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Article: Soft tissue and dentoskeletal profile changes associated with maxillary expansion and protraction headgear treatment

TitleSoft tissue and dentoskeletal profile changes associated with maxillary expansion and protraction headgear treatment
Authors
Issue Date1996
PublisherMosby, Inc. The Journal's web site is located at http://www.elsevier.com/locate/ajodo
Citation
American Journal of Orthodontics and Dentofacial Orthopedics, 1996, v. 109 n. 1, p. 38-49 How to Cite?
AbstractOne of the goals of early treatment of Class III malocclusion with maxillary expansion and protraction headgear is to significantly improve the dentofacial profile. The objectives of the present study were to determine (1) the interrelationships of the soft tissue and dentoskeletal profiles after maxillary expansion and protraction headgear treatment and (2) which cephalometric variables could contribute to an accurate prediction of the protraction effect on the soft tissue profile. Lateral cephalometric radiographs of 20 consecutively treated Class III patients (10 males, 10 females) by protraction headgear were included in this study. Their ages at the start of protraction headgear treatment ranged from 6 to 11 years, with an average of 8.1 +/- 2.1 years. None of the patients had previous orthodontic treatment. For each patient, the first lateral cephalogram was taken 6 months before the initiation of headgear treatment (T0), and the second radiograph at the start of treatment (T1). Therefore (T1-T0) represented 6 months of growth with no treatment. A third radiograph was taken 6 months after start of treatment (T2). In this way, (T2-T1)-(T1-T0) represented the effect the result of appliance therapy alone and each subject served as his/her own control. A computerized cephalometric analysis was used including variables assessing sagittal and vertical relationships of skeletal and soft tissue profiles, incisal relationships, soft tissue thickness, and lip structure. Data were analyzed by means of paired t tests, Pearson's product-moment coefficient correlation, and multiple regression analyses. The results showed significant improvements in dentofacial profile after 6 months of maxillary protraction. The skeletal and soft tissue facial profiles were straightened and the posture of the lips was improved. The normal incisal relationship (overjet) that was achieved had a significant impact on the soft tissues overlying both upper and lower incisors resulting in better lip competence and posture. Significant correlations were found between changes in the sagittal relationships of skeletal and soft tissue profiles in both the maxilla and the mandible (p < 0.05). The forward movement of the maxilla was accompanied by a corresponding forward movement of the soft tissue profile at 50% to 79% of the hard tissue. In the mandible, the downward and backward movements of the soft tissues were equivalent to 71% to 81% of the corresponding hard tissues. The lack of high r square values in the multiple regression analyses reflected a low prediction value for the maxillary variables, but moderately high prediction value for the mandibular variables that could be used in preorthopedic treatment planning. This study showed that significant dentoskeletal changes and improvements in dentofacial profile resulted from 6 months of treatment with maxillary expansion and protraction.
Persistent Identifierhttp://hdl.handle.net/10722/153956
ISSN
2015 Impact Factor: 1.69
2015 SCImago Journal Rankings: 1.249
ISI Accession Number ID

 

