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Maxillary sinus retention cysts (MRCs) are typically asymptomatic and require no treatment. An early 30s man presented with a decade-long history of severe left-sided chronic facial pain (CFP). Multiple prior treatments resulted in an edentulous patient with persistent pain. Imaging revealed a dome-shaped radiopaque change in the left maxillary sinus. History and clinical examination suggested persistent idiopathic facial pain, and doubts about the outcome of a surgical intervention were explained to the patient. Surgical removal of the MRC via lateral antrotomy led to complete symptom resolution of CFP. This case substantiates the importance of considering MRCs as a possible cause of CFP. It also emphasises the need for a systematic multidisciplinary approach in cases of unexplained CFP., Competing Interests: Competing interests: None declared., (© BMJ Publishing Group Limited 2024. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: Diagnosis of maxillary sinus pathology must include the clinical radiological study (CRS) and histopathological analysis. The aim of this study is 1) to describe the clinicopathological features of maxillary sinus lesions, obtained successively in a single medical centre over the last 10 years and 2) to determine the sensitivity and specificity for the diagnosis of malignant lesions based exclusively on the CRS., Methods: It is a single-centre observational retrospective clinical study on patients who attended the University Hospital Complex of Santiago de Compostela (CHUS) with sinus pathologies during the period of 2009-2019., Results: The sample consisted of 133 men (62.1%) and 81 women (37.9%), with an average age of 46.9 years (SD = 18.8). In terms of frequency, the most frequent pathology was the unspecified sinusitis (44.4%), followed by polyps (18.2%), malignant tumours (9.8%), inverting papilloma (7.5%), fungal sinusitis (4.7%), cysts (3.7%), benign tumours (2.3%), mucocele (2.3%) and other lesions (1.9%). Cysts and benign tumours were diagnosed earliest Vs malignant tumours (65.2 years (SD = 16.1)) were diagnosed the latest (p < 0.001). Based only on the CRS for malignancies, diagnostic indexes were 71.4% sensitivity and 97.9% specificity, with a Kappa value of 0.68 with (p < 0.001)., Conclusion: Maxillary sinus pathology is very varied with therapeutic and prognostic repercussions. CRS is sometimes insufficient and histopathological confirmation is essential.

Objectives: Mucous retention cysts (MRCs) of the maxillary sinuses are incidental findings in radiographs of the oral and maxillofacial structures. These cysts usually appear as rounded, dome-shaped, and soft-tissue masses, most often on the floor of the maxillary sinus. The aim of this study was to determine the prevalence of maxillary antral MRC and the effect of seasonal variation, sex and age in cone beam computed tomography (CBCT) images., Materials and Methods: In this simple, nonrandomized, cross-sectional study, CBCT images of patients were reviewed to evaluate the prevalence of MRCs and its location in the antrum, uni or bilateral, size, and season in which MRC occurred. The findings were analyzed using Statistical software SPSS and t-tests (P > 0.05)., Results: A total of 765 CBCT images were evaluated (380 males and 385 females); 180 were suggestive of MRCs, 110 occurred in males (28.9%) while 70 (18.2%) occurred in females, which resulted in a prevalence of 23.5%. The peak prevalence of MRC was found in spring (41.6% of all radiographs), but there was no significant statistical difference between the occurrence of MRCs in different seasons (P > 0.05)., Conclusion: This study showed no significant difference between the occurrences of MRCs in different seasons. There was no significant difference between male and female and different decades of life. Furthermore, there was no significant difference between the involvement of right and left maxillary sinuses and different walls of the antrum., Competing Interests: There are no conflicts of interest

Introduction: Maxillary sinus mucocele is an unusual clinic entity (incidence of 3-10%), represented by mucous secretion lined by respiratory stratified pavemented epithelium and its origin is mainly secondary to infections, inflammations, surgery, trauma or neoplasia., Case Report: We present a case of maxillary sinus mucocele. Subject of the study is a 74 aged patient referring positive anamnesis for nasal cavity surgery. His symptoms appeared six months ago and he complainted vertical ocular diplopia and ocular tension sensation, without rhinologic complaints. Oculistic examination confirmed an isolated left inferior rectus palsy, and CT showed mucous secretion occupying left maxillary sinus, with bone erosion to the orbital floor until orbital muscles. MRI is the gold standard for differential diagnosis with neoplastic lesions but the patient refused to perform this radio-diagnostic exam. He underwent to Endoscopic sinus surgery, consisting in middle meatal antrostomy and removal of the mucocele. Four months later the endoscopic follow-up showed regular maxillary cavity and regular ocular motility., Conclusion: In our opinion the rebuilding of the eroded bone is not mandatory if the integrity of the maxillary upper wall mucosa is respected, and antrostomy with drainage allows to recover ocular and paranasal sinus function. KEY WORDS:, Diplopia, Endoscopic sinus surgery.

