Surgical management of maxillary sinusitis of endodontic origin after reestablishing maxillary sinus floor healing through a nonsurgical approach: a case report
Article information
Abstract
When root canal infections breach the maxillary sinus floor (MSF), maxillary sinusitis of endodontic origin (MSEO) can result. This case illustrates the surgical management of MSEO following the nonsurgical reestablishment of the MSF. A 55-year-old woman presented with left facial pain and was diagnosed with MSEO originating from the left upper first molar. Despite undergoing nonsurgical root canal treatment, there was no evidence of bony healing after 6 months. However, cone-beam computed tomographic (CBCT) scans revealed the reestablishment of MSF. Subsequently, surgical intervention was carried out using a dental operating microscope. Two years after surgery, CBCT images indicated that the mucosal edema had resolved, and the MSF was well reestablished. Preserving the MSF is crucial for the success of endodontic surgery. When MSEO is present, the integrity of the MSF must be assessed to determine appropriate treatment options.
INTRODUCTION
Endodontic microsurgery has a high success rate and a favorable prognosis [1], making it a reliable treatment option for periradicular pathosis that does not respond to nonsurgical endodontic treatment. However, when this surgical approach is performed on maxillary posterior teeth, there is an increased risk of maxillary sinus perforation due to the close proximity of the tooth root apices to the maxillary sinus floor (MSF) [2]. Maxillary sinusitis can occur when the Schneiderian membrane on the MSF is violated by root canal infections originating from the maxillary teeth. This condition is often referred to as maxillary sinusitis of endodontic origin (MSEO) [3], which was previously known as ‘endo-antral syndrome’ [4]. Additionally, in some instances, the MSF may be extensively damaged by the expansion of pathological tissue. If endodontic surgical procedures are carried out under these circumstances, the roots of the maxillary teeth may become directly exposed to the sinus, potentially leading to unfavorable healing outcomes. Therefore, it is important to consider the proactive healing of the MSF prior to surgical intervention by first performing nonsurgical endodontic treatment. However, to our knowledge, there are no case reports demonstrating the healing of the MSF that facilitates subsequent surgical intervention.
In this context, this case report presents the surgical management of MSEO following the reestablishment of the MSF through a nonsurgical approach.
CASE REPORT
Dental history and diagnosis
A 55-year-old Asian woman presented with complaints of left facial pain. Her medical history was unremarkable. Approximately 3 years prior, she underwent nonsurgical root canal treatment on her maxillary first molar (#26) and second molar (#27) at a private clinic. Examination of the molars in the left upper quadrant revealed normal probing depths, no visible buccal gingival swelling, and no sensitivity to percussion. A periapical radiograph displayed root canal fillings in #26 and #27, along with periradicular radiolucency around the buccal root apexes of #26 (Figure 1A). Frontal and sagittal cone-beam computed tomography (CBCT) images showed a significant periradicular lesion with mucosal edema in the left maxillary sinus (Figure 1B, C). Notably, the MSF between the root apexes of #26 and the maxillary sinus was almost indiscernible.
Nonsurgical endodontic treatment. (A) Diagnostic X-ray image. An asterisk indicates periapical radiolucency around the mesiobuccal root. Coronal (B) and sagittal (C) views of diagnostic cone-beam computed tomography (CBCT) images show the destroyed maxillary sinus floor (MSF; white arrowheads) and mucosal edema on the MSF. (D) Periapical X-ray image taken after 6 months. Coronal (E) and sagittal (F) views of CBCT images demonstrate the reestablished MSF (yellow arrowheads).
Based on these findings, a diagnosis of MSEO with a periapical abscess originating from tooth #26 was made. Due to the risk of unfavorable outcomes, such as endo-antral communication, a surgical approach was ruled out. Instead, nonsurgical root canal treatment was planned. Written informed consent was obtained from the patient.
