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The observation of an interatticotympanic diaphragm in the middle ear (ME) cleft and the functional histology of the mucosa led to a concept of ME morphofunctional partition. There are two separate compartments: an anterioinferior one, principally devoted to the mucociliary clearance function, and a posterosuperior one, more devoted to the gas exchange function. With this concept of partition we are better able to understand the mechanisms involved in the pathogenesis of otitis media. Clinical as well as surgical management is thereby enhanced.

This study concerns the distance between the centre of gravity of blood vessels and the basement membrane of the middle ear cleft mucosa. The measurements were performed perpendicular to the long axis of the cross-section of the vessels, and revealed a significant difference between two regions of the middle ear cleft. At the level of the postero-superior part (epitympanum, aditus ad antrum, mastoid antrum and highest part of the mastoid air cells system), the distance between the blood vessels and the basement membrane of the mucosa was statistically shorter than in the antero-inferior part of the middle ear cleft. This indicates a privileged function of gaseous exchange of the postero-superior part of the middle ear cleft and may divide the middle ear cleft into different functional parts.

The observation of an inter-attico-tympanic diaphragm in the middle ear (ME) cleft and the functional histology of the mucosa lead to a concept of ME morpho-functional partition. There are two separate compartments: an antero-inferior one, principally devoted to the muco-ciliary clearance function, and a postero-superior one, more devoted to the gas exchange function. With this concept of partition the mechanisms involved in the pathogeny of "otitis media" can be better understood.

The pathogenesis of tympanic retraction pockets is analyzed. Middle-ear pressure and the behavior of the lamina propria and stratified squamous epithelium of the tympanic membrane were considered. Predisposing factors are discussed. Conservative surgical treatment is recommended for retraction pockets that are not adhered to the walls of the middle ear. Radical surgery should be reserved for adhered pockets. The management of mastoid cavities is discussed.

The author attempts to analyse the pathogenesis of the retraction pocket. Middle ear pressure, behaviour of both the tympanic membrane lamina propria and the stratified squamous epithelium are considered. Predisposing factors are presented. A conservative surgical treatment is suggested in cases of non-fixed retraction pockets; a radical surgical treatment is reserved for the fixed pockets. The management of mastoid cavities is discussed.

The tympanic membrane allograft myringoplasty is used for the radical treatment of chronic middle ear disease and the repair of tympanic perforations which are sequellae of the chronic middle ear conditions. In the first part, basic principles, tissue bank and surgical procedures, are explained in detail. The second part shows that this technique ensures not only total eradication of the pathology, but is favoured by the specific morpho-, physio- and bio-compatibilities of the allograft.

This article deals with the morphological as well as histological changes of the tympanic membrane and bone from early embryological life until mature age. An overview of the continuous changes is given with reference to pertinent clinical implications.

The mechanisms which govern under normal conditions the balance of middle ear pressure are discussed. The regular periodic active process of gas transfer through the Eustachian tube, the steady gas diffusion between middle ear and blood compartment and finally the pressure buffer role played by the mastoid are successively considered.

In this paper we present the results of an etiological study in 155 hearing-impaired children and young adults, born between 1960 and 1984, inmates of the IRSA institute (Royal Institute for Deaf and Blind children). Special reference to genetic factors was given. One third of the inmates of this institute were children of immigrants, the majority Italians and North-Africans. The study revealed the following classification for the Belgian pupils: hereditary deafness 22.9%; acquired deafness 44.9% and deafness of unknown origin 32.1%; in the group of immigrants, it was 39.1%, 45.6% and 15.2%, respectively. Six of the 45 patients with a genetic form of deafness presented a distinct syndrome, Usher syndrome (2 patients) being the most frequent. Autosomal dominant inheritance was present more often in the deaf population than in the hearing-impaired population (hearing loss below 80 db), but the difference was not statistically significant. Even after 1980 congenital rubella remained the most frequent exogenous factor causing congenital deafness and, furthermore, we documented for the first time in a retrospective study cytomegalovirus infection as a cause of hearing loss. Atypical retinal abnormalities not related to congenital rubella syndrome were found in 10 inmates by systematic ophthalmological examination: 7 in the unknown group, 1 in the genetic group and 2 in the acquired (meningitis) group.

