Surgical correction of nasal obstruction in the treatment of mild sleep apnoea: importance of cephalometry in predicting outcome.

BACKGROUND: A study was undertaken to determine if cephalometric radiographs could identify those who will benefit from nasal surgery in patients with a sleep apnoea hypopnoea syndrome (SAHS) and chronic nasal obstruction.
METHODS: Fourteen patients with SAHS were enrolled. Those with normal posterior airway space and mandibular plane to hyoid bone distances on preoperative cephalometric radiographs were matched with those with abnormal cephalometry for the frequency of sleep disordered breathing and body mass index. Polysomnographic studies (all subjects) and nasal resistance measurements (n = 10) were performed one to three months before and two to three months after surgery (septoplasty, turbinectomy, and polypectomy).
RESULTS: There was no difference in the baseline results of the polysomnographic studies between the two groups of patients. Nasal resistance decreased from a mean (SE) value of 2.9 (0.3) cm H2O/l/s before surgery to 1.4 (0.1) cm H2O/l/s after surgery in the normal cephalometry group and from 2.7 (0.3) cm H2O/l/s to 1.3 (0.3) cm H2O/l/s in the other group. The apnoea + hypopnoea index returned to normal (< 10 breathing abnormalities/hour) in all but one subject with normal cephalometric measurements, and sleep fragmentation improved with a decrease in the arousal index from 23.9 (3.3)/hour at baseline to 10.6 (2.5)/hour after surgery. Both of these parameters remained unchanged after surgery in the patients with abnormal cephalometry.
CONCLUSIONS: Normal cephalometry is helpful in identifying patients with mild SAHS and nasal obstruction who will benefit from nasal surgery. The presence of craniomandibular abnormalities makes it unlikely that nasal surgery will improve sleep related breathing abnormalities.