Developmental anomaly of the process of Folius.

We present four cases of an ossicular anomaly considered to consist of an abnormality of the anterior process and manubrium mallei (malleus handle). In one case, a thick bony bar was found extending from the neck of the malleus which fused with the posterior bony wall or the tympanic bone. No trace of the short process and umbo of the malleus was recognized. In two other cases, a similar bony bar was seen as well as a cartilaginous malleus handle that apparently was attached to the anterior part of the bony bar. On the basis of these findings, the bony bar was assumed to represent abnormally developed mesenchyme bone (os goniale), which later develops into the anterior process of the malleus. In the last case, no bony bar was seen, but a V-shaped ossicle was recognized, one end of which was connected to the malleus head by fibrous tissue. Since this abnormally shaped ossicle was bony and hard and no trace of the short process and umbo characteristic of the handle of the malleus was found, it was though to be an abnormally developed os goniale.