Title	Stability of Treating Open Bite with Maxillary Posterior Intrusion Using Absolute Anchorage Vs. Surgical Correction
Clinical Question	What is the stability of intruding maxillary posterior teeth to correct an open bite when compared to surgical correction?
Clinical Bottom Line	Research indicates that the most stable way to correct an anterior open bite is with surgery. The problem is that these various studies have different definitions of success and relapse. Therefore one should consider surgical correction vs. non-surgical correction on a case-by-case basis to determine which treatment is best. (See Comments on the CAT below)
Best Evidence
PubMed ID Author / Year Patient Group Study type (level of evidence) 20889043 Baek/2010 9 adults with anterior open bite Case series Key results Previous studies show that surgical treatment of open bites with a LeFort I osteotomy have a range of 7-21% relapse rate. Other studies show a 30% relapse rate for treatment of anterior open bites with intrusion of the mandibular posterior teeth. This study concentrated on intruding maxillary posterior teeth with mini-implants as anchorage. The maxillary posterior teeth were intruded by an average of 2.39 mm which allowed the mandible to rotate forward and a decrease in the ANB occurred (mean 0.66 degrees). An average of 0.99 mm reduction in overbite occurred during the first year. After 3 years the patients were recalled again and the average reduction in overbite from post-treatment to 3 years was 1.20 mm. This was an average of 17% relapse in overbite after 3 years. 10832998 Proffit/2000 54 patients with >2mm open bite occlusion Retrospective Case Series Key results This study concluded that a >2 mm decrease in overbite rarely occurred beyond 1 year after surgical correction. The overall conclusion is that when the maxilla is moved superiorly in the treatment of anterior open bite there is a 10% chance of 2-4 mm relapse long term.
Evidence Search	orthodontic[All Fields] AND ("therapy"[Subheading] OR "therapy"[All Fields] OR "treatment"[All Fields] OR "therapeutics"[MeSH Terms] OR "therapeutics"[All Fields]) AND anterior[All Fields] AND ("open bite"[MeSH Terms] OR ("open"[All Fields] AND "bite"[All Fields]) OR "open bite"[All Fields])
Comments on The Evidence	The study by Baek was a retrospective study which only had 9 subjects. The lack of subjects makes it very difficult to determine the stability of this treatment. Any outliers would greatly affect the means of this study, making the results unreliable. The study by Proffit concluded that there was only a 10% relapse of 2-4mm after surgical correction. They do not indicate what the percentage of overall relapse was (<2mm), so it is difficult to compare the overall stability of surgery vs non surgery when correcting anterior open bites.
Applicability	Many patients present with anterior open bites. It is important to know that there are other treatment options besides surgery to help correct these malocclusions.
Specialty	(Oral Surgery) (Orthodontics)
Keywords	stability open bite, maxillary intrusion, absolute anchorage, surgical correction
ID#	731
Date of submission	11/15/2010
E-mail	zirbel@uthscsa.edu
Author	Cassandra Zirbel, DDS
Co-author(s)
Co-author(s) e-mail
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 (FOR PRACTICING DENTISTS', FACULTY, RESIDENTS and/or STUDENTS COMMENTS ON PUBLISHED CATs) by Jaclyn Vu, Stephanie Lomeli, Ryan Chenausky (San Antonio, Texas) on 01/06/2014 A PubMed search on this topic was conducted on January 6, 2014 and found a more recent publication on the efficacy of implant-anchorage devices: Deguchi 2011, PubMed: 21435540 . The RCT included 30 individuals and concluded that implant-anchorage can achieve ideal occlusion in adults with severe open bite.