Development and characterization of an animal model of dental sinusitis

CONCLUSION

The results of this study confirm that the present rabbit model of dental maxillary sinusitis (dMxS) is reproducible and simulates human dental sinusitis with respect to initiation, progression and inflammation. It is applicable to further studies of sinusitis of odontogenic origin.

OBJECTIVES

To induce acute dMxS in rabbits by using their own oral microflora to create a periapical infection and to follow morphological, radiographic, bacteriological and histological changes to the sinus mucosa.

MATERIAL AND METHODS

The experimental animals comprised 26 New Zealand White rabbits. Maxillary premolar root canals were identified bilaterally and the continuously growing germs of the roots were severed by diathermy. The animals were randomized into 2 groups: in Group 1 (n=20) the teeth were left open for the entire study period; in Group 2 (n=6) the root canals were sealed 1 week after the initial intervention. The animals in Group 1 were sacrificed at intervals ranging from 2 h to 9 months after intervention. All animals in Group 2 were sacrificed 6 months after intervention. After macroscopic and radiographic examination, post-mortem inspection of the paranasal sinus cavity and maxillary complex and microbiological sampling, the entire nasal sinus complex with the hard palate in situ was resected and processed for serial coronal sectioning.

RESULTS

In Group 1, after 3 months, the radiographic changes ranged from widening of the periodontal space to bone reaction. At sacrifice, changes in the sinus mucosa ranged from signs of mucosal inflammation to purulent dMxS. Microbial growth, predominantly Gram-negative aerobes, increased over time. In Group 2, the findings were generally more pronounced. Anaerobic microorganisms were predominant. In both groups the findings were consistent with dMxS.

Clinical relevance of nasal polyps in individuals recruited from a general population-based study

OBJECTIVE

To compare the clinical presentations of individuals with nasal polyps detected by endoscopy in a general population sample with those of patients with nasal polyp disease seeking medical attention.

MATERIAL AND METHODS

A total of 38 individuals with nasal polyps from a population-based sample were compared with 38 matched controls and a third group consisting of 44 patients who presented to an outpatient clinic with symptoms and diagnosed nasal polyps Upper and lower airway symptoms were registered. Polyp size, peak nasal inspiratory flow (PNIF), olfactory function and health-related quality of life were measured.

RESULTS

Compared with the individuals with nasal polyps in the population sample, patients actively seeking medical care for nasal polyposis experienced more symptoms of nasal blockage and an impaired sense of smell, and had more extensive polyps and reduced PNIF. There were equal frequencies of asthma symptoms in these two groups. Compared with the controls, the individuals with nasal polyps in the population sample had a greater frequency of asthma symptoms and aspirin intolerance and also experienced an impaired sense of smell.

CONCLUSION

Nasal polyps alone, as seen occasionally, are indicative of airway disease involving the upper and lower respiratory tracts.

Sensitivity of a new grading system for studying nasal polyps with the potential to detect early changes in polyp size after treatment with a topical corticosteroid (budesonide)

We have previously compared different scoring systems for endoscopic staging of nasal polyps. Of the five methods evaluated, we found that two were better than the others with regard to reproducibility and agreement between physicians. One method was lateral imaging, developed by the authors, and the other was a scoring system developed by Lildholdt et al. The main objective of the present study was to compare the sensitivity of these two methods. Another aim was to study the effect on nasal polyposis of topical nasal corticosteroids over a 2-week period. Patients with bilateral nasal polyposis (n = 100) were randomized to a 2-week treatment with a topical corticosteroid (budesonide aqueous nasal spray: 128 microg b.i.d.) or placebo in a double-blind manner. Nasal symptoms were scored before treatment and after 3, 7 and 14 days of treatment, and the patients underwent nasal endoscopy at clinical visits. Patients treated with active substance had an improvement in their symptoms, an effect already detectable after 3 days of treatment, compared with those who received placebo. In addition, a statistically significant decrease in polyp size could be registered after 14 days using lateral imaging but not with the other scoring system. In conclusion, lateral imaging was more sensitive and could detect effects earlier than the other scoring system and can be recommended for the endoscopic staging of nasal polyps in clinical studies.

