Odontogenic Sinusitis of Endodontic Origin: Successful Management Through Endodontic Treatment

Abstract

Odontogenic sinusitis is a maxillary sinus infection arising from dental pathology, primarily involving posterior maxillary teeth due to their anatomical proximity to the sinus floor. Endodontic infections are a significant etiological factor, yet the condition is frequently underdiagnosed due to its overlapping presentation with sinonasal sinusitis. The present cases illustrate the diagnosis, management, and outcomes of maxillary sinusitis of endodontic origin through endodontic interventions. Two patients with histories of recurrent maxillary sinusitis underwent dental evaluations after conventional medical therapies failed. Cone-beam computed tomography confirmed the dental etiology in all cases, identifying inadequately treated second mesiobuccal (MB2) canals or significant periapical pathology. Endodontic retreatments were employed to address the underlying dental causes, followed by resolution of sinus symptoms within days. Follow-up imaging demonstrated ongoing bone healing and resolution of sinus involvement. These cases underscore the importance of addressing the dental etiology in maxillary sinusitis of endodontic origin to achieve complete symptom resolution and minimize recurrence. Cone-beam computed tomography proved instrumental in diagnosing and planning treatment, enabling precise management of periapical and sinus conditions. The cases highlight the necessity of a multidisciplinary approach, involving dental and medical professionals, to optimize outcomes.

1. Introduction

Odontogenic sinusitis is a distinct form of maxillary sinus infection that originates from dental pathology, particularly from the posterior maxillary teeth [1,2,3]. Its etiology is closely linked to the anatomical proximity of these teeth to the maxillary sinus floor, which creates a unique pathway for infection to spread [3,4]. Endodontic infections, characterized by pulp necrosis and apical periodontitis (also referred to as periapical lesion), are among the most common causes of odontogenic sinusitis [1,3]. Research indicates that dental etiology accounts for 30–72% of maxillary sinusitis cases, particularly in unilateral maxillary sinus clouding [5,6,7]. These conditions enable the migration of pathogens or inflammatory mediators into the sinus, initiating a cascade of inflammatory and infectious processes [3]. Despite its prevalence, odontogenic sinusitis often remains underdiagnosed, primarily due to its overlapping clinical presentation with sinonasal sinusitis.

Common manifestations of odontogenic sinusitis arising from endodontic infections include periapical mucositis and periapical osteoperiostitis, which result from the spread of infection or inflammation from periapical tissues into the sinus cavity [7]. These conditions often progress insidiously, potentially leading to partial or complete sinus obstruction if left untreated [1,5,7]. Misdiagnosis is frequent, as the symptoms—such as nasal congestion, facial pain, and sinus pressure—closely mirror those of sinonasal sinusitis, complicating clinical differentiation. Identifying dental etiology is further complicated by a lack of awareness and insufficient knowledge among healthcare providers. Addressing odontogenic sinusitis effectively requires a targeted approach that not only resolves the sinus infection but also eliminates its underlying dental source, ensuring comprehensive and long-lasting patient care [3]. Advanced imaging technologies, such as cone-beam computed tomography (CBCT), play a pivotal role in facilitating accurate detection, diagnosis, and treatment planning, enabling clinicians to manage these cases with greater precision and confidence.

The present cases aim to contribute to the understanding of odontogenic sinusitis by presenting two cases where maxillary sinusitis of endodontic origin was successfully treated through endodontic procedures. These cases illustrate the varied presentations, diagnostic challenges, and outcomes associated with odontogenic sinusitis, offering insights into its effective management through interdisciplinary collaboration and evidence-based endodontic care.

