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Article: Treatment response and long-term dentofacial adaptations to maxillary expansion and protraction.

TitleTreatment response and long-term dentofacial adaptations to maxillary expansion and protraction.
Authors
Issue Date1997
PublisherWB Saunders Co. The Journal's web site is located at http://www.journals.elsevierhealth.com/periodicals/ysodo
Citation
Seminars In Orthodontics, 1997, v. 3 n. 4, p. 255-264 How to Cite?
AbstractThe purpose of this article is to summarize the short-term and long-term results of the authors' clinical prospective study on the treatment of Class III malocclusion using the protraction facemask. An attempt is made to answer questions pertaining to this treatment modality. Twenty patients with skeletal Class III malocclusion were treated consecutively with maxillary expansion and a protraction facemask. A positive overjet was obtained in all cases after 6 to 9 months of treatment. These changes were contributed to by a forward movement of the maxilla, backward and downward rotation of the mandible, proclination of the maxillary incisors, and retroclination of the mandibular incisors. The molar relationship was overcorrected to Class I or Class II dental arch relationship. The overbite was reduced with a significant increase in lower facial height. The treatment was found to be stable 2 years after removal of the appliances. At the end of the 4-year observation period, 15 of the 20 patients maintained a positive overjet or an end-to-end incisal relationship. Patients who reverted back to a negative overjet were found to have excess horizontal mandibular growth that was not compensated by proclination of the maxillary incisors. A review of the literature showed that maxillary expansion in conjunction with protraction produced greater forward movement of the maxilla. Maxillary protraction with a 30 degrees forward and downward force applied at the canine region produced an acceptable clinical response. The reciprocal force from maxillary protraction transmitted to the temporomandibular joint did not increase masticatory muscle pain or activity. Significant soft tissue profile change can be expected with maxillary protraction including straightening of the facial profile and better lip competence and posture. However, one should anticipate individual variations in treatment response and subsequent growth changes. Treatment with the protraction facemask is most effective in Class III patients with a retrusive maxilla and a hypodivergent growth pattern. Treatment initiated at the time of initial eruption of the upper central incisors helps to maintain the anterior occlusion after treatment.
Persistent Identifierhttp://hdl.handle.net/10722/154012
ISSN
2015 Impact Factor: 0.346
2015 SCImago Journal Rankings: 0.252

 

DC FieldValueLanguage
dc.contributor.authorNgan, PWen_US
dc.contributor.authorHagg, Uen_US
dc.contributor.authorYiu, Cen_US
dc.contributor.authorWei, SHYen_US
dc.date.accessioned2012-08-08T08:22:48Z-
dc.date.available2012-08-08T08:22:48Z-
dc.date.issued1997en_US
dc.identifier.citationSeminars In Orthodontics, 1997, v. 3 n. 4, p. 255-264en_US
dc.identifier.issn1073-8746en_US
dc.identifier.urihttp://hdl.handle.net/10722/154012-
dc.description.abstractThe purpose of this article is to summarize the short-term and long-term results of the authors' clinical prospective study on the treatment of Class III malocclusion using the protraction facemask. An attempt is made to answer questions pertaining to this treatment modality. Twenty patients with skeletal Class III malocclusion were treated consecutively with maxillary expansion and a protraction facemask. A positive overjet was obtained in all cases after 6 to 9 months of treatment. These changes were contributed to by a forward movement of the maxilla, backward and downward rotation of the mandible, proclination of the maxillary incisors, and retroclination of the mandibular incisors. The molar relationship was overcorrected to Class I or Class II dental arch relationship. The overbite was reduced with a significant increase in lower facial height. The treatment was found to be stable 2 years after removal of the appliances. At the end of the 4-year observation period, 15 of the 20 patients maintained a positive overjet or an end-to-end incisal relationship. Patients who reverted back to a negative overjet were found to have excess horizontal mandibular growth that was not compensated by proclination of the maxillary incisors. A review of the literature showed that maxillary expansion in conjunction with protraction produced greater forward movement of the maxilla. Maxillary protraction with a 30 degrees forward and downward force applied at the canine region produced an acceptable clinical response. The reciprocal force from maxillary protraction transmitted to the temporomandibular joint did not increase masticatory muscle pain or activity. Significant soft tissue profile change can be expected with maxillary protraction including straightening of the facial profile and better lip competence and posture. However, one should anticipate individual variations in treatment response and subsequent growth changes. Treatment with the protraction facemask is most effective in Class III patients with a retrusive maxilla and a hypodivergent growth pattern. Treatment initiated at the time of initial eruption of the upper central incisors helps to maintain the anterior occlusion after treatment.en_US
dc.languageengen_US
dc.publisherWB Saunders Co. The Journal's web site is located at http://www.journals.elsevierhealth.com/periodicals/ysodoen_US
dc.relation.ispartofSeminars in Orthodonticsen_US
dc.subject.meshAdaptation, Physiologicalen_US
dc.subject.meshCephalometry - Statistics & Numerical Dataen_US
dc.subject.meshChilden_US
dc.subject.meshExtraoral Traction Appliancesen_US
dc.subject.meshFemaleen_US
dc.subject.meshHumansen_US
dc.subject.meshMaleen_US
dc.subject.meshMalocclusion, Angle Class Iii - Physiopathology - Radiography - Therapyen_US
dc.subject.meshMaxillofacial Developmenten_US
dc.subject.meshOrthodontic Appliance Designen_US
dc.subject.meshOrthodontics, Interceptive - Methodsen_US
dc.subject.meshProspective Studiesen_US
dc.subject.meshTime Factorsen_US
dc.subject.meshTreatment Outcomeen_US
dc.titleTreatment response and long-term dentofacial adaptations to maxillary expansion and protraction.en_US
dc.typeArticleen_US
dc.identifier.openurlhttp://library.hku.hk:4550/resserv?sid=HKU:IR&issn=1073-8746&volume=3&issue=4&spage=255&epage=264&date=1998&atitle=Treatment+Response+and+Long-Term+Dentofacial+Adaptations+to+Maxillary+Expansion+and+Protraction-
dc.identifier.emailHagg, U: euohagg@hku.hken_US
dc.identifier.emailYiu, C: ckyyiu@hkucc.hku.hken_US
dc.identifier.emailWei, SHY: cdowei@hkuxa.hku.hk-
dc.identifier.authorityHagg, U=rp00020en_US
dc.identifier.authorityYiu, C=rp00018en_US
dc.description.naturelink_to_subscribed_fulltexten_US
dc.identifier.doi10.1016/S1073-8746(97)80058-8-
dc.identifier.pmid9573887-
dc.identifier.scopuseid_2-s2.0-0031324001en_US
dc.identifier.hkuros29792-
dc.identifier.volume3en_US
dc.identifier.issue4en_US
dc.identifier.spage255en_US
dc.identifier.epage264en_US
dc.publisher.placeUnited Statesen_US
dc.identifier.scopusauthoridNgan, PW=7006250823en_US
dc.identifier.scopusauthoridHagg, U=7006790279en_US
dc.identifier.scopusauthoridYiu, C=7007115156en_US
dc.identifier.scopusauthoridWei, SH=7401765260en_US

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