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Related Experiment Video

Updated: May 4, 2026

Dissection of the Auditory Bulla in Postnatal Mice: Isolation of the Middle Ear Bones and Histological Analysis

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Published on: January 4, 2017

Middle ear malformations in identical twins.

Naoko Kidowaki¹, Toru Kamitani², Takashi Nakamura²

¹Department of Otolaryngology, Otsu Municipal Hospital, Otsu, Shiga, Japan.

Auris, Nasus, Larynx

|December 21, 2013

Summary

Identical twins presented with congenital incudo-stapedial disconnection, a rare middle ear anomaly. Surgical repair improved hearing, suggesting a shared developmental origin for the incus and stapes.

Keywords:

Alternative theory Congenital middle ear malformations Identical twins The lenticular process

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Area of Science:

Otolaryngology
Genetics
Developmental Biology

Background:

Congenital middle ear anomalies are typically isolated and non-hereditary.
Incudo-stapedial disconnection is a rare malformation affecting hearing.

Observation:

Two cases of identical twins with bilateral congenital incudo-stapedial disconnection are presented.
Both patients exhibited conductive hearing impairment.
Computed tomography (CT) confirmed the incudo-stapedial disconnection in affected ears.

Findings:

Surgical exploration revealed absence of the incus's long process and presence of its lenticular process in both twins.
Ossicular chain reconstruction successfully improved hearing in both cases.
The shared anomaly in identical twins suggests a potential genetic or developmental basis.

Implications:

This case series highlights a rare, potentially hereditary, middle ear anomaly in identical twins.
The findings suggest a common embryonic origin for the lenticular process of the incus and the stapes.
Further research into the genetic and developmental factors of incudo-stapedial disconnection is warranted.