Long-term stability of Class II, Division 1, nonextraction cervical face-bow therapy: II. Cephalometric analysis

Stability of Class II malocclusion treatment with Class II elastics

INTRODUCTION

The objective of this study was to compare the long-term cephalometric stability after successful therapy of nonextraction Class II malocclusion with elastics and with headgear.

METHODS

The sample comprised 43 patients with Class II malocclusion and was divided into 2 groups. The elastic group (EG) consisted of 20 patients treated with fixed appliances associated with Class II elastics, and the headgear group (HG) consisted of 23 patients treated with fixed appliances and extraoral headgear. Pretreatment, posttreatment, and long-term posttreatment lateral radiographs were evaluated; t tests were used to compare the long-term posttreatment changes between the groups.

RESULTS

The groups were matched regarding initial age, time of long-term posttreatment evaluation, initial malocclusion severity, quality of treatment result, and all pretreatment cephalometric variables. Intergroup comparisons of long-term posttreatment changes showed that the HG group presented significantly greater mandibular protrusion, occlusal plane angle decrease, and maxillary molar mesialization. However, long-term posttreatment stability was similar in overjet, overbite, and molar relationships.

CONCLUSIONS

Nonextraction Class II malocclusion treatment with elastics or extraoral headgear have similar long-term posttreatment stability.

Association between arch width changes and long-term stability 20 years after orthodontic treatment with and without extractions

OBJECTIVES

To investigate long-term stability 20 years after orthodontic treatment and the association with arch width changes during treatment.

MATERIALS AND METHODS

This retrospective study investigated 103 patients with Class I and II malocclusions treated with fixed appliances with and without extractions. The sample was treated by one experienced orthodontist and collected from a private orthodontic office. Dental casts were obtained pretreatment (T1), posttreatment (T2), and long-term postretention (T3); they were scanned and converted to STL files. Measurements were evaluated in for the upper and lower arch: intercanine width (IC), intermolar (IM) width, Little's irregularity index (LII).

RESULTS

There were 73 female and 30 male patients. Class I was present in 74 patients and Class II in 29. Average postretention time was 17.2 (±6.5) years after an average active retention time of 3.4 (±1.17) years. Extraction was performed in 55 patients while 48 received nonextraction treatment. Bonferroni Post Hoc test showed that LII in the upper and lower arches at T1 was significantly higher in the extraction group (P < .001). Upper and lower arch LII at T3 was slightly higher in extraction cases but remained under 2.05 mm. LII at T3 in the upper and lower arches showed negative correlation with IM T3 in the upper arch (Pearson, N = 103, P = .047), while IC in the upper and lower arches at T3 correlated with IM T3 in the upper and lower (N = 103, P < .001).

CONCLUSIONS

Clinically relevant long-term stability in both arches was found in extraction and nonextraction cases. Intermolar width and its change during orthodontic treatment was an influential factor on long-term stability in extraction cases.

Clinical application of maxillary tissue bone-borne expander and biocreative reverse curve system in the orthodontic retreatment of severe anterior open bite with transverse discrepancy: A case report

Anterior open bite and transverse discrepancy are often accompanied by hyperdivergent skeletal patterns. In addition, degenerative joint disorders and vertical maxillary excess contribute to an unfavorable convex facial profile with a retruded chin. Correction of this complex three-dimensional problem with orthodontic treatment alone is considered challenging owing to anatomical limitations. Moreover, a history of orthodontic treatment with premolar extraction makes retreatment difficult. This case report illustrates the application of a maxillary tissue bone-borne expander and biocreative reverse curve system in a 23-year-old female patient with a severe anterior open bite and transverse discrepancy who underwent orthodontic treatment with four premolar extractions. By setting the treatment target under precise diagnosis and using appropriate appliances, a satisfactory treatment result could be achieved without orthognathic surgery.

Stability of Class II malocclusion treatment with the distal jet followed by fixed appliances

INTRODUCTION

This retrospective study aimed to assess the stability of Class II malocclusion treatment with the distal jet, followed by fixed appliances.

