{"id":{"repo_id":"freiburg-diss","oai_identifier":"oai:freidok.uni-freiburg.de:1241"},"canonical_url":"https://search.dev.ndltd.org/etd/freiburg-diss/oai:freidok.uni-freiburg.de:1241","repository":{"repo_id":"freiburg-diss","name":"University of Freiburg","base_url":"https://freidok.uni-freiburg.de/oai/oai2.php"},"display":{"title":"Long-Term stability of the correction of the unilateral posterior crossbite","abstract":"The aim of this retrospective odontometric study was to evaluate the stability of orthodontically corrected<br>unilateral crossbite. This was done by comparing the long-term therapeutic results of patients treated either with rapid maxillary expansion (RME) or with slow expansion devices in the early (mean age: 7.2 years) or in the late mixed dentition (mean age: 9.9 years).<br>One hundred patients were selected from the files of the Department of Orthodontics, School of Dental<br>Medicine, Albert-Ludwig-University, Freiburg i.Br., Germany.<br>Patients’ selection was based on standardized conditions: Maxillary expansion had to be performed either with a removable expansion plate (n= 50), or with a rapid maxillary expansion technique (RME) using a tissue-borne, fixed, split acrylic appliance (n= 50). The slow expansion appliance (n= 50) was activated by 0.2 mm per week and the result was retained for 3 to 6 months after expansion had been achieved. The RME device (n= 50) was activated twice a day (0.4 mm) and the treatment result was retained for a minimum of 3 months.<br>All measurements were made on plaster casts made at the following timepoints:<br>(a) T1 = before treatment, (b) T2 = after posterior crossbite correction, (c) T3 = at the end of active orthodontic treatment, (d) T4 = ca. 2 years after the end of orthodontic treatment.<br>All recordings were performed by one examiner to the nearest of 0.1 mm, using a Boley gauge. Overjet,<br>overbite, midline deviation and the following cephalometric parameters were also registered: angle ANB, SNA, SNB for evaluation of the skeletal classification of the malocclusion, and the SN- MeGo angle and the SGo:<br>NMe % (percentage ratio between the posterior and anterior facial height) for determination of the patient’s growth pattern.<br>The statistical analysis of the data revealed the following relevant results:<br>- The observation periods were approximately 8 years for the early-treatment groups and 6.5 years for the late-treatment groups.<br>- 79% of the treated patients showed long-term stability of the corrected unilateral posterior crossbite.<br>This finding was independent of the patient’s age at the start of treatment and of the applied orthodontic<br>expansion device.<br>- 72% of the patients were successfully treated for the mandibular midline deviation.<br>- At the end of active treatment 50% of our cases showed a skeletal Class III craniofacial morphology.<br>- The mean change was 1.1 ± 2.8 mm in the maxillary interpremolar arch width and 2.3 ± 2.1 mm in the<br>intermolar arch width in the slow expansion groups. The RME groups showed a mean change of 3.6 ±<br>2.7 mm in interpremolar arch width and of 3.8 ± 2.7 mm in intermolar arch width; this was significantly<br>greater than in the comparison groups.<br>In subjects where the wider lower arch is a co-factor for the crossbite, the treatment approach should be focused on both arches and not only on the constricted upper arch. The mean mandibular arch width values of the relapsed cases in the present study were initially greater than those of the non-relapsed cases.","abstract_html":"The aim of this retrospective odontometric study was to evaluate the stability of orthodontically corrected&lt;br&gt;unilateral crossbite. This was done by comparing the long-term therapeutic results of patients treated either with rapid maxillary expansion (RME) or with slow expansion devices in the early (mean age: 7.2 years) or in the late mixed dentition (mean age: 9.9 years).&lt;br&gt;One hundred patients were selected from the files of the Department of Orthodontics, School of Dental&lt;br&gt;Medicine, Albert-Ludwig-University, Freiburg i.Br., Germany.