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Despite the high success rate of autologous grafts in tympanic membrane repair, clinical alternatives are required for the closure of unresponsive chronic perforations that can lead to recurring infection and hearing loss. Tissue engineering and regenerative medicine approaches have emerged as another strategy to repair the eardrum, in addition to negating the need for donor tissue harvest and related surgical iatrogenicities. This review highlights the main approaches using biomaterials, growth factors, and cell therapies towards the healing of complex TM perforations. In addition, we discuss the challenges and advances for the development of reliable animal models, which will allow the optimisation and development of novel techniques. Finally, we indicate technologies that are currently used clinically and others that are closer to the market. The advances here discussed on tissue engineering and regenerative medicine strategies applied to the field of TM perforations will allow otologists, surgeons, and researchers to better bring novel technologies to the bedside as well as to develop new ones., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2022 Published by Elsevier Ltd.)

The design of ventilation tubes or grommets is thought to have a considerable influence on their performance. A computational model (finite element method) was used to investigate the significance of four design parameters of a commonly used design of ventilation tube. The design parameters were: the length of the shaft, the diameter of the flanges, the thickness of the flanges, and the material type. A statistical analysis technique, known as a factorial analysis of variance, was used to examine the importance of the four design parameters on the dynamical behaviour of the middle ear with the implant in situ and on the magnitude of stress induced at the implant/tympanic membrane interface. We predicted that the ventilation tube alters the frequency response of the middle ear; specifically the shaft length and the thickness of the flanges were found to have a significant effect upon the vibratory pattern at the umbo. A reduced length of tube and an increased size of flange were also found to be significant for minimising membrane stress (both with P<0.001). Thus, design parameters of critical influence on optimising performance were identified.

Objective: It has been suggested that fracture of the hamulus during palatoplasty in children with cleft palate may lead to adverse otological sequelae, however, there is little evidence to support this., Study Design and Setting: The otological records of 42 children with repaired cleft palate (excluding submucous cleft palate) aged 8 years old or older were examined. A questionnaire regarding the incidence, treatment, and outcome of middle ear problems was completed by the parents of 68 children with repaired cleft palate, aged 9 years old or older., Results: There was no significant difference between children who did and did not undergo hamular fracture with regard to tympanic membrane appearance, audiometry, history of ear problems (P = 1.000), ear infections (P = 0.622), ventilation tube insertion (P = 0.532), or surgery for chronic otitis media (P = 1.000). Parents of children not undergoing hamular fracture reported a higher incidence of below normal hearing (P = 0.023).Conclusion and significance There is no evidence that hamular fracture during palatoplasty affects long-term otological outcome in cleft palate.

Objective: To examine the incidence and natural history of middle ear disease in children with congenital velopharyngeal insufficiency (VPI) without cleft palate., Setting and Subjects: Children with congenital VPI attending the combined cleft clinic at a tertiary cleft center. The diagnosis of congenital VPI in all cases was confirmed be the observation of hypernasality, nasal air escape, or both by a speech and language therapist and the demonstration of incompetence of the velopharyngeal sphincter by means of nasoendoscopy or videofluoroscopy. Children with overt cleft palate or postsurgical VPI were excluded., Design: The children's medical records were reviewed, and a questionnaire regarding history of ear problems was sent to all parents. Children were divided into those with Pruzansky type I VPI (showing bifid uvula, midline diastasis of soft palate, or submucous cleft of the hard palate) and Pruzansky type II VPI (no visible stigmata)., Main Outcome Measures: Incidence of reported ear problems, ear infections, hearing loss, and surgical intervention for middle ear disease in the whole group and in each of the subgroups., Results: Seventy-one parents returned completed questionnaires. The overall incidence of middle ear disease was 63%, with 28% reported to have below-normal hearing. There was no significant difference between children with Pruzansky types I and II VPI with respect to incidence of otopathology or hearing loss., Conclusions: Irrespective of the presence of any visible palatal abnormalities, children with congenital VPI showed a substantial incidence of otopathology and should thus be closely monitored.