METHODS

Seventy-five cephalograms of 30 subjects were divided into 2 groups. The treated group consisted of 15 patients who were evaluated at the pretreatment, posttreatment, and long-term posttreatment stages. The control group consisted of 15 subjects with normal occlusion, comparable to the experimental group at the long-term posttreatment period. Intergroup comparison of posttreatment changes was evaluated with t tests.

RESULTS

In the long-term posttreatment period, there was no significant change in the anteroposterior position of the maxilla and mandible to the cranial base. The lower anterior face height had a significantly smaller increase in the treated than in the control group. The maxillary molars in the treated group had significantly smaller vertical development, and the mandibular incisors had significantly greater labial tipping and protrusion than the control group. The treatment produced significant improvement in molar relationship and reduction of overbite and overjet, which remained stable in the long-term posttreatment period. There was greater upper lip protrusion in the experimental than in the control group in the long-term posttreatment period.

CONCLUSIONS

Treatment of Class II malocclusions with the distal jet, followed by fixed appliances, showed good long-term stability in molar relationship, overbite, and overjet.

Transverse stability of Class II malocclusion correction with the pendulum appliance

INTRODUCTION

This study aimed to evaluate the stability of transverse changes after Class II malocclusion correction with the pendulum fixed distalizer, followed by preadjusted edgewise fixed orthodontic appliances.

METHODS

This longitudinal study was conducted in the maxillary dental casts of 20 Class II malocclusion subjects (mean age, 12.5 years; 14 females and 6 males). Eighty 3-dimensional maxillary dental casts were analyzed; 20 at the beginning of treatment, 20 after distalization, 20 after edgewise appliance debonding, and 20 at 5 years posttreatment. Maxillary transverse distances between canines, first premolars, second premolars, first molars, and second molars were analyzed using Geomagic Studio 5 (3D Systems, Rock Hill, SC).

RESULTS

There were no significant changes in intercanine distance during and after treatment. There were significant interfirst and intersecond premolar distance increases during treatment. There were significant interfirst and intersecond molar distance increases during the distalization phase. However, there were significant decreases in these distances at the end of treatment. There were no significant long-term posttreatment changes.

CONCLUSIONS

The intercanine distance remains stable during and after treatment. The interfirst and intersecond premolar distances significantly increase during treatment and remain stable after treatment. The interfirst and intersecond molar distances increase during the distalization phase, decrease at the end of treatment, and remain stable after treatment.

Long-term skeletal effects of high-pull headgear followed by fixed appliances for the treatment of Class II malocclusions

OBJECTIVES

The long-term skeletal effects of Class II treatment in growing individuals using high-pull facebow headgear and fixed edgewise appliances have not been reported. The purpose of this study was to evaluate the long-term skeletal effects of treatment using high-pull headgear followed by fixed orthodontic appliances compared to an untreated control group.

MATERIALS AND METHODS

Changes in anteroposterior and vertical cephalometric measurements of 42 Class II subjects (n = 21, mean age = 10.7 years) before treatment, after headgear correction to Class I molar relationship, after treatment with fixed appliances, and after long-term retention (mean 4.1 years), were compared to similar changes in a matched control group (n = 21, mean age = 10.9 years) by multivariable linear regression models.

RESULTS

Compared to control, the study group displayed significant long-term horizontal restriction of A-point (SNA = -1.925°, P < .0001; FH-NA = -3.042°, P < .0001; linear measurement A-point to Vertical Reference = -3.859 mm, P < .0001) and reduction of the ANB angle (-1.767°, P < .0001), with no effect on mandibular horizontal growth or maxillary and mandibular vertical skeletal changes. A-point horizontal restriction and forward mandibular horizontal growth accompanied the study group correction to Class I molar, and these changes were stable long term.