Nonsurgical and surgical procedures and follow-up visits
Tooth #26 was anesthetized with a 2% lidocaine solution containing 1:100,000 epinephrine by infiltration. The root canal filling material was removed using a reciprocating nickel-titanium instrument (Reciproc R25; VDW, Munich, Germany). Copious irrigation with 5% sodium hypochlorite was performed, and a calcium hydroxide-based intracanal medicament (Calcipex II; Nippon Shika Yakuhin, Shimonoseki, Japan) was placed into the root canals. At the subsequent visit, the patient’s symptoms had significantly decreased, and the canals were filled with gutta-percha and a bioceramic sealer (White Endoseal MTA; Maruchi, Wonju, Korea). The access cavities were restored with a light-cure resin composite (Filtek Z350 XT; 3M ESPE, St. Paul, MN, USA). Additionally, root canal treatment on tooth #27 was performed using the same protocols as for #26. Two months later, the patient’s symptoms had resolved, and full zirconia crowns were placed on teeth #26 and #27.
At the 6-month follow-up, the patient reported a sensation of fullness in the left facial area. A periapical radiograph revealed no evidence of bony healing (Figure 1D). Interestingly, the frontal and sagittal views from CBCT scans showed a remarkable reestablishment of the cortical MSF, although the size of the mucosal edema and periradicular bony lesion remained unchanged (Figure 1E, F). Consequently, surgical intervention was planned. After informed consent for the surgical procedures was obtained, the procedure began with the reflection of the mucoperiosteal flap, followed by enucleation of the inflamed tissue and resection of the buccal roots-ends (Figure 2A–C). Then, root-end cavities were then prepared with an ultrasonic tip (KiS tip, Young Specialties, Algonquin, IL, USA) and filled with mineral trioxide aggregate (Endocem MTA; Maruchi) (Figure 2D–F). The excised tissue was sent for pathological examination and was diagnosed as a radicular cyst characterized by stratified squamous epithelium and infiltration of chronic inflammatory cells (Figure 3A, B). Additionally, numerous cholesterol crystals were identified (Figure 3C).
Surgical endodontic treatment procedure. (A) Clinical appearance of the cystic capsule (yellow asterisk). (B) Mesiobuccal root apex within the bony cavity. (C) Preparation of the retrograde cavity using an ultrasonic tip. (D, E) Root-end cavities filled with mineral trioxide aggregate. (F) Postoperative periapical radiographs.
Histological features of the cystic tissue (hematoxylin and eosin staining). (A) The cyst was lined with fibrous connective tissue and stratified squamous epithelium (×40). (B) A dense infiltration of chronic inflammatory cells is evident (highlighted within the white rectangular box) (×100). (C) Cholesterol clefts were observed within the cystic wall (indicated by the yellow rectangular box) (×100).
Two years post-surgery, the patient exhibited no symptoms. Additionally, the periapical radiograph and CBCT images indicated bony healing around the roots of tooth #26, and mucosal edema had resolved with a well-reestablished MSF (Figure 4). However, on the coronal view of the CBCT, a well-demarcated radiolucency was observed around the buccal aspect of the palatal root (Figure 4C).
Two-year follow-up radiographs. (A) The periapical radiograph demonstrates bony healing and maxillary sinus floor (MSF) around the root apices. (B, C) Cone-beam computed tomography images reveal favorable bony healing and normal mucosa with a well-defined MSF. The MSF depicted in the radiographs is marked with white arrowheads. Well-demarcated radiolucent areas around the palatal root are indicated with yellow arrows.
DISCUSSION
In this case, we opted to perform nonsurgical endodontic treatment to remove the microorganisms within the root canals and to promote the healing of the lesion. At the 6-month follow-up, we confirmed the remarkable reestablishment of cortical MSF integrity, despite the recurrence of the patient’s symptoms and the absence of radiographic changes in the size of the mucosal edema and the bony lesion itself (Figure 1E, F). This phenomenon may have occurred because the overall bacterial load was reduced by nonsurgical endodontic treatment, leading to a decrease in cystic pressure on the MSF. The periradicular lesion in this case was likely a bay cyst, as it was associated with failed root canal treatment and responded to a nonsurgical approach [5]. It is also postulated that the reduction in cystic pressure resulted in less force exerted on the maxillary sinus, particularly under the influence of gravity, thus facilitating the healing of the MSF.
