Root resorption caused by a maxillary sinus mucocele: a casereportJosé Marques, DDS,a Rui Figueiredo, DDS,b José Manuel Aguirre-Urizar, DDS, MD, PhD,c

Leonardo Berini-Aytés, DDS, MD, PhD,d and Cosme Gay-Escoda, MD, DDS, PhD,e Barcelonaand Leioa, SpainUNIVERSITY OF BARCELONA, IDIBELL RESEARCH INSTITUTE, AND UNIVERSITY OF THE BASQUE COUNTRY

A maxillary sinus mucocele is an infrequent but benign lesion that develops from the obstruction of aseromucous glandular duct of the maxillary sinus mucosa. This clinical entity is generally asymptomatic and self-limited. Mucoceles are described as rounded dome-shaped soft tissue masses frequently located on the floor of themaxillary sinus. In this paper, we present a case of a slightly radiopaque well defined shadow arising from the leftmaxillary sinus floor that produced the root resorption of the upper second left molar. After the surgical removal of thelesion through a Caldwell-Luc approach, histologic study confirmed the initial diagnosis of mucocele. This case reportemphasizes the need of clinical and radiologic follow-up to detect any complications associated with these benignlesions, because, in rare occasions, they can show an aggressive growth pattern. (Oral Surg Oral Med Oral Pathol

Oral Radiol Endod 2011;111:e37-e40)

Mucoceles develop when a duct of a seromucous glandof the maxillary sinus mucosa becomes obstructed,resulting in a cystic dilation of the gland. This contin-ued mucous secretion might lead to the development ofan expanding epithelial-lined mass which thins andultimately erodes the bone sinus margins.1-3

The reported incidence of these lesions is 1.4%-9.6%, occurring primarily during the third and fourthdecades of life, and it is usually discovered when rou-

Supported by an educational assistance agreement for oral surgeryamong the University of Barcelona, the Consorci Sanitari Integral,and the Servei Català de la Salut-Generalitat de Catalunya (CatalanHealth Service).This study was researched and compiled by the consolidated Re-search Group in Dental and Maxillofacial Pathology and Treatmentof the Institut d‘Investigació Biomèdica de Bellvitge (IDIBELL).aFellow, Master of Oral Surgery and Orofacial Implantology, Schoolof Dentistry, University of Barcelona.bAssociate Professor of Oral Surgery and Professor, Master of OralSurgery and Orofacial Implantology, School of Dentistry, Universityof Barcelona; IDIBELL Research Group.cProfessor and Chairman, Unit of Oral Medicine, Unit of Oral andMaxillofacial Pathology, Faculty of Medicine and Dentistry, Univer-sity of the Basque Country/EHU, Leioa, Spain.dProfessor of Oral Surgery and Professor, Master of Oral Surgery andOrofacial Implantology, School of Dentistry, University of Barce-lona; IDIBELL Research Group.eChairman and Full Professor, Oral and Maxillofacial Surgery, andDirector, Master of Oral Surgery and Orofacial Implantology, Schoolof Dentistry, University of Barcelona; IDIBELL Research Group;Oral and Maxillofacial Surgeon, Teknon Medical Center.Received for publication Dec. 8, 2010; accepted for publication Dec.15, 2010.1079-2104/$ - see front matter© 2011 Mosby, Inc. All rights reserved.

doi:10.1016/j.tripleo.2010.12.008

tine radiologic examinations are taken.3-4 Generally,mucoceles are a self-limiting condition, with a rate ofspontaneous regression and disappearance of 17.6%-38%.4

The etiology underlying mucocele formation is mul-tifactorial. Impediments to sinus ostium ventilation arethought to be the primary cause, resulting from ana-tomical obstruction, mucosal hyperplasia, mass lesions,or other mechanical factors.5,6 Fu et al.6 classify para-nasal sinus mucoceles as primary and secondary, basedon their anatomic and invasive characteristics. The pro-posed mechanisms for primary mucocele formation arethe inflammatory blockage of mucus drainage, secre-tory duct obstruction and cystic degeneration of polyps.Furthermore, it is suggested that the retention of resid-ual mucosa in the wound and long-term contact oftissue fluid could also lead to the formation of second-ary mucoceles. The same study states that primarymucoceles have a greater potential to cause intraorbitalextension compared with secondary mucoceles.6 Theselesions are relatively common complications of sinus-itis and are seen most often in the frontal and ethmoidregions.7 Radiographically, the mucocele is a roundeddome-shaped soft tissue mass frequently located on thefloor of the maxillary sinus and usually filled with clearyellowish fluid.7-9 It is generally asymptomatic, but itcan cause facial swelling, nasal obstruction, postnasaldrip, nasal discharge, headache, or periorbital or dentalpain due to pressure exerted on the mucosa lining. Inrare cases, it can also grow and encroach on the inferiororbital floor, causing ocular displacement, nerve com-

pression, lower lid distortion, ptosis, and proptosis.10

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OOOOEe38 Marques et al. May 2011

