MORFOLOGIA DOS RECESSOS TIMPANICOS POSTERIORES

The sinuses of the posterior wall of the tympanic cavity are formed between the bony ridges, bridges and other osseous prominences, remnants of the tympanum widening process. Anatomical limits and relationships of these sinuses were observed in 100 human temporal bones. Many morphological variabilities were found due to different levels of development of the middle ear posterior wall. The most important sinuses of this complex are the Sinus tympani and the Facial Sinus (Facial recess) seen in all cases. The Lateral tympanic sinus is well-formed in 83% of the cases and the Posterior tympanic sinus in 20% of our series.

Morphological aspects of tympanic bulla after lateral osteotomy in cats

OBJETIVO: Avaliar a morfologia da bulla tympanica de gatos após osteotomia lateral unilateral. MÉTODOS: Foram utilizados 20 gatos distribuídos em dois grupos de 10 animais cada, de acordo com o período de observação: B1 (8 semanas) e B2 (16 semanas). RESULTADOS: Nas radiografias em projeção lateral oblíqua realizadas no pós-operatório imediato observou-se a interrupção do meato acústico externo da bulla tympanica operada de todos os gatos de ambos os grupos (McNemar, p=0,0010*). Esta característica ainda pode ser observada nas radiografias realizadas 8 ou 16 semanas após a cirurgia (McNemar: B1 p=0.0020*; B2 p=0.0312*). Os exames macroscópicos revelaram que a bulla tympanica operada apresentava conformação semelhante a da bulla tympanica normal, com preservação da cavidade timpânica. Na maioria das bullae tympanicae operadas observou-se a presença de tecido conjuntivo na área de osteotomia. O resultado do teste de McNemar foi significante em ambos os grupos (B1 p=0,0020*; B2, p=0,0010*). A histomorfometria mediu a extensão de tecido conjuntivo presente no local da osteotomia. Não houve diferença estatisticamente significante entre os dois grupos (Mann-Whitney, p=0,0524). CONCLUSÕES: A osteotomia lateral não alterou de maneira significativa a conformação da bulla tympanica. A regeneração total da bulla tympanica geralmente não ocorreu antes de 16 semanas de pós-operatório.

Contribution of the study of the styloid prominence in the posterior tympanic cavity

70 human temporal bones were analyzed with the aid of an otologic microscope. The styloid prominence was found to be extremely variable in shape, location and occurrence. Depending on the degree of development, the prominence establishes important relationships with the sinus tympani, with the fossula of the cochlear fenestra, and with the suprapyramidal recess. Serial sections were used to study the relationship of the styloid process with the facial nerve inside the bony mass of the mastoid portion of the temporal bone.

Isolated Bilateral Blowout Fracture With Extensive Pneumatization of the Maxillary Sinuses

The blowout fracture injuries are often associated with fractures of the zygomatic complex and other facial structures but can also occur in an isolated fashion. Isolated bilateral blowout fractures are uncommon and constitute a challenge with regard to both assessment and reconstruction. This article describes an uncommon case of isolated bilateral blowout fracture in a patient with extensive pneumatization of the maxillary sinuses.

Morphological aspects of tympanic bulla after ventral osteotomy in cats

To evaluate tympanic bulla healing after experimental ventral osteotomy in cats. Twenty adult cats were submitted to unilateral ventral bulla osteotomy and divided into two groups: cats of A1 group (n=10) were euthanized at 8 weeks and cats of A2 group (n=10), at 16 weeks postoperative. Signs of Horner's syndrome or damage to the inner ear were not found. Open-mouth radiographs taken in the immediate postoperative showed interruption in the contour of the larger compartment of the operated bulla. The result of Mcnemar'test was significant in A2 group (*p=0.0156). Macroscopic exams revealed that the operated bullae were similar to the normal ones, with preservation of the tympanic cavity. Connective tissue at the osteotomy site of the larger compartment was significantly found in the operated bullae in both groups (McNemar test: A1 p=0.0020*; A2 p=0.0078*). Histomorphometric analyses showed that the connective tissue length at the osteotomy site was shorter in A2 group than in the A1 group (Mann-Whitney test: p=0.0021*). Experimental ventral osteotomy did not alter significantly the tympanic bulla conformation and complete regeneration of tympanic bulla frequently did not occur before 16 weeks of postoperative period.

