Post-traumatic Actinomycotic Oro-antral Fistula Closure with Three-dimensional Stereolithographic Modeling and Patient-Specific Titanium Implant

Abstract

We report an interesting case of a post-traumatic actinomycotic oro-antral fistula of the left posterior maxilla, that was not salvageable via local flaps due to the size of the defect and was managed with the patient-specific titanium implant, fabricated by three-dimensional stereolithographic model planning followed by primary closure.

Introduction

Significant progress has been made in the evaluation and management of maxillofacial fractures, However, not all fractures of the midface require Open Reduction and Internal Fixation (ORIF). Depending on the aesthetic and functional indications, some may be managed by closed treatment [1]. Comminuted fractures of the maxillary sinus walls are seldom reconstructed in surgical practice, but they may lead to complications such as maxillary sinusitis and fistula [2].

Although cervicofacial actinomycosis is rarely encountered [3], infection of the maxillary sinus by Actinomyces species, which are considered commensals of the oral environment, can lead to disruptive osteomyelitic changes of the maxilla which in itself is a rare condition, owing to the well-known fact that osteomyelitis in the maxilla is uncommon, due to its abundant blood supply[4].

Here, we report an interesting case of actinomycotic osteomyelitis of the left maxilla after midfacial trauma, leading to oro-antral fistula (OAF), which was managed successfully by patient-specific titanium implant by three-dimensional stereolithographic modeling and planning.

Case Report

A 29-year-old gentleman reported to our Out-Patient Department with complaints of nasal stuffiness and congestion, with pain over the left maxilla for the past two weeks. He was previously treated in our unit two months back, for a left zygomaticomaxillary complex fracture, which was managed by non-surgical treatment. The Computed Tomography (CT) taken at the time of the traumatic insult showed comminuted maxillary sinus walls with left maxillary hemosinus (Fig. 1). Intraoral examination showed osteomyelitic changes in the left posterior maxilla clinically and was sampled for histopathological examination. The microscopic study revealed actinomycotic osteomyelitis of the left posterior maxilla, involving the left maxillary sinus. Hence, the patient was started on Penicillin G, two million units intravenously, four times a day, for one month, followed by oral Penicillin V, two grams per day, divided into four daily doses, for three months. Follow-up until the next four months showed symptomatic improvement with no specific complaints from the patient. However, the patient complained of nasal regurgitation after four months and was evaluated to have an oro-antral fistula involving the vestibular sulcus of 28. Cone Beam CT (CBCT) of the left maxilla was taken to assess the bone defect, which showed erosion of the posterior wall of the left maxillary sinus. Hence, the patient was planned for closure of the fistula after controlling the actinomycotic infection of the maxilla. Simultaneously, the stereolithographic (STL) models were fabricated with Digital Imaging and Communications in Medicine (DICOM) data of CBCT left maxilla (Fig. 2), for three-dimensional planning. Based on the STL model analysis and surgical planning, a titanium-based patient-specific implant (PSI) was fabricated (Fig. 3).

Fig. 1.

CT axial cut showing the left posterolateral maxillary sinus wall fracture with hemosinus (Green arrow)

Fig. 2.

STL model fabricated with DICOM data, showing the posterolateral maxillary sinus wall defect (Black arrow)

Fig. 3.

Fabricated cantilever PSI with two points of fixation anteriorly (Yellow arrows) for accessibility

A crevicular incision with an anterior vertical releasing limb was placed on the left maxilla and a mucoperiosteal flap was reflected. The defect in the posterior wall of the left maxillary sinus was exposed (Fig. 4) and the sinus was debrided with copious normal saline and 100 mL metronidazole solution. As the defect could be seen extending till the posterior inaccessible region of the maxilla, mucosal tunneling was done to facilitate the placement of the implant. After sufficient tunneling, the PSI was positioned over the defect, with the resorbable Guided Tissue Regeneration (GTR) collagen membrane (Healiguide®, 15 × 20 mm, two sheets) stabilized with 3–0 resorbable sutures over the buccal aspect of PSI (Fig. 5), fixation was done with two 2 × 6 mm titanium screws, and the mucosa was closed primarily after fistulectomy (Fig. 6). A nasogastric tube was placed to avoid wound contamination during the initial post-operative period. The wound healed satisfactorily and the patient was symptomatically better. The sinus tissue curetted intra-operatively and sent for microbiological examination did not show any bacterial colonies. Therefore, the patient was advised to stop the oral antibiotics and kept under regular follow up.

Fig. 4.

Intraoperative exposure of the defect

Fig. 5.

Resorbable GTR membranes sutured over the PSI

Fig. 6.

Fixed PSI, before closure of the flap

Discussion

Cervicofacial actinomycosis by itself being a rare chronic bacterial infection, is not commonly seen after a history of traumatic insult to the midface. Osteomyelitis of the maxilla is not often encountered by a head and neck surgeon due to the nature of the maxillary bone being more porous and the presence of abundant blood supply [4]. In our case, as the patient reported with symptoms of maxillary osteomyelitis and maxillary sinusitis after a history of trauma, the sampled tissue specimen was sent for microscopic examination and culture and sensitivity. Following the diagnosis of actinomycotic osteomyelitis of the maxilla, the patient was treated by medical therapy. Although the infection subsided, the patient developed a fistula, precipitating communication between the left maxillary sinus cavity and the oral cavity.

Many options exist for the surgical management of OAF, varying from simple primary closure to the usage of bone grafts and local flaps, depending on the size of the underlying bone defect [5]. Radiographic evaluation such as CBCT of the maxilla plays an important role in analyzing the bone defect exactly, before planning and surgical intervention [6]. As the size of the bone defect was large, extending 5 × 3 cms (anteroposteriorly x superoinferiorly), and the location of the defect in the posterior-most region of maxilla being inaccessible, fixation and immobilization of bone grafts could be cumbersome. Therefore, we planned for fabricating the STL models, that are vital in the three-dimensional understanding of the defect and surgical planning. Besides, PSI offer exemplary choice in the reconstruction of maxillofacial defects, as they are custom-made and ameliorate the precision and efficiency [7]. However, the oral mucosa tends to migrate and produce in-growths over the meshed titanium implants, thereby affecting the outcome. This particular drawback was overcome by the usage of resorbable, Guided Tissue Regeneration (GTR) membranes, sutured over the PSI.

Conclusion

Post-traumatic actinomycosis of the maxilla in itself being a rare and challenging entity in the maxillofacial surgical experience, osteomyelitis of the involved maxilla further worsens the treatment outcome and predictability. Hence, this case report aims to emphasize the importance of the complete resolution of the infectious process before OAF closure has been attempted, and the role of three-dimensional planning and PSI, offering excellent outcome and predictablity in the management of the same.

Funding

The authors did not receive any external source of funding.

Declarations

Conflict of interest

The authors declare no conflict of interest.

Ethics Approval

This is a case report study. The Institutional Review Board has confirmed that no ethical approval is required.

Informad Consent

Written informed consent was obtained from the patient for case photos and publishing purpose.