Odontogenic infections, primarily arising from untreated dental caries, periapical abscesses, or periodontal infections, constitute a major cause of maxillofacial space infections and can rapidly spread through the contiguous fascial spaces of the head and neck [1,2]. Their spread is influenced by gravity, muscle attachments, and the continuity of fascial planes. Among maxillary anterior teeth, the canine is of particular significance because of its long root and proximity to critical anatomical spaces [3].

When periapical infection from the maxillary canine penetrates the buccal cortical plate above the attachment of the levator anguli oris muscle, it may involve the canine space, which is situated between the levator anguli oris muscle inferiorly and the levator labii superioris muscle superiorly [4]. This space communicates with the infraorbital space, located beneath the orbit and bordered by the orbicularis oculi and levator labii superioris muscles [5].

Clinically, canine and infraorbital space infections manifest as diffuse swelling of the midface, obliteration of the nasolabial fold, periorbital edema, tenderness, erythema, and sometimes restricted ocular movement [6]. If untreated, the infection may spread to the orbit or even the cavernous sinus via the valveless angular vein, leading to complications such as orbital cellulitis or cavernous sinus thrombosis [7,8].

Prompt recognition and early surgical intervention remain the mainstay of treatment. Surgical drainage, extraction of the offending tooth, and broad-spectrum antibiotic therapy form the cornerstone of management [9]. Delay in management can result in significant morbidity, including visual disturbances and systemic infection [10].

This report describes a rare case of infraorbital space infection secondary to a canine space infection originating from carious exposed upper anterior teeth. The case was successfully managed surgically at Zoram Medical College and Hospital , Mizoram.

Study Design and Setting

This study was designed as a single-patient case report conducted in the Department of Ophthalmology and Dentistry , Zoram Medical College and Hospital , Mizoram. The study duration was one month (from presentation to follow-up). Ethical clearance was obtained from the Institutional Ethical Committee prior to documentation and publication of this case [11]. Informed consent was obtained from the patient for both treatment and publication purposes.

 Patient Selection

A 65-year-old female patient presented with symptoms of facial swelling, pain, and tenderness in the right infraorbital region. The inclusion criteria consisted of:

• Presence of infraorbital swelling secondary to an odontogenic cause.
• Clinical and radiographic evidence of canine space involvement originating from a carious upper anterior tooth.

Exclusion criteria included:

• Non-odontogenic causes of infraorbital swelling (e.g., trauma, neoplastic lesions).
• Patients with immunocompromised status or systemic conditions altering healing response.

 Clinical Examination

Comprehensive ophthalmological  and intraoral examinations were conducted. Findings included:

• Diffuse swelling in the infraorbital region extending to the midface.
• Obliteration of the nasolabial fold on the affected side.
• Carious exposure of the right maxillary canine and lateral incisor with vestibular obliteration.

 Investigations

Radiographic examination: Non contrast CT  face with coronal, axial and  sagittal section with 3D was performed, revealing periapical radiolucency in the right maxillary canine region.

 Hematological investigations: Complete blood count demonstrated leukocytosis, suggestive of acute infection.

 Surgical Procedure

Local anesthetic (2% lignocaine with 1:80,000 adrenaline) was used for the surgery. To provide access to the canine and infraorbital space, an intraoral vestibular incision was made in the right maxillary canine region. After draining the purulent exudate, the cavity was irrigated with povidone-iodine solution and regular saline. To guarantee constant drainage, a corrugated rubber drain was installed for 48 hours. To remove the infection's source, the troublesome teeth—the lateral incisor and maxillary right canine—were pulled.

 Postoperative Care and Follow-Up

The patient was prescribed intravenous antibiotics ( Linezolid 600 mg 12 hourly for 7 days )  and analgesics (Ibuprofen 400 mg TID).  Warm saline rinses were advised from the third postoperative day. The patient was reviewed on the third, seventh, and fourteenth postoperative days and followed up for one month. No recurrence was observed during the follow-up period.

A 65 -year-old female presented to the Department of Ophthalmology, Zoram Medical College and Hospital , Mizoram, with a 5-day history of swelling and pain localized to the right infraorbital and canine regions. The swelling was gradually progressive, associated with mild fever, and caused discomfort in closing the right eye. No history of trauma, sinusitis, or recent upper respiratory infection was reported.

