Differential treatment effects of two anchorage systems for rapid maxillary expansion: a retrospective cephalometric study.
OBJECTIVE
The purpose of this study was to compare cephalometric changes resulting from treatment with two appliances for rapid maxillary expansion: (1) a strictly tooth-borne appliance and (2) a combined tooth- and bone-borne appliance.


METHODS
Pre- and posttreatment lateral cephalograms of 100 patients were analyzed by cephalometry. Of these patients, 50 were treated with strictly tooth-borne and another 50 with combined tooth- and bone-borne appliances. Mean pretreatment age was 13.04 ± 4.82 years, and mean treatment duration was 7.12 ± 2.37 months. To identify any implications for clinical therapy, additional subgroups were formed based on the pretreatment cephalometric findings for skeletal Class I (0° < ANB ≤ 4°) or Class III (ANB ≤0°). Paired t-tests were used for intragroup and analysis of variance (ANOVA) for intergroup comparisons. Results were considered statistically significant at p ≤ 0.05.


RESULTS
Both appliance types resulted in significant cephalometric changes in the maxilla and mandible. Compared to the strictly tooth-borne appliances, the combined tooth- and bone-borne appliances were found to cause more pronounced advancement of the maxilla (SNA angle) notably among the Class III patients.


CONCLUSIONS
Hybrid (combined tooth- and bone-borne) appliances for rapid maxillary expansion might be preferable in the treatment of skeletal Class III patients, since they possibly exert a more pronounced skeletal effect on the sagittal position of the maxilla.
Orthodontic Practice, Reinheim, Germany.|Department of Orthodontics, University of Heidelberg, Heidelberg, Germany.
Jan
J
Hourfar
Orthodontic Practice, Tönisvorst, Germany.|Department of Orthodontics, Saarland University, Kirrberger Strasse 100, 66424, Homburg/Saar, Germany.
Gero Stefan Michael
GS
Kinzinger
Department of Orthodontics, Saarland University, Kirrberger Strasse 100, 66424, Homburg/Saar, Germany.|Orthodontic Practice, Traben-Trarbach, Germany.
Björn
B
Ludwig
Department of Orthodontics, Saarland University, Kirrberger Strasse 100, 66424, Homburg/Saar, Germany.
Julia
J
Spindler
Department of Orthodontics, Saarland University, Kirrberger Strasse 100, 66424, Homburg/Saar, Germany. joerg.lisson@uniklinikum-saarland.de.
Jörg Alexander
JA
Lisson
D000293:Adolescent; D001863:Bone Screws; D002508:Cephalometry; D002648:Child; D015921:Dental Implants; D017267:Dental Prosthesis Design; D019544:Equipment Failure Analysis; D005260:Female; D006801:Humans; D008297:Male; D008310:Malocclusion / Q000000981:diagnostic imaging* / Q000628:therapy*; D052280:Orthodontic Anchorage Procedures / Q000295:instrumentation* / Q000379:methods; D010155:Palatal Expansion Technique / Q000295:instrumentation*; D012189:Retrospective Studies; D016896:Treatment Outcome
D015921:Dental Implants
Analysis of cephalograms; Angle class I; Angle class III; Cephalometric study; Rapid maxillary expansion