Objective: Otitis media with effusion is known to be very common among children with cleft palate, however, less is known regarding the natural history and outcome in this group. The purpose of the present study was to examine the incidence, natural history, treatment, and outcome of middle ear disease in children with clefts., Methods: A questionnaire was sent to the parents of all children registered on the cleft lip and palate database at our institution. The medical records of all respondents were also reviewed. Statistical analysis of the results was performed using Fisher's exact test in contingency tables and binary logistic regression analyses, where appropriate., Results: 397 fully completed questionnaires were returned. Ear disease was much more common in children with cleft palate, or cleft lip and palate, than in children with cleft lip. Among children with cleft palate, ear problems (infections and/or hearing loss) were most prevalent in the 4-6-year-old age group. However, ear problems persisted at a substantial level for many years after this; only after the age of 12 years did problems appear to settle. The incidence of below normal current hearing and of surgery for chronic otitis media was significantly related to history of ear infections (P=0.000 and 0.000, respectively), and to increased number of ventilation tube insertions (P=0.000 and 0.000, respectively)., Conclusions: Middle ear disease is common in children with cleft palate, and, unlike the case for children without clefts, has a prolonged recovery, and a substantial incidence of late sequelae. The higher incidence of below normal hearing and surgery for chronic otitis media in children undergoing a greater number of ventilation tube insertions, although most likely reflecting an increased underlying severity of otitis media in these children, also underlines the lack of long-term benefits of ventilation tubes in this group.

Hypothesis: It was hypothesized that the differences in the bioacoustic performance of ossicular replacement prosthesis designs, and insertion positions, could be quantified using finite element analysis., Background: Many designs of prosthesis are available for middle ear surgery. The materials used, and the shape of the implants, differ widely. Advances in computer simulation technologies offer the possibility of replicating the in vivo behavior of the different prostheses. If this can be achieved, insight into the design attributes required for improved biofunctionality may be gained., Methods: Micro-computed tomography and nuclear magnetic resonance imaging were used to obtain geometric information that was translated into a finite element model of the outer and middle ear. The forced frequency response across the hearing range of the normal middle ear was compared with the middle ear reconstructed with partial and total ossicular replacement prostheses., Results: The amplitude of vibration of the footplate was more similar to that of the normal ear when a Kurz total ossicular replacement prosthesis was implanted than when a Xomed total ossicular replacement prosthesis was implanted. This may be attributed to the latter's titanium link. Partial ossicular replacement prostheses were stiffest and had lower umbo vibrations and higher stapedial footplate vibrations. In all cases but one, the vibration of the prostheses had resonances that caused the vibration of the stapes footplate to be noticeably different from normal., Conclusion: The authors confirmed the hypothesis that finite element modeling can be used to predict the differences in the response of ossicular replacement prostheses. This study shows that computer simulation can potentially be used to test or optimize the vibroacoustic characteristics of middle ear implants.

Otitis media with effusion is a common finding in children with cleft palate. However, although middle ear effusions have been reported to be almost universal among infants with cleft palate, less is known regarding the epidemiology, natural history, and outcome of middle ear disease among older children with cleft palate. Furthermore, considerable controversy surrounds the management of otitis media with effusion in these children: many authors have advocated a policy of early or scheduled ventilation tube insertion on account of the high incidence of hearing loss and speech difficulties; others have advocated a more conservative policy on account of the high incidence of complications from ventilation tubes and lack of evidence supporting a policy of early intervention. In the present paper, we review the epidemiology, aetiology, and natural history of middle ear disease in children with cleft palate. We also discuss the controversies involved in the management of these patients.

Otitis media with effusion (OME) is common among children with cleft palate, and may lead to such long-term consequences as hearing loss, tympanic membrane retraction, and chronic otitis media (COM). In total, 104 children with cleft lip and/or palate treated for OME at our institution were reviewed. Mean duration of follow-up was 6.9 years, and mean age at latest follow-up was 9.6 years. The incidence of COM was 19%, and the incidence of cholesteatoma was 1.9%. Ears showing such long-term sequelae of OME as hearing loss, tympanic membrane retraction, and chronic otitis media, were noted to have undergone a significantly greater number of ventilation tube insertions than ears not showing these sequalae. Our findings would suggest that a conservative approach to the management of OME in children with cleft palate is more likely to be beneficial in the long term.

