Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “sinusitis”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,531 records · Page 85Linked to original sources
PubMed1998

Does inhaled pollen enter the sinus cavities?

BACKGROUND: While there is evidence of an increased incidence of sinusitis in patients with allergic rhinitis, it is unclear whether an allergic process occurs in the sinus tissues per se. OBJECTIVE: The purpose of this study was to determine whether inhaled pollen reaches the sinus mucosa. METHODS: Tc99m labeled ragweed pollen was inhaled by five non-atopic adults. Imaging studies of the sinuses were performed with a tomographic rotating gamma camera. To determine the sensitivity of the technique, the nose and the maxillary sinuses of cadaver heads were painted with varying amounts of Tc99m and then similarly scanned. RESULTS: Scans of the cadaver heads showed clear resolution between the nasal cavity and the maxillary sinus. It was determined that 20 microci was the smallest amount of Tc99m that could be resolved to be in the sinuses. Scans of subjects showed intense activity in the nasal cavity but none in the paranasal sinuses despite the delivery of a supraphysiologic dose of Tc99m ragweed pollen. CONCLUSION: Inhaled ragweed pollen does not appear to enter the paranasal sinuses. It is unlikely that an inhaled antigen-IgE antibody reaction occurs in the sinus mucosa.

Cadaver↗
PubMed1999

Bacteriology of endoscopically normal maxillary sinuses.

The bacteriology of maxillary sinuses with normal endoscopic findings is reported in this study. When transantral sinoscopy was used to examine the maxillary sinuses, the whole maxillary sinus was inspected with different-angle endoscopes. If no lesion was seen over the whole maxillary sinus mucosa, no secretion existed in the maxillary sinus cavity, and the maxillary sinus ostium was wide open, the maxillary sinus was considered endoscopically normal. The bacteriology of these endoscopically normal maxillary sinuses was studied by passing cotton-tipped sticks through the cannula to collect swab specimens. In some cases, a biopsy forceps was also passed to obtain mucosal specimens. The specimens were sent to the laboratory for aerobic and anaerobic cultures. Between July 1990 and May 1998, 83 swab and 31 mucosal specimens were collected from 69 patients who had not taken any antibiotic within 10 days before endoscopy. The culture rates were 62.3 per cent (35/53) from swab specimens and 57.1 per cent (eight out of 14) from mucosal specimens in patients with the diagnosis of chronic paranasal sinusitis, and were 46.7 per cent (14/30) from swab specimens and 41.2 per cent (seven out of 17) from mucosal specimens in patients without this diagnosis. This study shows that endoscopically normal maxillary sinuses are not sterile.

Adolescent↗
PubMed1999

Nasal nitric oxide concentration in paranasal sinus inflammatory diseases.

In normal upper airways, nitric oxide is generated by the paranasal sinus epithelium and then diffuses into the nasal cavities. This study examined whether or not nasal NO concentration is affected by paranasal sinus inflammatory diseases. The influence of obstruction (nasal polyposis) and/or inflammation (allergy or chronic sinusitis) of the paranasal sinuses on nasal NO concentration was evaluated in nasal allergic (n=7 patients) or nonallergic (n=20) polyposis, nonallergic chronic sinusitis (n=10) and Kartagener's syndrome (n=6) and compared with control subjects (n=42). A score of alteration of the paranasal sinus (number of altered and occluded sinuses) was determined by a computed tomography scan. The nasal NO concentration in nasal nonallergic polyposis (150+/-20 parts per billion (ppb)) was significantly decreased compared with both controls (223+/-6 ppb, p=0.01) and polyposis with allergy (272+/-28 ppb, p<0.0001). In each group, the nasal NO concentration was inversely correlated with the extent of tomodensitometric alteration of the paranasal sinuses. In Kartagener's syndrome, the nasal NO concentration (14+/-2 ppb) was drastically decreased compared with all other groups, despite the presence of open paranasal sinuses. Thus, the nasal NO concentration in patients with nasal polyposis appeared to be dependent on both the allergic status and the degree of obstruction of the paranasal sinuses.

Adult↗
PubMed1988

Nasal and sinus pain: current diagnosis and treatment.