&lt;br&gt;Patients’ selection was based on standardized conditions: Maxillary expansion had to be performed either with a removable expansion plate (n= 50), or with a rapid maxillary expansion technique (RME) using a tissue-borne, fixed, split acrylic appliance (n= 50). The slow expansion appliance (n= 50) was activated by 0.2 mm per week and the result was retained for 3 to 6 months after expansion had been achieved. The RME device (n= 50) was activated twice a day (0.4 mm) and the treatment result was retained for a minimum of 3 months.&lt;br&gt;All measurements were made on plaster casts made at the following timepoints:&lt;br&gt;(a) T1 = before treatment, (b) T2 = after posterior crossbite correction, (c) T3 = at the end of active orthodontic treatment, (d) T4 = ca. 2 years after the end of orthodontic treatment.&lt;br&gt;All recordings were performed by one examiner to the nearest of 0.1 mm, using a Boley gauge. Overjet,&lt;br&gt;overbite, midline deviation and the following cephalometric parameters were also registered: angle ANB, SNA, SNB for evaluation of the skeletal classification of the malocclusion, and the SN- MeGo angle and the SGo:&lt;br&gt;NMe % (percentage ratio between the posterior and anterior facial height) for determination of the patient’s growth pattern.&lt;br&gt;The statistical analysis of the data revealed the following relevant results:&lt;br&gt;- The observation periods were approximately 8 years for the early-treatment groups and 6.5 years for the late-treatment groups.&lt;br&gt;- 79% of the treated patients showed long-term stability of the corrected unilateral posterior crossbite.&lt;br&gt;This finding was independent of the patient’s age at the start of treatment and of the applied orthodontic&lt;br&gt;expansion device.&lt;br&gt;- 72% of the patients were successfully treated for the mandibular midline deviation.&lt;br&gt;- At the end of active treatment 50% of our cases showed a skeletal Class III craniofacial morphology.&lt;br&gt;- The mean change was 1.1 ± 2.8 mm in the maxillary interpremolar arch width and 2.3 ± 2.1 mm in the&lt;br&gt;intermolar arch width in the slow expansion groups. The RME groups showed a mean change of 3.6 ±&lt;br&gt;2.7 mm in interpremolar arch width and of 3.8 ± 2.7 mm in intermolar arch width; this was significantly&lt;br&gt;greater than in the comparison groups.&lt;br&gt;In subjects where the wider lower arch is a co-factor for the crossbite, the treatment approach should be focused on both arches and not only on the constricted upper arch. The mean mandibular arch width values of the relapsed cases in the present study were initially greater than those of the non-relapsed cases.","abstract_has_math":false,"creators":["Bartzela, Theodosia"],"institution":null,"degree_name":null,"degree_level":null,"degree_discipline":null,"degree_department":null,"school":null,"contributors":["Jonas, Irmtrud"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":null,"date_issued":"","date_published":null,"updated_at":"2026-07-24T02:22:03Z","subjects":["Stability posterior crossbite"],"languages":[],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"https://freidok.uni-freiburg.de/data/1241","outbound_label":"Repository record","outbound_source":"source_url"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Jonas, Irmtrud"]},{"key":"dc:creator","label":"Author","values":["Bartzela, Theodosia"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:type","label":"Dc Type","values":["DoctoralThesis"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Stability posterior crossbite"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["The aim of this retrospective odontometric study was to evaluate the stability of orthodontically corrected<br>unilateral crossbite. This was done by comparing the long-term therapeutic results of patients treated either with rapid maxillary expansion (RME) or with slow expansion devices in the early (mean age: 7.2 years) or in the late mixed dentition (mean age: 9.9 years).<br>One hundred patients were selected from the files of the Department of Orthodontics, School of Dental<br>Medicine, Albert-Ludwig-University, Freiburg i.Br., Germany.<br>Patients’ selection was based on standardized conditions: Maxillary expansion had to be performed either with a removable expansion plate (n= 50), or with a rapid maxillary expansion technique (RME) using a tissue-borne, fixed, split acrylic appliance (n= 50). The slow expansion appliance (n= 50) was activated by 0.2 mm per week and the result was retained for 3 to 6 months after expansion had been achieved. The RME device (n= 50) was activated twice a day (0.4 mm) and the treatment result was retained for a minimum of 3 months.