Temporomandibular joint ankylosis is a condition where there is an intracapsular union of the disc-condyle complex thus restricting the mandibular movement. There can be either fibrous adhesions or bony fusion [1] TMJ ankylosis can be congenital or acquired. It is more commonly associated with trauma, previous surgical manipulation, local or systemic infection, systemic disease such as ankylosing spondylitis, rheumatoid arthritis, sickle cell anaemia, fibrodysplasia ossificans progressive and psoriasis [2,4]. The clinical features of TMJ ankylosis are limited or nil mouth opening, retrognathia which further leads to facial disfigurement, speech problems, snoring, difficulty in breathing, poor oral and dental hygiene and last but not least psychological consequences.

Conducted anaesthesia in a 12-year-old patient with unilateral TMJ ankylosis (inter incisor distance of 5mm) posted for condylectomy and interpositional arthroplasty [1]. Blind nasal intubation, retrograde intubation and tracheostomy are the other available substitutes in the absence of the availability of a flexible fiberscope. However, all of the above-mentioned techniques require expertise and patient cooperation and are associated with few complications. Hence, they used propofol infusion @ 50 µg/kg/min for TIVA (Total Intravenous Anaesthesia) thus maintaining spontaneous respiration till condylectomy was done with an extraoral approach. Later on, intubation was done using direct laryngoscopy.

Fiberscope-assisted video laryngoscope intubation in a 6-year-old boy [2]. The child presented with restricted mouth opening along with an inability to eat. On examination, the mouth opening was found to be 12 mm with decreased condylar movements on both sides and hence the diagnosis of bilateral TMJ ankylosis was made. After induction with sevoflurane (2-4%), a reusable Glidescope with a paediatric-size blade was inserted in the retromolar space to visualise the glottic aperture. Afterwards, nasal intubation was done with a cuffed endotracheal tube pre-mounted on a flexible fiberscope with simultaneous visualization of the glottic aperture with a video laryngoscope. They suggested the use of a video laryngoscope for a better view in patients with abnormal airway anatomy. Though, flexible fiberscope-guided intubation is the gold standard but in circumstances like this where there is limited mouth opening just to accommodate a Glidescope blade, the above-mentioned technique may be adopted.

Retrospective evaluation of airway management in 48 patients with TMJ ankylosis [3]. The age group of the patients studied ranged from 5 to 50 years. Out of the total studied population, about 23% of them were below 10 years old and 29% were between 10 to 20 years old. They aimed to determine the morbidity and mortality associated with blind awake intubation. The most common complications associated with blind awake intubation were sore throat (42%), epistaxis (10%) and soft tissue injury (6%). Inside the operation theatre, two drops of xylometazoline nasal drops were instilled after looking for nasal patency. Later on, bilateral superior laryngeal and transtracheal nerve blocks were given. In paediatric patients, incremental doses of ketamine were given so as to maintain airway reflexes. Patient preoxygenated and blind awake nasal intubation was done. After securing the tube in place patient was induced with an induction agent followed by a muscle relaxant.

In blind awake nasal intubation, the tube may theoretically pass through any of the routes like submucosal dissection into the mucous membrane of the nose, epiglottis, vallecula, oesophagus, pyriform fossa or anterior wall of the larynx. Thus, an anaesthesiologist must be able to troubleshoot when the endotracheal tube is in the wrong place. The tube should be quickly passed through the vocal cords during the latter phase of inspiration as vocal cords are maximally abducted in this phase of inspiration. The tube can be successfully passed during explosive cough also because again laryngeal aperture is maximally dilated.

The surgical and anaesthetic management of young patients with TMJ ankylosis [4]. They stated that the usual age of onset of TMJ ankylosis is 10 years. The inter incisor gap is the clinical indicator; IIG < 5mm is termed “complete ankylosis.” CT scans are considered essential for both pre-operative evaluation and post-surgical assessment. Orthopantomogram (panoramic radiograph of the maxilla and mandible in two dimensions) is an important diagnostic aid. By using this coronoid process one side can be compared with that of the contralateral side.

