Reliability of large language models in managing odontogenic sinusitis clinical scenarios: a preliminary multidisciplinary evaluation.

PURPOSE: This study aimed to evaluate the utility of large language model (LLM) artificial intelligence tools, Chat Generative Pre-Trained Transformer (ChatGPT) versions 3.5 and 4, in managing complex otolaryngological clinical scenarios, specifically for the multidisciplinary management of odontogenic sinusitis (ODS). METHODS: A prospective, structured multidisciplinary specialist evaluation was conducted using five ad hoc designed ODS-related clinical scenarios. LLM responses to these scenarios were critically reviewed by a multidisciplinary panel of eight specialist evaluators (2 ODS experts, 2 rhinologists, 2 general otolaryngologists, and 2 maxillofacial surgeons). Based on the level of disagreement from panel members, a Total Disagreement Score (TDS) was calculated for each LLM response, and TDS comparisons were made between ChatGPT3.5 and ChatGPT4, as well as between different evaluators. RESULTS: While disagreement to some degree was demonstrated in 73/80 evaluator reviews of LLMs' responses, TDSs were significantly lower for ChatGPT4 compared to ChatGPT3.5. Highest TDSs were found in the case of complicated ODS with orbital abscess, presumably due to increased case complexity with dental, rhinologic, and orbital factors affecting diagnostic and therapeutic options. There were no statistically significant differences in TDSs between evaluators' specialties, though ODS experts and maxillofacial surgeons tended to assign higher TDSs. CONCLUSIONS: LLMs like ChatGPT, especially newer versions, showed potential for complimenting evidence-based clinical decision-making, but substantial disagreement was still demonstrated between LLMs and clinical specialists across most case examples, suggesting they are not yet optimal in aiding clinical management decisions. Future studies will be important to analyze LLMs' performance as they evolve over time.

Total times to treatment completion and clinical outcomes in odontogenic sinusitis.

BACKGROUND: Multidisciplinary collaboration is essential for effective odontogenic sinusitis (ODS) management. One point of debate has been the optimal timing of primary dental treatment and endoscopic sinus surgery (ESS), but differences in time to completion of these treatment pathways have not been studied. METHODS: A retrospective cohort study was conducted on ODS patients from 2015 to 2022. Demographic and clinical variables were recorded, and various durations of time were analyzed from rhinologic consultation through treatment completion. Resolution of sinusitis symptoms and purulence on endoscopy was also recorded. RESULTS: Eighty-nine ODS patients were analyzed (47.2 % male, median 59 years-old). Of the 89 ODS patients, 56 had treatable dental pathology, and 33 had no treatable dental pathology. Median time to treatment completion for all patients was 103 days. Of 56 ODS patients with treatable dental pathology, 33 had primary dental treatment, and 27 (81 %) required secondary ESS. In patients who underwent primary dental treatment followed by ESS, median time from initial evaluation to treatment completion was 236.0 days. If ESS was pursued primarily followed by dental treatment, median time from initial evaluation to treatment completion was 112.0 days, which was significantly shorter than if dental treatment was pursued primarily (p = 0.002). Overall symptomatic and endoscopic resolution was 97.8 %. CONCLUSIONS: After dental and sinus surgical treatment, ODS patients experienced 97.8 % resolution of symptoms and purulence on endoscopy. In patients with ODS due to treatable dental pathology, primary ESS followed by dental treatment resulted in a shorter overall treatment duration than primary dental treatment followed by ESS.

Diagnosing odontogenic sinusitis of endodontic origin: A multidisciplinary literature review.

