Volume 2, Issue 3 US $6.00 Editor: Pathologic conditions of the Allan G. Farman, BDS, PhD (odont.), DSc (odont.), maxillary sinus Diplomate of the By Dr. Allan G. Farman in American Board of Oral image layer will be demonstrated. collaboration with Dr. C.J. Nortjé and Maxillofacial As the panoramic image layer most Radiology, Professor of closely reflects the dental arch, Radiology and Imaging Radiography of the maxillary sinus disease occasionally arises Sciences, Department of sinuses is often undertaken using within the sinuses outside the image Surgical and Hospital computed tomography, magnetic layer. Dentistry, The University of resonance imaging, or the Diseases of the maxillary sinus Louisville School of occipito-mental plain x-ray film are comparatively frequent, even in Dentistry, Louisville, KY. projection. However the panoramic apparently young individuals – with radiograph has been found rates in excess of one in five Contributor: superior to the latter for detection individuals examined using the of “cyst-like densities.” [1]. The Waters’ projection (mucosal Dr. C.J. Nortjé, BChD, PhD, DSc, occipito-mental technique, first thickening 12.3%; cysts or polyps Professor and Chairman of described by Waters and Waldron, 7.2%; opacified sinus 3.3%) [5]. For Oral and Maxillofacial clearly demonstrates the superior, this reason, it is incumbent upon the Radiology, Tygerberg, South inferior and lateral margins of the dental practitioner to understand Africa, President-Elect of the International Association of maxillary sinuses while reflecting the panoramic radiological features Dentomaxillofacial Radiology. the shadows of the petrous of disease and normal variations temporal bones downwards below within the paranasal sinuses. the inferior margin of the sinuses [2]. Certainly the patient should not be Featured Article: It also demonstrates well any soft referred to an ear, nose and throat tissue or fluid contents of the sinus specialist for every instance of Pathologic conditions of [1]; however, this method does not antral mucosal thickening or the maxillary sinus display the cortices of the anterior mucous retention cyst (Fig. 1 &2), nor and posterior wall. should the dentist ignore features In The Recent Literature: While CT, MRI and the Waters’ that possibly reflect an early projection are well suited to malignancy. The reputation of a Oral Cancer demonstrate the maxillary sinuses, practitioner is greatly enhanced these methods are only employed given appropriate referrals that can Maxillofacial Trauma if there are signs and symptoms of make the difference between life disease, by which time the and death. Failure to diagnose, on prognosis for patients having such the other hand, can result in insidious disease as squamous-cell notoriety. carcinoma can be poor [3]. Nortjé et al [3] were among the Extensive lesions occupying the first to comprehensively study the maxillary sinus can produce appearance on panoramic dental surprisingly few clinical features [4]. radiographs of pathological For this reason, the panoramic conditions affecting the maxillary radiograph can be the primary sinuses, comparing inflammatory indication of maxillary sinus conditions of dental origin, disease. While panoramic iatrogenic disease/foreign bodies, radiography can be used to non-odontogenic inflammatory detect maxillary sinus disease, it conditions, cysts, benign cannot be used to entirely exclude neoplasms, malignant neoplasms sinus pathology. Only the portions and dysplasias affecting the of the sinus that are within the maxilla. “ The early detection of insidious maxillary sinus disease can be very important for the patient’ prognosis, especially in the case of malignant neoplasia.” Chronic abscesses resulted in a Fig. 1. Mucous retention loss of the outline of the lower “cyst”: detail from panoramic radiograph shows border of the sinus where it abutted domed soft tissue density in the associated tooth, and a related left maxillary sinus (arrow). thickening of the sinus mucosa was occasionally evident. Radicular cysts (generally associated with the root apex of a carious or fractured tooth) and residual cysts caused an upward displacement of the floor of the sinus, but the cortical outline remained intact. Extensive dental cysts extended into the sinus away from the original epicenter (Fig. 3). Even a very large radicular cyst arising in the maxilla resulted in surprisingly little in the Fig. 2. Mucous retention way of clinically noticeable jaw cyst of maxillary sinus (arrow) shown using the expansion. Dentigerous cysts had a occipito-mental projection similar effect on the floor of the (Waters’ projection). This maxillary sinus to that observed for projection can be made radicular cysts, however, the using the ceph