<br>All measurements were made on plaster casts made at the following timepoints:<br>(a) T1 = before treatment, (b) T2 = after posterior crossbite correction, (c) T3 = at the end of active orthodontic treatment, (d) T4 = ca. 2 years after the end of orthodontic treatment.<br>All recordings were performed by one examiner to the nearest of 0.1 mm, using a Boley gauge. Overjet,<br>overbite, midline deviation and the following cephalometric parameters were also registered: angle ANB, SNA, SNB for evaluation of the skeletal classification of the malocclusion, and the SN- MeGo angle and the SGo:<br>NMe % (percentage ratio between the posterior and anterior facial height) for determination of the patient’s growth pattern.<br>The statistical analysis of the data revealed the following relevant results:<br>- The observation periods were approximately 8 years for the early-treatment groups and 6.5 years for the late-treatment groups.<br>- 79% of the treated patients showed long-term stability of the corrected unilateral posterior crossbite.<br>This finding was independent of the patient’s age at the start of treatment and of the applied orthodontic<br>expansion device.<br>- 72% of the patients were successfully treated for the mandibular midline deviation.<br>- At the end of active treatment 50% of our cases showed a skeletal Class III craniofacial morphology.<br>- The mean change was 1.1 ± 2.8 mm in the maxillary interpremolar arch width and 2.3 ± 2.1 mm in the<br>intermolar arch width in the slow expansion groups. The RME groups showed a mean change of 3.6 ±<br>2.7 mm in interpremolar arch width and of 3.8 ± 2.7 mm in intermolar arch width; this was significantly<br>greater than in the comparison groups.<br>In subjects where the wider lower arch is a co-factor for the crossbite, the treatment approach should be focused on both arches and not only on the constricted upper arch. The mean mandibular arch width values of the relapsed cases in the present study were initially greater than those of the non-relapsed cases.","In einer retrospektiven odontometrischen Studie wurde die Stabilität des kieferorthopädisch übergestellten unilateralen Kreuzbisses überprüft. Dabei wurden die Langzeittherapieergebnisse in Abhängigkeit von der angewandten Dehnungsapparatur (forcierte Gaumennahterweiterung bzw. aktive Dehnplatte) und dem Patientenalter zu Behandlungsbeginn (Frühbehandlung: ×= 7,2 Jahre bzw. Spätbehandlung: ×= 9, 9 Jahre) vergleichend gegenüber gestellt.<br>Insgesamt wurden die Behandlungsunterlagen von 100 Patienten aus der Behandlungskartei der Abteilung für Kieferorthopädie des Universitätsklinikums Freiburg i. Br. ausgewertet. Die Auswahl der Patienten erfolgte unter standardisierten Bedingungen.<br>Die Oberkieferdehnung war entweder mit einer herausnehmbaren aktiven Platte (n=50) oder mit einer festsitzenden, schleimhautgetragenen Gaumennahterweiterungsapparatur (RME) (n=50) durchgeführt worden. Bei der langsamen Dehnung (n=50) war das Gerät um 0,2 mm/Woche aktiviert und das Ergebnis nach abgeschlossener Zahnbogenerweiterung 3-6 Monate retiniert worden. Die RME-Apparatur (n=50) wurde zweimal/Tag(= 0,4 mm) erweitert und die erzielte Expansion für mindestens drei Monate stabilisiert.<br>Die odontometrischen Messungen erfolgten an Ober- und Unterkiefergipsmodellen, die zu folgenden Zeitpunkten angefertigt worden waren: (a) T1= zu Behandlungsbeginn, (b) T2= nach Überstellung des Kreuzbisses, (c) T3= am Ende der aktiven kieferorthopädischen Behandlung, (d) T4= ca. zwei Jahre nach Abschluss der kieferorthopädischen Therapie. Alle Messungen wurden von einem Untersucher bis zu einer Genauigkeit von 0,1 mm mit Hilfe einer Schublehre durchgeführt. Zusätzlich wurden die Parameter Overjet, Overbite, die Mittellinienabweichung und folgende röntgenkephalometrische Dimensionen erfasst: Die Winkel ANB, SNA und SNB zur Bestimmung der skelettalen Klassifikation der Anomalie sowie der Winkel SN-MeGo und das prozentuale Verhältnis der Gesichtshöhen (SGo: NMe %) zur Analyse des kraniofazialen Wachstumsmuster in der vertikalen Ebene.<br>Die statistische Auswertung der erhobenen Daten zeigte die folgenden relevanten Ergebnisse:<br>• Der Beobachtungszeitraum betrug in den Frühbehandlungsgruppen ca. 8 Jahre und in den Gruppen mit<br>späterem Therapiebeginn 6,5 Jahre.