Intranasal and sinus disease may result in disabling head and facial pain and serious complications. Awareness of the symptoms of acute and chronic sinusitis and their various presentations will enhance diagnostic accuracy and improve patient outcome. It is important to remember that the nasal mucosa is under autonomic control. Sinus symptomatology, whether from anatomic abnormality or chronic inflammation, may occur with and will typically be exacerbated by increased parasympathetic outflow or reduced sympathetic tone. Thus, the possibility of underlying intranasal or sinus disease must be considered in patients with atypical migraine or vascular instability headaches. A new appreciation of the impact of sinusitis on facial and head pain syndromes is developing among otolaryngologists because of the improved diagnostic capabilities afforded by combined intranasal endoscopy and modified CT. In the past, patients with nasal complaints and facial pain who had normal plain radiographs were often passed off as "chronic nasal complainers" and given decongestants or the recommendation to see a psychiatrist. On the other hand, patients with symptoms and radiologic abnormalities often underwent radical surgery aimed at the maxillary or frontal sinus, sometimes with persistence or worsening of their complaints. Now, however, underlying causes for these problems can often be found in the ostiomeatal complex and corrected with minimally invasive surgery. In general, the major sinuses appear to be more sensitive to pain before the development of chronic mucosal changes. Minor disease in critical locations within the ostiomeatal complex may therefore give rise to greater symptomatology than diffuse disease in less critical sites. Although head CT may be a routine part of the neurologist's examination in patients with headache or facial pain, routine CT techniques are inadequate to evaluate fully the ostiomeatal complex and sinuses and must be modified to rule out adequately pain of sinus origin. Nasal endoscopic examination provides a noninvasive examination by which patients may be selected for sinus CT and is a necessary part of a complete evaluation. Close cooperation between the neurologist and otolaryngologist-head and neck surgeon is therefore essential for the accurate diagnosis of this often puzzling group of patients.

Facial Pain↗
PubMed1994

[Sinusitis in HIV infection].

Case notes of 722 HIV-infected patients who had died between March 1986 and August 1993 were analysed to evaluate the prevention and characteristic features of sinusitis associated with HIV infection. In 73 patients (10%) sinusitis had been diagnosed at least once on the basis of radiological or clear-cut clinical criteria. In addition, 15 patients with sinusitis were identified among those attending an HIV out-patient clinic. There were altogether 126 episodes of sinusitis in 88 patients (62 men, 26 women; mean age 33 [19-69] years). In 62 patients the CD4 lymphocyte count was under 100/microliters. The most commonly affected site was the maxillary sinuses. Patients with mirror formation had a significantly longer duration of illness than those without (P = 0.021). In 58 patients the symptoms of fever, headache and rhinitis were predominantly caused by the sinusitis, in 49 only partially so, and in 19 sinusitis was a chance diagnosis. In 10 of 49 attacks of sinusitis the concurrent disease (e.g. cerebral toxoplasmosis, malignant non-Hodgkin lymphoma) had not been recognized by the referring doctor. There were 1-5 recurrences over an observation period of 11.8 (0-72) months in 23 patients.-These findings show that sinusitis frequently occurs in HIV-infected patients, takes a protracted course and is difficult to distinguish from concomitant diseases by its clinical presentation. If symptoms persist, possible concurrent respiratory infection or CNS involvement must be looked for. Sinus needle aspiration is of decisive importance to ascertain the causative organism.

Adult↗
PubMed2005

A comparison between nitric oxide output in the nose and sinuses: A pilot study in one volunteer.

From a study of nitric oxide (NO) output in the nose and sinuses it seems that: (i) the results obtained regarding the regulation of NO output in the nose do not necessarily apply to the sinuses; (ii) the results obtained for one group of sinuses may not apply to another; and (iii) NO output in the sinuses does not behave as one would expect if it serves to protect against infection.A pilot study was undertaken in one subject to determine whether the control of NO output in the nose differs from that in the sinuses.NO output was measured by aspirating different gaseous concentrations of oxygen (and/or carbon dioxide) through the nasal airways or punctured maxillary and frontal sinuses before and after i.v. administration of L-arginine (20 mg/kg). In the absence of gaseous oxygen in the nose or maxillary antrum, the effect of L-arginine on NO output was the same as that in the presence of oxygen. In the frontal sinus, the effect of L-arginine on NO output was blocked by the absence of gaseous oxygen. NO output in the nose and frontal sinus showed similar changes after either i.v. administration of L-arginine or removal of oxygen from the air. NO output in the maxillary antrum was virtually unaffected by either procedure. NO output in the nose was largely unaffected by the gaseous carbon dioxide content but that in the frontal and maxillary sinuses was profoundly inhibited by it. In both sinuses, suppression of NO output by carbon dioxide was countered by oxygen. Alterations in the oxygen or carbon dioxide content of the maxillary antrum did not alter NO output in the frontal sinus, or vice versa. After i.v. infusion of L-arginine, nasal NO output remained elevated for >1 h.

