The facial nerve is highly tortuous and has the longest course through a bony canal among all body nerves. Its course shares similarities and variations with other middle ear structures, making it susceptible to iatrogenic injuries during ear surgeries. This study aims to analyse the facial nerve's course and variations through the temporal bone, observing average morphometric values in relation to surrounding structures. Conducted at KLES Dr. Prabhakar Kore Hospital, Belagavi, this study utilized 25 wet cadaveric temporal bones obtained from fresh cadavers at J. N. Medical College. Dissections were performed to study the facial nerve's course and its variations, along with morphometric comparisons to other intratemporal structures. The greatest variation was found in the depth of the second genu, measured by adding the short process of incus to the spine of Henle and short process of incus to the second genu, ranging from 12.6 mm to 19.2 mm. The lengths of the mastoid (9.80 mm) and tympanic segments (5.71 mm) were relatively consistent. The processus cochleariformis was a reliable landmark for the tympanic segment. Isolated facial nerve anomalies are rare and typically occur with other middle ear developmental anomalies. Minute morphometric variations, however, can lead to iatrogenic injuries. While advanced imaging aids in identifying these variations, temporal bone dissection remains crucial for otologists to avoid injuries and address nerve pathologies effectively.

The aim of this study was to present a comprehensive three-dimensional (3D) morphology of the petrous bone with computer image-processing technology, which could be beneficial for the teaching of anatomy and for surgical procedures. The unstained celloidin sections of human temporal bone were digitized with high resolution and quality, and then processed with Amira® software to include alignment, segmentation and reconstruction. The integral structure of the human inner ear was presented with computer modeling, including the petrous bone, bone labyrinth, internal carotid artery canal, internal jugular vein canal, sigmoid sinus, inferior petrosal sinus, glossopharyngeal meatus, vagal meatus, internal acoustic meatus, facial nerve canal, greater superficial petrosal nerve, vestibular aqueduct, extraosseous portion of the endolymphatic sac, round and oval window, processus cochleariformis and pyramidal eminence. The 3D model showed detailed structure of the external and internal petrous bone, as well as their spatial relationship. The present study suggests the feasibility of comprehensive 3D reconstruction of the petrous bone using unstained celloidin sections, which may provide advantages for future study.

Anatomical characteristics of the fossula fenestrae vestibuli were tested and analysed precisely on 200 samples of temporal bones. The fossula is usually ovoid and shallow but can be, exceptionally, elongated, narrow and deep. It is surrounded by four walls. In 45.5 per cent of cases the upper wall is formed only by the facial canal and in 54.5 per cent of cases a bony lamella is found beneath the facial canal; the promontory forms the lower wall; the front wall is formed by the bony lamella and part of the processus cochleariformis; the back wall is clearly defined in only 22.8 per cent of cases and is formed by the bony lamella of the medial wall of the tympanic cavity. In 13.2 per cent of cases the floor of the fossula partially covers the prominence of the facial canal and in two per cent the eminentia pyramidalis. Bony recesses in this region occur fairly frequently: sinus subfacialis in 60 per cent, sinus retrofenestralis in 77.2 per cent, and sinus subrostralis in 25 per cent of the cases. These anatomical variations can influence the result of surgical intervention.

Cholesteatomas, arising within the middle ear space behind an intact tympanic membrane, have been detected more frequently in recent years. This article reviews 19 children (with a mean age of 4.3 years) who underwent surgery over a 7-year period for removal of cholesteatomas from behind intact tympanic membranes. Most of these children were referred by pediatricians who had detected an asymptomatic whitish middle ear mass. Many had histories of treatment for otitis media. Patients with similar histories were excluded from the series if there had been a prior perforation, myringotomy, or otologic surgery. In the series, one fourth of the children had associated congenital malformations, and there were 3 times as many boys as girls. In two thirds of the cases, the cholesteatoma was manifested as an anterior-superior middle ear mass that seemed to arise from the processus cochleariformis, undersurface of malleus area. Many could be removed via an extended anterior tympanotomy operative approach. The results of surgery are reviewed. The possible origins of these localized cholesteatomas are considered. Are they congenital defects that arise from misplaced keratinizing epithelium? Do they arise from mesenchymal cells whose differentiation is stimulated by inflammatory changes within the middle ear?

In a boy of 10 with primary cholesteatoma of the right ear the following anomaly of the facial nerve was demonstrated: The nerve enters the mastoid posteriorly to the labyrinth, in Trautmann's area, there it makes a right-angled turn forward and runs in a horizontal, slightly upward direction through mastoid and antrum, crossing the lateral canal, via the epitympanum in close relation to body of incus and head of malleus, in which it had moulded a groove. It leaves the epitympanum superiorly to the processus cochleariformis, and joins the geniculate ganglion; from there completely normal course in tympanic and mastoid portion of Fallopian canal. The nerve could be preserved. Its identity was confirmed by electric stimulation. There were no other anomalies. The embryologic, forensic and surgical aspects of this anomaly are discussed. Reference is made to the paper of Prentiss and Dean 1905, the only known observation that resembles this case in some aspects.