PURPOSE: Endodontic disease is one of the most common causes of bacterial odontogenic sinusitis (ODS). Diagnosing ODS of endodontic origin involves otolaryngologists confirming sinusitis, and dental specialists confirming endodontic sources. The purpose of this study was to conduct a multidisciplinary literature review to highlight clinical and microbiological features of ODS, and the most optimal diagnostic modalities to confirm endodontic disease. METHODS: An extensive review of both medical and dental literature was performed by rhinologists, endodontists, and an infectious disease specialist. Frequencies of various clinical and microbiological features from ODS studies were collected, and averages were calculated. Different endodontic testing and imaging modalities were also evaluated on their abilities to confirm endodontic disease. RESULTS: ODS patients most often present with unilateral sinonasal symptoms for over 3 months, purulence on nasal endoscopy, and overt dental pathology on computed tomography (CT). Subjective foul smell, and maxillary sinus cultures demonstrating anaerobes and α-streptococci (viridans group) may be more specific to ODS. For endodontic evaluations, cold pulp testing and cone-beam CT imaging are most optimal for confirming pulpal and periapical disease. CONCLUSION: Diagnosing ODS requires collaboration between otolaryngologists and dental specialists. Clinicians should suspect ODS when patients present with unilateral sinonasal symptoms, especially foul smell. Patients will generally have purulent drainage on nasal endoscopy, and both sinus opacification and overt dental pathology on CT. However, some patients will have subtle or absent dental pathology on CT. For suspected endodontic disease, endodontists should be consulted for at least cold pulp testing, and ideally cone-beam CT.

Odontogenic sinusitis publication trends from 1990 to 2019: a systematic review.

PURPOSE: Odontogenic sinusitis (ODS) is underrepresented in the literature compared to other forms of rhinosinusitis, specifically in sinusitis guidelines and position statements. ODS publication characteristics could help explain why ODS has received less attention in sinusitis guidelines and position statements. The purpose of this study was to explore trends in the quantity and quality of ODS studies over 3 decades from 1990 to 2019. METHODS: A systematic review was performed to identify all ODS studies from 1990 to 2019. The following variables from all ODS studies were compared between and across the 3 decades: authors' specialties, journal specialties, authors' geographic origins (continents), study topics, study designs, and evidence levels. RESULTS: From 1990 to 2019, there were 254 ODS studies that met inclusion criteria. Numbers of publications increased each decade, with 161 being published from 2010 to 2019. Otolaryngologists and dental authors published over 75% of ODS studies each decade, with 60-75% of ODS articles being published in otolaryngology or dental journals. European and Asian authors published the most ODS studies each decade. Overall, 92-100% of ODS publications per decade were level 4 and 5 evidence, with no significant changes between or across decades. CONCLUSION: While numbers of ODS publications increased each decade from 1990 to 2019, evidence levels remained low without significant changes over time. Otolaryngologists and dental authors published the majority of ODS studies each decade, with a minority of these studies being multidisciplinary. More ODS studies are needed across all aspects of the condition, and future projects would benefit from improved study designs and multidisciplinary collaboration.

Recognizing odontogenic sinusitis: A national survey of otolaryngology chief residents.

PURPOSE: Odontogenic sinusitis is underrepresented in sinusitis literature as well as in the otolaryngology teaching curriculum sponsored by the American Academy of Otolaryngology-Head and Neck Surgery. Otolaryngologists and residents in training may therefore have a decreased awareness of the condition. The objective of this study was to survey otolaryngology chief residents toward the ends of their training to determine how often they considered odontogenic sinusitis as a cause of unilateral sinus disease. MATERIALS AND METHODS: An online REDCap survey was conducted from December 2018 to January 2019. Online surveys were emailed to 119 Otolaryngology residency program directors in the United States of America, which were then forwarded to their chief residents. Surveys included 3 demographic and 4 clinical questions. Clinical questions included 3 computed tomography-based questions requiring either differential diagnoses or most likely diagnosis, and 1 question on residents' perceived prevalence of odontogenic sinusitis as a cause of unilateral sinus opacification. Answer choices were tabulated and compared based on geographic region and post-residency career plans. RESULTS: Of 293 chief residents emailed, 94 completed the survey (32.1%). While answer choices on imaging-based questions varied, odontogenic sinusitis was generally underrecognized. Approximately 70% of residents felt odontogenic sinusitis represented 0%-40% of unilateral sinus opacification. There were no statistically significant differences in answers based on geographic distribution or post-residency career plans. CONCLUSIONS: Otolaryngology chief residents recognized odontogenic sinusitis with variable accuracy on imaging, and generally underestimated its prevalence as a cause of unilateral sinus opacification. Efforts should be made to teach otolaryngology residents about odontogenic sinusitis.