CONCLUSIONS

One phase treatment for Class II malocclusion with high-pull headgear followed by fixed orthodontic appliances resulted in correction to Class I molar through restriction of horizontal maxillary growth with continued horizontal mandibular growth and vertical skeletal changes unaffected. The anteroposterior molar correction and skeletal effects of this treatment were stable long term.

Stability of treatment with self-ligating brackets and conventional brackets in adolescents: a long-term follow-up retrospective study

OBJECTIVES

The aim of this study was to assess the long-term stability of treatment with self-ligating brackets compared with conventional brackets.

MATERIALS AND METHODS

The long-term follow-up retrospective study sample consisted of two groups of patients: group SL (including passive and interactive self ligating braces) comprised 30 subjects treated with self-ligating brackets at a mean pretreatment (T0) age of 13.56 years, with a mean follow up period for 7.24 years; group CL comprised 30 subjects treated with conventional brackets at a mean pretreatment age of 13.48 years, with a mean follow up period for 7.68 years. Relapse were evaluated by dental casts examination using the Peer Assessment Rating (PAR) index and the Little irregularity index. The two groups were evaluated for differences in the changing of PAR and Little irregularity index using paired-t tests. Inter-observer and intra-observer reliability was assessed by means of the Pearson's correlation coefficients method.

RESULTS

There were no significant differences changed in PAR and the Little irregularity index between groups for the long-term follow-up period.

CONCLUSIONS

The study revealed that brackets type did not affect the long-term stability. Considering self-ligating brackets were expensive, given comprehensive consideration for the patients to choose suitable orthodontic bracket type was of critical importance.

Treatment of a Class II Division 1 malocclusion with miniscrew anchorage

This case report describes the treatment of a 30-year-old woman with a Class II Division 1 malocclusion, characterized by a large overjet, a deep overbite, and a V-shaped maxillary dental arch. She had a convex profile with a retrognathic mandible and marked lip protrusion. Treatment involved extraction of 4 first premolars and miniscrew implant anchorage for space closure. The total treatment time was about 20 months. Ideal overjet and overbite relationships were established, and the facial profile was improved substantially. The 2-year follow-up records show a morphologically and functionally stable result.

Effect of timing on the outcomes of 1-phase nonextraction therapy of Class II malocclusion

INTRODUCTION

The aim of this cephalometric study was to evaluate the role of timing in relation to skeletal maturity on the outcomes of nonextraction comprehensive Class II therapy.

METHODS

Three samples of patients with Class II Division 1 malocclusion were treated with headgear combined with fixed appliances and Class II elastics. Lateral cephalograms were taken of all subjects before therapy (T1) and at an average interval of 6 months after therapy (T2). The first sample (23 subjects) was treated before the pubertal growth spurt, the second sample (24 subjects) received therapy during the pubertal growth spurt, and the third sample (13 subjects) was treated at a postpubertal stage of development. The average T1 to T2 interval was approximately 30 months for all patients, with an average treatment duration of 24 months. Longitudinal observations of a group of 17 subjects with untreated Class II malocclusions were compared with the treated groups at the 3 skeletal maturation intervals with nonparametric statistics.

RESULTS

Class II treatment before or during the pubertal growth spurt induced significant favorable skeletal changes (restricted maxillary advancement in prepubertal patients and enhanced mandibular growth in pubertal patients). Patients treated after the pubertal growth spurt had only significant dentoalveolar changes.

CONCLUSIONS

The greatest amount of dentoskeletal correction of Class II malocclusion with 1-phase nonextraction treatment occurred in patients treated during the pubertal growth spurt.

Comparison of mandibular arch changes during alignment and leveling with 2 preadjusted edgewise appliances

INTRODUCTION

Our objective was to compare the effects of 2 preadjusted appliances on angular and linear changes of the mandibular incisors, and transverse mandibular arch dimensional changes over a minimum of 30 weeks. This was a prospective, randomized, controlled, clinical trial a the Royal London Hospital, School of Dentistry, in London and the Kent and Canterbury Hospital in Canterbury, United Kingdom.