The experience with 1.645 transplantation procedures by ENT surgeons, trained in tympano-ossicular allograft technique following J. Marquet, is reported. The grafts originated from different tissue banks. The anatomical and functional results one year postoperatively were analysed. There appeared to be no statistical differences between tissue banks, nor between surgeons. Contrary to the anatomical results, functional differences existed between allograft tympanoplasties and some types of allograft tympano-ossiculoplasties. It was concluded that the routine use of allograft tympano-ossiculoplasty offers a major tool in otological surgery and that it is the method of choice by the ENT surgeons trained by the School of J. Marquet.

The morphogenesis of the tympanic part of the temporal bone The aim of this report is to describe the relative movement of the tympanic membrane and its supporting structures during embryonic and postnatal life, leading to its final position in a vertical plane. Previous studies were based on ultra thin sections which led to changes in orientation during development being missed. The importance of the present description is to provide a baseline with which abnormal ear development in certain congenital syndromes may be compared.

Basic information on the healing process of tympanic membrane perforations is scarce and sometimes contradictory. So the histological and histopathological course of the closure of tympanic membrane perforations was studied in experiments on mice and hamsters. From this investigations it seems evident that traumatic tympanic membrane perforations close nearly always spontaneously in animals. This fact must be kept in mind in the evaluation of techniques and results of tympanoplasties in animal experiments. Furthermore the squamous epithelium of the eardrum plays an important role in the regeneration of tympanic perforations. The closure of the connective tissue defect has always a tendency to lay behind the healing of the epithelial layer. This mechanism differs from the normal healing process of skin wounds where the squamous epithelium migrates over a newly formed granulation tissue layer. On the basis of these findings some practical considerations can be made on tympanoplasties in human.

The aim of this study is to point out some anatomical and physiological characteristics concerning the tympano-ossicular system, in the view to contribute to the elaboration of an optimal prosthesis of the middle ear.

Different tests for evaluating the residual speech perception in deaf people are presented. First results obtained with different groups of deaf people are discussed.

Morphological analysis of the tympanic part of the temporal bone has lead us to comment a particular structure: the foramen of Huschke. This foramen is founded during the embryological development and results from the growth and fusion of two tympanic tubercles. The foramen of Huschke normally closes up like a diaphragm before the age of five years. It may however, persist in a few rare cases (2/300).

Although an apparently limited subject, bone tissue in the middle ear, its structure and development, is a relatively vast one and there is no question of discussing it in detail here. On the other hand, many points still remain obscure and research workers find it sometimes difficult to understand each other clearly. We shall therefore dwell on a few points which deserve both emphasis and clarification.

This study was carried out on 100 tomograms of the petrous bone using Guillen's transorbital view of the anatomy of the middle ear. It provides basic data concerning the morphology, size and surface area of the tympanum, the epitympanum and the hypotympanum. It correlates the surface area of the epi- and hypotympanum, and suggests certain embryological interpretation. This study contributes to the diagnostic radiology of the middle ear in the following ways: 1 It provides basic data for the interpretation of tomograms in patients with ossicular dislocation. 2 It provides essential data for the radiology of congenital malformation and of tumours. 3 It puts in perspective certain criteria used for the diagnosis of cholesteatoma. Finally, this study justifies the use of preoperative radiological investigation.

The purpose of our work was to analyze the morphology and the physiology of the tympano-ossicular allografts used for reconstruction of the middle ear. The first section of the article concerns the removal and preservation of the allografts. We then describe the results of the morphologic observations concerning the tympanic membrane, the fibrocartilaginous ring, meatal skin, and ossicular chain. The demonstration of some characteristics of the physiology of the allograft supports the results of this study.