Arginine↗
PubMed1998

Indications for sinus surgery: how appropriate are the guidelines?

Sinusitis is the most commonly reported chronic disorder in America. More than 75,000 sinus surgical procedures were performed in 1993. Evaluating the appropriateness of procedures is a major focus of health care reform. The American Academy of Otolaryngology-Head and Neck Surgery (AAO-HNS) collaborated with Value Health Sciences, Inc. (VHS) to develop guidelines for the use of sinus surgery. The clinical utility of these guidelines is presented. Patients undergoing sinus surgery at Barnes Hospital in St. Louis, Missouri, between November 1994 and July 1995 were eligible. Relevant patient information was used to prospectively rate surgery on the nine-point VHS appropriateness scale (1 to 3, inappropriate; 4 to 6, equivocal; 7 to 9, appropriate). Of 55 patients, 37 (67%) had chronic sinusitis, 10 (18%) recurrent sinusitis, five (9%) chronic sinusitis with nasal polyps, and three (6%) sinusitis with moderate to severe asthma; 27 (49%) had previous sinus surgery. Appropriateness ratings ranged from 1 to 9, with nine (16%) procedures rated as inappropriate, 22 (40%) uncertain, and 24 (44%) appropriate. There were no significant differences in the ratings of appropriateness between the group of patients who had undergone previous sinus surgery and the group of patients who had not. Overall, the guidelines were easily applied and clinically pertinent.

Adult↗
PubMed1999

Nasal obstruction: an alternative to ostiomeatal complex dysfunction in sinus disease.

OBJECTIVES: Ostial patency is thought to be essential to the function of the maxillary sinus. Ostiomeatal complex dysfunction has been implicated as a major factor in the pathogenesis of sinus disease. However, recent work in our laboratory has indicated that other factors may also contribute to this process. The objective of this study was to determine the effect of nasal obstruction in maxillary sinus gas composition, independent of its effect on ostial ventilation. STUDY DESIGN: Prospective controlled animal study. METHOD: Independent models of nasal obstruction and ostial occlusion in contralateral sinuses were established. Ipsilateral models of nasal obstruction and ostial occlusion were also created. Gas samples from each of the manipulated sinuses were analyzed on a gas chromatogram and compared. RESULTS: Results revealed a dramatic and highly significant increase in antral carbon dioxide (CO2) concentrations in the sinuses ipsilateral to either an occluded ostium or an obstructed nostril, compared with the controls. These effects on CO2 concentrations were additive when ipsilateral nasal obstruction and ostial occlusion were created. Furthermore, the effect of nasal obstruction in modulation of antral CO2 levels was found to be beyond its effect on hypoventilation of the sinus and to be independent of ostial functional status. CONCLUSIONS: We have established independent models of nasal obstruction and ostial occlusion in the same animal. Our findings suggest that ostiomeatal complex dysfunction might not be the sole underlying factor in the pathogenesis of sinus disease in all individuals. Integrity of nasal airflow seems to have a significant effect on the maintenance of the aerobic antral environment, essential to the maintenance of normal sinus function. Modulation of maxillary sinus gas composition by nasal airflow, independent of ostial patency, may be explained by the possible presence of flow-sensitive receptors in the upper respiratory tract mucosa. Work to identify such receptors is currently in progress.

Animals↗
PubMed2004

Revision endoscopic frontal sinus surgery.