2. Case Reports

2.1. Case 1

A 51-year-old male presented with a two-year history of recurrent unilateral maxillary sinusitis. Symptoms recurred approximately every four months and included fever, malaise, left nasal purulence, nasal congestion with anterior and posterior discharge, hemifacial pain, reduced olfaction, and a complaint of a fetid odor. By the second year, nasal polyps had developed. Despite multiple courses of short- and long-term antibiotics (e.g., doxycycline and clarithromycin) and corticosteroids, the symptoms persisted. The patient reported being under the care of otolaryngologists and undergoing nasal endoscopy, which revealed purulent secretions. Given the lack of improvement with medical management, endoscopic sinus surgery was considered. However, the otolaryngologist recommended dental evaluation to rule out a possible odontogenic origin, advising consultation with an endodontist. Dental evaluation and radiographic findings revealed a root canal treatment on tooth #26, reportedly performed approximately five years earlier (Figure 1A). Clinical examination revealed an absence of pulp vitality in teeth #25 and #26, consistent with previous endodontic treatment, while tooth #27 responded positively to cold testing. Mild percussion pain was noted on tooth #26, further raising suspicion of dental etiology. To further investigate, cone-beam computed tomography (CBCT) was requested, providing a detailed view of the region. CBCT imaging identified an untreated second mesiobuccal (MB2) canal, which was determined to be the likely source of the patient’s symptoms (Figure 1B–D). Based on these findings, endodontic retreatment was planned. A dental operating microscope (Zeiss Extaro; Carl Zeiss Meditec, Jena, Germany) was used throughout the procedure to ensure enhanced visualization. After administering anesthesia, a rubber dam was placed to isolate the operative field. The root-canal filling material was removed using ProTaper Retreatment files (D1, D2, and D3). Reinstrumentation of all canals was subsequently performed with Reciproc Blue R25 and R40 instruments (VDW, Munich, Germany). The MB2 canal was specifically prepared using the R-Pilot instrument and Reciproc Blue R25 (VDW, Munich, Germany). Irrigation was carried out with 5.25% sodium hypochlorite, and final irrigation was completed with 17% EDTA. Passive ultrasonic irrigation (PUI) was employed using ultrasonic tips to enhance irrigant efficacy. The canals were obturated with Reciproc Blue gutta-percha cones (VDW, Munich, Germany) and AH Plus Jet root canal sealer (Dentsply-Sirona, Ballaigues, Switzerland). Finally, the access cavities were sealed with glass ionomer at the canal orifices, followed by a light-cured composite resin for the remainder of the cavity. The retreatment procedure was conducted in a single session, successfully locating and treating the MB2 canal, as well as addressing the other root canals (Figure 1E,F). Remarkably, all sinusitis symptoms were resolved within a week of the procedure. At the nine-month follow-up, the patient reported no recurrence of symptoms, and imaging demonstrated ongoing bone healing (Figure 1G–I). Regular follow-up appointments were recommended to monitor continued recovery and prevent recurrence.

2.2. Case 2

A 36-year-old female presented with a six-month history of recurrent unilateral maxillary sinusitis. Symptoms included facial pain exacerbated by bending forward, persistent headache, fever, malaise, continuous purulent discharge from the left nostril, nasal congestion with anterior and posterior discharge disrupting sleep, left hemifacial pain, reduced olfaction, and a complaint of a fetid odor. Despite extensive treatment, including multiple courses of short-term antibiotics (Clavulin BD^® for 14 days twice and doxycycline 200 mg for 21 days), long-term antibiotics (clarithromycin 250 mg for three months), corticosteroids, and nasal sprays, her symptoms persisted. The patient had been under the care of otolaryngologists and underwent nasal endoscopy, which confirmed the presence of purulent secretions. Due to the persistence of symptoms and before making any further decisions, the otolaryngologist suggested a dental evaluation to investigate a potential odontogenic cause, recommending consultation with an endodontist. Endodontic evaluation revealed a prior root canal treatment on tooth #26, reportedly performed approximately two years earlier. Clinical examination raised suspicion of dental etiology, prompting a cone-beam computed tomography (CBCT) scan for detailed imaging. CBCT analysis identified an inadequately treated MB2 canal with insufficient obturation in the apical third, likely contributing to the patient’s symptoms (Figure 2A–F). Based on these findings, endodontic retreatment was planned. A dental operating microscope (Zeiss Extaro; Carl Zeiss Meditec, Jena, Germany) was used throughout the procedure to ensure enhanced visualization. After administering anesthesia, a rubber dam was placed to isolate the operative field. The root-canal filling material was removed using ProTaper Retreatment files (D1, D2, and D3). Reinstrumentation of all canals was subsequently performed with Reciproc Blue R25 and R40 instruments (VDW, Munich, Germany). The MB2 canal was specifically prepared using the R-Pilot instrument and Reciproc Blue R25 (VDW, Munich, Germany). Irrigation was carried out with 5.25% sodium hypochlorite, and final irrigation was completed with 17% EDTA. Passive ultrasonic irrigation (PUI) was employed using ultrasonic tips to enhance irrigant efficacy. The canals were obturated with Reciproc Blue gutta-percha cones (VDW, Munich, Germany) and AH Plus Jet root canal sealer (Dentsply-Sirona, Ballaigues, Switzerland). Finally, the access cavities were sealed with glass ionomer at the canal orifices, followed by a light-cured composite resin for the remainder of the cavity. The retreatment procedure was performed in a single session, addressing the inadequately treated MB2 canal and optimizing the obturation of all root canals (Figure 2L–O). Remarkably, all sinusitis symptoms were resolved completely within five days of the procedure. At the first follow-up, approximately two months later, the patient reported no recurrence, and imaging demonstrated complete resolution of sinus involvement, including the frontal and ethmoidal sinuses (Figure 2O–S). To ensure sustained recovery and monitor for any signs of recurrence, regular follow-up appointments over the next two years were recommended.