Objectives: The purpose of the present study was to evaluate the frequency, locations, and dimensions of mucous retention cysts of the maxillary sinus and analyze potential associated dental pathology., Materials and Methods: A total of 156 cone beam computed tomography (CBCT) scans were included in the analysis, resulting in an evaluation of 310 maxillary sinuses. The presence of mucous retention cysts (MRC) manifesting as dome-shaped radiopacities in the sinus was diagnosed. Their locations were recorded, and dimensions (mm) were measured in coronal and sagittal/axial slices. The patients were grouped into (a) patients/sinuses with MRCs (test), and (b) patients/sinuses with healthy or any other changes (control) for further comparison and evaluation., Results: There were 40 sinuses (12.9%) with a presence of a total of 56 MRCs. The mean age of involved patients was 29.0 years. The analysis showed that gender, age, sinus side, status of dentition, endodontic status, and periodontal status did not have a significant influence on the presence of MRCs when compared between test and control groups. Age and endodontic status exhibited a significant association with cyst location., Conclusions: Most of the sinuses analyzed (79.5%) did not present any MRC, and only 28.6% of the cysts diagnosed were found on the floor of the maxillary sinus. The mean dimension of the MRCs measured 6.28 ± 2.93 mm. No influencing factors on the presence or absence of MRCs were found in the present study., Clinical Relevance: Most MRCs were not located on the floor of maxillary sinus. Future studies should assess their impact on surgical interventions in the sinus.

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.

Background: Although cone beam computed tomography (CBCT) images of the maxillofacial region allow the inspection of the entire volume of the maxillary sinus (MS), identifying anatomic variations and abnormalities in the image volume, this is frequently neglected by oral radiologists when interpreting images of areas at a distance from the dentoalveolar region, such as the full anatomical aspect of the MS. The aim of this study was to investigate maxillary sinus abnormalities in asymptomatic patients by using CBCT., Methods: 1113 CBCT were evaluated by two examiners and identification of abnormalities, the presence of periapical lesions and proximity to the lower sinus wall were recorded. Data were analyzed using descriptive statistics, chi-square tests and Kappa statistics., Results: Abnormalities were diagnosed in 68.2% of cases (kappa = 0.83). There was a significant difference between genders (p < 0.001) and there was no difference in age groups. Mucosal thickening was the most prevalent abnormality (66%), followed by retention cysts (10.1%) and opacification (7.8%). No association was observed between the proximity of periapical lesions and the presence and type of inflammatory abnormalities (p = 0.124)., Conclusions: Abnormalities in maxillary sinus emphasizes how important it is for the dentomaxillofacial radiologist to undertake an interpretation of the whole volume of CBCT images.

Background: The aim of the present study is to determine the relationship between dental findings and mucosal abnormalities of the maxillary sinus among dental patients, using cone-beam computed tomography (CBCT)., Methods: Two hundred fifty CBCT scans of dental patients were studied. Dental findings of the upper posterior teeth, including periodontal bone loss, periapical lesions, and root canal fillings, were assessed. The presence of mucosal thickening and mucosal cysts of the maxillary sinus was recorded. Logistic regression analysis was used to determine the influence of periodontal bone loss, periapical lesions, and root canal fillings on these sinus mucosal abnormalities., Results: Mucosal thickening was present in 42% of patients and in 29.2% of sinuses studied. Mucosal cysts were observed in 16.4% of patients and in 10% of sinuses studied. Both abnormalities were present more frequently among males than females. Severe periodontal bone loss was significantly associated with mucosal thickening (odds ratio: 3.02, P <0.001), whereas periapical lesions and root canal fillings were not. There was no association between dental findings and mucosal cysts., Conclusions: Severe periodontal bone loss was significantly associated with mucosal thickening of the maxillary sinus. Sinuses with severe periodontal bone loss were three times more likely to have mucosal thickening. Mucosal cysts were not associated with any dental findings.