<br>• Bei 79 % der behandelten Patienten war der übergestellte unilaterale Kreuzbiss im Langzeitergebnis<br>stabil. Dieser Befund war unabhängig vom Alter des Patienten zu Therapiebeginn und von der angewandten Dehnungsapparatur.<br>• Bei 72% war eine zu Therapiebeginn bestehende mandibuläre Mitteverschiebung eingestellt.<br>• Am Ende der aktiven Behandlung bestand bei 50% der Patienten eine skelettale Klasse III.<br>• In den Gruppen mit langsamer Dehnungstherapie war im Oberkiefer die vordere Zahnbogenbreite um<br>(x=) 1,1 ± 2,8 und die hintere Bogenbreite um (×=) 2,3 ± 2,1 mm erweitert. Die Vergleichszahlen in den<br>RME-Gruppen betrugen (×=) 3,6 ± 2,7 mm bzw. (×=) 3,8 ± 2,7 mm; der größere Dehnungseffekt durch<br>die Gaumennahterweiterung war signifikant.<br>Bei Patienten, bei denen ein transversal erweiterter Unterkiefer einen Kofaktor in der Genese der Anomalie des seitlichen Kreuzbisses bildet, muss der Therapieansatz in beiden Kiefern erfolgen und sich nicht nur auf den komprimierten Oberkiefer konzentrieren. Die Mittelwerte der Unterkieferzahnbogenbreiten waren bei Patienten, die im Langzeitbefund ein Rezidiv des seitlichen Kreuzbisses zeigten, bereits zu Beginn der kieferorthopädischen Therapie größer als bei denjenigen mit Stabilität der Kreuzbissüberstellung."]},{"key":"dc:format.medium","label":"Dc Format Medium","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["Long-Term stability of the correction of the unilateral posterior crossbite","Langzeitstabilität des überstellten unilateralen Kreuzbisses"]}]}],"canonical_facts":{"dc:contributor":["Jonas, Irmtrud"],"dc:creator":["Bartzela, Theodosia"],"dc:description.abstract":["The aim of this retrospective odontometric study was to evaluate the stability of orthodontically corrected<br>unilateral crossbite. This was done by comparing the long-term therapeutic results of patients treated either with rapid maxillary expansion (RME) or with slow expansion devices in the early (mean age: 7.2 years) or in the late mixed dentition (mean age: 9.9 years).<br>One hundred patients were selected from the files of the Department of Orthodontics, School of Dental<br>Medicine, Albert-Ludwig-University, Freiburg i.Br., Germany.<br>Patients’ selection was based on standardized conditions: Maxillary expansion had to be performed either with a removable expansion plate (n= 50), or with a rapid maxillary expansion technique (RME) using a tissue-borne, fixed, split acrylic appliance (n= 50). The slow expansion appliance (n= 50) was activated by 0.2 mm per week and the result was retained for 3 to 6 months after expansion had been achieved. The RME device (n= 50) was activated twice a day (0.4 mm) and the treatment result was retained for a minimum of 3 months.<br>All measurements were made on plaster casts made at the following timepoints:<br>(a) T1 = before treatment, (b) T2 = after posterior crossbite correction, (c) T3 = at the end of active orthodontic treatment, (d) T4 = ca. 2 years after the end of orthodontic treatment.<br>All recordings were performed by one examiner to the nearest of 0.1 mm, using a Boley gauge. Overjet,<br>overbite, midline deviation and the following cephalometric parameters were also registered: angle ANB, SNA, SNB for evaluation of the skeletal classification of the malocclusion, and the SN- MeGo angle and the SGo:<br>NMe % (percentage ratio between the posterior and anterior facial height) for determination of the patient’s growth pattern.<br>The statistical analysis of the data revealed the following relevant results:<br>- The observation periods were approximately 8 years for the early-treatment groups and 6.5 years for the late-treatment groups.<br>- 79% of the treated patients showed long-term stability of the corrected unilateral posterior crossbite.<br>This finding was independent of the patient’s age at the start of treatment and of the applied orthodontic<br>expansion device.<br>- 72% of the patients were successfully treated for the mandibular midline deviation.<br>- At the end of active treatment 50% of our cases showed a skeletal Class III craniofacial morphology.