幼小児鼓膜内軟骨組織についての検討

抄録

The cartilage was found in the tym nic membrane of 10 temporal bones (7 cases) out of 173 temporal bones (93 cases) from cadavers of children aged under 10 years. In the tympanic membrane the cartilage was noted in the connective tissue layer of the postero-superior quadrant of the tense portion, especially around its uppermost area. The age of 4 out of 7 cases was under 1 month. The cause of death was mostly congenital diseases. However, no abnormality was noted in the middle and inner ears except for the presence of the residual mesenchymal tissue in some parts of the middle ear cavity. Other parts of the tympanic membrane and the auditory ossicles were normally developed and appeared normal. The cartilage in the child tympanic membrane may be a remnant tissue in the developmental process of the malleus. The significance of the cartilage in the tympanic membrane was discussed from the viewpoint of embryology of the auditory ossicles and the tympanic membrane.