Dental Evaluation: Endodontic and Periodontal.

Endodontic and periodontal disease are distinct etiologies that can lead to odontogenic sinusitis (ODS). Apical periodontitis and periodontitis are both polymicrobial infections but with different pathogens affecting different parts of the tooth and alveolar bone. Diagnosing both conditions requires specific clinical examination in addition to radiographic assessment. Understanding the terminology and pathophysiology of these conditions and how they are identified should improve diagnostic and therapeutic outcomes, as well as future ODS research.

Unilateral Sinus Disease: What Is, and Is Not Odontogenic Sinusitis?

The differential diagnosis of unilateral sinus disease (USD) is broad, and while concerning etiologies like sinonasal neoplasia, invasive fungal sinusitis, and cerebrospinal fluid rhinorrhea should always be considered, most cases are due to noninvasive inflammatory or infectious conditions. To diagnose USD appropriately, clinicians must integrate the clinical history and examination, nasal endoscopy, computed tomography (CT), and possibly MRI. Odontogenic sinusitis (ODS) is the most common cause of unilateral maxillary sinus opacification on CT, with 45% to 75% of such cases being odontogenic in nature. This study provides USD diagnostic considerations and reinforces the diagnostic approach to ODS.

Sinus Evaluation for Odontogenic Sinusitis.

This article summarizes how to diagnose common and nuanced cases of odontogenic sinusitis (ODS) through a collaborative approach between otolaryngologists and dental specialists, with a heightened focus on the role of otolaryngologists in the diagnostic process. A critical part of the diagnostic framework is that otolaryngologists must confirm the infectious sinusitis but also suspect ODS to ensure he or she refers the patient to a dental specialist to confirm or refute ipsilateral infectious maxillary dental pathology. To confirm the purulent sinusitis of ODS, nasal endoscopy is most critical. Computed tomography imaging is an important part of the workup.

Collaboration between otolaryngologists and oral surgeons in maxillary sinus elevation planning.

BACKGROUND: The collaboration between otolaryngologists and dental providers is crucial for the planning and execution of maxillary sinus elevation (MSE) procedures, which are integral to successful dental implant placements. PURPOSE: This article examines the essential role of otolaryngological assessments in identifying potential sinonasal risks that could impact the outcomes of MSE. MATERIALS AND METHODS: A comprehensive narrative review of existing literature was conducted. DISCUSSION: The review underscores the importance of thorough preoperative evaluations, including patient history, computed tomography (CT) or cone-beam CT (CBCT) scans, and nasal endoscopy, to mitigate sinonasal health risks. It details various clinical scenarios and patient assessments, emphasizing a systematic approach to diagnosing and managing sinonasal conditions proactively. The discussion reveals that while some sinus conditions may not significantly affect MSE success, conditions impacting mucociliary clearance and sinus drainage are critical risk factors requiring otolaryngological intervention. Additionally, the article introduces a grading system to assist clinicians in identifying patients who would benefit from otolaryngological evaluations prior to MSE. CONCLUSION: This review highlights the value of interdisciplinary collaboration and standardized protocols in enhancing the predictability and safety of MSE procedures, ultimately improving patient outcomes.

Management of Endodontic Disease for Odontogenic Sinusitis.

Primary dental treatments for odontogenic sinusitis (ODS) due to endodontic infections (pulpal necrosis and apical periodontitis ± periapical abscess) include extraction and root canal treatment (RCT). Published evidence is lacking on the success of primary endodontic treatment for purulent ODS, with the majority of RCT-related series reporting on its success at resolving reactive maxillary sinus mucositis. Dental extraction is the most definitive treatment of endodontic disease causing ODS, but compromises the functional dentition and still often fails to resolve the purulent sinusitis. This article highlights key concepts of RCT and dental extraction techniques, as well as their published success at resolving ODS.