Evaluation of methods for endoscopic staging of nasal polyposis

Endoscopy is needed for reliable evaluation of the treatment of nasal polyposis. In this study, we compared the reproducibility of various score systems for staging nasal polyposis and the inter-individual variations between investigators. The mass of the polyps was assessed by five methods, three new techniques (numbers 1, 2 and 3) and two established ones (numbers 4 and 5). These were: 1, lateral imaging projecting the extension of the polyps by drawing on a schematic picture of the lateral wall of each nasal cavity; 2, assessment of polyp obstruction estimating the proportion of the total nasal cavity volume occupied by polyps; 3, nasal airway patency--determining the relationship between the patient's patent airway lumen and an imaginary maximal nasal airway lumen; 4, a score system with four steps ad modum Lildholdt et al.--determining their relationship to fixed anatomical landmarks; and 5, a score system with three steps ad modum Lund and Mackay--determining their relationship to the middle meatus. High correlations were found between the first and the second assessments by a given investigator with all five methods used to score nasal polyposis. High correlations were also shown between the various methods. When three investigators examined a given patient, there were no significant differences between the investigators using score systems 1, 3 and 4. However, with score systems 2 and 5, there was insufficient agreement between the investigators. The patient's symptom of nasal blockage was not a good indicator of the size of the polyps, especially as regards small polyps. Two of the best methods tested (1 and 4) were selected for further clinical studies regarding evaluation of the sensitivity of score systems to detect changes in polyp size during treatment.

Allergic rhinitis and upper respiratory tract infections

The existence of a relationship between allergic rhinitis and upper respiratory tract infection (URI) has not yet been verified. In a prospective study, 64 patients with allergic rhinitis and 23 non-allergic individuals were followed for 11.4 months. All participants kept a diary in which they recorded symptoms of URI, nasal discharge, blocked nose, sneezing and sinusitis. The allergic individuals did not have more frequent or more long lasting URI or sinusitis more frequently than non-allergic subjects.

Chronic sinusitis: clinical and pathophysiological aspects

Sinusitis can be defined as inflammation of the paranasal sinus mucosa. However, the definition of chronic sinusitis is not yet fully established. As chronic sinusitis occurs both on an infectious and non-infectious basis there are many symptoms, local as well as general, from the upper respiratory tract. It is generally agreed that the time aspect of the disease is important. Long-term symptoms, i.e. more than 3 months, and objective findings of mucosal inflammation are criteria for chronic sinusitis. In clinical practice it is also important to realize that mucosal changes usually persist for at least 8 weeks after the treatment of an acute infection. Interest has lately been focused on local sinusal inflammation, especially on the inflammatory cells whose immunoactive products seem to keep inflammation ongoing even after the infection is cured. It is not clear to which extent the mucosal damage, with granulation tissue, polyp formation and fibrosis, is reversible. In chronic sinusitis, the ostial function is disturbed, especially in patients with nasal polyposis. This function must be re-established, but it is still uncertain whether obstruction in the osteomeatal complex is primary or secondary to other factors. Further research into local immunological factors and analysis of the development of special local tissue pathology in sinusitis is necessary in order to be able to establish exactly why acute sinusitis does not resolve but turns into a chronic inflammatory disease.

Cytogenetical observations in two cases of polymorphous low-grade adenocarcinoma of the salivary glands

The cytogenetical findings in two cases of cultured salivary polymorphous low-grade adenocarcinoma (PLGA) are reported. The first PLGA was a carcinoma ex pleomorphic adenoma of the parotid gland. This had a pseudodiploid stemline characterized by extensive and complicated structural rearrangements. The chromosomal findings showed many similarities to those in the only previously studied case of PLGA (also a carcinoma ex pleomorphic adenoma of the parotid). The results in both could fit with abnormalities superimposed on those typical of mixed tumors. The second PLGA reported derived from a minor salivary gland. It showed a completely different picture, distinguished by a hypodiploid, almost exclusively numerical, variation and the occurrence of a stemline characterized by only monosomy 22. Etiological differences were proposed as one possible explanation for the cytogenetical differences between the two types of PLGA.

