Successful surgical management of bilateral temporomandibular joint ankylosis in a pediatric patient: A case report on gap arthroplasty and coronoidectomy

S. Thayumanavan1, Karthik Ramakrishnan2, Abishek johnson babu3, Cynthia karthik4

1Consultant Pedodontist, Maa Kauvery, Trichy, Tamil Nadu

2,3,4Consultants – Oral and Maxillofacial Surgery, Maa Kauvery, Trichy, Tamil Nadu

Abstract

Temporomandibular joint (TMJ) ankylosis in pediatric patients is a rare but debilitating condition that affects facial growth, mastication, and speech. We report the case of an 8-year-old male presenting with severe trismus, facial swelling, and multiple dental infections. After comprehensive evaluation, the patient underwent bilateral TMJ gap arthroplasty with coronoidectomy and multiple extractions under general anesthesia. Intraoperatively, a functional interincisal opening of 40 mm was achieved. Postoperative recovery was uneventful, with early initiation of physiotherapy. This case highlights the critical importance of meticulous surgical planning, multidisciplinary collaboration, and structured rehabilitation in managing complex TMJ ankylosis cases.

Background

Pediatric temporomandibular joint (TMJ) ankylosis is most often the result of trauma, infection, or systemic diseases and can significantly impair jaw function and facial development. Untreated, it leads to micrognathia, malocclusion, airway compromise, and psychosocial difficulties. The gold standard for treatment involves surgical release of the ankylotic mass, coronoidectomy, and structured postoperative physiotherapy to prevent re-ankylosis. Surgical success depends on airway management, accurate surgical technique, and long-term rehabilitation.

Children with bilateral TMJ ankylosis typically present with restricted mouth opening, poor oral hygiene, speech impairment, and difficulty in eating. In this case, an 8-year-old boy presented with classic features of TMJ ankylosis compounded by multiple dental infections and dentoalveolar abscess. The patient had been symptomatic for over three years, with delayed surgical intervention due to parental apprehension. The goal of treatment was to surgically restore jaw mobility and eradicate oral infections, ensuring long-term functional and developmental improvement.

Case Presentation

Clinical Examination

On extraoral examination, the patient exhibited micrognathia, a symmetrical facial profile with noticeable fullness on the right side of the mandible, and severe trismus with an interincisal opening of approximately 5 mm. Intraoral examination revealed multiple decayed teeth and infected root stumps, with poor oral hygiene. A diffuse swelling was noted on the right mandibular body region, tender on palpation.

Signs and Symptoms

Pain on mastication

  • Inability to chew solid food
  • Difficulty in speech articulation
  • Swelling over right mandibular region
  • Restricted mouth opening (5 mm)
  • Multiple carious teeth and root stumps
  • Difficulty in maintaining oral hygiene

Radiographical Findings

Panoramic Radiograph and 3D CT Scan revealed:

  • Bilateral bony ankylosis of the TMJ
  • Elongated and hyperplastic coronoid processes
  • Multiple radiolucency’s around non-vital molars
  • Evidence of dent alveolar abscess on the right side ◦
  • No apparent cranial anomalies

Diagnosis

  • Bilateral bony ankylosis of the temporomandibular joint
  • Coronoid process hyperplasia
  • Chronic dentoalveolar abscess
  • Multiple grossly decayed and non-restorable teeth

Surgical Technique

Anesthesia and Airway Management

The patient was evaluated by the pediatrician and anesthesiology teams preoperatively. Anticipating a challenging airway due to bilateral TMJ ankylosis and a mouth opening of only 5 mm, nasal fiberoptic intubation was meticulously executed under general anesthesia. Intravenous access was secured; throat pack was placed to prevent aspiration.

Patient Positioning and Preparation

The patient was positioned supine with the head stabilized on a head ring. Skin was disinfected with povidone-iodine and spirit, and the surgical field was draped in a sterile fashion. A wide surgical field was maintained to allow bilateral access to TMJ regions.

Bilateral Preauricular Approach to TMJ

A preauricular incision was made bilaterally, approximately 2 cm anterior to the tragus along the natural skin crease. Sharp and blunt dissection was performed through the SMAS layer, exposing the superficial temporal fascia. Dissection proceeded to expose the zygomatic arch and the TMJ capsule, with careful identification and preservation of facial nerve branches (particularly temporal and zygomatic branches).

The TMJ capsule was incised longitudinally. The ankylotic mass, consisting of a bony fusion between the condylar head and glenoid fossa, was identified bilaterally. A high condylectomy was performed using rotary instruments and osteotomes. Approximately 1.5–2 cm of the ankylosed bone was resected on each side, creating an adequate gap between the mandibular ramus and skull base. The entire bony bridge was removed meticulously to prevent recurrence. The resection margins were smoothened with a round bur and bone file to eliminate any sharp edges or spicules.

Retraction was applied to access the coronoid process from the superior and lateral aspect via the same preauricular incision. The temporalis muscle was dissected off the coronoid process. The coronoid process was identified and sectioned at its base using a bur and osteotome. The segment was delivered superiorly and removed without complications. This step was repeated on the contralateral side. Coronoidectomy was essential to eliminate muscular restriction and optimize postoperative mouth opening.

Following bilateral gap arthroplasty and coronoidectomy, passive mobilization of the mandible was performed. An interincisal mouth opening of 40 mm was achieved intraoperatively. The joint space was irrigated with normal saline and inspected for any residual fibrous or bony adhesions. he TMJ capsule was loosely approximated. Layered closure was done using 3-0 Vicryl for deeper layers and 5-0 Prolene for skin closure in a subcuticular fashion. Intraoral extracted sockets were sutured with 3-0 absorbable sutures.

Multiple grossly decayed teeth and infected root stumps were removed under the same anesthetic session. Debridement was carried out, and sockets were irrigated thoroughly with antiseptic solution and saline. Hemostasis was verified bilaterally. Drains were placed on both sides to prevent hematoma formation.

Diagnostic Images

Procedure.

Postoperative Measures

The throat pack was removed, and the patient was extubated uneventfully. The child was monitored in the PACU and then shifted to the High Dependency Unit for 24 hr. Postoperative antibiotics, steroids, analgesics, and supportive care were initiated. On postoperative day 2, aggressive jaw physiotherapy was started.

Discussion

TMJ ankylosis in children is a challenging condition that affects facial growth and jaw function. Surgical intervention is crucial to restore normal function and prevent further complications. In our case, careful preoperative planning, management of the patient’s airway, and a well-executed surgical procedure were essential for achieving a successful outcome.

Aggressive postoperative physiotherapy is key to ensuring the success of the surgery and preventing re-ankylosis. Early mobilization of the jaw can significantly improve mouth opening and reduce the risk of long-term complications. The role of a multidisciplinary team—including oral and maxillofacial surgeons, pediatricians, anesthesiologists, and physiotherapists—was crucial to the overall success of this case.

Conclusion

Pediatric TMJ ankylosis requires early intervention to avoid serious long-term functional and aesthetic issues. This case underscores the importance of comprehensive surgical planning, careful airway management, and prompt rehabilitation. Achieving a 40 mm mouth opening in a child previously suffering from severe trismus highlights the value of a well-coordinated, multidisciplinary approach. Long-term follow-up and consistent physiotherapy are vital for sustaining functional outcomes and preventing re-ankylosis.

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