This study was undertaken to develop a functional model of otitis media with effusion (OME) in the pig (Sus scrofa), with the purpose of investigating the origin of lymphocytes populating the middle ear during the course of an inflammatory process. The relevance of the model to the human condition of OME is to a large extent dependent on the anatomical and physiological similarities between the middle ear cavity and the pharyngeal lymphoid tissue of the pig and man. Anatomical specimens were collected from 7 young Large White pigs to determine the gross anatomy of the middle ear cavity and the histological characteristics of the middle ear mucosa. It was found that the anatomy of the 3 parts of the middle ear cavity in man and in the pig is broadly similar, although some minor differences were observed. The porcine eustachian tube was seen to be cartilaginous throughout its length in contrast to the part osseous, part cartilaginous structure found in man ; the porcine ossicles were slightly different in shape to those of man and the air cell system was situated inferior to the tympanic cavity in the pig as opposed to posteriorly in man. This paper describes the structure and morphology of the pig middle ear cavity and compares and contrasts it with that of man. The minor differences observed are of anatomical importance but do not diminish the usefulness of the pig middle ear cleft as a potential model for human middle ear disorders.Key words : Otitis media. The pig offers a number of advantages as a model for human pathological processes in that it is omnivorous and many elements of both its anatomy and physiology are similar to those of the human. A large number of monoclonal antibodies have been developed against a variety of pig antigens in recent years, and there is increasing interest in the development of the pig as a xenotransplantation donor for man. These factors taken together mean that the pig is potentially a good model in which to study the immunological processes involved in middle ear inflammation. More specifically, for the purposes of our future studies on lymphocyte homing it is of particular importance that the pig has a full complement of the pharyngeal lymphoid aggregates which constitute Waldeyer's ring in the human. Studies of lymphocyte homing into inflamed middle ear mucosa have been carried out in a number of laboratory Correspondence to Mr J. P. Pracy,

Amyloidosis of the upper aerodigestive tract is rare. However, the larynx is the commonest site within the upper airways to be affected. Three cases of uncomplicated primary amyloidosis of the larynx and one case of laryngeal amyloidosis with more generalized dissemination throughout the head and neck are presented. In this article the different presentations of laryngeal amyloidosis and principles of management of this condition at that site are highlighted.

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Pseudohypacusis is a condition in which a hearing loss is exhibited in the absence of any organic disease. The mainstay of diagnosis is a lack of consistency in audiological testing. It is usually easier to diagnose in children than in adults, as children are less able to produce consistently erroneous results on repeated testing. In spite of this, the diagnosis is often missed in children, probably due to a lack of awareness of the condition. We present the findings in ten children seen in the past year. Initially they had average pure tone thresholds of 51.3 db in the right ear and 51.4 db in the left ear. All of the children underwent repeat pure tone audiometry and speech audiometry. In nine cases the speech audiograms confirmed the diagnosis. In one child the speech audiogram was consistent with a mild hearing loss subsequently confirmed as a 30-40 db low frequency sensorineural hearing loss. Following a programme of close follow up and support, the pure tone thresholds returned to within normal limits in nine children and to a level consistent with the clinical impression in the child with a sensorineural loss. None of the children required brain stem evoked response audiograms to confirm the diagnosis.

Ectopic and supernumerary teeth occur in a wide variety of sites. Those that have been reportedinclude the mandibular condyle, coronoid process, orbit, palate, nasal cavity and the maxillaryantrum. Eruption of teeth into these sites is rare, and easily overlooked. We present two casesin which eruption of teeth into the nose and paranasal sinuses was associated with significant morbidity and show how this was relieved by appropriate surgery.

The aspiration of contrast medium during the investigation of swallowing disorders is a well recognized hazard. It is therefore essential that the contrast medium administered is non-irritant to the lungs. A case is presented to illustrate the problems associated with the aspiration of a relatively non-irritant contrast medium.

No abstract

The treatments previously used for lymphangiomas of the head and neck in children-surgery and intralesional injection of sclerosants-are associated with significant morbidity. A new treatment-intralesional injection of OK-432-was used for lymphangiomas of the head and neck in 11 children. The results were total shrinkage in two, marked shrinkage in two, slight shrinkage in five and no response in two. The results were not affected by previous surgery nor by whether aspiration prior to injection was possible. There were no recurrences in those children in whom shrinkage occurred and no child had subsequent surgery following injection. The results of this series support those of previous series showing that OK-432 injection is an effective and safe treatment for lymphangiomas of the head and neck in children.