A case report of a 5-year-old child with bilateral TMJ ankylosis with an inter-incisor gap of 4 mm and mandibular hypoplasia [5]. The primary plan was fiberoptic nasotracheal intubation while emergency needle cricothyrotomy and tracheostomy were arranged as stand-by. Nebulisation with 2 ml of 2% lignocaine along with instillation of xylometazoline drops were done 30 min prior to shifting the patient to the operating room. Premedication was done with glycopyrrolate and midazolam. Inhalational induction was done with sevoflurane. An appropriate-size cuffed endotracheal tube was introduced through the more patent nostril after the lignocaine jelly application. The ETT was connected to the Jackson Rees circuit, and confirmation was done with chest and bag movements. Appropriately sized paediatric fiberoptic bronchoscope was not available, so, they introduced the available size bronchoscope through the other nostril. Thus with ETT in one nostril and bronchoscope in the other, under fiberoptic vision, ETT was advanced gently with minimal external laryngeal manipulation. Hence, they described an improvised technique of intubation in TMJ ankylosis when a paediatric-size fiberoptic bronchoscope is not available.

Hereby, we will be discussing the pre-operative as well as intra-operative anaesthetic management of six paediatric patients up to 18 years of age with TMJ ankylosis who were operated in our hospital (Figure 1-3).

Figure 1: AP and lateral 3D scans in CT highlighting temporomandibular joint.

Figure 2: Nil mouth opening preoperatively.

Figure 3: Inter-incisor gap increased to 3.5 cm post-surgery.

An 8-year-old boy weighing 27kgs presented to dentistry OPD in our hospital with a complaint of inability to open his mouth followed by a fall from the roof. The diagnosis of left TMJ ankylosis was made with an orthopantomogram (OPG) and CT face along with history and clinical assessment. All the investigations were within normal limits according to the age and type of surgery. The patient was then posted for removal of ankylotic mass, coronoidotomy and interpositional gap arthroplasty using temporalis myofascial flap after getting fitness from the anaesthesia team. We had the ENT team on standby for emergency tracheostomy as well. The patient was nebulised with asthalin and budecort on the day of surgery. After taking the patient to the operating room, all standard monitors were attached and baseline readings were taken. Bag and mask ventilation done with appropriate size mask. Injection Midazolam 0.5 mg IV and injection Glycopyrrolate 0.1 mg IV were given as premedication followed by injection Fentanyl 60 mg IV and injection Propofol 60 mg IV. Then, a depolarising muscle relaxant injection Succinylcholine 50 mg IV was given. The patient was then nasally intubated with cuffed endotracheal tube number 5.5 under the guidance of an ambuscope, confirmation done by bilateral chest rise and end-tidal CO₂. 

A patient aged 12 years posted for a similar surgery had retrognathia and deviation of mouth to the left side along with a decreased inter-incisor gap. Premedication was done with injection of Midazolam 0.5 mg IV and injection Glycopyrrolate 0.2 mg IV. The patient was nebulised with lignocaine 4% in the preoperative room for 30-45 minutes and xylometazoline drops were put in bilateral nostrils. The patient was then taken inside the operating room. Injection Fentanyl and injection Ketamine were given according to the weight of the patient so as to maintain spontaneous respiration. Inhalational maintenance was done with sevoflurane. With appropriate size endotracheal tube awake nasal fiberoptic bronchoscopy attempt was done twice but not able to pass the tube beyond vocal cords. Next, two blind nasal intubation attempts were taken by an experienced anaesthetist but still it was unsuccessful. The procedure was abandoned and the patient was shifted to the recovery room. The next time we used a fiberoptic bronchoscope in the less patent nostril for vision and the endotracheal tube was railroaded over the airway exchange catheter through the other more patent nostril which we used for navigation in order to secure the airway.

Another operated case of left TMJ ankylosis around 9 years back was posted again for TMJ ankylosis release. The patient underwent cricothyroidotomy in previous surgery and had a scar of the same. However, the X-ray neck Anteroposterior and lateral view both were normal. The patient had inter incisor gap of 5 mm along with retrognathia. The upper lip bite was grade 3. In the preoperative room patient was nebulised with 4 ml of 2% lignocaine for 30 minutes and xylometazoline drops were instilled in both nostrils. The patient was shifted to the operative room and a bilateral superior laryngeal nerve block was given with 1.5 ml of 2% lignocaine along with transtracheal nerve block with 1.5 ml of 2% lignocaine under aseptic precautions. Awake fiberoptic intubation was done with normal endotracheal tube number 5 fixed at 24 cm, however, some difficulty was faced while negotiating the tube because of a subglottic scar from cricothyroidotomy in previous surgery. The confirmation of the tube endotracheally was done with a fiberoptic bronchoscope, capnograph and bilateral chest rise. The intraoperative period was uneventful. The patient was not extubated on the table and was sent to the ICU for elective mechanical ventilation and further management in view of the difficult airway. The patient was extubated the next day uneventfully. 