PURPOSE OF REVIEW: Recurrent or persistent frontal sinus disease after endoscopic sinus surgery poses formidable challenges owing to the frontal sinus outflow tract's complex variable anatomy, close proximity to vital structures, and predilection for scarring and stenosis. Frontal sinus obliteration used to be the preferred technique of most sinus surgeons for addressing difficult frontal sinus disease; however, several effective endoscopic techniques exist as excellent alternative procedures for addressing this difficult clinical problem. RECENT FINDINGS: Several endoscopic techniques have been described for addressing these problems including endoscopic frontal sinusotomy, the frontal sinus rescue procedure, endoscopic transseptal frontal sinusotomy, and the modified Lothrop procedure. Advances in treating recurrent frontal sinus disease have included recent articles reviewing the long-term outcomes of some of these techniques, the prevalence of frontal sinus cells, the optimization of medical management, and the spectrum of postoperative debridement regimens. SUMMARY: When used in the appropriate setting, these less invasive revision endoscopic techniques provide excellent results with low morbidity and several advantages. This article reviews recent developments in the treatment of recurrent or persistent frontal sinus disease including incorporation of these techniques.

Endoscopy↗
PubMed1994

The effect of exogenous adenosine in patients with neurally-mediated syncope and sick sinus syndrome.

The effects of a 20-mg i.v., bolus of adenosine 5' triphosphate (ATP) on the heart rhythm was studied in 79 patients affected by neurally-mediated syncope (26 cases) or sick sinus syndrome (22 cases) or both syndromes (31 cases) and in 31 healthy control subjects in order to examine the sensitivity of cardiac purinoceptors in such circumstances. During ATP infusion, the sinus cycle lengthened to > 2 seconds in no control, in 1 (4%) patient with neurally-mediated syncope, in 5 (23%) patients with sick sinus syndrome, and in 13 (42%) patients with both neurally-mediated and sick sinus syndromes (P = 0.01). Atrioventricular block occurred in 14 (45%) of controls, in 10 (38%) patients with neurally-mediated syncope, in 4 (18%) patients with sick sinus syndrome, and in 13 (42%) patients with both neurally-mediated syncope and sick sinus syndrome (n.s.). Thus, exogenous ATP exerts different effects on patients with neurally-mediated syncope and patients with sick sinus syndrome. In fact, intrisic disease of the sinus node is necessary to modulate an abnormal adenosine-mediated sinus arrest, whereas patients affected by neurally-mediated syncope alone show a normal sensitivity to the drug administration. The effect of ATP on atrioventricular conduction is greater than that on sinus node and is of similar magnitude in patients and controls; thus the clinical meaning of ATP induced atrioventricular block remains uncertain.

Adenosine Triphosphate↗
PubMedDate not supplied

Antrolithiasis in the frontal sinus.

A very rare case of sinusitis with antrolithiasis in the left frontal sinus of a 63-year-old male patient is reported. Various conservative treatments had no effect on the decrease of his left frontal pain and of postnasal drip. Neither bacteria nor fungus were detected in the discharge. Computed tomographic scanning revealed several high-dense spots in an isodense shadow in the left frontal sinus. At first, endoscopic sinus surgery (ESS) was employed and a stony mass was detected in the nasofrontal duct and sinus. Patency of the nasofrontal duct was insured and a sticky paste and small masses were removed as well as possible. However, the flow of discharge from the frontal duct continued after surgery. We performed a second operation with extranasal approach and additional stones in the sinus were successfully removed. Most cases of antrolithiasis are caused by a foreign body or caseous sinusitis with fungus. The maxillary sinus is the most common site of disease in antrolithiasis. It is unknown why the present case of antrolithiasis was in the frontal sinus. In such cases of antrolithiasis or cases having pastelike contents in the frontal sinuses, we conclude that ESS may be an unsuccessful treatment and a classical surgical approach may be required.

Endoscopy↗
PubMed2001

Dynamic assessment of paranasal sinus ventilation using xenon-enhanced computed tomography.

Disease of the paranasal sinuses is a common and costly condition. Evaluation of the efficacy of either medical or surgical methods of treatment is limited by the lack of quantitative methods to characterize sinus ventilation, which may be an important determinant of the baseline physiological state of the sinuses. Xenon-enhanced computed tomography (Xe-CT) measurement of sinus ventilation provides a noninvasive method of quantifying maxillary sinus ventilation using the nonradioactive, radiodense gas Xe as a tracer. Study subjects breathed a mixture of Xe gas and oxygen through a close-fitting nasal mask during serial CT imaging of a single radiographic plane through the maxillary sinuses--a generally well-tolerated protocol. Analysis of the sinus density-time curves allowed calculation of first-order exponential time constants from which specific ventilation rates could be determined for individual sinuses. Previously developed data analysis techniques were used to assess the statistical significance of the data and determine confidence intervals, allowing examination of the effects of noise in the data, and to demonstrate areas for further study protocol refinement. We conclude that Xe-CT measurement of sinus ventilation is a potentially valuable noninvasive technique for the diagnostic imaging of the human maxillary sinus.