Radiologic identification of disaster victims: a simple and reliable method using CT of the paranasal sinuses

To assess the reliability of radiologic identification using visual comparison of ante and post mortem paranasal sinus computed tomography (CT).

[Computer-aided surgery of the paranasal sinuses and the anterior skull base]

Endoscopic or microscopic surgery for chronic rhinosinusitis with or without nasal polyps is a routine intervention in daily practice. It is often a delicate and difficult minimally invasive intervention in a narrow space, with a tunnel view of 4 mm in the case of endoscopy and frequent bleeding in chronically inflamed tissue. Therefore, orientation in such a "labyrinth" is often difficult. In the case of polyp recurrence or tumors, the normal anatomical landmarks are often missing, which renders orientation even more difficult. In such cases, computer-aided navigation together with images such as those from computed tomography or magnetic resonance imaging can support the surgeon to make the operation more accurate and, in some cases, faster. Computer-aided surgery also has great potential for education.

The role of the sinuses of Valsalva in aortic root flow dynamics and aortic root surgery: evaluation by magnetic resonance imaging

BACKGROUND AND AIM OF THE STUDY: Combined replacement of the aortic valve and ascending aorta using a composite graft represents the standard treatment for dilated aortic root with concomitant structural damage of the aortic valve, especially when the aortic valve cannot be preserved. Unfortunately, hemodynamic changes associated with prosthetic replacement of the aortic root have not been fully elucidated. The study aim was to compare hemodynamics within the replaced aortic root using either a prosthetic vascular graft with bulges mimicking the sinuses of Valsalva and including a stented pericardial valve, or a straight xenopericardial conduit and a stentless porcine valve. METHODS: Between July 2004 and March 2006, a total of 35 patients (mean age 65.2 years: range: 32-80 years) was enrolled into the present study. Aortic root replacement was performed in nine patients with a Valsalva graft (Gelweave Valsalva; Vascutek, Renfrewshire, UK) including a stented pericardial valve, and in 19 patients with a xenopericardial conduit containing a stentless porcine valve. All patients underwent postoperative magnetic resonance imaging (MRI). A control group of seven patients allowed for comparison with native aortic root hemodynamics. RESULTS: Maximum flow-velocity above the aortic valve as one marker of compliance of the aortic root was slightly higher in patients with a Valsalva graft compared to native aortic roots (1.9 m/s versus 1.3 m/s, p = 0.001), but was significantly lower than in patients with the xenopericardial graft without neo-sinuses (1.3 m/s versus 2.4 m/s, p < 0.001). CONCLUSION: The pre-shaped bulges in the prosthetic Valsalva graft effectively mimic the native sinuses of Valsalva, improve compliance of the aortic root, and result in a more physiologic flow pattern, as demonstrated by postoperative MRI.

Incidence of anatomical variations and disease of the maxillary sinuses as identified by cone beam computed tomography: a systematic review.

PURPOSE To analyze available evidence on the incidence of anatomical variations or disease of the maxillary sinuses as identified by cone beam computed tomography (CBCT) in dentistry. MATERIALS AND METHODS A focused question was developed to search the electronic databases MEDLINE, EMBASE, the Cochrane Oral Health Group Trials Register, and CENTRAL and identify all relevant papers published between 1980 and January 19, 2013. Unpublished literature at ClinicalTrials.gov, in the National Research Register, and in the Pro-Quest Dissertation Abstracts and Thesis database was also included. Studies were included irrespective of language. These results were supplemented by hand and gray literature searches. RESULTS Twenty-two studies were identified. Twenty were retrospective cohort studies, one was a prospective cohort study, and one was a case control study. The main indication for CBCT was dental implant treatment planning, and the majority of studies used a small field of view for imaging. The most common anatomical variations included increased thickness of the sinus membrane, the presence of sinus septa, and pneumatization. Reported sinus disease frequency varied widely, ranging from 14.3% to 82%. There was a wide range in the reported prevalence of mucosal thickening related to apical pathology, the degree of lumenal opacification, features of sinusitis, and the presence of retention cysts and polyps. More pathologic findings in the maxillary sinus were reported in men than in women, and the medial wall and sinus floor were most frequently affected. CONCLUSION CBCT is used primarily to evaluate bony anatomy and to screen for overt pathology of the maxillary sinuses prior to dental implant treatment. Differences in the classification of mucosal findings are problematic in the consistent and valid assessment of health and disease of the maxillary sinus.

