Dental infection and sinusitis...more common than we think
Odontogenic Sinusitis: The Overlooked Source of Sinus Disease
Understanding Odontogenic Sinusitis Odontogenic sinusitis (ODS) represents a distinct and often under-recognised subset of chronic rhinosinusitis (CRS). It is defined as sinus inflammation secondary to a dental or odontogenic process—hence sometimes referred to as secondary CRS. While CRS is classically associated with mucosal disease of nasal origin, a surprising proportion arises from dental pathology extending into the maxillary sinus. In the modern rhinology clinic, understanding, recognising, and optimally managing ODS is critical for effective patient outcomes. According to the European Position Paper on Rhinosinusitis and Nasal Polyps 2020 (Fokkens et al.), odontogenic processes should always be considered in unilateral sinus disease, particularly when maxillary involvement predominates. Epidemiology and Clinical Suspicion Unilateral disease is the first red flag. Studies show that nearly half of all unilateral maxillary opacifications have an odontogenic origin. Turfe et al. (2019) analysed 45 % of unilateral cases and found: - 44 % reported a foul smell, - 87 % had middle-meatal purulence, - 66 % had no mention of ODS on radiology, and - 88 % involved extra-maxillary extension—most commonly into the frontal sinus (60 %). Even more strikingly, in dental literature summarised by Vitali et al. (2023), the pooled global prevalence of ODS among affected sinuses reached 51 % (range 40–61 %). Risk factors included: - Apical lesions (odds ratio 4.03), - Periodontitis (OR 5.49), and - Bone loss—moderate (OR 2.57) to severe (OR 13.8). This data illustrates that half of what we call “maxillary sinusitis” is actually dental in origin.
Mechanisms: How Dental Pathology Breaches the Sinus The proximity of upper posterior teeth roots to the maxillary sinus floor creates a delicate anatomical relationship. Periapical infection, periodontitis, tooth extraction, or implant manipulation can disrupt the sinus membrane, providing a conduit for bacteria, foreign material, and inflammatory mediators to invade the sinus cavity. This invasion triggers mucosal inflammation, impaired mucociliary clearance, and eventual pan-sinus spread if untreated. As the disease evolves, secondary sinus involvement—especially of the ethmoid and frontal sinuses—is common, explaining why patients often present with broad sinonasal symptoms despite an odontogenic origin. Predictive Clinical Features Clinically, ODS can mimic routine sinusitis but carries several predictive hallmarks: Predictive Factor ODS Non-ODS p-Value Posterior discharge 63 % 45 % 0.004 Frontal involvement 58 % 38 % 0.019 (Goyal et al., 2021). A patient with posterior nasal discharge, unilateral frontal sinus opacification, or a foul odour should immediately prompt the clinician to review dental history, imaging, and examine the upper molars.
Diagnostic Imaging Pitfalls Despite modern CT capability, radiologists frequently miss odontogenic causes—two-thirds of ODS cases in Turfe et al.’s series had no mention of dental pathology on the report. High-resolution imaging with coronal bone windows should be scrutinised for: - Periapical lucencies, - Oro-antral fistulae, - Retained root fragments, and - Evidence of maxillary bone loss. Collaboration with dental colleagues is essential; panoramic and cone-beam CT may reveal subtle periapical pathology invisible on sinus CT alone. Medical Therapy: Often Ineffective A key distinguishing feature of ODS is its poor response to medical therapy. Because the nidus lies outside the sinus mucosa—within infected bone or dental structures—antibiotics and topical steroids seldom produce sustained relief. Temporary symptom reduction may occur, but recurrence is almost universal unless the dental source is eliminated. Thus, the maxim in ODS management is simple: “If you don’t treat the tooth, you’ll keep treating the sinus.” Dental Extraction Alone: How Often Is It Enough? Evidence suggests that 30–50 % of ODS cases resolve with dental extraction alone when disease is confined to the maxillary sinus. However, outcomes vary depending on the literature base: - Otolaryngology literature: Up to 77 % resolution reported with dental treatment alone—but many of these cases involved radiologic mucosal thickening without clinical symptoms, not true ODS. - True clinical ODS: Persistent symptoms are common, particularly when infection extends beyond the maxillary sinus or when secondary mucociliary dysfunction has set in. Craig et al. (2019) and Simuntis et al. (2020) note that extra-maxillary disease or persistent purulence predicts failure of dental-only management. When to Operate: The Role of Endoscopic Sinus Surgery (ESS) Once ODS is established, combined dental and sinus treatment produces the most reliable and fastest recovery. Antibiotics alone almost always fail because the obstructed ostiomeatal complex prevents drainage, and the dental nidus remains active. Optimal sequencing - ESS can precede or follow dental intervention, but timing affects recovery. - Yassin-Kassab et al. (2023) found: - Primary dental treatment: Mean resolution = 236 days. - Combined dental + ESS: Mean = 112 days (p = 0.002). Thus, combined therapy halves recovery time and achieves >97 % resolution rates. Surgical Principles and Extent of ESS The extent of sinus surgery should be tailored to disease spread: Disease Extent Surgical Strategy Evidence Isolated maxillary disease Maxillary antrostomy alone Equivalent outcomes to full