Nasoseptal Flap to Repair Large Maxillary Sinus Floor Defects.

This case highlights the successful use of a large nasoseptal flap to repair a large maxillary sinus floor defect. Surgeons can therefore rely on this flap for repairing maxillary sinus floor defects of most sizes and locations. Laryngoscope, 134:87-91, 2024.

Maxillary sinus opacification after surgery in asymptomatic patients: Transient swelling of the sinus mucosa or graft dispersion into the maxillary sinus. A radiographic report of three cases after a follow-up period of at least 5 years.

Maxillary sinus grafting is a predictable regenerative technique to facilitate maxillary posterior implant placement when there is insufficient vertical bone height inferior to the maxillary sinuses to allow placement of implants of adequate dimensions. It enables an increase in vertical bone height, which makes implant placement easier. Maxillary sinus mucosal membrane perforation is one of the most common intraoperative complications during maxillary sinus grafting and may result in extrusion of graft material into the sinus. When this occurs, the mucociliary function of the maxillary sinus may expel the extruded graft material through its natural ostium, though graft particles may remain in the sinus or possibly occlude the natural ostium. After grafting, transient maxillary sinus mucosal oedema may occur. A postoperative CBCT scan may reveal varying degrees of sinus opacification, namely partial, subtotal or total. Although it is always possible to identify graft material, which may enter the sinus as a result of membrane perforation that might not even be visible to the implantologist during the surgical procedure, it is challenging to assess whether sinus opacification is due to mucosal thickening or mucus accumulation. The aim of the present case series was to offer a pragmatic approach to managing asymptomatic patients whose CBCT scans demonstrated partial, subtotal or total maxillary sinus opacification with bone graft particles that seemed to have been extruded into the sinus.

Maxillary Antrostomy Versus Complete Sinus Surgery for Odontogenic Sinusitis With Frontal Sinus Extension.

OBJECTIVES: Endoscopic sinus surgery (ESS) is often necessary when managing odontogenic sinusitis (ODS), but ESS extent for ODS with extramaxillary sinus involvement has been incompletely studied. This study compared outcomes after wide maxillary antrostomy (MA) alone versus complete ESS for ODS with frontal sinus involvement. METHODS: A multicenter prospective cohort study was conducted on patients with uncomplicated ODS (no extrasinus spread) who underwent ESS when computed tomography demonstrated maxillary, anterior ethmoid (AE), and frontal sinus opacification. Multiple preoperative and postoperative variables were recorded, including 22-item sinonasal outcome tests (SNOT-22) and endoscopic findings. Ultimate SNOT-22 and endoscopic resolution, and time to SNOT-22 and endoscopic resolution were compared between patients who underwent MA alone versus "complete" ESS (maxillary, ethmoid, frontal; not sphenoid). RESULTS: Of 70 patients, mean age was 59.2 years, and 55.7% were male. Thirty-five underwent MA alone, and 35 had complete ESS. At first postoperative visits (mean 9.3 days), AE sinus purulence was more likely resolved after complete ESS compared with MA (97.1% vs. 71.4%, p = 0.006). However, time to resolution of AE purulence was comparable by 6 weeks postoperatively (p = 0.158). There were no significant differences in times to foul smell resolution and achieving ≥9 point SNOT-22 reduction (p > 0.05). CONCLUSIONS: For ODS with frontal sinus involvement, MA alone and complete ESS both resulted in rapid and long-term symptomatic resolution. While ultimate resolution of sinus purulence was equivalent between surgery groups, complete ESS did lead to faster resolution of frontoethmoidal purulence in a significant number of cases. LEVEL OF EVIDENCE: 2 Laryngoscope, 2024.

Inflammatory endotype of odontogenic sinusitis.