Aims: There is increasing evidence that pseudoexfoliation (PXF) not only affects ocular anterior segment structures, but may also be a systemic disease. This study was undertaken to assess the relationship between PXF and sensorineural hearing loss., Methods: Patients with PXF were identified from hospital records and underwent complete ocular examination. The sum of pure-tone hearing thresholds measured at 1, 2 and 3 kHz (HTL1,2,3) in each ear was compared with the ISO 7029 standard sex-matched, median age-associated hearing loss summed over the same frequencies (AAHL1,2,3). The proportion of ears with thresholds higher than the ISO 7029 median AAHL1,2,3 on the same side as eyes without PXF was compared with the proportion of ears ipsilateral to eyes with PXF but without glaucoma and similarly the proportion of ears on the same side as eyes with PXF and glaucoma., Results: In total, 69 patients were studied, of whom 39 were male (56.5%). The mean age of the male patients was 75.8 years, while that of the female group was 75.1 years. All patients had PXF affecting at least one eye. Overall 101 ears (73.7%) had a higher HTL1,2,3 than the ISO 7029 median AAHL1,2,3 which included 56 ears of 78 in the male group (71.8%) and 45 ears of 59 in the female group (76.3%). There was no significant difference between the proportion of ears with HTL1,2,3 higher than the ISO 7029 median AAHL1,2,3 on the same side as eyes without PXF, with PXF but not glaucoma and with PXF and glaucoma, in either the male or female groups., Conclusions: A large proportion of patients with PXF have sensorineural hearing loss in comparison to age-matched controls, regardless of whether or not there is associated glaucoma. This finding supports the theory that PXF may be a systemic condition.

Acute post-operative pulmonary embolism is a serious potentially life-threatening complication which is not anticipated in young patients undergoing non-major surgery. We report a case in which a 32-year-old previously healthy woman developed a major pulmonary embolism following tonsillectomy. Subsequent investigations revealed the presence of an occult malignancy. This case highlights the role of paraneoplastic hypercoagulable states in the aetiology of venous thromboembolism and the importance of thromboprophylaxis in the presence of confirmed or suspected malignancy. To our knowledge no case of major pulmonary embolism occurring after tonsillectomy has been previously reported.

Finite element analysis is used to determine the mechanical behaviour of structures. The deformation of a structure caused by a force can be calculated, and the stresses and strains within the component can be found. In brief, a geometric representation-a 'drawing'-of the structure is loaded into a computer, and a component is divided into 'elements' which usually have the shape of 'bricks'. A common analogy is a 'lego' brick assembly. The deformation of an element can be determined using engineering formulae, and the deformation of the whole structure can be determined when the elements are re-asssembled. There have been very few analyses of the biomechanical behaviour of ventilation tubes, or grommets, even though clinical studies have indicated that tube design and material determines extrusion rates and may influence tympanosclerosis. This paper reports a comprehensive biomechanical analysis of the effect of a grommet on the tympanic membrane. Analytical and computer simulation techniques (finite element analysis) are used to determine the changes in the vibratory motion and stresses in the membrane when a Reuter-Bobbin ventilation tube is inserted. It is found that the presence of a ventilation tube significantly affects the motion of the membrane in the neighbourhood of the implant. When the effect of implant material is investigated, it is found that the amplitude of motion of a heavier metal implant is less than a lighter polymeric implant. If it is true that higher motion predisposes towards early extrusion, then the lighter implant (polyethylene) is predicted to have a higher extrusion rate. Regarding the maximum stresses in the tympanic membrane, they form a crescent-shaped region in the anterior and posterior quadrants in the regions where tympoansclerosis is observed. The magnitude and pattern of the stress is predicted not to depend significantly on the presence of the tube. This suggests that tympanosclerosis is not determined by the implant per se and therefore that no tube design feature can be expected to prevent it.