Objective: We report a rare case of bilateral maxillary mucoceles. This was the primary presentation in a child with an underlying diagnosis of cystic fibrosis., Case Report: A five-month-old infant presented with isolated symptoms of nasal congestion. Initial examination and investigation with computed tomography identified the cause to be bilateral maxillary mucoceles. The child was investigated for cystic fibrosis and found to be positive. Given the young age and anatomy, a modified surgical approach was used to treat the mucoceles, comprising endoscopic and bilateral uncapping of the maxillary mucocele, uncinectomy, and middle meatal antrostomy. The child was then followed up with appropriate treatment for cystic fibrosis. At six-week follow up, there was no recurrence of symptoms., Conclusion: Maxillary mucoceles are extremely rare but can present in patients with chronic sinusitis or cystic fibrosis. To our knowledge, there are no prior reports of this condition being the primary indicator of underlying cystic fibrosis in the absence of upper respiratory tract symptoms. Doctors should be aware that mucoceles can present in very young individuals and may indicate an underlying diagnosis of cystic fibrosis. A high index of clinical suspicion will avoid delays in diagnosis and long-term management.

Purpose: To assess the prevalence of radiographic signs of maxillary sinus pathology in patients undergoing dental implant treatment and to compare the efficacy of panoramic radiography, computed tomography (CT), and three-dimensional (3D) CT with Implametric software in the diagnosis of sinus pathology., Materials and Methods: Thirty patients were selected at random from those being treatment-planned to receive implant-supported restorations in the maxilla and who had a panoramic radiograph, a conventional CT scan in acetate, and a 3D CT scan in digital format. The radiographic maxillary sinus findings were categorized as: (1) no sign of pathology, (2) mucosal thickening, (3) mucous cyst, or (4) occupation of the entire sinus., Results: Seventeen women and 13 men were included, with a mean age of 50.9 years. There was a 38.3% prevalence of radiographic abnormalities (23.3% mucosal thickenings, 10% mucous cysts, and 5% occupation of the entire sinus). Of the 23 sinuses that displayed radiographic signs of pathology, only 1 (4.3%) was correctly diagnosed by the panoramic radiograph., Conclusions: The most common radiographic maxillary sinus finding was mucosal thickening, followed by mucous cysts and occupation of the whole sinus. Conventional CT can be considered a reliable method for the diagnosis of maxillary sinus pathology.

Objectives: The aim of this study was to estimate the prevalence and analyse the risk factors of mucous retention cysts (MRCs) of the maxillary sinus., Methods: From November 2002 to May 2007, 6293 panoramic radiographs were taken and retrospectively reviewed to estimate the prevalence of MRCs and to analyse risk factors (month, relative air humidity and mean temperature). The months in which MRCs occurred were recorded and analysed. The Spearman rank correlation coefficient was used to correlate MRCs with relative air humidity, environmental temperature and month (significance level R(2)>0.85)., Results: Of the 6293 radiographs analysed, 201 (3.19%) images were suggestive of MRCs. No significant correlation was found between MRCs and relative humidity (R(2) = 0.15) of the air or temperature (R(2) = 0.40). The months with the highest numbers of MRC cases were September, October and November., Conclusions: The prevalence of MRCs was low, and no statistical correlation was found between MRCs and relative humidity of the air, mean temperature or month.

Ectopic teeth are rarely found in the maxillary sinus. When they are, they represent an anomaly of odontogenic development that is generally associated with odontogenic cysts, trauma, or idiopathic etiology. Although affected patients are often asymptomatic, documented morbidities include sinus disease that is often refractory to treatment. The diagnosis is usually made by plain-film radiography. Computed tomography is indicated when an ectopic tooth is associated with an antral mass and prior to surgery. Treatment of symptomatic patients and those with an antral mass is surgical, with either a Caldwell-Luc operation or an endoscopic procedure. We describe what we believe is the first reported case of a third molar in the roof of the maxillary sinus associated with a mucocele, and we review the literature.

Maxillary sinus retention cysts are occasionally found on dental radiographs. The objective of this study was to verify the frequency of maxillary sinus retention cysts in consecutive panoramic radiographs from 173 patients (77 males, 96 females) in an orthodontic office. The chi-square test was used for statistical analysis. Ten patients (5.8%) of the total sample presented a maxillary sinus retention cyst. Males had a higher frequency (9.1%) than females (3.1%), but this difference was not significant (P>.05). Overall, the frequency of maxillary sinus retention cysts in orthodontic patients is rather low and does not differ from the general population., (© 2009 Quintessence Publishing Co, Inc. All Rights Reserved)

Objective: To present a previously unreported cause of frontal mucocele., Case Report: A patient presented with a frontal mucocele and maxillary sinusitis. Computed tomography revealed an ectopic maxillary tooth as the cause of her signs and symptoms. Removal of the tooth by a Caldwell-Luc procedure facilitated resolution of the mucocele. Conventional treatment of mucoceles by endoscopic sinus surgery, and other rhinological sequelae of ectopic teeth, are considered., Conclusion: This is the first documented case of an ectopic tooth causing a frontal mucocele, and demonstrates how effectively the patient's symptoms resolved on removal of the tooth.