BACKGROUND: Odontogenic sinusitis (ODS) is distinct from non-odontogenic rhinosinusitis with regard to clinical features as well as diagnostic and therapeutic approaches. While numerous studies have explored immune profiles of chronic rhinosinusitis, very few studies have explored the inflammatory endotype of ODS. METHODS: Odontogenic sinusitis was diagnosed by confirming infectious sinusitis adjacent to infectious maxillary odontogenic pathology. Maxillary sinus cultures and mucosal biopsies were obtained during endoscopic endonasal surgery in ODS and control patients. Controls were patients undergoing endoscopic skull base surgery with no sinus disease. Specimens were snap frozen in liquid nitrogen and stored at -80°C. Analysis was performed using a multiplex assay to measure Th-1 (TNFα, IFNγ, IL-2,12,18), Th-2 (IL-4,5,9,13), Th-17 (IL-17A,17F,22), and innate (CCL5,CXCL9,CXCL10, IL-6,8,10,12,23,27) immune pathways. Groups were compared via independent sample t-tests; if assumptions were violated, nonparametric Wilcoxon ranked sum tests were performed. RESULTS: Specimens from 22 ODS patients were compared to nine controls. ODS mucosal tissue was sampled in the setting of the following dental pathologies: post-dental extraction (n = 15), untreated apical periodontitis (n = 2), apical periodontitis after root canal therapy (n = 2), and maxillary sinus bone grafting with or without dental implantation (n = 3). The following cytokines were significantly elevated in ODS compared to controls: IFNγ, TNFα, IL-6, 8, 10, 27, and CXCL9. IL-17 levels were similar in both ODS and controls. Therefore, ODS demonstrated heightened innate and Th1 immune activity. CONCLUSION: ODS demonstrated both innate immune and Th1 inflammatory endotypes. Further studies are needed to explore ODS immunopathobiology and its potential impact on ODS management.

Odontogenic sinusitis: A state-of-the-art review.

Odontogenic sinusitis (ODS) is more common than historically reported, and is underrepresented in the sinusitis literature. ODS is distinct from rhinosinusitis in that it is infectious sinusitis from an infectious dental source or a complication from dental procedures, and most commonly presents unilaterally. ODS clinical features, microbiology, and diagnostic and treatment paradigms are also distinct from rhinosinusitis. ODS evaluation and management should generally be conducted by both otolaryngologists and dental providers, and clinicians must be able to suspect and confirm the condition. ODS suspicion is driven by certain clinical features like unilateral maxillary sinus opacification on computed tomography, overt maxillary dental pathology on computed tomography, unilateral middle meatal purulence on nasal endoscopy, foul smell, and odontogenic bacteria in sinus cultures. Otolaryngologists should confirm the sinusitis through nasal endoscopy by assessing for middle meatal purulence, edema, or polyps. Dental providers should confirm dental pathology through appropriate examinations and imaging. Once ODS is confirmed, a multidisciplinary shared decision-making process should ensue to discuss risks and benefits of the timing and different types of dental and sinus surgical interventions. Oral antibiotics are generally ineffective at resolving ODS, especially when there is treatable dental pathology. When both the dental pathology and sinusitis are addressed, resolution can be expected in 90%-100% of cases. For treatable dental pathology, while primary dental treatment may resolve the sinusitis, a significant percentage of patients still require endoscopic sinus surgery. For patients with significant sinusitis symptom burdens, primary endoscopic sinus surgery is an option to resolve symptoms faster, followed by appropriate dental management. More well-designed studies are necessary across all areas of ODS.

Extrasinus Complications From Odontogenic Sinusitis: A Systematic Review.

