Title More Evidence Required to Determine the Long-Term Skeletal Expansion of Bone-Borne Palatal Expanders
Clinical Question In late adolescent patients needing maxillary expansion, does a tooth-borne palatal expander or a bone-borne palatal expander produce more long-term skeletal expansion?
Clinical Bottom Line In late adolescent females, bone-borne expanders produce greater skeletal expansion in the palate when compared to tooth-borne expanders. However, does the increased immediate skeletal expansion seen with bone-borne palatal expanders translate into more long-term expansion?
Best Evidence  
PubMed ID Author / Year Patient Group Study type
(level of evidence)
25490552Lin/201528 female late adolescent patientsNonrandomized Clinical Comparison
Key resultsThe midpalatal suture was successfully opened and expanded in both the tooth-borne palatal expander (hyrax) and the bone-borne palatal expander (C-expander). The C-expander group showed greater statistically significant suture expansion than did the hyrax group (P<0.05). The hyrax produced more significant buccal tipping in all areas than did the C-expander (P<0.01 or 0.001).
Evidence Search tooth-borne[All Fields] AND ("Vet Surg"[Journal] OR "vs"[All Fields]) AND bone-borne[All Fields] AND rapid[All Fields] AND ("maxilla"[MeSH Terms] OR "maxilla"[All Fields] OR "maxillary"[All Fields]) AND expanders[All Fields]
Comments on
The Evidence
Validity: Although Lin’s study contained a small sample size, the groups were similar at the start, he treated the groups the same, and ended the trials with an over 80% completion rate. Compliance was adequate among the subjects, but the subjects’ treatments were not blinded to the researchers. Perspective: This study only included twenty-eight females that were past their peak in skeletal growth (17-18 years old), which is past the recommended time for rapid maxillary expansion. Also, it included short-term findings but no long-term follow-up of the expansion. This presents an issue when applying the data for long-term results. Concerning appliance design, Lin stated that making comparisons between bone-borne palatal expanders used in various other studies was not possible because there is no standardization in their design, thus the lack of studies with which to compare Lin's findings. Based on this one randomized controlled trial, a bone-borne palatal expander produces more skeletal expansion than that of a tooth-borne expander. The tooth-borne expander can also cause unwanted dental changes, like buccal tipping of molars and premolars. More studies are needed with larger sample sizes, standardized bone-borne appliance design, and longer follow-up periods to best answer this question.
Applicability Many young people present with transverse maxillary deficiency, and rapid maxillary expansion is a widely accepted method of treatment. Obviously each patient presents with a different degree of necessary palatal expansion; however, the patient should be informed of the procedures involved in each appliance – the surgery of a bone-borne expander versus the bonding of a tooth-borne expander. The age of the patient will be taken into consideration when deciding upon treatment. It is also important to discuss the desired outcome with the patient, and the possibility of failure to gain the necessary separation of the palatal suture with a given appliance.
Specialty (General Dentistry) (Orthodontics) (Pediatric Dentistry)
Keywords Tooth-borne Palatal Expander, Bone-borne Palatal Expander, Rapid Maxillary Expansion, RME
ID# 2847
Date of submission 03/26/2015
E-mail EdwardsC3@livemail.uthscsa.edu
Author Collette Edwards
Co-author(s) e-mail
Faculty mentor Ann Larsen DDS, MS
Faculty mentor e-mail ajortho@yahoo.com
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
None available