Humans↗
PubMed2004

Effect of WEB 2170 BS, platelet activating factor receptor inhibitor, in the rabbit model of sinusitis.

Platelet activating factor (PAF), a potent inflammatory mediator, is a biologically active phospholipid. Recent studies have shown that PAF may play an important role in the pathogenesis of inflammation. WEB 2170 BS has been shown to be a PAF antagonist both in vitro and in vivo. Nitric oxide (NO) is present in the mammalian nasal airways and originates primarily from the paranasal sinuses. Measurement of NO is thought to be a surrogate marker of upper airway inflammation. In this study, the antiinflammatory effects of WEB 2170 BS were investigated in a rabbit model of sinusitis. To induce experimental sinusitis, we applied killed Staphylococcus aureus percutaneously to the maxillary sinus of rabbits without occlusion of the natural ostium. Either WEB 2170 BS solution or placebo was administered intraperitoneally 2 hours before sinus inoculation, and this procedure was repeated twice daily for 4 days. The outcome of the treatment was determined by the measurement of NO metabolite levels and NO synthase activity in the samples of sinus mucosa and by histopathologic evaluation of sinus mucosa. The pathological grading was determined by the number of inflammatory cells found in the sinus mucosa. The levels of NO metabolites and NO synthase activity were found to be significantly lower in the WEB 2170 BS-treated group than in the control group. Histopathologic analysis of the sinus mucosa indicated decreased inflammation in the treated group as compared to the controls. These results demonstrate that WEB 2170 BS may produce significant anti-inflammatory effects in this model of sinusitis.

Animals↗
PubMed1990

Fungal diseases of the sinuses.

With recent advances in medicine, fungal diseases are becoming not only better understood, but also increasingly important in the management of patients with paranasal sinus disease. Fungal sinus diseases run the gamut from allergic fungal rhinitis and allergic fungal sinusitis, through fungus balls, to invasive and fulminant fungal sinusitis. Allergic fungal sinusitis may be thought of as the sinus counterpart of allergic bronchopulmonary fungal disease. Patients typically are first seen with chronic sinusitis. They may be atopic, and the peripheral blood often shows elevated IgE levels and absolute eosinophil counts. Such patients may be managed conservatively, requiring only surgical drainage and corticosteroid therapy. Fungus balls are typified by the so-called "aspergilloma." Although patients often have some predisposing factor, such as local tissue hypoxia or massive fungal exposure, most patients are not immunocompromised. Fungus balls may be treated with the traditional Caldwell-Luc operation or with newer endoscopic procedures. Invasive or fulminant fungal sinusitis generally occurs in immunosuppressed patients and merits aggressive surgical excision and debridement, as well as systemic chemotherapy, usually amphotericin B. In this article, we review fungal disease of the paranasal sinuses and present findings from our review of patients with chronic sinusitis.

Humans↗
PubMed2004

The place of Riedel's procedure in contemporary sinus surgery.

Many operative procedures have been described to treat frontal sinus disease with varying results. Obliteration of the frontal sinus is attempted when drainage procedures fail. Most large series of patients undergoing sinus obliteration have reported recurrent disease yet the management of these patients is rarely discussed. We believe Riedel's procedure has an important role in the management of these patients. Riedel's procedure can help eradicate frontal sinus disease and symptoms when drainage and obliteration have failed and where there is persistent disease involving the anterior wall of the frontal sinus or the sinus itself. Whilst cranialization has a role in the removal of the mucosa or contents of the frontal sinus in craniofacial resection, the morbidity associated with it make Riedel's procedure preferable for dealing with chronic infection or locally invasive disease. Riedel's procedure also maintains a barrier in the form of the posterior wall of the frontal sinus and the intracranial contents. Post-operative disfigurement, the main criticism of this procedure, can be reduced to some extent by chamfering the margins of the frontal sinus along with the supraorbital rims and reconstructing the anterior wall at a later date if necessary. The authors are aware that any report about frontal sinus surgery should be judged after several years follow-up, and whilst not all these cases have been asymptomatic for a decade, several have been reviewed for many years.