In this study, a computer-based method called finite-element analysis is used to predict the forced-frequency response of the ear, with and without an ossicular replacement prosthesis (PORP 0362, Xomed Surgical Products). The method allows visualisation of the dynamical behaviour of the tympanic membrane (TM) and of the ossicles. The finite-element model is fully three-dimensional and includes both ligaments and muscles, and accounts for damping caused by the TM, ligaments, incudostapedial joint and the fluids of the inner ear. For validation, comparison is made with experimental measurements of umbo displacement taken from the literature. The translation and rotation (both anterior-posterior and inferior-superior) of the stapedial footplate are investigated. It is predicted that the translatory motion of the footplate decreases with increasing frequency, except when the frequency of the acoustic signal matches the natural frequencies of the ossicular chain or outer ear canal. The tilting motion of the stapedial footplate is also predicted to depend on frequency of excitation. The presence of a prosthesis changes the dynamical response considerably by shifting the natural frequencies of the ossicular chain. Ratios of stapes motion with and without the prostheses are plotted as a function of frequency allowing this effect to be clearly observed.

Medical device technology has an increasingly important role in surgical procedures. In this article, five case studies of bioengineering in surgery are described as follows: computer-aided design of vascular grafts; middle-ear prostheses; hip prosthesis stems for optimal cement pressurisation; prototype development of a device for measurement of abdominal sounds for monitoring digestive tract activity and a hand-access device for laparoscopic surgery. In each case, new bioengineering design methodologies are demonstrated. The general principles underlying the application of bioengineering in surgery are discussed.

For many years, the retrolabyrinthine approach has been limited to functional surgery of the cerebellopontine angle (CPA). As a result of the increased surgical exposure, particularly the opening of the internal auditory meatus (IAM), the widened retrolabyrinthine technique permits tumor excision from both the CPA and the IAM, regardless of the histological nature of the tumor. The authors have treated 60 acoustic neuromas of varying sizes via this approach (6% intrameatal tumors; 30% > 25 mm in diameter). The postoperative mortality rate was 0%. The risk of fistula formation was 3.3%, and 3.3% of the patients suffered from postoperative meningitis. The results for facial nerve function were equivalent to those obtained previously via a widened translabyrinthine approach and those in a series treated via a suboccipital approach (80% with Grades I and II, 15% with Grade III, and 5% with Grades V and VI). One patient (1.7%) required a secondary hypoglossal-facial nerve anastomosis and had attained a Grade IV result 6 months later. Postoperatively 21.7% of these patients maintained socially useful hearing and 20% had mediocre hearing. Socially useful hearing was preserved in 50% of a subgroup of 20 patients who had both good preoperative hearing and a tumor that involved less than half of the IAM regardless of its volume. Additionally, 15% had mediocre hearing that could be improved with hearing aids. Because of its efficacy in preserving hearing, the authors favor the retrolabyrinthine over the occipital approach, with the latter being considered less subtle and more aggressive.

This work makes use of recent finite element discretization of the human tympanic membrane where the known anisotropy of the tympanic membrane is implemented by a series of thin beam elements superimposed on thin shell membrane elements. These thin beam elements were introduced in order to simulate the fibre structure of the tympanic membrane. The onset of tympanosclerosis has been modelled as a gradual increase in tympanic membrane density and modulus in the affected area. This increased density results in a fall of 55% of the first natural frequency for only a 16% area of drum sclerosis. Additionally the amplitude response is significantly reduced. Repair of the membrane was simulated by removal of the fibre system from the affected area. Under these circumstances the natural frequencies virtually return to the healthy state but the mode shapes of vibration do not. The repair to the membrane, although not significantly altering frequency values, has resulted in a disruption to the normal mode shape patterns with consequences in the movements conveyed to the stapes and cochlear fluids.