METHODS

Sixty- six consecutive patients satisfying the inclusion criteria were enrolled and randomly allocated to treatment with a self-ligating bracket system (SmartClip, 3M Unitek, Monrovia, Calif) and conventional preadjusted edgewise brackets (Victory, 3M Unitek). Initial study models and cephalograms were obtained within a month of starting the trial. All subjects received treatment with the following archwire sequence: 0.016-in round, 0.017 x 0.025-in rectangular, 0.019 x 0.025-in rectangular martensitic active nickel-titanium archwires, and 0.019 x 0.025-in stainless steel archwires. Final records, including study models and a lateral cephalogram, were collected a minimum of 30 weeks after initial appliance placement. Lateral cephalograms were assessed for treatment-related changes in mandibular incisor inclination and position. Transverse dimensional changes in intercanine, interpremolar, and intermolar dimensions, and the amount of crowding alleviated during the study period were assessed by comparison of pretreatment and posttreatment models. All measurements were made with a digital caliper (150 mm ISO 9001 electronic caliper, Tesa Technology, Renens, Switzerland).

RESULTS

Sixty patients completed the study. After adjustment for pretreatment values, duration of treatment, and amount of crowding alleviated during the study period, bracket type had little effect on incisor inclination (P = 0.437) and positional changes (P = 0.35), and intercanine (P = 0.967), inter-first premolar (P = 0.495), and inter-second premolar (P = 0.905) dimensions. However, the self-ligating appliance produced slightly more expansion in the molar region, a difference that was statistically significant (P = 0.009). Pretreatment values for incisor inclination (P = 0.044) and transverse dimensions (P = 0.000) affected inclination and transverse changes, respectively, with proclination less likely when the labial segment was proclined at the outset and expansion unlikely during leveling and alignment in wider arches. Greater alleviation of crowding during the study period resulted in more incisor proclination (P = 0.000) and advancement (P = 0.000).

CONCLUSIONS

There was little difference overall in the pattern of arch alignment and leveling related to the 2 preadjusted appliances. However, there was a statistically greater increase in intermolar width in the group treated with the self-ligating appliance, although the difference was only 0.91 mm.

Long-term stability of dentoalveolar and skeletal changes after activator-headgear treatment

The aim of this study was to analyze the long-term stability of combined activator-headgear treatment on skeletal and dental structures in Class II patients. The material comprised 26 subjects, 10 girls and 16 boys. All had a molar Class II relationship, overjet > or =6 mm, and overbite > or =5 mm. They were treated in one practice with combined activator and headgear appliances. Lateral cephalometric radiographs and dental study casts were taken before treatment (T0, mean age 11.9 years), at the end of activator-headgear treatment (T1, mean age 15.9 years), and 12-15 years out of retention (T2, mean age 28.6 years). Nineteen cephalometric and nine dental cast variables were evaluated using a paired sample t-test between T0-T1, T1-T2, and T0-T2. At T1, the majority of the cephalometric measurements showed statistically significant changes. ANB was significantly reduced by 2.3 degrees due to a significant increase in SNB, but only small changes were observed in SNA. The interincisal angle increased as a result of significant retroclination of both maxillary and mandibular incisors. All patients achieved a Class I molar relationship and a significant reduction in overjet and overbite. At T2, the results showed only slight relapse from T1. However, the relapse did not compromise the significant improvement in almost all the cephalometric and dental variables. Combined activator-headgear treatment improved the skeletal and dental conditions and the results remained stable in the long term.

Treatment and posttreatment changes with combined headgear therapy

OBJECTIVE

To determine the effects of combined headgear treatment in high-angle patients and to evaluate the differences 2 years after treatment.

