AN ANATOMIC STUDY OF THE TENSOR VELI PALATINI AND DILATATOR TUBAE MUSCLES IN RELATION TO EUSTACHIAN-TUBE AND VELAR FUNCTION

In a gross anatomic study of 20 sides in 16 human head specimens, the tensor veli palatini, the dilatator tubae, and the tensor tympani musc les were studied. The tensor veil palatini was observed to insert onto the anterior one-third of the pterygoid hamulus, whereas the dilatato r tubae rounded the middle one-third of the pterygoid hamulus without an insertion. Thus, the dilatator tubae, not the tensor veli palatini, could serve to tense the anterior velum, An insertion from the superi or pharyngeal constrictor muscle onto the posterior one-third of the h amulus could provide a curbing function for the dilatator tubae muscle . Adipose tissue, located at the hamulus, could provide lubrication fo r the tendinous fibers of the dilatator tubae as they round the hamulu s, The dilatator tubae was observed to attach to the hook of the eusta chian tube and is accepted as the tubal dilator. Observed on 13 of 20 sides in 11 specimens, the bulk of the dilatator tubae remained distin ct from the tensor veli palatini despite a connective tissue alliance and intermingling of some muscle fibers. On 5 of 20 sides in 5 specime ns, fibers of the dilatator tubae intermingled extensively with the te nsor veli palatini, Of the 20 dilatator tubae muscles dissected, 2 wer e observed to be deficient, The tensor veli palatini was observed to b e continuous with the tensor tympani. Full color versions of the figur es are available at the following website: http://www.shc.uiowa.edu/pa pers/tensor/.