Collision tumor affecting the paranasal sinuses of a geriatric donkey

Tumours of the paranasal sinuses are relatively uncommon in the horse. A collision tumour occurs when 2 separate tumour types arise in close proximity to each other and encroach on one another. This report describes the presence of neoplasia comprising glandular tissue and spindle cells growing concurrently in the frontal and caudal maxillary sinus of a geriatric donkey. As far as the authors are aware, this is the first description of a possible collision tumour in an equid.

Effect of tympanic cavity evacuation and flushing on microbial isolates during total ear canal ablation with lateral bulla osteotomy in dogs.

OBJECTIVE To evaluate differences in bacterial numbers, identity, and susceptibility in samples obtained from the tympanic cavity on entry (preflush) and after evacuation and lavage (postflush) and assess perioperative and empiric antimicrobial selection in dogs that underwent total ear canal ablation (TECA) with lateral bulla osteotomy (LBO) or reoperation LBO. DESIGN Prospective clinical study. ANIMALS 34 dogs. PROCEDURE TECA with LBO or reoperation LBO was performed on 47 ears. Pre- and postflush aerobic and anaerobic samples were obtained from the tympanic cavity. Isolates and antimicrobial susceptibility patterns were compared. RESULTS Different isolates (31/44 [70%] ears) and susceptibility patterns of isolate pairs (6/44 [14%] ears) were detected in pre- and postflush samples from 84% of ears. Evacuation and lavage of the tympanic cavity decreased the number of bacterial isolates by 33%. In 26% of ears, bacteria were isolated from post-flush samples but not preflush samples. Only 26% of isolates tested were susceptible to cefazolin. At least 1 isolate from 53% of dogs that received empirically chosen antimicrobials postoperatively was resistant to the selected drugs. Anaerobic bacteria were recovered from 6 ears. CONCLUSIONS AND CLINICAL RELEVANCE Accurate microbiologic assessment of the tympanic cavity should be the basis for selection of antimicrobials in dogs undergoing TECA with LBO. Bacteria remain in the tympanic cavity after evacuation and lavage. Cefazolin was a poor choice for dogs that underwent TECA with LBO, as judged on the basis of culture and susceptibility testing results.

The effect of flying and low humidity on the admittance of the tympanic membrane and middle ear system

Many passengers experience discomfort during flight because of the effect of low humidity on the skin, eyes, throat, and nose. In this physiological study, we have investigated whether flight and low humidity also affect the tympanic membrane. From previous studies, a decrease in admittance of the tympanic membrane through drying might be expected to affect the buffering capacity of the middle ear and to disrupt automatic pressure regulation. This investigation involved an observational study onboard an aircraft combined with experiments in an environmental chamber, where the humidity could be controlled but could not be made to be as low as during flight. For the flight study, there was a linear relationship between the peak compensated static admittance of the tympanic membrane and relative humidity with a constant of proportionality of 0.00315 mmho/% relative humidity. The low humidity at cruise altitude (minimum 22.7 %) was associated with a mean decrease in admittance of about 20 % compared with measures in the airport. From the chamber study, we further found that a mean decrease in relative humidity of 23.4 % led to a significant decrease in mean admittance by 0.11 mmho [F(1,8) = 18.95, P = 0.002], a decrease of 9.4 %. The order of magnitude for the effect of humidity was similar for the flight and environmental chamber studies. We conclude that admittance changes during flight were likely to have been caused by the low humidity in the aircraft cabin and that these changes may affect the automatic pressure regulation of the middle ear during descent. © 2013 Association for Research in Otolaryngology.