DC FieldValueLanguage
dc.contributor.authorNgan, Pen_US
dc.contributor.authorHägg, Uen_US
dc.contributor.authorYiu, Cen_US
dc.contributor.authorMerwin, Den_US
dc.contributor.authorWei, SHYen_US
dc.date.accessioned2012-08-08T08:22:29Z-
dc.date.available2012-08-08T08:22:29Z-
dc.date.issued1996en_US
dc.identifier.citationAmerican Journal of Orthodontics and Dentofacial Orthopedics, 1996, v. 109 n. 1, p. 38-49en_US
dc.identifier.issn0889-5406en_US
dc.identifier.urihttp://hdl.handle.net/10722/153956-
dc.description.abstractOne of the goals of early treatment of Class III malocclusion with maxillary expansion and protraction headgear is to significantly improve the dentofacial profile. The objectives of the present study were to determine (1) the interrelationships of the soft tissue and dentoskeletal profiles after maxillary expansion and protraction headgear treatment and (2) which cephalometric variables could contribute to an accurate prediction of the protraction effect on the soft tissue profile. Lateral cephalometric radiographs of 20 consecutively treated Class III patients (10 males, 10 females) by protraction headgear were included in this study. Their ages at the start of protraction headgear treatment ranged from 6 to 11 years, with an average of 8.1 +/- 2.1 years. None of the patients had previous orthodontic treatment. For each patient, the first lateral cephalogram was taken 6 months before the initiation of headgear treatment (T0), and the second radiograph at the start of treatment (T1). Therefore (T1-T0) represented 6 months of growth with no treatment. A third radiograph was taken 6 months after start of treatment (T2). In this way, (T2-T1)-(T1-T0) represented the effect the result of appliance therapy alone and each subject served as his/her own control. A computerized cephalometric analysis was used including variables assessing sagittal and vertical relationships of skeletal and soft tissue profiles, incisal relationships, soft tissue thickness, and lip structure. Data were analyzed by means of paired t tests, Pearson's product-moment coefficient correlation, and multiple regression analyses. The results showed significant improvements in dentofacial profile after 6 months of maxillary protraction. The skeletal and soft tissue facial profiles were straightened and the posture of the lips was improved. The normal incisal relationship (overjet) that was achieved had a significant impact on the soft tissues overlying both upper and lower incisors resulting in better lip competence and posture. Significant correlations were found between changes in the sagittal relationships of skeletal and soft tissue profiles in both the maxilla and the mandible (p < 0.05). The forward movement of the maxilla was accompanied by a corresponding forward movement of the soft tissue profile at 50% to 79% of the hard tissue. In the mandible, the downward and backward movements of the soft tissues were equivalent to 71% to 81% of the corresponding hard tissues. The lack of high r square values in the multiple regression analyses reflected a low prediction value for the maxillary variables, but moderately high prediction value for the mandibular variables that could be used in preorthopedic treatment planning. This study showed that significant dentoskeletal changes and improvements in dentofacial profile resulted from 6 months of treatment with maxillary expansion and protraction.en_US
dc.languageengen_US
dc.publisherMosby, Inc. The Journal's web site is located at http://www.elsevier.com/locate/ajodoen_US
dc.relation.ispartofAmerican Journal of Orthodontics and Dentofacial Orthopedicsen_US
dc.rightsAmerican Journal of Orthodontics and Dentofacial Orthopedics. Copyright © Mosby, Inc.-
dc.subject.meshCephalometryen_US
dc.subject.meshChilden_US
dc.subject.meshExtraoral Traction Appliancesen_US
dc.subject.meshFace - Anatomy & Histologyen_US
dc.subject.meshFemaleen_US
dc.subject.meshHumansen_US
dc.subject.meshLip - Anatomy & Histologyen_US
dc.subject.meshMaleen_US
dc.subject.meshMalocclusion, Angle Class Iii - Therapyen_US
dc.subject.meshMaxillofacial Developmenten_US
dc.subject.meshOrthodontics, Interceptive - Methodsen_US
dc.subject.meshPalatal Expansion Techniqueen_US
dc.subject.meshPredictive Value Of Testsen_US
dc.subject.meshProspective Studiesen_US
dc.subject.meshRadiographic Image Interpretation, Computer-Assisteden_US
dc.subject.meshRegression Analysisen_US
dc.subject.meshTreatment Outcomeen_US
dc.titleSoft tissue and dentoskeletal profile changes associated with maxillary expansion and protraction headgear treatmenten_US
dc.typeArticleen_US
dc.identifier.openurlhttp://library.hku.hk:4550/resserv?sid=HKU:IR&issn=0889-5406&volume=109&issue=1&spage=38&epage=49&date=1996&atitle=Soft+tissue+and+dentoskeletal+profile+changes+associated+with+maxillary+expansion+and+protraction+headgear+treatment-
dc.identifier.emailHägg, U: euohagg@hku.hken_US
dc.identifier.emailYiu, C: ckyyiu@hkucc.hku.hken_US
dc.identifier.emailWei, SHY: cdowei@hkuxa.hku.hk-
dc.identifier.authorityHägg, U=rp00020en_US
dc.identifier.authorityYiu, C=rp00018en_US
dc.description.naturelink_to_subscribed_fulltexten_US
dc.identifier.doi10.1016/S0889-5406(96)70161-0-
dc.identifier.pmid8540481en_US
dc.identifier.scopuseid_2-s2.0-0029687688en_US
dc.identifier.hkuros9501-
dc.identifier.hkuros20209-
dc.identifier.hkuros24107-
dc.identifier.volume109en_US
dc.identifier.issue1en_US
dc.identifier.spage38en_US
dc.identifier.epage49en_US
dc.identifier.isiWOS:A1996TR34600012-
dc.publisher.placeUnited Statesen_US
dc.identifier.scopusauthoridNgan, P=7006250823en_US
dc.identifier.scopusauthoridHägg, U=7006790279en_US
dc.identifier.scopusauthoridYiu, C=7007115156en_US
dc.identifier.scopusauthoridMerwin, D=16683389900en_US
dc.identifier.scopusauthoridWei, SH=7401765260en_US

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