OBJECTIVE: Odontogenic sinusitis (ODS) can cause infectious orbital, intracranial, and osseous complications. Diagnosis and management of complicated ODS have not been discussed in recent sinusitis guidelines. The purpose of this systematic review was to describe epidemiological and clinical features, as well as management strategies of complicated ODS. DATA SOURCES: PubMed, EMBASE, and Cochrane Library. REVIEW METHODS: A systematic review was performed to describe various features of complicated ODS. All complicated ODS studies were included in qualitative analysis, but studies were only included in quantitative analysis if they reported specific patient-level data. RESULTS: Of 1126 studies identified, 75 studies with 110 complicated ODS cases were included in qualitative analysis, and 47 studies with 62 orbital and intracranial complications were included in quantitative analyses. About 70% of complicated ODS cases were orbital complications. Only 23% of complicated ODS studies were published in otolaryngology journals. Regarding ODS-related orbital and intracranial complications, about 80% occurred in adults, and 75% were male. Complicated ODS occurred most commonly from apical periodontitis of maxillary molars. There were no relationships between sinusitis extent and orbital or intracranial complications. High rates of anaerobic and α-hemolytic streptococcal bacteria were identified in complicated ODS. Management generally included systemic antibiotics covering aerobic and anaerobic bacteria, and surgical interventions were generally performed to address both the complications (orbital and/or intracranial) and possible infectious sources (dentition and sinuses). CONCLUSION: ODS should be considered in all patients with infectious extrasinus complications. Multidisciplinary management between otolaryngologists, dental specialists, ophthalmologists, and neurosurgeons should be considered to optimize outcomes.

Expected Costs of Primary Dental Treatments and Endoscopic Sinus Surgery for Odontogenic Sinusitis.

OBJECTIVES: Treatment of odontogenic sinusitis (ODS) due to apical periodontitis (AP) is highly successful when both dental treatment and endoscopic sinus surgery (ESS) are performed. Variation exists in the literature with regard to types and timing of dental treatments and ESS when managing ODS. This study modeled expected costs of different primary dental and sinus surgical treatment pathways for ODS due to AP. STUDY DESIGN: Decision-tree economic model. METHODS: Decision-tree models were created based on cost and treatment success probabilities. Using Medicare and consumer online databases, cost data were obtained for the following dental and sinus surgical treatments across the United States: root canal therapy (RCTx), revision RCTx, apicoectomy, extraction, dental implant, bone graft, and ESS (maxillary, ± anterior ethmoid, ± frontal). A literature review was performed to determine probabilities of dental and sinus disease resolution after different dental treatments. Expected costs were determined for primary dental extraction, RCTx, and ESS pathways, and sensitivity analyses were performed. RESULTS: Expected costs for the three different primary treatment pathways when dental care was in-network and all diseased sinuses opened during ESS were as follows: dental extraction ($4,753.83), RCTx ($4,677.34), and ESS ($7,319.85). CONCLUSIONS: ODS due to AP can be successfully treated with primary dental treatments, but ESS is still frequently required. Expected costs of primary dental extraction and RCTx were roughly equal. Primary ESS had a higher expected cost, but may still be preferred in patients with prominent sinonasal symptoms. Patients' insurance coverage may also impact decision-making. LEVEL OF EVIDENCE: NA Laryngoscope, 132:1346-1355, 2022.

Odontogenic Sinusitis is a Common Cause of Operative Extra-Sinus Infectious Complications.

BACKGROUND: Orbital, intracranial, and osseous extra-sinus complications can arise from bacterial or fungal sinusitis. Odontogenic sinusitis (ODS) can cause extra-sinus complications, but its prevalence remains poorly characterized. OBJECTIVE: To determine the frequency of ODS as a cause of operative extra-sinus infectious complications and describe clinical features of all complicated sinusitis cases. METHODS: A multi-institutional retrospective review was performed on all operative sinusitis-related extra-sinus complications from 2011 to 2020. ODS was diagnosed by sinus computed tomography (CT) and dental evaluations when available. Demographics, complication types, sinusitis etiologies, and various clinical features were analyzed. RESULTS: Forty-five patients were included (mean age 55.5 years, 56% male). Of the extra-sinus complications, 40% were orbital only, 22% intracranial only, 13% osseous only, and 25% involved combined complications. The 2 most common causes of extra-sinus complications were ODS (40%) and mucopyocele (27%). When invasive fungal etiologies were excluded, and only unilateral maxillary opacification on CT was considered, nearly 60% of extra-sinus complications were due to ODS. Unilateral maxillary sinus opacification on CT was present in 100% of complicated ODS compared to 44% of nonodontogenic cases, and oral anaerobes were only identified in ODS cases. No complicated ODS patients underwent dental interventions during hospitalization. CONCLUSION: ODS was the most common cause of operative extra-sinus infectious complications. Clinicians should consider ODS high on the differential diagnosis of all patients presenting with complicated sinusitis, especially when sinusitis is unilateral and invasive fungal infection is not suspected.