3. Discussion

The success of endodontic treatment in resolving odontogenic sinusitis of endodontic origin, as demonstrated in this series, underscores the importance of addressing the underlying dental pathology to achieve complete resolution of sinus symptoms. Conventional sinonasal treatments, including antibiotics and decongestants, often provide temporary relief but fail to target the primary dental etiology [2,8,9]. By employing endodontic procedures to eliminate the source of infection, these cases achieved not only symptom resolution but also a reduction in the risk of recurrence, highlighting the efficacy of this targeted approach. Additionally, endodontic treatment offers a less invasive alternative to surgical interventions, such as functional endoscopic sinus surgery, preserving sinus and dental structures while promoting faster recovery [2,9].

A key element in the successful diagnosis and management of odontogenic sinusitis of endodontic origin is the utilization of advanced diagnostic tools. Cone-beam computed tomography plays a pivotal role in identifying subtle dental and sinus abnormalities that may be missed on conventional imaging modalities [10,11,12]. This technology enables detailed visualization of periapical lesions, mucosal thickening, and their interaction with the sinus cavity, aiding in accurate diagnosis and facilitating treatment planning [10,11,12]. Moreover, cone-beam computed tomography provides unparalleled precision in assessing root canal morphology, the extent of periapical pathology, and the proximity of root apices to the sinus floor, which are critical factors in planning endodontic procedures [12]. This detailed assessment minimizes the risk of procedural errors, enhances the predictability of treatment, and supports the identification of potential complications before they arise. The integration of such imaging techniques into diagnostic workflows should be reserved for specific clinical situations where additional information is required, such as suspected maxillary sinus pathology. While periapical radiography remains the gold standard for routine endodontic diagnosis, CBCT can provide valuable supplemental data in complex cases, enabling a more precise and comprehensive approach to treatment. This selective use of CBCT contributes to improved patient outcomes and reduces the likelihood of recurrence.

The MB2 canal, or second mesiobuccal canal, is a frequent anatomical feature of maxillary molars, yet its location and management present significant clinical challenges [4,11]. The failure to detect and adequately treat this canal is a leading cause of persistent periapical pathology and endodontic treatment failure [11], as highlighted by the cases in this series. Anatomical studies indicate that the MB2 canal is present in over 70% of maxillary first molars [13,14] and 40% of second molars [14], but its detection is complicated by its often narrow, calcified, and complex trajectory, which can be obscured by the pulp chamber floor anatomy. Advanced imaging tools, such as cone-beam computed tomography (CBCT), are highly valuable for identifying the presence and location of MB2 canals, providing detailed visualization that surpasses traditional radiographic methods [11,13]. Clinically, the successful management of MB2 canals can be significantly facilitated by the use of magnification and illumination provided by dental operating microscopes, along with specialized instruments and techniques tailored to the complex morphology of this canal system [15,16]. The cases described underscore the critical importance of recognizing the potential presence of MB2 canals and employing both advanced imaging and meticulous clinical techniques to address them. Adequate management of MB2 canals not only resolves persistent periapical issues but also prevents further complications, such as odontogenic sinusitis, underscoring their pivotal role in achieving long-term endodontic success.

Another crucial aspect to consider in the management of maxillary sinusitis of endodontic origin is patient education and awareness. Many individuals with odontogenic sinusitis may initially seek care from medical practitioners, unaware of the dental origin of their symptoms. Educating patients about the potential link between dental issues and sinusitis can encourage them to pursue comprehensive evaluations involving both dental and medical professionals. Furthermore, emphasizing preventive dental care, including routine checkups and timely treatment of dental pathologies, can reduce the incidence of odontogenic sinusitis. Highlighting the role of the dental practitioner not only as a treatment provider but also as a key player in preventing sinus complications reinforces the importance of integrated care and proactive management strategies.

Sealer extrusion beyond the apical foramen, commonly referred to as a “puff”, is a phenomenon that can occur during root canal treatment. Its clinical implications are context-dependent. In many cases, small amounts of extruded sealer are well-tolerated by periapical tissues and do not adversely affect healing outcomes [17,18]. In cases 1 and 2, the presence of puffs indicates overextension of the sealer. Nevertheless, clinical and radiographic follow-up demonstrated that, in both cases, this extrusion did not impact the healing of apical periodontitis or sinusitis. The findings of this study underscore the critical importance of a multidisciplinary approach in managing maxillary sinusitis of endodontic origin. Effective collaboration between dental professionals and otolaryngologists is essential to ensure accurate diagnosis and successful treatment, particularly in complex cases involving extensive sinus involvement or systemic complications. This case series highlights the efficacy of endodontic treatment in resolving maxillary sinusitis of endodontic origin, reinforcing the need for heightened awareness and seamless interdisciplinary cooperation. Future research should prioritize refining diagnostic criteria and developing standardized protocols to enhance the diagnosis, treatment, and overall management of odontogenic sinusitis, ultimately improving patient care and outcomes.