A 14-year-old boy was diagnosed with a case of TMJ ankylosis post-trauma. The patient had inter incisor gap of 2 mm along with retrognathia. The patient was nebulised with 4 ml of 4% lignocaine prior to the surgery and xylometazoline drops were instilled in bilateral nostrils. The patient was then taken inside the operation theatre, all standard monitors were attached and baseline readings were taken. Injection Midazolam 0.5 mg and injection Glycopyrrolate 0.2 mg IV were given as premedication. For awake fiberoptic bronchoscopy, injection Dexmedetomidine was started at loading dose @ 1 µg/kg for 10 minutes followed by maintenance @ 0.5 µg/kg/h thus maintaining spontaneous respiration. The airway was secured with normal endotracheal tube number 5.5 and fixed at 24 cm, confirmation was done by capnograph and equal bilateral air entry on auscultation. The intraoperative period went uneventful. The patient was extubated on the table.

Another 14-year-old patient with post-traumatic TMJ ankylosis and receding mandible was nasally intubated with an endotracheal tube 5.0 mm under general anaesthesia using a fiberoptic bronchoscope. The intraoperative period was uneventful and the patient was extubated in the operation theatre.

A 6-year-old patient with congenital TMJ ankylosis was premedicated with injection Midazolam 0.5 mg and injection Glycopyrrolate 0.1 mg IV. The patient was preoxygenated with 100% oxygen for 3 minutes. Patient then received injection Ketamine 10 mg IV along with injection Fentanyl 20 mg IV and injection Propofol 50 mg IV in incremental doses. Awake fiberoptic bronchoscopy was done however scope could not be negotiated beyond anterior nares. Later on, the airway was secured with an endotracheal tube size 5.0 mm blindly and confirmation was done by chest auscultation and capnograph. Long-acting muscle relaxant i.e. injection Atracurium 7 mg IV was given after nasal endotracheal intubation. The patient was maintained on Oxygen, Nitrous oxide and Isoflurane with an uneventful intraoperative period. The patient was extubated on the table and shifted to the recovery room for observation.

Besides nil or very little mouth opening along with retrognathia and other physical and psychological consequences the airway anatomy also gets altered in TMJ ankylosis. At the deeper plane of anaesthesia, airway obstruction occurs as the tongue falls back on the posterior pharyngeal wall. Upward jaw thrust is also impossible in TMJ ankylosis because of mandibular hypoplasia.3 there is a secondary narrowing of the oropharyngeal airway due to the shortening of mandibular rami with the narrowing of space between mandibular angles.4 Thus, making oral intubation with conventional direct laryngoscopy impossible. Difficult face mask ventilation may also be present. The most common and acceptable technique adopted nowadays is nasal intubation using a fibre optic bronchoscope. Earlier, blind nasal intubation and tracheostomy were the only available approaches. Awake fibreoptic intubation requires preoperative preparation of the patient. The paediatric airway is different from the adult airway physiologically and anatomically. Predicting paediatric difficult airway using conventional airway assessment tools is difficult, limited and has less sensitivity. Temporomandibular joint ankylosis further adds to the dilemma.5 The incidence of facial nerve injuries or one of its branches ranges from 1% to as high as 55% for TMJ surgery. An awake fiberoptic intubation is the gold standard for securing a difficult airway but in the paediatric population it is hardly possible and so we require deep sedation or general anaesthesia. Since airway collapse in patients with TMJ ankylosis is objectionable, the safest option is intubation under sedation while maintaining spontaneous ventilation. The novel technique of using gum elastic bougie in paediatric patients [6]. After induction with thiopentone and airway maintenance with air, oxygen and halothane, an ETT was passed through one nostril till maximum-intensity breath sounds could be heard. Next, another ETT was passed via the other nostril to deliver anaesthetic agents and maintain the depth of anaesthesia. Then, the gum elastic bougie was advanced through the first ETT into the glottis. The method proved to be less traumatic as compared to conventional blind nasal intubation. In circumstances like these, sometimes what seems to be difficult turns out to be simple and simple turns out to be difficult.

To conclude, difficult airway management is very demanding and moreover so in children. Nowadays we have a wide radius of options but the availability of desired equipment and drugs continues to be a problem. As awake intubation is impracticable in the paediatric age group, hence, detailed stepwise airway intervention must be laid out priorly. 

The authors declare that they have no conflict of interest.

None.

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