inadequacy, velopharyngeal insufficiency, and velopharyngeal dysfunction that are commonly found in the literature are reviewed. It is advocated that one should not attempt to use any of the terms to distinguish between neuromotor or structural causes for behavioral dysfunction. Although the terms can be used as synonyms, this is not always the case. When terms are used differently, it is important to make the specific usage clear from context.