Otocephalus: Histopathology and three-dimensional reconstruction

Abstract

Otocephaly is a lethal malformation of the first and second branchial arches, which consists of ventromedial displacement of the external ear structures (synotia), mandibular aplasia (agnathia), absence of the tongue (aglossia), and microstomia. We present the first complete description of the temporal bone findings in a case of otocephalus. A three-dimensional computer-assisted reconstruction of the right temporal bone was performed, allowing a unique graphic analysis. An extremely low-lying middle fossa tegmen was noted with malrotation of the middle ear structures. Severe ossicular malformations were also found. An anomalous course of the internal carotid artery was noted with indentation of the basal turn of the cochlea. All three layers of the otic capsule were incompletely developed. Cochlear bony dehiscences were noted. These findings are consistent with early arrest of fetal development and malrotation caused by lack of growth pressure from the mandibular arch. Implications of these findings in the embryologic development of the ear are discussed.

Transmission of the dysgnathia complex from mother to daughter

“…Only 17 cases of non-syndromal dysgnathia have been published since 1961 [Bixler et al, 1985;Black et al, 1973;Brecht and Johnson, 1985;Hinojosa et al, 1996;Johnson and Cook, 1961;Kamiji et al, 1991;Lawrence and Bersu, 1982;Leckie, 1975;Le Marec et al, 1976;Libersa and Heritier, 1974;Scholl, 1977;Shermak and Dufresne, 1996;Ursell, 1972;Van de Sande, 1966;Woon and Tan, 1979], and only two previous cases of isolated dysgnathia have survived infancy [Kamiji et al, 1991;Shermak and Dufresne, 1996]. Dysgnathia in association with holoprosencephaly, situs inversus, and other anomalies has been reported more frequently [Ades and Sillence, 1992;Carles et al, 1987;Gaba et al, 1981;Machin et al, 1985;Pauli et al, 1983;Porteous et al, 1992;Rolland et al, 1991;Hersh et al, 1989;Pauli et al, 1981;Leech et al, 1988;Meinecke et al, 1990;Persutte et al, 1990;Brown and Marsh, 1990;Dao et al, 1988;LeMaitre et al, 1982;Peiffer et al, 1992;Walker et al, 1995].…”

Agnathia–otocephaly complex: A case report and examination of the OTX2 and PRRX1 genes

“…Absence or hypoplasia of this structure can lead to abnormal positioning of the ears, which remain in their original midline embryonic location. Lack of growth pressure from the mandibular arch can also lead to arrested development and malrotation of middle ear structures and the temporal bone of the skull (Hinojosa et al, 1996).…”

Training and Simulation in Otolaryngology

“…Methods for characterizing the morphology and histopathology of the temporal bone soon followed (Sando 1986). Subsequently these methods were combined with computer-aided reconstruction techniques for visualization and morphometric analysis (Takagi 1988, 1989, Nakashima 1993, Yasumura 1993, Fujita 1994, Sakashita 1995, Sando 1996, Rosowski 1996, Hinojosa 1996, Ikui 1997, Sando 1998). Although specimen preparation and integration of the photomicrographs through manual methods was time intensive, the advantage of three-dimensional reconstructions to demonstrate subtle morphological relationships and changes clearly became evident.…”