MATERIALS AND METHODS

The study material consisted of lateral cephalograms of 21 patients (13 girls and eight boys; mean age 10 years 3 months) with Class II dental relationship. Only extraoral combined traction that was applied to maxillary first molars was used in the treatment of all patients. The patients were instructed to wear the appliance 20 hours per day until the molar relationship was corrected. The treatment time was approximately 5 months. At the beginning (T0), at the end (T1), and approximately 2 years after (T2) combined headgear treatment, lateral cephalometric radiographs were obtained.

RESULTS

SNA and ANB angles and convexity decreased significantly during treatment (T0-T1; P<.05 and P<.01, respectively), and the net changes (T0-T2) in ANB angle and convexity were also found to be statistically significant (P<.01). During treatment, significant distal movement was found in the upper first molar, and the second premolar and molar were also distalized significantly (P<.001). At the end of 2 years, there was a significant mesial migration of the upper molars and the second premolar during the posttreatment period, but all of them were positioned more distally compared to the beginning of treatment (P<.001). The decrease in molar relation was statistically significant during the T0-T1 and T0-T2 periods (P<.001).

Treatment stability with the eruption guidance appliance

INTRODUCTION

Although the eruption guidance appliance has been used to correct Class II malocclusions for many years and its effects have been demonstrated, there is no study on the stability of the changes it produces. Therefore, the objective of this study was to investigate the long-term stability of cephalometric dentoskeletal and occlusal changes after eruption guidance appliance therapy.

METHODS

Thirty-nine patients were evaluated. Occlusal evaluations were made with the peer asseessment rating index, and anterior tooth irregularity was evaluated with the Little irregularity index. Cephalometric and occlusal data were obtained at pretreatment, posttreatment, and postretention. The data were analyzed by dependent 1-way analysis of variance (ANOVA) for comparison between the 3 stages of the experimental group, with the Newman-Keuls test as a second step. To compare the cephalometric experimental group changes with mean population changes, the t test was used.

RESULTS

Cephalometrically, in the postretention stage, overjet remained stable, overbite showed significant relapse, and molar relationship improved toward a Class I relationship. The peer asseessment rating index showed stability of the occlusion. The Little irregularity index demonstrated a statistically significant relapse of crowding in the postretention stage.

CONCLUSIONS

Cephalometrically, overjet and molar relationship were stable in the long term after treatment with the eruption guidance appliance; however, there was relapse of the overbite. Occlusally, correction of the malocclusion elevated by the peer assessment rating was stable. There was relapse of the anterior teeth crowding.

Long-term stability of orthodontic treatment and patient satisfaction. A systematic review

OBJECTIVE

To evaluate morphologic stability and patient satisfaction at least 5 years after orthodontic treatment.

MATERIALS AND METHODS

Published literature was searched through the PubMed and Cochrane Library electronic databases from 1966 to January 2005. The search was performed by an information specialist at the Swedish Council on Technology Assessment in Health Care. The inclusion criteria consisted of a follow-up period of at least 5 years postretention; randomized clinical trials, prospective or retrospective clinical controlled studies, and cohort studies; and orthodontic treatment including fixed or removable appliances, selective grinding, or extractions. Two reviewers extracted the data independently and also assessed the quality of the studies.

RESULTS

The search strategy resulted in 1004 abstracts or full-text articles, of which 38 met the inclusion criteria. Treatment of crowding resulted in successful dental alignment. However, the mandibular arch length and width gradually decreased, and crowding of the lower anterior teeth reoccurred postretention. This condition was unpredictable at the individual level (limited evidence). Treatment of Angle Class II division 1 malocclusion with Herbst appliance normalized the occlusion. Relapse occurred but could not be predicted at the individual level (limited evidence). The scientific evidence was insufficient for conclusions on treatment of cross-bite, Angle Class III, open bite, and various other malocclusions as well as on patient satisfaction in a long-term perspective.

CONCLUSIONS

This review has exposed the difficulties in drawing meaningful evidence-based conclusions often because of the inherent problems of retrospective and uncontrolled study design.

