Abstract
Cleft lip (CL), palate (CP), or both (CLP) are one of the most common congenital abnormalities in humans, causing a heavy burden to the affected and their next of kin. We examined biopsy material from CL of seven children: Six 2 to 6 month-old babies and one 4-year-old boy. The samples were taken at the first surgical cleft lip repair. Light microscopy (LM) haematoxylin and eosin stained paraffin sections and toluidine blue stained 0.5–1 μm Durcupan sections from material processed for transmission electron microscopy (TEM), revealed abnormal “ragged” wavy muscle fibres in all seven children. The routine TEM confirmed our results LM; we found no other changes in the soft tissues in TEM; blood vessels of loose connective tissue and nerve fibres were normal. Therefore, we believe that myopathic changes in the cleft lip muscle fibres cannot be of neuronal origin.