Mucocoeles are cyst-like lesions of the paranasal sinuses, which may rarely erode through the bony orbit and so displace or compress orbital contents. Such patients may present to ophthalmologists and other health care professionals with diverse problems including facial pain and swelling, proptosis, double vision, ptosis, infra-orbital anaesthesia, epiphora and optic nerve dysfunction with reduced vision. We present an illustrated interventional case report of an 81-year-old gentleman with a 2-week history of swelling around the left lower eyelid and malar region associated with double vision both in the primary position and particularly downgaze. We discuss the aetiology, diagnosis and contemporary management of maxillary mucocoeles and also the Caldwell-Luc procedure. The article serves as a reminder that maxillary mucocoeles may slowly and covertly invade the orbit and should be considered in the differential diagnosis in patients presenting with proptosis, globe displacement and an orbital or adnexal mass.

Objectives: Retention cysts of the maxillary sinus are an incidental finding on radiographs. These cysts usually appear as rounded, dome-shaped, soft tissue masses, most often on the floor of the maxillary sinus. The aim of this study was to investigate the long-term natural course of retention cysts of the maxillary sinus., Methods: Between November 1997 and October 2002, 40 patients were incidentally found to have retention cysts of the maxillary sinus on Waters view films. Seventeen of these patients were followed for 38 to 102 (mean, 60) months. Medical records, endoscopic nasal examinations, and Waters view of all 40 patients were reviewed. The size of each retention cyst and the ratio of cyst size to antral size were measured., Results: Of the 40 patients, 21 (52.5%) had cysts in the left maxillary sinus, 17 (42.5%) had cysts in the right maxillary sinus, and 2 (5%) had cysts in both sinuses. Thirty of the 43 (69.7%) cysts appeared to arise from the floor of the sinus. Cyst size ranged from 108 mm to 1,001 mm, and the ratio of cyst size to antral size ranged from 12.8% to 96.9%, as measured on Waters view. Follow-up Waters view films in 17 patients showed that seven cysts disappeared completely, two decreased in size, four showed no significant change in size, and five increased in size., Conclusions: Most retention cysts of the maxillary sinus spontaneously regressed or showed no significant change in size over the long term. These findings suggest that, in the absence of associated complications, "wait and see" may be the appropriate management strategy for these retention cysts.

Maxillary sinus mucoceles account for less than 10% of all paranasal sinus mucoceles. They are reported mostly as long-term sequelae of Caldwell-Luc operations. Orbital involvement is an extremely rare condition that might result in orbital complications. A 43-year-old woman presented to the ophthalmology department with progressive ophthalmologic complaints. She was referred to our department for suspicion of a mass in the left maxillary sinus. The patient had undergone a left Caldwell-Luc sinus procedure two years before followed by two maxillary sinus lavages. Findings of computed tomography and magnetic resonance imaging of the paranasal sinuses were suggestive of a maxillary mucocele. Endoscopic sinus surgery and Caldwell-Luc procedure were performed to remove the mucocele that filled the maxillary sinus. Because the eyeball prolapsed through the defect in the inferior orbital wall to the maxillary antrum, a Silastic sheath was placed between the orbital base and the eyeball. No postoperative complication was observed.

Mucoceles are defined as chronic, cystic lesions in the paranasal sinuses. When the mucocele content becomes infected, the lesion is defined as mucopyocele. Involvement of the maxillary sinus is rare. A 26-year-old male patient presented with left-sided facial swelling and nasal obstruction that had a history of six months. He had several episodes of sinus infections treated with antibiotics. His visual acuity was not affected. A computed tomography scan showed complete opacification of the left maxillary sinus with expansion through the medial wall of the antrum and hard palate, and thinning and destruction of the adjacent bony structures. The lesion was excised via a sublabial approach. During surgery, the cystic mass had yellowish color with foul-smelling mucopurulent material. In light microscopy, the cystic mass was diagnosed as mucopyocele.