Commonly, these lesions do not require treatment,unless symptoms appear.4 Traditionally, mucoceleshave been treated by means of direct puncture andaspiration through the inferior meatus or natural os-tium, or removed by using the Caldwell-Luc approach.More recently, endoscopic intranasal sinus surgery hasbeen used to remove mucoceles of the maxillary si-nus.9,11,12 However, this approach requires furthertraining and appropriate equipment, raising treatmentcosts. Furthermore, the patient’s anatomy can increasethe difficulty of this procedure.13,14

The present paper describes the diagnosis and treat-ment of a case of a maxillary sinus mucocele that wasproducing the root resorption of the upper second leftmolar. A review of the literature focusing on the mainclinicopathologic and therapeutic aspects is also pro-vided.

CASE REPORTA 39-year-old female, allergic to latex and metamizole,

showing no systemic pathology, reported to her dentist toextract the left lower first molar. In the panoramic radiogra-phy, a slightly radiopaque well defined shadow arising fromthe left maxillary sinus floor, compatible with mucocele, was

Fig. 1. A, Preoperative panoramic radiography, showing anopacified lesion in the left maxillary sinus floor, as well as theroot resorption of the left upper second molar. B, Panoramicreconstruction of a computerized tomographic scan, showinga rounded dome-shaped radiopacified mass with smoothclear-cut margins of bone erosions occurring in the sinuswalls.

detected (Fig. 1, A). The roots of the left upper second molar,

which were in direct contact with the lesion, presented aconsiderable degree of resorption. Nevertheless, pulp vitalitywas maintained for this tooth. The clinical examination didnot show any relevant changes, and the patient was com-pletely asymptomatic. A computerized tomographic (CT)scan of the paranasal sinus confirmed the existence of anopacified lesion in the left maxillary sinus floor (Fig. 1, B).

Because this lesion showed an aggressive pattern, espe-cially considering the resorption of the adjacent second molar,it was decided to remove it by using the Caldwell-Luc ap-proach under local anesthesia (articaine in a 4% solution withepinephrine 1:100,000 [Ultracain; Normon, Madrid, Spain]).A horizontal incision was made in the alveolar ridge, withvertical releasing incisions at the level of the canine and thesecond molar. After raising a full-thickness flap, the bone wasremoved from the lateral wall of the maxillary sinus withsterile low-speed handpieces using a diamond drill, underprofuse sterile saline irrigation. The sinus mucosa was raisedand perforated through the window to dissect and remove thecystic lesion (Fig. 2). A reabsorbable collagen membrane

Fig. 2. A, Removal of the cystic lesion through the windowpreviously made in the lateral wall of the left maxillary sinus.B, Appearance of the removed lesion.

(BioGide; Geistlich Biomaterials, Wolhusen, Switzerland)

OOOOEVolume 111, Number 5 Marques et al. e39

was then used to seal the sinus membrane perforation, as wellas the lateral wall of the maxillary sinus. The mucoperiostealflap was detached to facilitate stress-free repositioning, and4/0 silk sutures (Silkam; Braun, Tuttlingen, Germany) wereused to close the wound. After the surgical procedure, thepatient was prescribed an antibiotic (amoxicillin 875 mg andclavulanate 125 mg every 8 hours for 10 days [Augmentine875/125 mg; GlaxoSmithKline, Madrid, Spain]), a nonsteroi-dal antiinflammatory drug (ibuprofen 600 mg every 8 hoursfor 7 days [Algiasdin 600; Esteve; Barcelona, Spain]), asingle dose of a corticosteroidal drug (methylprednisolone 40mg [Urbason 40 mg; Aventis Pharma, Madrid, Spain]), and amouthrinse (0.12% chlorhexidine digluconate every 12 hoursfor 15 days [Clorhexidina Lacer; Lacer, Barcelona, Spain]).Postoperative instructions together with explanations on theprescribed drugs were given verbally as well as written in-formation to the patient. No complications were registered.

The histologic study confirmed a definitive diagnosis ofmucocele. The cyst wall was �1 mm thick and showed a thinlayer of soft connective tissue, with a moderate lymphoplas-macytic inflammatory infiltrate, as well as foaming macro-phages and congested vascular structures. The sample wascoated by a ciliated pseudostratified epithelium with someareas of squamous metaplasia phenomena (Fig. 3).

