Ultrastructural study of the levator veli palatint muscle in cleft palate patients

ABSTRACT

muscle fiber of the soft palate in cleft palate patients may be causally related with of a persistent postoperative velopharyngeal incompetency in some patients, despite a successful palatoplasty. The present study was aimed to ultrastructurally characterize of the levator veli palatini muscle in patients with cleft palate. Biopsies were taken from palatoplasty in 10 cleft palate patients, and observed with electron microscope. In most cases, mild atrophy and broad peripheral collagenous fibrosis were observed. In some cases, changes of muscle fibers in size and form, and features of nonneurogenic myopathy such as fibrosis of peripheral tissue and lysis of muscle cells were observed. Various sizes of abnormal pleomorphic mitochondria could be found, and features of mitochondrial myopathy - muscle cell transformation and distorted arrangement from abnormal deposit of mitochodria - were confirmed. Histologic features were similar between patients who had taken surgical operation previously and those who underwent their first surgery. These results suggest that nonneurogenic myopathy and mitochondrial myopathy should be causally related with a persistent postoperative velopharyngeal incompetency in cleft palate patients.