This study was undertaken in an attempt to better understand the mechanics of sound transmission at the footplate following stapedotomy. The insertion of a Teflon (polytetrafluoroethylene) stapes prosthesis introduces new constraints within the reconstructed ossicular chain which have an effect on the normal vibration patterns of the tympanic membrane. In a finite element model of the ear, constraints have been reproduced as a series of spring constants in the incus/prosthesis/footplate interfaces incorporating damping to simulate the impedance of the inner ear. At zero damping, the frequency response at the pseudo stapes footplate exhibit several maxima and minima between 800 Hz and 2.5 Hz. At higher damping values, these maxima and minima become smoothened out with two or three naturals occurring over the same frequency range. Severe ankylosis of a diseased footplate is reproduced by over-damped conditions. The umbo, incus and stapes footplate vibrate in phase with similar frequencies at light damping levels. The movement of the prosthesis at the pseudo-footplate can be large in the out of plane axis of the ossicular chain, unless sufficient support is provided at the reconstructed footplate. Clinically, this would suggest the vein graft interposed between the piston and stapedotomy hole should endow resistance and elasticity to the system.

A prospective study evaluating the benefits of preoperative ultrasonography of paediatric neck abscesses is presented. Twenty-three consecutive children who presented with suspected neck abscesses to the Accident and Emergency Department at the Temple Street Children's Hospital between 1990 and 1992 have been evaluated prospectively. On admission, ultrasonography showed a collection of pus in 11 children and these underwent incision and drainage. The other 12 had intravenous antibiotics. Six of these remained pyrexial and had a repeat ultrasound after 72 h revealing pus which was drained. The remaining were managed successfully with medical treatment. In this study there were no negative surgical interventions and we recommend ultrasonography for preoperative evaluation of children with suspected inflammatory neck abscesses.

Infection is a well-recognized triggering factor for both guttate and chronic plaque psoriasis. We investigated prospectively 13 patients with recalcitrant psoriasis exacerbated by recurrent tonsillitis, who underwent tonsillectomy between 1990 and 1993. There were 12 female patients and one male, with a mean age of 17 yr (range 6-28). Six patients had guttate psoriasis resistant to standard treatments and seven patients had chronic plaque psoriasis exacerbated by tonsillitis that was severe enough to warrant at least one admission to hospital. Patients were followed by chart review and postal questionnaire. Psoriasis was cleared completely after tonsillectomy in five out of the six patients (83%) with guttate psoriasis and was improved in one patient. Two out of seven patients with plaque psoriasis (29%) were cleared, two (29%) were improved and three (42%) were unchanged. We conclude that tonsillectomy may be a successful treatment modality in selected patients with recalcitrant guttate or chronic plaque psoriasis.

A representative finite element model of the healthy ear is developed commencing with a description of the decoupled isotropic tympanic membrane. This model was shown to vibrate in a manner similar to that found both numerically (1, 2) and experimentally (8). The introduction of a fibre system into the membrane matrix significantly altered the modes of vibration. The first mode "remains as a piston like movement as for the isotropic membrane. However, higher modes show a simpler vibration pattern similar to the second mode but with a varying axis of movement and lower amplitudes. The introduction of a malleus and incus does not change the natural frequencies or mode shapes of the membrane for certain support conditions. When constraints are imposed along the ossicular chain by simulation of a cochlear impedance term then significantly altered modes can occur. More recently a revised model of the ear has been developed by the inclusion of the outer ear canal. This discretisation uses geometries extracted from a Nuclear Magnetic resonance scan of a healthy subject and a crude inner ear model using stiffness parameters ultimately fixed through a parameter tuning process. The subsequently tuned model showed behaviour consistent with previous findings and should provide a good basis for subsequent modelling of diseased ears and assessment of the performance of middle ear prostheses.

Background: Langerhans' cell histiocytosis (LCH) is an uncommon, poorly understood granulomatous disease, characterized by the idiopathic proliferation of Langerhan's cells or their marrow precursors. In 1985, the Philadelphia Work-shop adopted the term "Langerhans' cell histiocytosis" (LCH) to differentiate it from reactive and neoplastic causes of histiocytosis., Methods: This study includes 73 pediatric patients diagnosed with this condition in Dublin, Ireland, and Nottingham, England, during a 34-year period (1959 to 1993). These patients are reviewed with respect to clinical presentation, difficulty with making a histological diagnosis, their management, and outcome., Results: A total of 49 patients (67%) had head and neck involvement. Bony involvement was the most frequent sign, most frequently located in the skull. There were 11 deaths (15%) in this series, all associated with multisystem disease, and nine of these deaths were in children younger than 2 years of age., Conclusions: The role of otolaryngologists is important in the early and accurate evaluation, staging, and diagnosis of LCH. It may mimic more common diseases, such as otitis externa, acute mastoiditis, skin rash, gingivitis, or cervical lymphadenopathy. Patients with multisystem disease may be so ill at presentation that the head and neck lesions may be overlooked. The current management of LCH has become increasingly conservative, and in the 1990s, fewer cases are given chemotherapy or radiotherapy. The prognosis is very good for single-system disease and poor for multisystem disseminated disease with early onset.