There is considerable confusion in the literature regarding the terminology and distribution of cysts and pseudocysts of the maxillary antrum, which are therefore often lumped together as dome-shaped shadows on the floor of the maxillary sinus. We report a case of a mucocoele of the maxillary antrum that occurred in a 25-year-old male and review the clinical, radiographic and histological features of cysts and pseudocysts of the maxillary sinus including antral mucocoeles, postoperative maxillary cysts, pseudocysts and retention cysts; and highlight some of the pertinent distinguishing features. Awareness of the appropriate nomenclature and correlation of clinical, radiographic and histological features will generally result in the correct diagnosis and proper treatment.

5 patients (1 woman, 4 men) with mucoceles of the paranasal sinuses were hospitalized in ENT Department in Kalisz from 1992 to 2001. In two cases mucocele was in frontal sinus and penetrated to orbita, in next two cases it was in maxillary sinus. In the case of woman mucocele was in ethmomaxillary complexus and destroyed medial and inferior orbit's walles. All patients were operated and completely cured.

Four patients with mucocele of maxillary sinus, observed between 1995 and 2001, with two years' follow-up, are described. Aim of the present study was to establish whether endoscopic marsupialization of the maxillary sinus mucocele is adequate resolutive treatment without complete removal of the mucocele wall, using more invasive approaches. The surgical procedure used was endoscopic endonasal marsupialization by a middle and/or inferior meatal antrostomy. Outcome confirms that this technique is the gold standard treatment in this disorder. In fact, complete removal of the mucocele wall is not necessary thus avoiding the risk of iatrogenic lesions of neighbouring structures in the case of a bony erosion (orbital floor, posterior wall of the maxillary sinus).

Two cases of post-traumatic maxillary sinus mucoceles are described. In both scenarios, the patients had sustained severe facial injuries many years prior to presentation. Proptosis and globe displacement were identified clinically, and both patients had radiographic evidence of a maxillary sinus mucocele. Maxillary sinus mucoceles may occur as a late complication of facial fractures even if the draining ostium is normal.

Endoscopic endonasal surgery has been applied to the treatment of paranasal mucoceles. The approach is, however, hard to be adopted for maxillary mucoceles when the cyst is situated in the anterior and/or lateral portion of the maxillary sinus, has a thick bony lateral wall of the inferior nasal meatus, and when the patients develop compartmentalized cysts following facial trauma or sinus operation. We devised an endoscopic approach via the vestibule of the nose to reach any part of the maxillary sinus and applied it for the treatment of postoperative maxillary mucoceles, which could not be opened following the usual endoscopic approach with favorable outcomes.

CT signs of thirty-six cases of maxillary mucocele surgically and pathologically proved were analyzed. 20 of 36 cases revealed as low density lesion. 16 of 36 cases revealed as isodensity or high density lesion. They were morphologically classified as three types: nodular type, inflammatory type, bony defect type. Cystic morphology and fluid density within the lesion obviously indicated mucocele. Differential diagnosis should be made between mucocele and polyps, when the lesion revealed as soft tissue density. Inflammatory type need to be distinguished from maxillary inflammation. And bony defect type should be distinguished from the benign or malignant tumor of maxillary sinus. The islet sign and bone sclerosis are considered to be valuable for the differential diagnosis.

The authors report a case of an antral mucocele secondary to obstruction of the antral ostium by a non-Hodgkin's lymphoma. Antral mucoceles are rare, and this is the first report of one such caused by a nasal lymphoma.

A rare case of compartmentalized maxillary sinus mucocele 12 years after a Caldwell-Luc operation is reported. The two separate mucoceles were drained intranasally by endoscopic sinus surgery. The clinical features of this mucocele are presented and the incidence, presentation and theories on formation of post-operative mucoceles are reviewed.

Mucocoeles of the paranasal sinuses most commonly occur in the frontal or anterior ethmoidal sinuses. We report two rare cases of mucocoele of the maxillary sinus and describe the presentation, investigations and treatment. A review of the literature on this rare clinical entity is included, with specific reference to diagnostic imaging to distinguish mucocoeles from neoplastic sinus disease.

Maxillary sinus mucocoeles are rare, but may cause significant problems outside the sinus including diplopia and cheek swelling. We present 9 patients suffering from maxillary sinus mucocoele, including one patient with bilateral involvement, representing 10 involved sinuses. Eight sinuses were treated endoscopically and followed-up for 3 to more than 6 years; one of these developed a recurrence. Two sinuses were treated using a classical external approach (Caldwell-Luc), one at the beginning of our series, and one as the endoscopic technique was difficult to perform due to loss of anatomical landmarks. One of these two sinuses developed a recurrence and was then successfully treated endoscopically. We discuss the aetiology, pathogenesis and appropriate treatment of this unusual condition. Endoscopic treatment appears to be effective and leads to minimal recurrence. The aim is to perform a wide removal of the medial wall of the maxillary sinus including most of the inferior turbinate, immediately posterior to the lachrymal duct leaving intact the sinus mucosa. In some cases, however, the endoscopic technique can be difficult to perform due to loss of essential anatomical landmarks and in these cases recourse to an external approach may be necessary.