Ostial function in allergic rhinitis

In order to evaluate the maxillary ostial function a double-blind, group comparative study with intranasal budesonide and placebo was carried out in 20 adult patients suffering from seasonal rhinitis. The trial started with an entry visit 3 weeks before pollen peak with clinical assessments (physical examination and ostial diameter measurements) followed by a 3-week treatment period. Treatment was either intranasal budesonide 200 micrograms b.i.d. or matching placebo b.i.d. The trail ended at pollen peak with clinical assessment. The results showed normal ostial diameters in the patients suffering from seasonal rhinitis. There were no statistical significant differences in ostial diameter change between the treatment groups except between budesonide and placebo in sitting position at measurement time 0 min. It seems that pollen does not reach the ostial region.

The comparative efficacy and safety of clarithromycin and amoxycillin in the treatment of outpatients with acute maxillary sinusitis

The efficacy and safety of clarithromycin and amoxycillin in the treatment of acute maxillary sinusitis were compared in a single-blind, multicentre outpatient study. Fifty patients were randomly assigned to receive either clarithromycin 500 mg 12-hourly or amoxycillin 500 mg 8-hourly orally. Clinical signs and symptoms, sinus culture and blood and urine laboratory profiles were assessed prior to treatment, at four to six days during treatment, and within 48 h of the end of therapy (usually 9-11 days). Patients from whom beta-lactamase producing strains were isolated were excluded from the study. Both antibiotics achieved a clinical success rate of 91% within 48 h post-treatment; radiological resolution or improvement was observed in 91% of patients treated with clarithromycin and 89% of patients who received amoxycillin. Bacteriological cure was achieved in 88% and 91% of evaluable patients for clarithromycin and amoxycillin, respectively. Adverse events were reported for 16% of patients in the clarithromycin group compared to 26% in the amoxycillin group. Gastrointestinal disturbance was the most commonly occurring adverse event in both groups. The results of this study suggest that clarithromycin is as effective and well tolerated as amoxycillin in the treatment of acute maxillary sinusitis.

Ostial and nasal patency in chronic maxillary sinusitis. A long-term post-treatment study

In a long-term follow-up study (mean 3.5 years) after treatment of chronic maxillary sinusitis of either rhinogenous or dental origin, 72 sinuses in 66 patients were examined with respect to maxillo-ostial and nasal resistance. In sinusitis of rhinogenous etiology, the mean equivalent ostial diameter was pathologically narrowed (0.89 mm, in patients treated conservatively) whereas it was normal (2.51 mm) in sinusitis of dental etiology (dental treatment in combination with local sinus surgery). In the former group, all sinuses were diseased, compared with 3 out of 23 in the dental group. In order to distinguish between functional and organic ostial stenosis, the patients were also tested after physical exercise. The functional ostial diameter in healthy sinuses was significantly increased in contrast to the diseased sinuses. In one patient the narrow ostium was due to mucosal swelling only, but in the other cases was caused mainly by an organic stenosis. In sinusitis of rhinogenous etiology, a pathologically increased nasal resistance was found in 14.3%, while the corresponding figure in the dental group was 4.3%. Improved sinusal and nasal ventilation, achieved either pharmacologically or, preferably by surgical intervention, seems necessary for successful treatment of chronic maxillary sinusitis.

Short and long-term treatment results in chronic maxillary sinusitis

The diagnostic criteria and the length of the observation period are essential factors influencing the results of treatment of maxillary sinusitis. In 198 patients (244 sinuses) with chronic maxillary sinusitis of either rhinogenous or dental etiology all patients were judged as cured or improved at the short-term control 1-3 months after completion of therapy. The long-term observation (mean 3.5 years) revealed different figures of healing. Satisfactory results after conservative therapy were seen in only 34% while the Caldwell-Luc operation gave good results in 80%. In sinusitis of dental origin, dental treatment combined with local sinus surgery was successful in 90%. In 78 sinuses investigated by sinoscopy, discrepancy between the symptoms and the endoscopic findings was seen in 14 cases (18%). Information obtained by questionnaire is therefore unreliable. In 30 sinuses operated upon with the Caldwell-Luc procedure, discrepancy between radiographic and endoscopic findings was seen in 3 cases (10%). Contributory factors, e.g. nasal polyps, dental infections and nasal allergy were found in 48 out of 84 sinuses not completely healed at the long-term control. Patients treated for chronic maxillary sinusitis must be followed up over a long period. A clinical control after 1-2 years, including sinoscopy or sinus radiographs, is recommended even in patients free from symptoms of sinusitis. Sinoscopy seems to be more reliable than sinus radiography and should be performed if the sinus radiographs show any pathology. The patients are also recommended to visit their dentists regularly, due to the close relationship between dental infections and chronic maxillary sinus diseases.