There have been many attempts at identifying substances and describing methods that would assist the surgeon and be of benefit to the patient undergoing a tonsillectomy. The use of bismuth subgallate as a haemostatic adjunct during tonsillectomy has only been described previously in retrospective studies. A controlled prospective randomized trial of 100 paediatric patients, in which 50 patients had a tonsillectomy performed using bismuth subgallate as a haemostatic agent and in which the remainder did not have any associated haemostatic substance, is presented here. Data on 72 patients was analysed, 39 patients belonging to the bismuth subgallate group and the remaining 33 to the control group. The time for haemostasis was three to 18 (mean 7.8) minutes in the bismuth group. It was four to 16 (mean 9.9) minutes in the non-bismuth group. These figures are statistically significant. The range of ties used in the bismuth group was none to three (mean 1.5) ties and one to seven (mean 3.4) ties in the non-bismuth group. These figures are also statistically significant. The remainder of the recorded parameters did not differ significantly. It was found that bismuth subgallate/adrenaline paste decreases operating time by significantly reducing the haemostasis time and the number of ties required but does not decrease post-operative morbidity.

In this work, the natural frequencies of vibration of two different stapes prosthesis replacement reconstructions have been analysed using the finite element method. Prosthesis 1 was constructed of fine stainless steel wire and a Teflon base, while prosthesis 2 was made entirely of Teflon. The results have indicated that generally, the first natural frequency of vibration falls as the prostheses become larger and more bulky. However, the fall in the first natural for prosthesis 1 was modest when compared with that of the isolated tympanic membrane. An important variable influencing frequencies and mode of vibration of the reconstruction was the tightness of fit of the prostheses within the remaining ossicular chain. The tightness of fit in this work was modelled as a range of spring constants applied at the stapes pseudo footplate, together with a series of joint elements at the incus tip/prosthesis head for the Teflon implant. When these spring constraints were below approximately 10 N/mm, the reconstruction exhibited normal mode 1 vibration behaviour, but at larger spring values, an abnormal mode 1 became established resembling the normal mode 2 vibration characteristics. The formation of new geometries and surfaces following reconstruction, introduces new constraints between umbo and stapes footplate particularly at the natural/artificial interfaces. These unnatural constraints may inhibit and modify the natural movements normally occurring at the stapes footplate leading to abnormal modes of vibration.

The presentation and management of four cases of spontaneous haemorrhage from the tonsil in association with acute tonsillitis are reported and discussed. Interestingly, younger patients presented with haematemesis. This is a newly recognised, rare, but potentially dangerous complication of acute tonsillitis. Its possible aetiology, pathophysiology and treatment options are discussed.

Langerhan's cell histiocytosis is an uncommon granulomatous disease, characterized by the idiopathic proliferation of Langerhan's cells or their marrow precursors. It encompasses the diseases previously associated with histiocytosis X-eosinophilic granuloma, Hand-Schuller-Christian syndrome and Letterer-Siwe syndrome. A series of 54 patients were diagnosed with this condition in Dublin over a 33-year-period (1959-1992). Twenty-seven patients had aural symptoms, of whom 15 had no other lesions at the time of presentation. Otorrhoea was the most frequent otological symptom, followed by lesions in the temporal bone. LCH may mimic common aural conditions such as otitis externa, otitis media or acute mastoiditis and a high index of suspicion is required to recognize it on clinical presentation. The clinical presentation of multi-focal disease may be so dramatic that the otologic findings may be initially overlooked. The mortality rate was 14.8%. Therapeutic regimes included no treatment, curettage, chemotherapy, radiotherapy or multi-modality treatment.