ESS at 6 weeks (Craig et al., 2025) Extra-maxillary involvement (e.g. frontal, ethmoid) Complete ESS Slightly faster early resolution; similar final outcomes Oro-antral fistula (OAF) ESS + OAF closure Combined or staged management recommended Implant-related ODS ESS mandatory ± implant removal 94.7 % success rate (Allevi et al., 2022) The Craig et al. (2025) randomised comparison of 70 patients demonstrated no significant long-term difference between limited antrostomy and full ESS—though full ESS produced faster early endoscopic clearance. In short, a conservative approach is often sufficient, provided drainage and source control are achieved. Odontogenic Sinusitis Following Dental Implants With the surge in dental implant procedures, ODS following sinus lifts or grafts has become an important iatrogenic category. A systematic review by Allevi et al. (2022) covering 581 patients found: - 94.7 % success with ESS-based treatment, - Failures (2.6 %) occurred mainly in patients with sinus grafts or prior lifts, and - Most failures required implant removal. This underlines that ESS remains the cornerstone of managing post-implant sinusitis, even when the dental prosthesis must be sacrificed. Treatment Algorithm: Evidence-Based Integration The combined literature and clinical consensus allow a stepwise treatment framework for ODS: Clinical Category Management Strategy Rationale Treatable dental source; minimal sinus symptoms Dental treatment → reassess at 1–3 months Half may resolve without ESS Treatable dental source; significant sinus symptoms or extra-max disease Combined or staged ESS + dental management Faster resolution; prevents chronicity Oro-antral fistula (OAF) Combined ESS + OAF closure Prevents recurrent contamination No treatable dental source (e.g. prior extraction, healed) Culture-directed antibiotic trial → ESS if persistent Ensures residual infection eradicated Post-implant ODS ESS ± implant removal Highest cure rates with combined approach Medical therapy plays a supportive role only—for symptom relief, complication control, or post-surgical management. Timing, Sequencing, and the “Dental vs ENT First” Debate Which comes first—dental or sinus surgery? Recent multidisciplinary consensus (Craig et al., 2021; Otolaryngol Clin N Am 2024) resolves the controversy: - If sinus symptoms dominate, perform ESS first, followed by dental repair. - If dental infection dominates, begin with dental extraction, reassessing in 6–12 weeks. - The order matters less than ensuring both are addressed. - Incomplete treatment of either domain (tooth or sinus) yields high recurrence rates. The consensus highlights that collaboration between dentists, oral surgeons, and rhinologists is indispensable for success. Prognosis and Outcomes Outcomes for ODS are excellent when both dental and sinus disease are treated. - Combined therapy: Resolution > 95 %. - Dental-only or ESS-only therapy: Variable; recurrence up to 50 %. - Post-implant ODS: 95 % success with ESS. Patients typically note rapid relief of malodour and postnasal discharge, with SNOT-22 improvements mirroring idiopathic CRS outcomes at 6 weeks post-ESS. Clinical Pearls for Practitioners - Suspect ODS in any unilateral maxillary opacification. Half of such cases have dental origins—look beyond the mucosa. - Don’t rely solely on radiology reports. Up to 66 % omit dental pathology—review images personally. - Beware the “normal tooth” trap. Subclinical apical lesions or prior root canal therapy can still harbor infection. - ESS is not always extensive. A well-executed antrostomy may suffice if drainage and source control are achieved. - Communicate early with dental colleagues. A co-managed plan shortens disease duration and minimizes repeated antibiotics. Broader Lessons: Odontogenic Sinusitis as a Model for Multidisciplinary Care ODS embodies the intersection of rhinology and dentistry—a reminder that the paranasal sinuses do not exist in isolation. The high prevalence of dental origins in unilateral sinus disease mandates cross-disciplinary diagnostic pathways. From a systems perspective, improved radiology reporting templates and structured ENT–dental referral algorithms could reduce diagnostic delays that currently average months. Furthermore, ODS highlights the limits of empiric antibiotics in CRS. It is a paradigm of source control over symptomatic therapy—a principle applicable across infectious and inflammatory medicine. Conclusion Odontogenic sinusitis is common, under-diagnosed, and highly treatable. It accounts for roughly half of all unilateral maxillary sinus opacifications, yet remains missed on radiology two-thirds of the time. The key to successful management lies in recognition and collaboration: - Identify the dental source, - Employ combined dental and sinus treatment, and - Tailor surgery to disease extent. Medical therapy alone almost never cures ODS, but when treated with an integrated, multidisciplinary approach, patients enjoy rapid, durable resolution and restored sinonasal health. Assynthesis of the international literature makes clear, the future of sinus care will increasingly depend on the seamless collaboration between dentists and rhinologists—because half the sinuses we treat begin with a tooth. (All data and references from Harvey R., 2025 — “Odontogenic Sinusitis: Optimal Management,” Dept. of Otolaryngology, St Vincent’s Hospital Sydney / UNSW / Macquarie University, and the cited primary sources within the presentation.) https://www.researchreview.com.au/au/Pages/podcasts-details-public.aspx?site=au&pid=895