Effects of phenylpropanolamine on ostial and nasal airway resistance in healthy individuals

Ostial airway resistance (OAR) of 11 maxillary ostia and the airway resistance of the nasal cavity (NAR) in 6 healthy persons were tested before and after administration of phenylpropanolamine (Ppa) and placebo. The effects of physical exercise were also tested. After logarithmic transformation, the resistance values showed a normal distribution. Significant effects on the ostial resistance in relation to initial values were found after Ppa medication. The effect was more pronounced in recumbency than in the sitting position. Physical exercise also gave a significant reduction of ostial resistance while placebo treatment was without effect. On comparison of the Ppa- and placebo-groups in an extended statistical analysis, more striking differences were found both for OAR and NAR. In this model study, Ppa thus showed effects in healthy individuals.

Effects of phenylpropanolamine on ostial and nasal patency in patients treated for chronic maxillary sinusitis

Ostial and nasal patency were measured in different body positions and after phenylpropanolamine (Ppa) treatment in 12 patients earlier treated for chronic unilateral maxillary sinusitis of varying severity. Six of the sinuses were of normal appearance on sinoscopy. Phenylpropanolamine in a single dose of 100 mg was found to increase the equivalent ostial diameter significantly in the sitting and recumbent positions. The drug also reduced the nasal airway resistance. The Ppa effect might be of benefit in patients treated for chronic maxillary sinusitis.

Chronic maxillary sinusitis. Definition, diagnosis and relation to dental infections and nasal polyposis

Various definitions have been proposed for the term 'chronic sinusitis' but too often reports on chronic sinusitis lack a definition. In order to improve the diagnosis and treatment of this disease, and also to facilitate comparisons between clinical investigations, definitions of 'chronic maxillary sinusitis' of either rhinogenous or dental origin are proposed. It is suggested that the differential diagnosis should be based upon the duration of symptoms, ENT and dental examinations, sinus radiographs and/or sinoscopy, and results of conservative treatment. In a study conducted over a 5-year period, 198 patients with 244 affected sinuses fulfilled the proposed criteria. The incidence of chronic maxillary sinusitis in the population was 0.02%. A dental cause was found in 40.6% of the sinuses. The dental cause could be confirmed by routine dental examination in only 43 of 99 cases, while an extended maxillo-dental examination was conclusive in the other cases (56/99). Marginal periodontitis was found as frequently as periapical granuloma and together they constituted 83% of all dental causes. Sinusitis of dental origin was rare before the age of 30. Every sixth patient was found to have nasal polyposis. When related to the number of affected sinuses, the incidence of nasal polyposis was 13.1% in sinusitis of dental origin and 23.4% in that of rhinogenous origin. The importance of close cooperation between the ENT specialist and the oral surgeon is stressed.

Mast cells on the surface of the mucous membrane--a general feature of inflammatory reactions in the nose?

A redistribution of mast cells towards the epithelial lining of the nasal mucous membrane has been shown to be a part of the allergic inflammatory reaction in hay fever. This results in an increased number of metachromatically stained cells on the surface of the mucous membrane. The involvement of mast cells in other inflammatory reactions in the human nose is not clarified and this may partly be due to methodological difficulties. Utilizing a recently developed imprint technique, specimens were taken from patients with infectious rhinosinusitis in acute and chronic stages. The total number of mast cells on 2 cm2 of the imprint area were counted. Mast cells in extremely low numbers were found in 5 out of 26 patients. Our results indicate that mast cell migration is not present in patients with infectious inflammatory reactions of the nasal mucous membrane.

Chronic maxillary sinusitis. Differential diagnosis and genesis

By a careful ENT and oral examination of 111 patients with suspected chronic maxillary sinusitis, the diagnosis was verified in only 56% (62/111). In 29 of these 62 patients (47%) a relation to dental infections was found, periodontitis being as frequent as apical granulomas. In 61% of the patients, in whom the diagnosis chronic maxillary sinusitis could not be verified, dental infections and/or myofascial pain dysfunction syndrome (MPD) were the most common and likely cause of the symptoms. A careful oral examination including dental radiographs is thus important in patients with chronic maxillary sinusitis.