Radiographic protrusion of dental implants in the maxillary sinus and nasal fossae: A multidisciplinary consensus utilising the modified Delphi method.

The aim of the present study was to generate an international and multidisciplinary consensus on the clinical management of implant protrusion into the maxillary sinuses and nasal fossae. A total of 31 experts participated, 23 of whom were experts in implantology (periodontologists, maxillofacial surgeons and implantologists), 6 were otolaryngologists and 2 were radiologists. All the participants were informed of the current scientific knowledge on the topic based on a systematic search of the literature. A list of statements was created and divided into three surveys: one for all participants, one for implant providers and radiologists and one for otolaryngologists and radiologists. A consensus was reached on 15 out of 17 statements. According to the participants, osseointegrated implants protruding radiographically into the maxillary sinus or nasal fossae require as much monitoring and maintenance as implants fully covered by bone. In the event of symptoms of sinusitis, collaboration between implant providers and otolaryngologists is required. Implant removal should be considered only after pharmacological and surgical management of sinusitis have failed.

Predicting Odontogenic Sinusitis in Unilateral Sinus Disease: A Prospective, Multivariate Analysis.

BACKGROUND: Odontogenic sinusitis (ODS) is a common cause of unilateral sinus disease (USD), but can be challenging to diagnose due to nonspecific clinical presentations, potentially subtle to absent dental pathology on sinus computed tomography (CT), and underrepresentation in the sinusitis literature. OBJECTIVE: Identify sinonasal clinical variables predictive of ODS in patients presenting with unilateral maxillary sinus opacification on sinus CT. METHODS: A prospective cohort study was conducted on 131 consecutive patients with USD and at least partial or complete maxillary sinus opacification on sinus CT. Patients' demographics, sinonasal symptoms (anterior and posterior drainage, nasal obstruction, facial pressure, smell loss, and foul smell), 22-item sinonasal outcome test, nasal endoscopy findings, CT findings, and histopathology were collected. Patients' diagnoses included ODS, chronic rhinosinusitis with or without nasal polyps, and inverted papilloma. Demographic and clinical data were compared between patients with unilateral ODS and non-odontogenic disease using univariate and multivariate analyses. RESULTS: Of the 131 USD patients, 65 had ODS and 66 had non-odontogenic disease. The following variables were significantly associated with unilateral ODS on multivariate analysis: middle meatal pus on endoscopy (OR= 17.67, 95% CI-5.69, 54.87; p = 0.001), foul smell (OR= 6.11, 95% CI-1.64, 22.82; p=.007), facial pressure (OR= 3.55, 95% CI-1.25, 10.12; p = 0.018), and any frontal opacification on CT (OR= 5.19, 95% CI-1.68, 16.06; p = 0.004). Any sphenoid opacification on CT was inversely related to ODS (OR = 0.14, 95% CI-0.03, 0.69; p = 0.016). The study was adequately powered. CONCLUSION: With unilateral maxillary sinus disease, the following features were significantly associated with ODS: foul smell, ipsilateral facial pressure, middle meatal pus on endoscopy, and any frontal sinus opacification on sinus CT. Additionally, any sphenoid sinus opacification on CT was inversely related to ODS. Presence or absence of these clinical variables can be used to increase or decrease one's suspicion of an odontogenic source of sinusitis.