dentigerous cyst enveloped the attachment available for use with panoramic crown of an unerupted tooth. As the systems. tooth was displaced there was the appearance of a tooth suspended within the sinus. Odontogenic keratocysts are homogeneous radiolucencies that might be unilocular, crenulated or multilocular in outline, and occasionally they envelope unerupted teeth (Fig. 4). These also tend to displace the sinus floor and to extend into the sinus while producing little in the way of jaw expansion. Benign tumors in general displaced the sinus floor and expanded into the maxillary sinus rather than outwards (Fig. 5). Trabeculation within multilocular tumors such as the myxoma and the ameloblastoma frequently obscured the maxillary sinus outline. In comparison with benign Fig. 3. Radicular cyst on carious right neoplasms, malignant tumors maxillary lateral incisor. The lesion is a affecting the portion of the sinus well-delineated unilocular homogeneous radiolucency. It has grown so large that it screened by the plane of the has caused a displacement of the panoramic radiograph resulted in ipsilateral anterior wall and floor of the irregular erosion of bone. maxillary sinus. Primary malignancies affecting the maxillary sinus include squamous-cell carcinoma, adenoid cystic carcinoma and adenocarcinoma [7]. The maxillary sinus may also be affected secondarily by extension malignancies of the oral soft tissues or jaw, and also, although rare, is the site of metastases from distant sites [8]. Owing to their radio-opacity, roots or whole teeth displaced into Fig. 4. Odontogenic keratocyst: multiple lesions in the sinus are readily apparent even both jaws in nevoid basal cell carcinoma syndrome. when not centered within the The maxillary lesions are unilocular while the image layer. These need to be mandibular lesions are crenulated and multilocular. There is displacement of “enveloped” teeth, some differentiated from sinus bone of which apparently “float” in the maxillary sinuses nodules and antroliths (calcified (e.g. arrows). “stones” arising in the antral lining) both of which entities could be Fig. 5. Benign mistaken for teeth or displaced neoplasm, roots [9]. Foreign bodies, such as adenomatoid bullets, are clearly demonstrated; odontogenic tumor: however care needs to be made to unilocular lesion in the left maxilla subjacent differentiate between clearly to the canine tooth demarcated real images, and (cropped panoramic, blurred magnified ghost images of occlusal and foreign bodies or jewelry more specimen distally and lower placed in or on radiographs). Note displacement of the contralateral side of the face. maxillary sinus floor Oroantral fistulas following dental (arrow). extraction are only noticeable on panoramic radiography when large – and within the panoramic image layer. Regarding inflammatory conditions of non-odontogenic origin, these are usually clearly demonstrated on panoramic radiography if they involve mucosal thickenings arising from the floor of the maxillary sinus. The most Fig. 6. Fibrous dysplasia: cropped panoramic radiograph frequent example of such a showing mature (late) lesion of process is the mucous retention the left maxilla, obscuring the phenomenon. This is seen as a sinus. The lesion is radio- smooth dome-shape swelling of opaque with some radiolucent the mucosa with homogeneous mottling. It has a ground (frosted) glass appearance. radiodensity. The sinus floor is not The lesion melds with the displaced or eroded. A mucous normal surrounding bone. retention phenomenon is rarely symptomatic; it requires no Fig. 7. Paget’s treatment. Antral polyps are only disease of bone: clearly demonstrated when Note cotton-ball situated in the panoramic image radio-opaque layer. This is rarely the case; sclerotic deposits. There is maxillary hence, other radiographic views cortical expansion. are preferred. Opacified sinuses The lesion is or fluid levels may be found with bilateral, crossing acute sinusitis, which the midline accompanies the common (panoramic and lateral skull cold in 0.5-5% of cases [5;6]. radiographs). The maxilla can also be the site of a variety of dysplastic and fibro-osseous conditions. Fibrous dysplasia can cause the partial or complete occlusion of the sinus on the affected side of the maxilla (Fig. 6). This may arise in young children and is usually apparent by adolescence. It is generally unilateral. By way of comparison, Paget’s disease of Fig. 8. Late stage bone can also cause occlusion maxillary sinus of the sinus, but can affect both squamous-cell carcinoma sides of the maxilla and is found eroding through in an aging population (Fig. 7). the palate. Cherubism may affect the Prognosis is poor. maxillary tuberosities bilaterally This patient has as well as the mandibular