Clinical Examination:

Ophthalmological findings: Diffuse swelling extending from the infraorbital margin to the midface, resulting in obliteration of the nasolabial fold on the affected side. The overlying skin was erythematous, warm, and mildly tender to palpation. Mild periorbital edema was noted, with slight difficulty in eyelid closure due to the swelling.

Intraoral findings: Carious exposure of the right maxillary canine and lateral incisor with vestibular obliteration and tenderness on palpation of the vestibule.

 Preoperative Investigations:

Hematological investigations revealed leukocytosis (WBC count: 13,800/mm³), indicative of an acute infection.

Non Contrast CT face with coronal, axial and sagittal section with 3D  showed periapical radiolucency in relation to the right maxillary canine region, suggesting periapical pathology as the primary source.

Surgical Intervention:

An intraoral vestibular incision was made in the right maxillary canine region while the patient was under local anesthesia (2% lignocaine with 1:80,000 adrenaline). After draining around 5 mL of viscous, purulent exudate, the area was irrigated with povidone-iodine solution and regular saline. For 48 hours, a corrugated rubber drain was installed to allow for constant draining. During the same procedure, the lateral incisor and maxillary right canine teeth that were the source of the problem were extracted.

Postoperative Care:

The patient was prescribed intravenous Linezolid 600 mg 12 hourly for seven days, along with analgesics (Ibuprofen 400 mg three times daily) and advised to initiate warm saline rinses from the third postoperative day.

Clinical Progression:

Outcome:
By the third postoperative day, there was significant improvement in pain and swelling, and the patient became afebrile. The drain was removed on Day 3. By Day 7, the swelling and tenderness had resolved entirely, and the patient regained normal eyelid function. At one month follow-up, no recurrence or residual infection was observed, and the facial contour had returned to normal.

Infraorbital space infections, though relatively uncommon compared to buccal or submandibular space infections, can result in significant morbidity due to their anatomical proximity to the orbit and potential communication with the cavernous sinus [12]. Odontogenic infections originating from the maxillary anterior teeth, particularly the canine, are among the primary etiological factors for such infections [1].

The pathogenesis of these infections involves pulp necrosis, often secondary to untreated dental caries, leading to periapical abscess formation. Once the infection breaches the buccal cortical plate superior to the levator anguli oris muscle, it gains access to the canine space and may extend further into the infraorbital space [4]. The clinical presentation includes midfacial swelling, obliteration of the nasolabial fold, periorbital edema, tenderness, and occasionally restriction of eyelid movement [5].

In severe cases, the infection may spread via the valveless angular vein to the cavernous sinus, resulting in cavernous sinus thrombosis, or to the orbital contents, causing orbital cellulitis. Such complications may lead to permanent visual impairment or systemic sepsis if untreated [7,13].

The cornerstone of management is early diagnosis and timely surgical intervention. In this case, an intraoral vestibular approach was selected for drainage, which is widely preferred for cosmetic reasons and to avoid external scarring [9]. Surgical drainage allows decompression of the infected space and evacuation of purulent material, while placement of a corrugated drain facilitates continued drainage and prevents re-accumulation of infection [10].

Antibiotic therapy is essential in conjunction with surgical management. Intravenous Linezolid was used in this case for its broad-spectrum activity against aerobic and anaerobic microorganisms commonly involved in odontogenic infections, such as Streptococcus viridans and Staphylococcus aureus [14]. Adjunctive analgesics and warm saline rinses aided in symptom relief and postoperative healing.

Clinical Outcome and Relevance

The patient showed significant improvement within three days of intervention, with resolution of swelling and restoration of normal eyelid function by one week. At one-month follow-up, no recurrence or residual deformity was noted, aligning with previous findings that early intervention significantly reduces morbidity and prevents spread to deep facial spaces [15].

This case underscores the importance of early recognition, immediate drainage, and elimination of the primary source of infection in infraorbital and canine space infections. It also highlights that intraoral drainage, when feasible, offers excellent cosmetic and functional outcomes without the need for external incisions.

Early diagnosis and prompt surgical management of infraorbital space infections secondary to canine space involvement are essential to prevent potentially life-threatening complications. Intraoral incision and drainage, combined with removal of the primary source of infection and appropriate antibiotic therapy, ensure rapid resolution of symptoms and minimize morbidity. Regular follow-up is crucial to monitor healing and prevent recurrence.

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