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Maxillary Sinusitis of Endodontic Origin

 By Dr. Roderick W. Tataryn

As endodontists, we take pride in our ability to accurately diagnose endodontic disease, diligently sleuthing out pulpal and periapical pathoses with careful clinical tests and radiographic imaging.  We que into the slightest variations in percussion, palpation, thermal responses, and periodontal defects, and we notice tiny subtleties on radiographic imaging. But what happens when endodontic infection doesn’t look or feel like typical endodontic infection? What if endodontic disease, even in its most advanced, symptomatic stages, produces no dental pain, no clinical signs of swelling or sinus tracts, and no radiographic findings of ligament widening or osseous changes? And what if patients suffering with these advanced endodontic infections seek care from medical doctors who attempt treatments, sometimes for years, without ever recognizing the endodontic source? This situation is more common than perhaps many of us realize, occurring daily, all around us in our communities.

Endodontic infections that develop in the maxillary posterior teeth can easily spread into the maxillary sinuses causing pathological effects that frequently go unrecognized by both patients and clinicians alike. Failure to diagnose and properly manage these endodontic infections can lead to symptomatic sinus disease, defined as maxillary sinusitis of endodontic origin (MSEO).

Patients with MSEO experience common sinonasal symptoms, which include congestion, rhinorrhea, retrorhinorrhea, facial pain, and foul odor, yet they rarely experience typical endodontic symptoms. Thermal pain is normally absent because source teeth for MSEO are either necrotic or have failing endodontic therapy. Percussion tenderness is typically absent in MSEO because periapical infection is essentially draining into the sinus, eliminating pressure.  For this same reason, swelling or intraoral sinus tracts rarely form.

Patients with sinonasal symptoms and without localized dental pain will often first seek care from their primary care physician or ear, nose and throat (ENT) specialist who may misdiagnose and treat MSEO as a rhinogenic sinus infection. Unfortunately, odontogenic sinus infections are often overlooked during routine ENT examinations and by radiologists reading sinus CT imaging. Sadly, current ENT clinical guidelines for the medical management of sinusitis offer no guidance in this area, making no mention of dental infections as a potential etiology for sinus disease despite abundant evidence in the medical literature of its high prevalence. Studies indicate that more than 40% of maxillary sinusitis cases are odontogenic, increasing to over 70% when maxillary sinus infections are unilateral. The American Association of Endodontists has recently published a Position Statement on Maxillary Sinusitis of Endodontic Origin as well as a Colleagues for Excellence issue to be widely distributed among our dental and medical colleagues in attempt to raise awareness of this condition and direct patients to endodontists who can properly diagnose and treat it.

Symptomatic or asymptomatic apical periodontitis near or in direct contact with antral mucosa will typically produce a localized mucosal tissue edema in the floor of the sinus termed periapical mucositis (PAM). PAM may progress causing partial or full obstruction of the maxillary sinus, which also can advance to involve other paranasal sinuses. Often no evident apical bony destruction occurs, especially when root apices protrude through the sinus floor, making many PAM or sinus obstructions difficult to recognize radiographically as having an endodontic source. A history of unilateral sinus infections, particularly if recurrent and/or associated with a patent ostium, is a strong indicator for possible MSEO. As with all endodontic diagnoses, a determination of etiology cannot be made based on radiographic examination alone.  Careful clinical endodontic examination is imperative to confirm or rule out an endodontic source for mucosal abnormalities or sinusitis.

When diagnosing a possible endodontic etiology for sinusitis, the endodontist must look carefully for any teeth with pulpal necrosis and evaluate all prior endodontic treatments for possible failure in the suspected quadrant. Because MSEO is a bacterial disease, only teeth with an infected necrotic pulp or failing endodontic treatment will cause significant sinonasal disease or sinonasal symptoms. When examining maxillary posterior teeth with existing root canal treatment, one must carefully examine for any untreated or sub-optimally filled canals, inadequate core restorations, or leaking coronal restorations that may provide evidence of endodontic failure and a bacterial source for MSEO.

The objectives for treatment of MSEO are removal of the pathogenic microorganisms, their by-products, and pulpal debris from the infected root canal system that are causing the sinus infection and preventing reinfection. Use of systemic antibiotics to manage MSEO should follow the guidelines set forth in the AAE Guidance on the Use of Systemic Antibiotics in Endodontics. Apart from spreading infections, antibiotic therapy is unwarranted in the treatment of MSEO and ineffective as a definitive solution. While antibiotic therapy may offer temporary relief of symptoms by improving sinus clearing, their sole use is inappropriate without definitive debridement and disinfection of the root canal system.

Similarly, surgical intervention of the maxillary sinus that is focused strictly on removing diseased sinus tissue and establishing drainage is inadequate if the endodontic component is neglected. Although these procedures are performed by ENT surgeons with the goal of re-establishing sinus aeration and drainage, and may provide relief of some symptoms, it is well documented that neglecting the dental etiology and focusing only on medical and surgical therapies of the ostiomeatal complex (OMC) will not resolve MSEO.

The dental literature provides numerous case reports showing full resolution of MSEO following endodontic treatment. It should be noted, however, that endodontic treatment alone may not resolve all cases of MSEO, therefore clinical and radiological follow-up is essential as concomitant management of the associated rhinosinusitis by an ENT specialist may be necessary in some cases. Improved communication and collaborative referral relationships between general dentists, endodontists, and ENT surgeons is essential to achieve the best outcomes for patients suffering with MSEO.

MSEO is fundamentally an endodontic infection manifesting in the maxillary sinus.  It is up to us as endodontists to bring awareness to the medical community of this underappreciated and frequently unrecognized disease process. After all, MSEO is endodontic disease.

Works Cited

Longhini AB, Ferguson BJ. Clinical aspects of odontogenic maxillary sinusitis: a case series. Int Forum Allergy Rhinol 2011;1:409–415.

Patel NA, Ferguson BJ. Odontogenic sinusitis: an ancient but under-appreciated cause of maxillary sinusitis.  Curr Opin Otoloaryngol Head Neck Surg 2012;20:24-28.

Pokorny A, Tataryn R. Clinical and radiologic findings in a case series of maxillary sinusitis of dental origin. Int Forum Allergy Rhinol 2013;3:973-979.

Rosenfeld RM, Piccirillo JF, Chandrasekhar SS, et al. Clinical practice guideline (update): Adult sinusitis executive summary. Otolaryngol Head Neck Surg 2015;152:598–609.

Fouad AF, Byrne BE, Diogenes AR, et al. AAE Guidance on the Use of Systemic Antibiotics in Endodontics. American Association of Endodontists Position Statement 2017:1-8. Available at: .

Tataryn RW, Lewis MJ, Horalek ML, et al. Maxillary Sinusitis of Endodontic Origin. American Association of Endodontists Position Statement 2018:1-11. Available at: .