Nerve sheath tumours of the head and neck region mainly involve the eighth cranial nerve with only 4 per cent occurring in the paranasal sinuses. Only 32 cases of benign schwannomas occurring in the paranasal sinuses have been reported. We present a further case, review the current literature, and discuss the clinical details and specific histological features.

Alloplastic materials have been used in middle ear reconstruction since 1952. Biologically, biomaterials and specifically ceramics can be defined as being bioinert, bioactive or biodegradable; these terms being descriptive of the biochemical response provoked by the material in the host tissue. Various ceramics, carbons and polymers and their reactions have been studied by the author and his colleagues over the past 5 years utilising animal implantation and fibroblast culture studies aligned with experience from clinical usage. The qualities of the ideal alloplastic implant namely: biocompatibility, stabilisation and incorporation, the consistency of the implant and bioactive bonding and the biofunctionality or mechanics, are applied to the materials currently available. No single alloplastic material fulfills all criteria, the problems encountered in relation to the biomaterials are reported. A better understanding of the microstresses, fatigue and microfractures is necessary, before the ideal alloplastic biomaterial becomes available.

A case of relapsing polychondritis of the larynx and upper trachea is presented. We report the use of nebulized racemic ephedrine, as a new treatment modality of the life threatening airway oedema which characterizes acute exacerbations of this disease.

The normal anatomy and physiology of the middle ear is not reproduced in ossiculoplasty and an artificial mechanism for the transmission of sound results. This is true for all types of graft, be they of natural or man-made material. There are, therefore, 2 areas for consideration when looking at the problems encountered in such reconstructions: first, the materials' biocompatability and, secondly, the mechanical effects of the positioning of the graft in the reconstructed ossicular chain. The present work examines these mechanical effects using the finite element method to determine stress and displacement levels in the reconstructed ossicular chain. It is found that the stress levels at the implant-stapedial joint increases as the implant is gradually moved down the malleus. In contrast there is thought to be an increase in sound transmission as the implant is moved down the malleus. Changes in rigidity and hardness of the implant appear to make only modest stress attenuations at the implant-stapes interface.

Dizziness in childhood is not an infrequent symptom. Accurate history taking and close co-operation between otologist, paediatrician and neurologist are necessary in the approach to the dizzy child. Most cases of childhood dizziness settle in time and investigations should be carefully selected; those with severe and persistent dizziness or ataxia should be thoroughly investigated including: EEG, ENG, calorics and CT scan. The conditions causing dizziness in children are discussed and are illustrated with case histories from our series of 27 children. Dizziness of unknown aetiology, serous otitis media and benign paroxysmal vertigo were the most common diagnostic labels applied to our patients. Treatment is rarely necessary but dimenhydrinate or a labyrinthine sedative in those with troublesome vertigo, or the adjustment of the medical regime in those epileptics on phenytoin, may be beneficial. Surgical intervention is only required in those with an operable lesion.

The biocompatibility of the bioactive glass-ceramic Ceravital was investigated experimentally both in vivo and in vitro. In the former, ceramic discs were interposed in 30 rat middle ears for periods ranging from 6 weeks to 12 months. In the latter, Ceravital otological prosthesis were placed in human fibroblast culture. Reactions to the biomaterial were assessed by means of scanning electron microscopy (SEM) with chemical analysis facilities (EDAX, WDAX) and light microscopy. The interface reactions were similar in both in vivo and in vitro studies and confirmed the findings of other authors regarding the implants' biocompatibility and bioactivity. The technique of ion etching, however, enabled clear demonstration of this bioactivity on the implant surface, exposed merely to the middle-ear secretions, thus questioning the necessity of placing bone pâté on the implant head at surgery, in order to encourage bioactive bonding with the overlying drum. A clinical trial of Ceravital in 128 patients with an average follow-up period of 2 years is reported. Forty per cent of these patients underwent a type II tympanoplasty, 60 per cent a type III. Though relatively short-term, the results to date have been encouraging: 88 per cent of the implants have been well-tolerated; 70 per cent of the cases have yielded a satisfactory hearing result; and only 3 per cent of the implanted prostheses have been extruded.