Adult↗
PubMed1995

Evaluation of maxillary sinus aspiration in patients with fever of unknown origin.

The value of diagnostic maxillary sinus aspiration in patients with abnormal findings on sinus radiographs and fever of unknown origin is unclear. To better define indications for this procedure, the results of 51 sinus aspirations in 34 patients with fevers of unknown origin and abnormal findings on sinus radiographs were analyzed retrospectively. Results of aerobic and anaerobic cultures were evaluated in the context of clinical signs and symptoms at the time of the maxillary sinus puncture. Typical symptoms of paranasal sinus disease were found to be the best predictor of a positive culture. Of patients with sinusitis complaints, 86.4% had culture-positive aspirations, whereas only 8.3% of patients without clinical symptoms of sinusitis had culture-positive aspirations. This study indicates that symptoms of sinus disease play an important role in determining the benefit of sinus aspiration in this group of patients.

Adolescent↗
PubMed1999

The role of sinus imaging in the treatment of chronic cough in adults.

PRIMARY STUDY OBJECTIVE: To determine the appropriate role and timing of sinus imaging studies in the evaluation and treatment of chronic cough. DESIGN: Prospective study of chronic cough. All patients underwent sinus imaging, the results of which identified prospectively the following: (1) fluid in sinuses, with or without opacification, and (2) mucosal thickening. Patients then were treated using an algorithm that sequentially addresses the etiologies of chronic cough. Patients whose sinus imaging studies had demonstrated fluid were treated initially for sinusitis, but mucosal abnormalities alone were not considered an indication to change the algorithm. After workup, relationships between abnormalities on sinus imaging studies and diagnoses were determined. SETTING: University hospital pulmonary outpatient clinic. PATIENTS: Thirty-six patients (31 women, 5 men; mean age, 58.4 years). Cough duration averaged 5.2 years (range, 4 weeks to 30 years). RESULTS: Diagnoses were made in 100% of patients, and cough resolved in 86%. Mucosal thickening correlated with sinusitis as a cause of cough in only 29% of cases. CONCLUSIONS: Mucosal thickening is not diagnostic of sinusitis as a cause of chronic cough; in most patients, cough will resolve without treatment for sinusitis. Given this lack of specificity, it is reasonable to delay sinus imaging until after efforts at treating rhinitis have failed and, in the absence of complaint or findings of postnasal drip, until after completion of evaluation for asthma. The principles of diagnosis and treatment of chronic cough remain simple: go sequentially from the most common to the least common cause; use tools that begin with the most available and least expensive and invasive modality; then move as needed to tools that are more expensive and invasive.

Adult↗
PubMed2003

Assessment of the accuracy and safety of the different methods used in mapping the frontal sinus.

INTRODUCTION: Frontal sinus obliteration continues to be the gold standard for frontal disease control and is often employed as a last resort of treatment after more conservative therapies fail. Different methods of sinus mapping have been previously reported and include (1) 6-foot Caldwell radiography, (2) sinus probing, and (3) sinus transillumination. Image-guided technology was recently introduced to clinical practice, but its utility in frontal sinus mapping has not been evaluated. OBJECTIVE: To assess the accuracy and safety of the previously reported methods of frontal sinus mapping and compare them with image-guided mapping. STUDY DESIGN: Five cadaveric heads were used. The four mapping methods were applied to each head along five different axes of the frontal bone: 0, 45, 90, 135, and 180 degrees. The true frontal sinus margin was ascertained. Measurements were made from the true sinus limits to the margin points estimated by the four frontal sinus mapping methods. RESULTS: The image-guided mapping method provided was the most accurate when compared with the other mapping methods (p < .01). The image-guided mapping method was also the least likely to overshoot the real margin compared with the other mapping methods (p < .001). The template method was the least accurate and least safe method. CONCLUSIONS: Image-guided mapping is the most accurate and safest method of mapping the frontal sinus margins.

Cadaver↗