Proposta para classificação, segundo a severidade, dos indivíduos portadores de más oclusões do Padrão Face Longa

OBJETIVO: o presente estudo teve como objetivo propor um método para classificação, segundo a severidade, dos indivíduos Padrão Face Longa, avaliando sua confiabilidade e reprodutibilidade. METODOLOGIA: foram utilizadas fotografias faciais (frontal, perfil e frontal sorrindo) de 125 crianças Padrão Face Longa (54 do gênero feminino e 71 do gênero masculino), selecionadas apenas considerando-se a morfologia facial, com idades entre 10 anos e 6 meses e 15 anos e 2 meses. As fotografias foram avaliadas, separadamente, por três examinadores, sendo reavaliadas após três semanas, em uma nova disposição aleatória. Os indivíduos foram graduados em três subtipos, de acordo com a severidade: moderado, médio e severo. Para avaliar as concordâncias intra e interexaminadores, foi utilizada a estatística Kappa (k). RESULTADOS: na avaliação intra-examinador, todos os examinadores obtiveram concordâncias substanciais, com o valor de Kappa variando de 0,64 a 0,66, havendo em todos os examinadores 80% ou mais de concordância. Quando comparadas as avaliações interexaminadores, as freqüências de concordância diminuíram, variando de 67,2% a 70,4%. A partir dos valores de Kappa, que variaram de 0,41 a 0,46, a interpretação foi considerada moderada. CONCLUSÕES: com base nesses resultados, o método foi considerado aplicável, com necessidade de complemento de informações provenientes de outros exames rotineiramente aplicados em Ortodontia. A aplicação clínica será demonstrada com intuito de evidenciar os níveis diferentes de severidade das más oclusões do Padrão Face Longa e as características do protocolo de tratamento recomendado.

Orthodontic treatment changes of chin position in Class II Division 1 patients

INTRODUCTION

Because most patients with skeletal Class II malocclusions also have mandibular deficiencies, treatment plans should include improvement in chin projection. On that basis, the purposes of this study were to (1) determine how Class II treatment affects anteroposterior (AP) chin position in growing subjects and (2) ascertain the most important determinants of AP chin position.

METHODS

Pretreatment and posttreatment lateral cephalograms of 67 treated patients (25 extraction headgear and Class II elastics, 23 nonextraction headgear, and 19 Herbst) were collected, traced, and digitized. The average pretreatment age was 12.2 years (range, 9-14 years), and the average treatment duration was 30.2 months (range, 17-65 months). Cephalometric changes were compared with 29 matched untreated Class II controls. Mandibular superimpositions were used to evaluate condylar growth and true mandibular rotation.

RESULTS

All 3 treatment methods produced normal dental relationships and restricted or inhibited AP maxillary growth, with no significant improvement of AP chin position. Differences between changes in vertical position of the maxilla, maxillary and mandibular molars, and condylar growth could not reliably predict changes in chin position. Analyses demonstrated that true mandibular rotation was the primary determinant of AP chin position. Stepwise multiple regression showed that, combined with true mandibular rotation, condylar growth and movements of the glenoid fossa accounted for 81% of the variation in AP changes of pogonion.

CONCLUSIONS

Contemporary treatments do not adequately address mandibular deficiencies. Future treatments must incorporate true mandibular rotation into Class II skeletal correction.

Evaluation of posttreatment changes in Class II Division 1 patients after nonextraction orthodontic treatment: Cephalometric and model analysis

BACKGROUND

The aim of this retrospective study was to evaluate changes in patients with Class II Division 1 malocclusions treated with cervical headgear and full fixed orthodontic appliances and without extractions.

METHODS

Lateral cephalograms and dental casts of 18 patients were obtained at the beginning and the end of treatment and at the postretention period. Pretreatment records were taken at 11.9 +/- 2.6 years, and the mean treatment time was 2.8 +/- 1.2 years. All patients were asked to use maxillary and mandibular Hawley retainers for 1 year. The average postretention interval was 5.3 years.