Glassy carbon implants in the middle ear of the rat model appear well tolerated over periods of 6 months. The implants are rapidly covered with a fibrous capsule resulting in some bonding to the surrounding tissue. At a later stage (12 wk), further development of this bond takes place through growth of bone onto the implant surface from adjoining bone lamellae. No adverse tissue reactions were found in the histological sections produced.

By use of scanning electron microscopy (SEM), together with energy dispersive chemical analysis, a study has been made of the comparison of an in vitro method of assessing interface reactions between bone and ceramic implants with the naturally occurring changes seen in the rat ear model. Interface reactions between bone and two ceramic materials were examined following 4 wk in culture and 4 wk implantation. In both cases a gradual chemical change occurred at the calcium silicate surface during the fibrous growth onto the ceramic material. Gradual mineralization of the connective fibres was found at the interface of the calcium silicate material, whereas, in the case of alumina ceramic a connective fibrous bond had formed with no associated chemical change at the ceramic surface.

A sequential double blind cross-over trial of tocainide hydrochloride, an oral analogue of lignocaine, is reported. The dosage of tocainide hydrochloride ranged from 200-600 mg daily. Of the 32 patients who completed the trial, 1 had complete relief and 2 had partial relief of their tinnitus whilst taking tocainide. An increased incidence of side-effects in patients taking tocainide was noted, in particular, headache, dizziness, nausea and skin rashes.

A patient is reported with a severe inherited phagocytic defect, chronic granulomatous disease, in whom otological complications occurred. Successful ear surgery in this condition is described.

The bioactive glass Ceravital is rapidly covered by a fibrous encapsulating layer when placed in the rat middle ear. In addition, the surface of the glass becomes gradually modified from purely a silicate to a phosphosilicate. It is suggested that this phosphosilicate layer acts as a reservoir for the gradual mineralization of the encapsulating collagenous fibrils, resulting eventually in the formation of a strong bony bond.

Implantation of three different polymeric composite materials in the rat middle ear showed that the nylon prosthesis was encapsulated more rapidly than the two poly(methyl methacrylate) based implants. Several PMMA based implants were only partially covered at the 6 mnth stage by a tenuous capsule made up of collagen and a mixed inflammatory cell infiltrate. The nylon material was covered at the 3 mnth stage with a thin capsule and healthy fibroblasts.

The biocompatibility of vitreous carbon and carbon fibre reinforced carbon (CFRC) as middle ear implants was investigated. In separate animal model systems, vitreous carbon was implanted in the middle ear of 20 DA rats for up to 6 months, whilst 3 varieties of CFRC (basic or crude, ultrasonically cleaned, glazed) were implanted in 98 guinea-pig middle ears for up to 4 months. Tissue reactions to implantation were assessed by means of stereoscopic and standard light microscopy, and scanning electron microscopy with chemical analysis facilities (EDAX, WDAX). Vitreous carbon and glazed CFRC were considered suitable for human implantation and a trial of the latter was started in 23 patients (14 partial, 9 total ossicular implants). At 9 months, only 52% of the implants were still in situ; 40% had been extruded and 8% had elicited inflammatory responses which would undoubtedly result in extrusion. Carbon particle dissemination with carbon fibre destruction and exposure as a result of peroperative prosthesis drilling were considered the likely causes for the failure of this implant.

Complications of sinusitis caused by 'viridans' streptococci, mainly Streptococcus milleri, are described. The identification, bacteriology and pathogenicity of the organism are discussed and an approach to antimicrobial therapy outlined.

A hitherto unreported 'hybrid' fibro-osseous lesion involving the nasal cavity and sinuses is reported. This lesion histologically demonstrated features of ossifying fibroma, cementifying fibroma and aneurysmal cyst. Whilst appearing benign in nature it behaved in a neoplastic manner which necessitated complete surgical excision. A combined clinical, radiological and histopathological approach is advocated and discussed in relation to the treatment of these lesions.