Maxillomandibular advancement and obstructive sleep apnea
Pirklbauer K, Russmueller G, Stiebellehner L, Nell C, Sinko K, Millesi G, et al. Maxillomandibular advancement for treatment of obstructive sleep apnea syndrome: a systematic review. J Oral Maxillofac Surg 2011;69:e165-76
The collapse of the upper airway when sleeping, known as obstructive sleep apnea syndrome, is related to adverse effects including daytime sleepiness, depression, and an increased risk of cardiovascular complications. Ventilation therapy, such as continuous positive airway pressure, is considered to be the gold standard for treatment of obstructive sleep apnea syndrome. However, the lifelong prognosis and cumbersome nature of the ventilation device leaves some patients unable to tolerate this mode of treatment. Maxillomandibular advancement is a treatment option for those who are opposed to ventilation therapy. Skeletal advancement results in an increase in pharyngeal diameter and a tightening of surrounding tissues, which decrease the collapsibility of the airway during sleep. This article reviews the available data regarding maxillomandibular advancement to treat patients with obstructive sleep apnea. After the quality of the studies was assessed, 39 articles were reviewed. No meta-analysis was performed because of the variability in methods used to evaluate obstructive sleep apnea syndrome and the success of surgical outcomes. Although the criteria used for outcome assessment varied greatly, the reported success rates of maxillomandibular advancement ranged from 65% to 100%. All studies advocated a minimum advancement of 10 mm. This sizeable advancement affected facial appearance, but, in all studies, most patients were satisfied with their postoperative esthetics regardless of a preoperative skeletal deficiency. The most common postoperative complications were hypesthesia, bleeding, and infection. In 1 study, a prospective randomized controlled trial, 50 consecutively treated obstructive sleep apnea patients assigned to a ventilation therapy group or a maxillomandibular advancement group were compared. At 1 year posttreatment, no statistically significant difference was found between the groups. The authors concluded that maxillomandibular advancement is a viable option for treatment of obstructive sleep apnea syndrome, especially for those who cannot tolerate ventilation therapy.
Reviewed by Michael Miyamoto
Interceptive treatment of palatally displaced canines
Naoumova J, Kurol J, Kjellberg H. A systematic review of the interceptive treatment of palatally displaced maxillary canines. Eur J Orthod 2011;33:143-9
Palatal displacement of maxillary canines (PDC) often results in tooth impaction requiring surgical and orthodontic treatments. This systematic review aimed to assess whether interceptive treatment in the mixed dentition prevents impaction of PDC. Based on a comprehensive review of electronic databases from 1966 to 2009, 686 articles were selected and rated according to a quality assessment tool. Only articles whose initial aim was to test the correlation between interventions in the late mixed dentition and impaction of PDC by examining radiographs and models were included; specific study designs included randomized clinical trials and prospective, retrospective observational studies with concurrent untreated and normal controls. Two articles were acceptable and analyzed. No evidence-based conclusion could be drawn because of the few studies identified, the heterogeneity in study designs, and the ambiguous results. Furthermore, these studies had problems with insufficient or lack of sample-selection descriptions, no discussions of confounding factors, and lack of blinding in measurements. The results of this systematic review highlight valuable guidelines for future studies and show a need for well-controlled randomized controlled trials regarding the effectiveness of various treatment strategies and for assessing which treatment is the most effective for treating PDC in the mixed dentition.
Reviewed by Rongning Wu