The maxillary sinus is an uncommon site for mucoceles within the paranasal sinuses. In this study nine patients with maxillary sinus mucoceles are presented. Six of these patients were treated by open approaches, and three were treated by endoscopic drainage alone. For uncomplicated maxillary sinus mucoceles, endoscopic drainage appears to be a reasonable approach, whereas for more complicated cases extending outside the sinus, open approaches may be required.

The prevalence of radiographic maxillary sinus findings in 293 elderly subjects (76, 81, and 86 years old) were investigated with the use of panoramic radiography: 124 subjects were edentulous in both jaws, 167 had an edentulous maxilla, and 169 had at least one natural tooth left. Mucous cysts or diffuse mucosal thickenings were found in 12% of the subjects. Of the mucosal thickenings, 70% were found in subjects with a dentate upper jaw (p < 0.05), suggesting an odontogenic origin for that proportion (40%) exceeding the prevalence in subjects edentulous in the maxilla. That the prevalence of mucous cysts was 5% both in subjects with a dentate upper jaw and in those with a edentulous upper jaw suggests nonodontogenic causes.

Although mucosal antral cysts (MACs) are a frequent finding in surveys of panoramic radiographs in several western populations, its prevalence has not been reported in an oriental population. The panoramic radiographs of two sets of 1000 consecutive patients attending the University of Hong Kong Dental School in 1981 and 1990 were reviewed. The mean prevalence of MACs was 5.2% and they were twice as frequent in males. There was no significant difference in either the prevalence or the mean area of the MACs in patients with periapical bone loss and/or complaining of pain and swelling arising from dental disease in the adjacent maxillary alveolus when compared with those without. It is concluded that the prevalence and presentation of MACs in this oriental population is broadly consistent with that reported in western populations.

Maxillary antral mucoceles are extremely rare. We report a case of a large antral mucocele presenting with facial asymmetry. The CT scan was essential for delineating the extent of the lesion and aiding in the pre-operative diagnosis. The pathogenesis, clinical features and radiological aspects of this entity are reviewed.

Mucocele of the maxillary sinus is a rare affection his pathogenesis is still discussed, with a prevalence of the injury's and inflammatory's theories. The diagnosis being confirmed by computed tomography imaging ... We report in this study, 3 cases of maxillary sinus mucocele, with a review of literature.

Sonography has recently gained attention as a non-invasive technique improving the diagnostic accuracy of conventional radiology as regards the pathologic conditions of the maxillary sinus. Eighty-two patients with various pathologies of the maxillary sinus--i.e. acute/chronic sinusitis, mucocele, mucopyocele, polyp, and carcinoma--were submitted to US after preliminary conventional radiographs and before CT and surgical treatment (both performed in selected cases only). US proved useful in detecting liquid exudate, mucosal hypertrophy, and lesions of the anterior wall, while it was not as accurate in detecting lesions of the posterior wall (unless fluid was present) and in establishing the nature of a solid lesion. The last two conditions are those where CT is mainly indicated.

Mucocoeles of the maxillary antrum extensive enough to cause local bone destruction appear to be extremely rare. Such a case is reported with the appropriate pathological and radiological findings. Perusal of the literature suggests that this condition, unlike mucocoeles arising in other sinuses, may closely mimic a carcinoma and all authors stress the necessity for Caldwell-Luc surgery to be certain of the diagnosis. Som and Shugar (1980) describe features visible on CT scanning which may help to differentiate between mucocoeles, pyocoeles and carcinomata. In spite of the relatively high incidence of cysts of the antrum, it is thought unlikely that mucocoeles in this location would arise from such a cyst; indeed it is likely that all mucocoeles arise from blockage of the outflow tract of the appropriate sinus. There is a high incidence of maxillary sinus mucocoele in Japan following Caldwell-Luc surgery (Hasegawa et al., 1979). Noyek and Zizmor (1976) suggest that compartmentalization of the antrum after operation may leave islands of mucosa without drainage; such a collection may give rise to a mucocoele.