Title Extraction orthodontic treatment may or may not cause a decrease in posterior airway size, with no association shown to sleep apnea.
Clinical Question For a healthy adult patient who had orthodontic treatment, does the extraction of four premolar teeth cause a decrease in the posterior airway space and therefore increase the chances of that patient developing sleep apnea?
Clinical Bottom Line Orthodontic treatment involving the extraction of four premolars has not been proven to cause sleep apnea. Very little research has been done in this area. The current research focuses on the size of the posterior airway, not sleep apnea. Much more research needs to be done before a definitive answer can be reached. (See Comments on the CAT below)
Best Evidence  
PubMed ID Author / Year Patient Group Study type
(level of evidence)
20677956Valiathan/201020 patients treated with four premolars extracted and 20 patients treated non-extraction, all Class I molars.Cohort
Key resultsExtraction of four premolars with retraction of incisors does not affect oropharyngeal airway volume. Measurements were 3D as provided by cone beam analysis.
21118911Germec-Cakan/2011Three groups all with Class I molars: 13 patients with four premolars extracted and spaces closed with maximum anchorage; 13 patients with four premolars extracted and spaces closed with minimum anchorage; 13 patients with non-extraction treatment.Cohort
Key resultsUvulo-glossopharyngeal airway dimensions were reduced in the maximum anchorage (extraction) group but not in the minimum anchorage (extraction) or non-extraction groups. All patients were Class I. Measurements were all two-dimensional (cephalometric tracings), no cone beams were used.
21793712Wang/201244 Class I patients all treated with extraction of four remoloars and space closure with maximum anchorage.Cohort
Key resultsThe patients were divided into two groups, high angle and low angle. They all had maximum anchorage incisor retraction. The pharyngeal airway size became narrower after treatment for both groups, regardless of their mandibular plane angle. All measurements were two-dimensional (cephalometric tracings), no cone beams were used.
Evidence Search extraction[All Fields] AND ("orthodontics"[MeSH Terms] OR "orthodontics"[All Fields]) AND ("pharynx"[MeSH Terms] OR "pharynx"[All Fields])
Comments on
The Evidence
All groups had small sample sizes. Only one study used 3D volumetric analysis. Oropharyngeal airway changes were not studied in regard to their possible effect on sleep apnea. There appears to be a correlation between the type of space closure (i.e. maximum anchorage) and a decrease in posterior airway space. More research needs to be done in this area.
Applicability More research is needed.
Specialty (Orthodontics)
Keywords orthodontics, extraction, posterior airway volume, sleep apnea
ID# 2335
Date of submission 02/11/2013
E-mail ajortho@yahoo.com
Author Ann Larsen, DDS
Co-author(s) Joseph Ryan
Co-author(s) e-mail RyanJK@livemail.uthscsa.edu
Faculty mentor
Faculty mentor e-mail
Basic Science Rationale
(Mechanisms that may account for and/or explain the clinical question, i.e. is the answer to the clinical question consistent with basic biological, physical and/or behavioral science principles, laws and research?)
None available
Comments and Evidence-Based Updates on the CAT
by Vishnu Raj (San Antonio, TX) on 03/03/2014
New papers worth evaluating - some found differences and some did not: PMID: 23324041 PMID: 22462464 PMID: 22369618