View the CAT printer-friendly / share this CAT
Title Favorable Stability of Correction of Posterior Cross-Bite with Conventional Maxillary Expansion
Clinical Question Is conventional maxillary expansion of mixed dentition stable?
Clinical Bottom Line The stability of posterior cross-bite correction is favorable when treated with conventional maxillary expansion.
Best Evidence (you may view more info by clicking on the PubMed ID link)
PubMed ID Author / Year Patient Group Study type
(level of evidence)
#1) 21195260Petren/201035 mixed dentition children with posterior crossbite, 20 mixed dentition chilldren with normal occlusionRadomized Clinical Trial
Key resultsThe overall changes during the 4 year study showed that treatment groups were comparable with the control group. Significant increases in maxillary transverse distances were found in all groups (P<0.01), except for inter-caine distance at the gingival margin. At 3 years post treatment, 34 of 35 treated patients had normal transverse relationships. However, during the post treatment period, statistically significant decrease in maxillary transverse dimensions occurred in the treatment group. This slight relapse did not negate correction of posterior cross-bite.
Evidence Search posterior crossbite stability longitudinal study
Comments on
The Evidence
Patients met the following inclusion criteria: mixed dentition (all incisors and first molars in occlusion), posterior cross-bite, no sucking habits or sucking habit discontinued at least one year before the trial, and no previous orthodontic treatment. Follow up period of three years was adequate for long-term conclusions because almost all subjects had reached complete permanent dentition. Assessment of transverse occlusions (cross-bite correction) and all study cast measurements were performed by examiners that were unaware of the group to which the patient belonged. Casts made at pre-treatment, end of treatment, and post-treatment were randomized for measurement.
Applicability Transverse discrepancies such as a posterior cross-bite is a common malocclusion in the mixed dentition and should be treated early and effectively to prevent negative long-term effects on growth of the patients teeth and jaws.
Specialty/Discipline (General Dentistry) (Orthodontics) (Pediatric Dentistry)
Keywords crossbite stability longterm conventional expansion
ID# 2322
Date of submission: 08/07/2012spacer
E-mail gordonas@uthscsa.edu
Author Adam Gordon
Co-author(s) e-mail
Faculty mentor/Co-author Clarence C. Bryk, DDS, MS
Faculty mentor/Co-author e-mail brykc@uthscsa.edu
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?)
post a rationale
by Adam Gordon (San Antonio, Texas) on 09/16/2012
The biological basis for this treatment is the mechanical force-induced mid-palatal suture remodeling. (publication PMID: 17398175 ) Tensional force applied to the mid-palatal suture of rats induces the replacement of cartilaginous tissues by bone. Furthermore, it has been suggested that mesenchymal cells located on the inner side of the cartilaginous tissue proliferate and differentiate into osteoblasts when the suture is expanded. Recent studies of cultured osteoblasts or chondrocytes have shown that mechanical strain results in changes in gene expression. For example, application of strain to osteoblasts increases mRNA levels of Cox-2 (cyclooxygenase-2) and the immediate early gene c-fos within an hour, as well as the levels of extracellular matrix proteins osteopontin and osteocalcin within 24 hours. The data formulated during this study indicate that expansive force across the midpalatal suture promotes bone resorption through activation of osteoclasts and bone formation via increased proliferation and differentiation of periosteal cells. Mid-palatal suture expansion also leads to decrease of the original secondary cartilage and formation of new cartilage within the suture area on the oral side.
Comments and Evidence-Based Updates on the CAT
post a comment
None available

Return to Found CATs list