RESULTS

The assessment of cephalometric findings showed that maxillary growth was restricted; maxillary incisor inclination, overjet, and overbite were decreased; the mandibular incisors were proclined; and a slight mandibular posterior rotation occurred at the end of treatment. At the postretention period, the maxilla remained stable, the mandible moved anteriorly, and the overjet increased slightly (1.25 mm, P < .01). The dental cast changes indicated that both maxillary and mandibular irregularity index values decreased significantly during treatment but increased after 5 years. Mandibular intercanine width decreased 0.47 mm ( P < .01) during the postretention period.

CONCLUSIONS

The redirection of maxillary growth remained stable in patients with Class II malocclusions treated with cervical headgear and fixed orthodontic appliances and without extractions, but treatment-induced mandibular rotations tended to return to their original patterns. Various dental changes occurred during the postretention period.

The effectiveness and long-term stability of overbite correction with incisor intrusion mechanics

BACKGROUND

Correction of deep overbite with subsequent achievement of long-term stability is difficult. The purpose of this study was to investigate the effectiveness and long-term stability of overbite correction with incisor intrusion mechanics.

METHODS

The treated group consisted of 25 subjects (13 female, 12 male) with deep overbite of at least 4 mm (mean overbite, 5.9 mm). The orthodontic treatment was initiated in the late mixed or early permanent dentition, and all patients were treated nonextraction. All patients had lateral cephalometric radiographs taken at pretreatment (T1), posttreatment (T2), and postretention (T3). The treatment included cervical headgear and lever arches to intrude mainly the maxillary incisors and occasionally the mandibular incisors. Premolars were not included in the fixed appliances during the treatment. The untreated group consisted of 25 age- and sex-matched subjects from the Bolton Growth Study.

RESULTS

The mechanics used were effective in overbite correction. During the posttreatment period, overbite increased by 0.7 mm.

CONCLUSIONS

Although this change was statistically significant, the amount was small and is considered clinically insignificant, given the severity of the overbite pretreatment. Furthermore, a net overbite correction (T3-T1) of 3.3 mm and postretention overbite on 2.6 mm is an excellent clinical outcome.

Long-term stability of Class I premolar extraction treatment

This study evaluates Class I, 4-premolar-extraction patients who were treated with the edgewise appliance by 1 practitioner, according to the philosophy of Tweed, and who had been out of retention a minimum of 5 years. The sample includes 32 patients, who started treatment at an average age of 12.8 years and who were examined a mean of 15 years posttreatment (11.7 years postretention). Cephalometric and model analyses were conducted to evaluate treatment and posttreatment tooth movements. The results showed that irregularity, as measured by the irregularity index, decreased 5.3 mm during treatment and increased 0.7 mm (SD 1.1 mm) during the posttreatment period. Eighty percent of the patients had satisfactory (<3.5 mm) mandibular incisor alignment over 10 years postretention, and none was in the severe category (>6.5 mm). Mandibular intercanine width increased (1.7 mm) during treatment, whereas intermolar width decreased (-2.1 mm). Maxillary molar widths remained unchanged posttreatment, and mandibular intercanine width decreased 1.4 mm from immediately posttreatment to postretention. Arch lengths decreased during treatment because of molar protraction and incisor retraction. Mandibular arch length continued to decrease posttreatment (-1.4 mm) because of mesial molar movement rather than distal incisor movement. Satisfactory long-term results can be achieved for most Class I, 4-premolar-extraction patients for whom evidence-based treatment objectives-including minimal alteration of the mandibular arch form and the retraction and uprighting or maintenance of mandibular incisors in their original position-have been met.

Orthopedic cervical headgear in class II treatment: case report

Early treatment for Class II malocclusion was undertaken with the objective of correcting skeletal disproportion by altering the growth pattern. A case of Class II, Division 1 malocclusion in the mixed dentition was corrected to Class I molar relationship using orthopedic cervical headgear, with nonextraction edgewise therapy. Cephalometric analysis indicated a reduction in the maxillomandibular discrepancy (ANB) correcting the Class II malocclusion to Class I malocclusion. The treatment showed that this was achieved by downward displacement and inhibition of the forward growth of the maxilla and growth of the mandible. There was no downward rotation of the mandible nor maxillary first molar extrusion. There was improvement in the jaw relationship.

