Submental Intubation

Definition and Historical Background

Why is it Needed? The Airway Problem in Facial Surgery

• Oral intubation (orotracheal) obstructs the mouth, preventing occlusion checks and intraoral work.
• Nasal intubation (nasotracheal) is contraindicated when nasal bones are fractured, when basilar skull fracture is suspected, or when nasal/NOE (naso-orbito-ethmoid) fractures need to be repaired.
• Tracheostomy is definitive but carries significant morbidity - early complication rate 6-8%, late complication rate up to 60% - including tracheal stenosis, tracheoesophageal fistula, voice changes, bleeding, stoma complications.

Anatomy

• Mylohyoid muscle - forms the muscular diaphragm of the floor of the mouth; must be perforated during the procedure
• Geniohyoid muscle - lies superior to mylohyoid
• Genioglossus muscle - must be avoided
• Wharton's duct (submandibular duct) - opens near the lingual frenulum; injury causes salivary fistula or mucocele
• Lingual nerve - runs medially; injury causes paresthesia/numbness of the tongue
• Sublingual gland - can be inadvertently injured
• Submental vessels (submental artery and vein) - branches of the facial artery/vein; care must be taken to avoid them
• The preferred passage is medial to the mandible, through a midline or paramedian path, to avoid the submandibular gland and facial vessels laterally.

Indications

1. Panfacial fractures - multiple fractures of the facial skeleton (mandible, maxilla, zygoma, orbit, frontal bone) requiring intraoperative maxillomandibular fixation (MMF) to check dental occlusion
2. Le Fort I, II, III fractures - when both nasal and oral access are needed
3. Naso-orbito-ethmoid (NOE) fractures - nasotracheal route is blocked
4. Mandible fractures - especially bilateral, symphyseal, or condylar fractures requiring MMF
5. Orthognathic surgery (Le Fort I osteotomy, BSSO) - access to occlusion needed intraoperatively
6. Skull base surgery - when neither nasal nor oral approach is suitable
7. Rhinoplasty / facelift in selected cases
8. Oral cancer surgery (OCSCC) - a listed option alongside tracheostomy per Bailey and Love's

Contraindications

• Need for prolonged postoperative mechanical ventilation (>24-48 hours) - tube must be converted to orotracheal or tracheostomy before extubation
• Active submental infection or cellulitis (Ludwig's angina, abscess in the submental area)
• Suspected deep floor-of-mouth pathology

• History of keloid or hypertrophic scarring (cosmetic concern)
• Severe neurological deficits requiring long-term airway management
• Previous submental surgery or scarring
• Very short or obese neck with limited submental anatomy
• Need for multiple sequential maxillofacial procedures
• Patients requiring extensive postoperative suctioning

Technique (Step-by-Step)

Equipment Required

• Reinforced (armored/spiral-wound wire) ETT - size 7.0 or 7.5 (preferred - resists kinking) or standard PVC tube with pilot balloon
• No. 15 scalpel blade
• Curved mosquito or Kelly hemostat
• Wound dilators (from a percutaneous tracheostomy set) or artery forceps
• Scissors, needle driver, absorbable sutures
• Lubricant

Steps

• Paramedian (52% preferred per systematic review) - 1-2 cm lateral to the midline, in a skin crease for better cosmesis
• Median/midline (33%) - directly in the midline

1. The subcutaneous tissue
2. The mylohyoid muscle (the key layer)
3. Into the floor of the mouth, immediately lingual to the mandibular alveolus

• The pilot balloon/cuff inflation line of the ETT is detached from the connector
• The proximal connector of the ETT is disconnected
• The circuit tubing is temporarily disconnected (brief apnea of approximately 30-60 seconds)
• The tube tip is grasped by the hemostat intraorally and pulled through the submental passage
• Alternatively (two-tube technique): a new tube is threaded through the submental tunnel and connected to the first tube intraorally, then pulled through

• The tube is reconnected to the circuit via the submental route
• The pilot balloon is reconnected to allow cuff inflation
• Tube position is reconfirmed with ETCO₂ and chest auscultation
• The tube is secured to the skin at the exit wound with a suture or tape

One-Tube vs. Two-Tube Technique

• One-tube technique (84% preferred): the same oral ETT is manipulated through the submental tunnel - quicker, less risk of disconnection
• Two-tube technique (6%): a new armored tube is passed through the tunnel and connected to the oral ETT inside the mouth before exiting - allows use of a fresh, purpose-selected tube

Intraoperative Management

• The tube exit from the submental skin is draped into the surgical field
• The tube is passed over the chest and connected to the anaesthetic circuit
• Surgeons can now freely place MMF (intermaxillary fixation with arch bars or wires) and check occlusion without any airway obstruction
• The anesthesiologist monitors the tube carefully - the submental route creates a curve that must not kink; the reinforced ETT prevents this
• Suction via the tube may be slightly more difficult due to the curve

Extubation and Tube Reversal

1. The tube is pulled back through the submental tunnel into the oral cavity
2. The standard connector is replaced
3. The tube is secured in the orotracheal position
4. Standard extubation follows when the patient is awake and protective reflexes have returned
5. The submental wound is irrigated and closed in layers (mylohyoid and subcutaneous tissue with absorbable sutures, skin with non-absorbable or absorbable sutures)

Complications

Intraoperative

Postoperative

• No deaths or life-threatening complications directly attributable to SMI have been reported in the literature.
• The 100% success rate was noted in the 2012 literature review (Jundt et al.) of 842 cases across 41 articles.

Comparison with Alternatives

Special Considerations

Advantages Summary

1. Preserves both the oral and nasal airway for surgical access
2. Allows intraoperative maxillomandibular fixation (MMF) and occlusion verification
3. Avoids tracheostomy and all its associated complications
4. Reversible within the same operation
5. No stoma, no prolonged wound care
6. Short procedure time (~10 min)
7. High success rate (~98-100%)
8. Shorter ICU stay compared to tracheostomy patients
9. Cosmetically acceptable scar in the submental region (hidden under the chin)

Key References

• Goh EZ et al. Systematic review of submental intubation 1986-2018. Br J Oral Maxillofac Surg 2020. [PMID 31718913] - 2,229 patients
• Jundt JS et al. Submental intubation: a literature review. Int J Oral Maxillofac Surg 2012. [PMID 21930363] - 842 patients, 100% success
• Lim D et al. Thirty years of submental intubation. Int J Oral Maxillofac Surg 2018. [PMID 29731193] - 1,021 patients
• Mahajan AD et al. Unlocking the Potential of Submental Intubation. Craniomaxillofac Trauma Reconstr 2024. [PMID 39553800]
• Bailey and Love's Short Practice of Surgery, 28th Edition (panfacial fractures and head/neck airway management sections)