title: Middle ear malformations in identical twins.
abstract: The majority of the congenital anomalies of middle ear are solitary and a non-hereditary. We report cases of identical twins with congenital incudo-stapedial disconnection. Case 1 was an 8-year-old girl. Hearing impairment was identified at the age of three. She was referred to our university hospital in April 2005. Pure-tone audiogram showed conductive hearing impairments. Computed tomography (CT) revealed the incudo-stapedial disconnections in both ears. The exploratory tympanotomies on the right and left ears were performed in May and July 2005, respectively. The surgical findings showed absence of the long process and presence of the lenticular process of the incus in both ears. After the reconstructions of ossicular chain, the hearing of both ears improved. Case 2 was an 11-year-old girl. The hearing impairment of the right ear was identified in May 2008. She was referred to our university hospital three months later. Pure-tone audiogram showed the conductive hearing impairment in the right ear. CT revealed the incudo-stapedial disconnection in the right ear. The surgery showed the same findings as those of case 1. Anomalies of both cases suggest that the lenticular process of the incus and the stapes originate from a common primordium.
authors.affiliation: Department of Otolaryngology, Otsu Municipal Hospital, Otsu, Shiga, Japan. Electronic address: naoko-k@koto.kpu-m.ac.jp.
authors.forename: Naoko
authors.initials: N
authors.lastname: Kidowaki
authors.affiliation: Department of Otolaryngology - Head and Neck Surgery, Kyoto Prefectural University of Medicine, Kyoto, Kyoto, Japan.
authors.forename: Toru
authors.initials: T
authors.lastname: Kamitani
authors.affiliation: Department of Otolaryngology - Head and Neck Surgery, Kyoto Prefectural University of Medicine, Kyoto, Kyoto, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Nakamura
authors.affiliation: Department of Otolaryngology - Head and Neck Surgery, Kyoto Prefectural University of Medicine, Kyoto, Kyoto, Japan.
authors.forename: Masakatsu
authors.initials: M
authors.lastname: Taki
authors.affiliation: Department of Otolaryngology - Head and Neck Surgery, Kyoto Prefectural University of Medicine, Kyoto, Kyoto, Japan.
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Sakaguchi
authors.affiliation: Suzuki ENT Clinic, Kyoto, Kyoto, Japan.
authors.forename: Toshihiro
authors.initials: T
authors.lastname: Suzuki
authors.affiliation: Department of Otolaryngology - Head and Neck Surgery, Kyoto Prefectural University of Medicine, Kyoto, Kyoto, Japan.
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Hisa
mesh_terms: D002648:Child; D004200:Diseases in Twins; D004429:Ear Ossicles / Q000002:abnormalities* / Q000601:surgery; D005260:Female; D006311:Hearing Disorders / Q000150:complications / Q000175:diagnosis* / Q000601:surgery; D006314:Hearing Loss, Conductive / Q000175:diagnosis* / Q000209:etiology / Q000601:surgery; D006801:Humans; D007188:Incus / Q000002:abnormalities* / Q000601:surgery; D014430:Twins, Monozygotic
keywords: Alternative theory; Congenital middle ear malformations; Identical twins; The lenticular process