Adenotonsillar hypertrophy is a major cause of obstructive sleep apnea (OSAS) in childhood. Increased
respiratory effort associated with OSAS is accompanied by an increase in pulse transit time (PTT) but also mandibular
movements (MMs) amplify with increased upper airway resistance. We compared dynamic changes in PTT and MMs
using a magnetic distance sensor during polysomnography (PSG) in a pre-school child with severe OSAS before and after
adenotonsillectomy. The results show that repetitive respiratory effort to overcome upper airway obstruction can be
identified in children using MMs.