Six months after surgery, the patient did not present anyclinical or radiographic complications. The thermal pulp vi-tality tests of the affected molar showed no alterations, and nopathologic mobility of the tooth was observed.

DISCUSSIONMucoceles of the paranasal sinuses are benign cyst-

like expansible lesions lined with a secretory respira-tory mucosa of pseudostratified columnar epithelium.This kind of lesion grows slowly, and could be origi-nated from an obstruction of the sinus outflow in com-bination with superimposed infection, which can causethe release of cytokines from lymphocytes and mono-cytes. The cytokine release would stimulate fibroblaststo secrete prostaglandins and collagenases, which couldeventually lead to bone resorption.5,10

The diagnosis of mucocele is made on the basis ofsymptoms, imaging, surgical exploration, and, fore-most, histologic confirmation. The symptoms com-monly associated with the presence of mucoceles arerelated to their expansion, usually through the least-resistant path, and subsequent pressure on surroundinganatomic structures.4,5 In the present case, the patientdid not present any symptoms related to this lesion;however, root resorption of the second left upper molarwas taking place. This is a quite uncommon phenom-enon, and we failed to find in the literature any pub-lished cases showing similar findings.

CT is paramount for the diagnosis of mucoceles. Itnot only demonstrates sinus involvement, but it alsoprovides information about bone erosion and other ef-fects on neighboring structures. CT shows mucocele as

a homogeneous lesion with smooth clear-cut margins of

bone erosions occurring in the sinus walls. In contrast,malignant lesions usually present irregular shapes, ero-sions or destruction of the sinus walls, infiltration intothe surrounding soft tissues, and irregular margins ofbone absorption.5,9,10

It is very important to perform a correct differentialdiagnosis, including mucoceles and other radiopaquelesions, benign or malign, of the maxillary sinus. Be-nign lesions refer to neurofibroma, dermoid, epider-moid, and cementifying fibroma, angiofibroma, invert-ing papiloma, and cylindroma. Malignant lesionsinclude adenoid cystic carcinoma, plasmocytoma, em-bryonal rhabdomyosarcoma, lymphoma, schwannoma,and odontogenic tumors.5,9 In the absence of boneerosions, mucoceles must be differentiated from severalconditions, such as retention cysts, chronic sinusitis,antrochoanal polyp, and polyposis of the paranasal cav-

Fig. 3. Histologic images of the removed maxillary sinusmucocele (hematoxylin and eosin stain). The cyst is lined byrespiratory epithelium and shows a mild chronic inflamma-tory infiltrate. Magnification: A, �40; B, �50.

ities.5,9

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Wang et al.4 suggested the following guidelines formanagement of mucoceles of the maxillary sinus. Afterthe initial detection and in the absence of symptoms,follow-up radiography should be performed �48months later. If the lesion has not changed significantlyin size at that time there is a low probability that it willincrease in the longer term. Nevertheless, if the lesionhas enlarged significantly after 48 months, it is likely toincrease further. Therefore, a second follow-up within48 months is required. However, unless the mucocelecauses any complications, there is no need for anysurgical or medical treatment.4 In the present case re-port, the need for surgical removal was obvious, be-cause it was producing the root resorption of the adja-cent molar.

There are some surgical options available to elimi-nate these lesions. Some authors mention that intranasalendoscopy techniques offer good results with very lowmorbidity.9,11,12 Nevertheless, these procedures requirevery specific equipment, not usually available in dentaloffices, and the need for an experienced surgeon. Aconventional lateral wall approach also has some ad-vantages, in our opinion. It is a simple and safe tech-nique, with a very low complication rate, and thatallows a good exploration of the maxillary sinus. Fur-thermore, it permits performing sinus augmentationtechniques in the same surgical procedure.

The present case demonstrates that benign disorderssuch as mucoceles of the maxillary sinus can, in rareoccasions, show an aggressive growth pattern. There-fore, these lesions should be included in the differentialdiagnosis of pathologies that produce root resorption ofmaxillary premolars and molars. The surgical removalof this lesion allowed the preservation of the uppersecond molar, and no relapse was observed after 6months.

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Reprint requests:Rui FigueiredoFacultat d’OdontologíaUniversitat de BarcelonaCarrer Feixa Llarga s/nPavelló Govern, Despatx 2.908907 L’Hospitalet de LlobregatBarcelonaSpainhttp://www.ruibf.com

rui@ruibf.com