<br>- The mean change was 1.1 ± 2.8 mm in the maxillary interpremolar arch width and 2.3 ± 2.1 mm in the<br>intermolar arch width in the slow expansion groups. The RME groups showed a mean change of 3.6 ±<br>2.7 mm in interpremolar arch width and of 3.8 ± 2.7 mm in intermolar arch width; this was significantly<br>greater than in the comparison groups.<br>In subjects where the wider lower arch is a co-factor for the crossbite, the treatment approach should be focused on both arches and not only on the constricted upper arch. The mean mandibular arch width values of the relapsed cases in the present study were initially greater than those of the non-relapsed cases.","In einer retrospektiven odontometrischen Studie wurde die Stabilität des kieferorthopädisch übergestellten unilateralen Kreuzbisses überprüft. Dabei wurden die Langzeittherapieergebnisse in Abhängigkeit von der angewandten Dehnungsapparatur (forcierte Gaumennahterweiterung bzw. aktive Dehnplatte) und dem Patientenalter zu Behandlungsbeginn (Frühbehandlung: ×= 7,2 Jahre bzw. Spätbehandlung: ×= 9, 9 Jahre) vergleichend gegenüber gestellt.<br>Insgesamt wurden die Behandlungsunterlagen von 100 Patienten aus der Behandlungskartei der Abteilung für Kieferorthopädie des Universitätsklinikums Freiburg i. Br. ausgewertet. Die Auswahl der Patienten erfolgte unter standardisierten Bedingungen.<br>Die Oberkieferdehnung war entweder mit einer herausnehmbaren aktiven Platte (n=50) oder mit einer festsitzenden, schleimhautgetragenen Gaumennahterweiterungsapparatur (RME) (n=50) durchgeführt worden. Bei der langsamen Dehnung (n=50) war das Gerät um 0,2 mm/Woche aktiviert und das Ergebnis nach abgeschlossener Zahnbogenerweiterung 3-6 Monate retiniert worden. Die RME-Apparatur (n=50) wurde zweimal/Tag(= 0,4 mm) erweitert und die erzielte Expansion für mindestens drei Monate stabilisiert.<br>Die odontometrischen Messungen erfolgten an Ober- und Unterkiefergipsmodellen, die zu folgenden Zeitpunkten angefertigt worden waren: (a) T1= zu Behandlungsbeginn, (b) T2= nach Überstellung des Kreuzbisses, (c) T3= am Ende der aktiven kieferorthopädischen Behandlung, (d) T4= ca. zwei Jahre nach Abschluss der kieferorthopädischen Therapie. Alle Messungen wurden von einem Untersucher bis zu einer Genauigkeit von 0,1 mm mit Hilfe einer Schublehre durchgeführt. Zusätzlich wurden die Parameter Overjet, Overbite, die Mittellinienabweichung und folgende röntgenkephalometrische Dimensionen erfasst: Die Winkel ANB, SNA und SNB zur Bestimmung der skelettalen Klassifikation der Anomalie sowie der Winkel SN-MeGo und das prozentuale Verhältnis der Gesichtshöhen (SGo: NMe %) zur Analyse des kraniofazialen Wachstumsmuster in der vertikalen Ebene.<br>Die statistische Auswertung der erhobenen Daten zeigte die folgenden relevanten Ergebnisse:<br>• Der Beobachtungszeitraum betrug in den Frühbehandlungsgruppen ca. 8 Jahre und in den Gruppen mit<br>späterem Therapiebeginn 6,5 Jahre.<br>• Bei 79 % der behandelten Patienten war der übergestellte unilaterale Kreuzbiss im Langzeitergebnis<br>stabil. Dieser Befund war unabhängig vom Alter des Patienten zu Therapiebeginn und von der angewandten Dehnungsapparatur.<br>• Bei 72% war eine zu Therapiebeginn bestehende mandibuläre Mitteverschiebung eingestellt.<br>• Am Ende der aktiven Behandlung bestand bei 50% der Patienten eine skelettale Klasse III.<br>• In den Gruppen mit langsamer Dehnungstherapie war im Oberkiefer die vordere Zahnbogenbreite um<br>(x=) 1,1 ± 2,8 und die hintere Bogenbreite um (×=) 2,3 ± 2,1 mm erweitert. Die Vergleichszahlen in den<br>RME-Gruppen betrugen (×=) 3,6 ± 2,7 mm bzw. (×=) 3,8 ± 2,7 mm; der größere Dehnungseffekt durch<br>die Gaumennahterweiterung war signifikant.<br>Bei Patienten, bei denen ein transversal erweiterter Unterkiefer einen Kofaktor in der Genese der Anomalie des seitlichen Kreuzbisses bildet, muss der Therapieansatz in beiden Kiefern erfolgen und sich nicht nur auf den komprimierten Oberkiefer konzentrieren. Die Mittelwerte der Unterkieferzahnbogenbreiten waren bei Patienten, die im Langzeitbefund ein Rezidiv des seitlichen Kreuzbisses zeigten, bereits zu Beginn der kieferorthopädischen Therapie größer als bei denjenigen mit Stabilität der Kreuzbissüberstellung."],"dc:format.medium":["application/pdf"],"dc:subject":["Stability posterior crossbite"],"dc:title":["Long-Term stability of the correction of the unilateral posterior crossbite","Langzeitstabilität des überstellten unilateralen Kreuzbisses"],"dc:type":["DoctoralThesis"]},"updated_at":"2026-07-24T02:22:03Z"}