I read the article “Congenital maxillomandibular fusion: a report of three cases” by Hegab et al. with great interest. The occurrence of syngnathia is quite rare and there are no protocols or guidelines for managing such cases. There is high morbidity and even mortality associated with managing these cases. I would like to make two comments on the subject so that morbidity and mortality associated with these cases can be reduced.
The first comment regards Case 1, who died suddenly during jaw physiotherapy on the third postoperative day. The possible reason for this could have been prolonged apnea and activation of the trigemino-cardiac reflex during jaw physiotherapy. One should be aware of the triad of decreased mouth opening, severe retrognathia, and obstructive sleep apnea, which can lead to hypoxia and hypercarbia during jaw physiotherapy. When the mouth is opened forcefully during jaw physiotherapy, the already compromised airway is further obstructed by the descending mandible, leading to apnea.
There may also be activation of the trigemino-cardiac reflex due to pain and pressure during jaw physiotherapy, which can lead to bradycardia. A combination of hypoxia and bradycardia can lead to convulsions, asystole, and cardiac arrest, as might have happened in the case managed by the authors. The reader is referred to an excellent paper by Andrade et al. on this subject, in which they discuss this problem in detail.
Secondly, as evident from the reported cases, another main problem in managing syngnathia cases is the recurrence of fusion. There seem to be two main reasons for recurrence: a high osteogenic potential and difficulty in instituting jaw physiotherapy in neonates. Therefore, a strategy is needed to prevent the formation of heterotopic bone in these patients. The interposition of autogenous or alloplastic material in the gap created after release of the fusion has decreased the chances of relapse in temporomandibular joint ankylosis. I have effectively used the buccal pad of fat as interposition material in a case of syngnathia, as highlighted by the brief case report below.
An 8-year-old boy suffering from congenital maxillomandibular fusion was referred to us for management. Three previous surgeries carried out elsewhere, at varying ages, had failed. There was bilateral maxillomandibular fusion ( Fig. 1 A). The fusion was released via intraoral approach under general anaesthesia. The buccal pad of fat was exposed through the same approach and interposed in the gap on both sides. There was less volume of fat on the left side due to fibrosis and the previous multiple surgeries. We transposed some additional buccal pad fat from the other side to the left side as a free graft. Jaw physiotherapy was instituted with a Heister jaw opener postoperatively. The child has been followed up for 3 years without recurrence. At last follow-up, mouth opening of 22 mm was maintained.