Features of lateral cephalograms associated with difficult laryngoscopy in Japanese children undergoing oral and maxillofacial surgery

Summary Background Difficult laryngoscopy and tracheal intubation are occasionally encountered in children with congenital anomalies or micrognathia. However, no study has elucidated anatomical etiology in relation to craniofacial development. Methods Two hundred ten patients aged 8 months–18 years were analyzed. We analyzed the lateral cephalograms of: (i) eight patients in whom laryngoscopy was anticipated as difficult before anesthesia and who were unable to be intubated by direct laryngoscopy and needed fiberoptic bronchoscopy (group A); (ii) 11 patients in whom laryngoscopy was anticipated as difficult before anesthesia but who were able to be intubated by direct laryngoscopy (group B); and (iii) 191 patients in whom laryngoscopy was anticipated as easy before anesthesia and was actually found to be easy (group C). Eight cephalometric parameters were measured and age–parameter relationships were plotted. Logistic regression analysis was performed to characterize group A children for each of the cephalometric variables. Results Apparently insufficient growth of the mandible was observed in the group A children. Furthermore, the group A children of aged <4 years had undeveloped maxilla, longer mandibular plane–hyoid distances (≥1.3 cm), and deeper depth of the oropharynx; those of aged ≥4 years showed increased inclination of the mandible (sella–nasion plane to mandibular plane angle of ≥46.5°). Conclusions Difficult laryngoscopy and tracheal intubation are expected in children aged <4 years with lower-positioned hyoid bone caused by caudal larynx as well as undeveloped maxilla and mandible, and in those aged ≥4 years with increased inclination of the mandible as well as undeveloped mandible.