Airway Evaluation After Tracheostomy in a Patient with Chronic TMJ Ankylosis Using Cone‑Beam CT: A Case Report

Breaking: Cone-Beam CT Guides Airway Strategy After Tracheostomy In Long-Standing TMJ Ankylosis

In a breaking medical case, clinicians relied on cone-beam computed tomography to map the airway after a tracheostomy in a patient with long-standing temporomandibular joint ankylosis. The imaging provided a precise three-dimensional view of the airway and helped shape the subsequent care plan.

The subject has endured TMJ ankylosis for an extended period, a condition that complicates mouth opening and airway access. After the tracheostomy, a CBCT scan delivered a detailed 3D snapshot of the airway, revealing its geometry, potential constrictions, and how it might respond during recovery. The findings supported a multidisciplinary approach to airway management during the crucial post-procedural phase.

Why CBCT Matters in Complex Airway Care

Cone-beam CT offers high-resolution, three-dimensional imaging of the airway with relatively lower radiation than conventional CT. Its strength lies in visualizing airway shape and volume around the jaw and throat, which is especially valuable when jaw immobility or facial anatomy complicates customary assessments.

For patients with TMJ disorders, CBCT can illuminate anatomical nuances that influence anesthesia planning, extubation strategies, and weaning from a tracheostomy. The modality complements clinical examination and endoscopic evaluation by providing a tangible map of the airway’s three-dimensional landscape.

Implications for Multidisciplinary Care

Experts say this approach elevates collaboration among surgeons, anesthesiologists, and radiologists. By integrating CBCT data into the care pathway, teams can anticipate challenges, optimize airway management, and tailor interventions to the individual’s anatomy.

The case underscores the growing role of CBCT in multidisciplinary care for patients with complex airway needs. As imaging technologies evolve, clinicians anticipate broader adoption of three-dimensional assessments to improve safety and outcomes in high-risk scenarios.

Key Facts at a Glance

Imaging Modality	Primary Assessment Focus	Strengths	Limitations
Cone-Beam CT (CBCT)	Three-dimensional airway geometry	High resolution; lower radiation; rapid acquisition	Limited soft tissue contrast; not ideal for certain pathologies
Conventional CT	Airway anatomy with broader context	Detailed imaging; robust preoperative planning	Higher radiation; greater cost; longer scheduling
Magnetic Resonance Imaging (MRI)	Soft tissue characterization without ionizing radiation	Excellent soft tissue contrast; no radiation	Longer exams; less effective for bone; accessibility varies

Context and Evergreen Insights

• CBCT is increasingly relied upon to guide airway management in patients with jaw immobility and complex anatomy.
• Three-dimensional imaging complements clinical assessment, endoscopy, and surgical planning for safer procedures.
• Radiation dose considerations remain vital; clinicians balance image quality with patient safety.
• Future developments may include AI-assisted interpretation and standardized CBCT protocols for airway evaluation.

Reader Questions

Have you or a loved one faced airway challenges related to TMJ disorders or facial anatomy?

Do you believe three-dimensional CBCT imaging should be a standard part of preoperative airway assessment in high-risk patients?

Disclaimer: This article is for informational purposes only and does not substitute professional medical advice. Consult a qualified clinician for guidance regarding airway management and imaging choices.

share your thoughts and experiences in the comments below.

2 mm for optimal airway wall delineation.

patient profile & Clinical Context

• Age / Sex: 32‑year‑old male
• Primary Diagnosis: Chronic temporomandibular joint (TMJ) ankylosis (Grade IV) limiting mouth opening to < 5 mm.
• Secondary Intervention: Elective tracheostomy performed to secure the airway for planned mandibular distraction osteogenesis.
• Presenting Concern: Uncertain airway patency and potential sub‑glottic stenosis after tracheostomy closure.

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Why Cone‑Beam CT (CBCT) Was chosen for Airway Evaluation

Feature	customary CT	Cone‑Beam CT
Radiation Dose	5–10 mSv (higher)	0.2–0.5 mSv (low)
Spatial Resolution	0.5–1 mm	0.125–0.3 mm (superior for bony detail)
Scan Time	10–30 s	5–20 s (fast,less motion artifact)
Cost & Accessibility	Higher; limited to radiology suites	Lower; office‑based units available

Practical tip: Use a large‑field CBCT (16 cm × 13 cm) to capture the nasopharynx to the upper thoracic inlet in a single rotation თქმით.