Despite reestablishing the MSF after 6 months, the patient experienced a recurrence of symptoms associated with maxillary sinusitis, and there was no reduction in lesion size. Siqueira noted that there are instances where nonsurgical endodontic treatment adheres to the highest technical standards but still results in failure [6]. Research suggests that certain factors, both microbial and nonmicrobial, may contribute to the unsatisfactory outcomes of cases that have been adequately treated [7,8]. In this case, the periapical lesion was histologically diagnosed as a periapical cyst, associated with failed endodontic treatment. As a result, the cystic cavity is exposed to the infected root canal, increasing the risk of microorganisms egressing into the cavity. Persistent microorganisms and their by-products within the cystic lumen can sustain inflammation, potentially leading to treatment failure due to extraradicular infection. Additionally, the tissue removed during this case was histologically examined, revealing cholesterol crystals and chronic inflammatory cell infiltration (Figure 3). Cholesterol, being water-insoluble, forms thin, flat rhomboid plates, as observed in the cystic lesion [9]. Cholesterol crystals have been implicated as a causative factor in persistent chronic inflammation and are also suggested to hinder the healing of apical periodontitis lesions because macrophages are unable to phagocytize and degrade them [7,10]. Given that cholesterol forms similar crystals in apical periodontitis lesions, it is hypothesized that both extraradicular microbial factors (microorganisms within the cystic lumen) and nonmicrobial factors (cholesterol crystals) may have influenced the failure of the nonsurgical endodontic treatment in this case.
Two years after surgery, the patient exhibited no symptoms, and no radiographic pathosis was evident on periapical radiography. However, coronal views from CBCT scans revealed that a well-demarcated radiolucent area persisted around the buccal aspect of the palatal root (Figure 4C). This suggests that the lesion may be healing, or that an irritant might remain in or around the palatal root, which was not addressed surgically. The fact that we did not perform root-end surgery on the palatal roots, which could have precluded any issues, warrants discussion. Surgical management of the palatal root of the maxillary first molar presents technical challenges. Two approaches are suggested: the buccal or trans-antral approach [11], and the palatal approach, which involves raising a palatal flap to access the root [12]. In this case, we opted against root-end surgery on the palatal root for several reasons. Initially, the trans-antral approach was dismissed as it would render the regenerated MSF inconsequential. Moreover, combining the palatal approach with the buccal approach for managing the buccal roots could lead to a “through-and-through” or “transosseous” lesion, potentially necessitating additional procedures such as guided tissue regeneration with graft material and a barrier membrane. Beyond the surgical management of the palatal root, it is important to determine whether the lesion represents a chronic periapical lesion that has not resolved or is merely scar tissue, especially given the patient’s asymptomatic status for two years. Such determination requires histological examination, and it is important to note that radiological and histological findings do not always correlate. The criteria for evaluating the success or failure of root canal treatment include clinical and radiological assessments, as well as the passage of time [13]. Therefore, ongoing follow-up is necessary.
CONCLUSIONS
Preservation of the MSF is another important factor for successful endodontic surgery, and the integrity of the MSF must be assessed to determine appropriate treatment options, especially when MSEO occurs.
Notes
CONFLICT OF INTEREST
Kyung-San Min is the Editor-in-Chief of Restorative Dentistry and Endodontics and was not involved in the review process of this article. The authors declare no other conflicts of interest.
FUNDING/SUPPORT
None.
AUTHOR CONTRIBUTIONS
Conceptualization, Resources, Supervision: Yu MK, Min KS. Formal analysis, Visualization: Kang ES. Investigation: Kang ES, Kim MK. Methodology: Kang ES, Min KS. Validation: Yu MK, Kim MK. Writing - original draft: Kang ES. Writing - review & editing: Kim MS, Yu MK, Min KS.
DATA SHARING STATEMENT
The datasets are not publicly available but are available from the corresponding author upon reasonable request.
References