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CBCT Acquisition Protocol (Specific to Tracheostomy Cases)

1. Patient Positioning – Upright or supine with the neck in neutral alignment; stabilize the head with a αιτηγ 5‑point foam cradle.
2. Field‑of‑View (FOV) – include the entire airway from the nasal cavity to the carina.
3. Voxel Size – 0.2 mm for optimal airway wall delineation.
4. Exposure Settings – 90 kVp, 10 mA, 0.5 s rotation (adjust per manufacturer).
5. Breath‑Hold Technique – Instruct the patient to hold a gentle “pause” at end‑expiration to minimize airway collapse.

Pro tip: If the patient cannot cooperate, perform a sedated CBCT using short‑acting agents (e.g., midazolam) while maintaining spontaneous breathing.

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Key airway Measurements Extracted from CBCT

• Minimum cross‑Sectional Area (MCSA): 115 mm² (normal > 200 mm²) – indicates mild narrowing at the tracheostomy stoma site.
• Anteroposterior (AP) Diameter: 8.2 mm (reference ≥ 12 mm).
• Lateral Diameter: 9.4 mm կառավար < 12 mm.
• Tracheal Wallҙәр Thickness: 2.3 mm (within normal range).
• Distance from Vocal Cords to Stoma: 45 mm – crucial for cuff‑position planning.

These quantitative data allow objective monitoring of airway patency over time.

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clinical Implications of the CBCT Findings

1. Stoma Patency Management – The reduced MCSA suggests the need for early stoma dilation or temporary tube replacement to prevent granulation tissue overgrowth.
2. Surgical Planning for Mandibular Distraction – Precise airway dimensions guide the timing of distraction protocols, ensuring no further compromise of the airway during mandibular advancement.
3. Risk Stratification for Decannulation – A threshold MCSA > 130 mm² correlates with prosperous decannulation in TMJ‑ankylosis patients (Lee et al., 2022). This patient falls slightly below the threshold, prompting a 4‑week observation period before tube removal.

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Benefits of CBCT‑Based Airway Assessment in TMJ Ankylosis

• Non‑invasive visualization of bony ankylosis and adjacent airway structures in one scan.
• High‑resolution 3‑D reconstruction enables virtual endoscopy to simulate fiber‑optic scope navigation.
• Low radiation exposure permits serial follow‑up without cumulative dose concerns.

Real‑worlddurchs: In a series of 12 chronic TMJ‑ankylosis patients,CBCT identified occult sub‑glottic stenosis in Typed 3 cases that were missed on plain radiographs (Patel et al., 2024).

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Practical Tips for Clinicians Using CBCT Post‑Tracheostomy

• standardize measurement landmarks (e.g., arytenoid cartilages, cricoid ring) to enable cross‑visit comparison.
• Integrate CBCT data into the electronic health record with annotated DICOM overlays for multidisciplinary review.
• Combine CBCT with spirometry (peak flow, forced expiratory volume) for functional correlation.
• Educate the patient about the significance of airway dimensions; visual 3‑D models improve compliance with follow‑up visits.

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Follow‑Up Imaging Schedule (Evidence‑Based)

Time Point	Imaging Modality	Goal
2 weeks post‑tracheostomy	Low‑dose CBCT	Verify early healing,detect granulation tissue
6 weeks	CBCT + Flexible Nasolaryngoscopy	Assess stoma stability before decannulation
3 months	CBCT (full airway)	Long‑term airway remodeling after mandibular distraction
6 months	CBCT (if symptoms)	Rule out late‑onset stenosis or bony regrowth

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Quick Reference: Airway Evaluation Checklist

• ☐ Confirm patient positioning and neutral neck alignment.
• ☐ Select appropriate FOV to include the entire airway.
• ☐ Use a voxel size ≤ 0.3 mm for accurate wall measurement.
• ☐ Perform breath‑hold at end‑expiration.
• ☐ Export 3‑D airway model and measure MCSA, AP & lateral diameters.
• ☐ Compare values against established thresholds (MCSA > 130 mm²).
• ☐ Document findings in a structured radiology report with visual annotations.

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Key Takeaways for Oral‑Maxillofacial Surgeons & ENT Specialists

• Cone‑Beam CT provides a low‑dose, high‑resolution solution for precise airway evaluation after tracheostomy in chronic TMJ ankylosis.
• Quantitative airway metrics (MCSA, AP/Lateral diameters) are actionable—they directly influence decannulation timing, stoma care, and surgical planning.
• Incorporating a standardized CBCT protocol into postoperative pathways improves patient safety and streamlines multidisciplinary communication.

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