Sagittal and vertical changes after treatment of Class II Division 1 malocclusion according to the Cetlin method

This cephalometric study was designed to evaluate the dentoskeletal anteroposterior and vertical changes produced by Cetlin therapy (lower lip bumper, ACCO, cervical headgear) to correct Class II Division 1 malocclusion in the late mixed dentition. All measurements were made on 2 lateral headfilms, at pretreatment and at 1 year after beginning treatment. The selected sample (n = 110; 67 boys and 43 girls; mean age, 10 to 11 years) and the control group (n = 100; 48 boys, 52 girls; mean age, 10 to 11 years) matched for number, age, and malocclusion. The average observation interval was 13 months. The final measurements between intervals were averaged and tested for significance by analysis of variance. A one-factor (group) repeated measure model and a two-factor (group and facial type) repeated measure model were fitted to each variable separately and significance values were set at P </=.05. The Class I molar relationship was achieved in all treated subjects primarily through distalization of upper first molars. A significant distal tipping was found in 70% of the treated cases. The results showed a significant forward growth limitation of the maxilla with the use of cervical headgear. No significant change of mandibular position was found in the treated group compared with the control group. Both bite opening and proclination of upper and lower front teeth occurred. Cetlin therapy is reliable and effective for space recovery and interceptive Class II Division 1 treatment. Additional therapy may be needed later.

A comparison of the effects of rectangular and round arch wires in leveling the curve of Spee

A prospective randomized clinical study was designed to evaluate the effects of full continuous arch wires, rectangular in cross section, on the axial inclination of lower incisors. The intention of rectangular arch wires is to counteract the labial crown moment usually produced during leveling the curve of Spee with full arch mechanics. Patients were randomly assigned to 2 groups. Group 1 (N = 12) received round arch wires throughout the leveling stage. Group 2 (N = 16) started with flat 0.016 x 0.022 nickel titanium arch wires progressing to 0.016 x 0.022 stainless steel. The preadjusted 0.018 x 0.025 edgewise appliance was used in all cases. Lateral cephalometric radiographs and mandibular study models were taken before treatment and when the curve of Spee was leveled (or in some cases when the overbite was considered clinically acceptable). In group 1, the lower incisor proclined a mean of 6.75 degrees +/- 4.85 degrees (P <.01) and in group 2 it proclined a mean of 6.10 degrees +/- 3.95 degrees (P <.01). However, no significant difference in proclination was detected between the 2 groups. Statistically significant, but low, correlations were demonstrated between change in lower incisor axial inclination and relief of crowding r = 0.45) and change in mandibular arch depth r = 0.54), which was in turn inversely correlated with change in intercanine width r = -0.45). In both groups, the lower incisors proclined with uncontrolled tipping that can probably be attributed to the intrusive force introduced by the arch wire being labial to the center of resistance of the lower incisors. The ability of the rectangular arch wires to control labial proclination following leveling of the curve of Spee, as used in this study, was not supported.

Stability of orthodontic treatment outcome: follow-up until 10 years postretention

Dental casts of 1016 patients were evaluated for the long-term treatment outcome using the Peer Assessment Rating (PAR) index. The PAR index was measured at the pretreatment stage (n = 1016), directly posttreatment (n = 783), postretention (n = 942), 2 years postretention (n = 781), 5 years postretention (n = 821), and 10 years postretention (n = 564). The mean absolute change as well as the percentage of change per year (relapse) related to the postretention stage was calculated. An analysis of variance was applied to compare the mean change in the PAR between cases with and without a fixed retainer at the postretention stage and up to 10 years postretention. Drop-out analysis showed that more Class II Division 2 cases were lost to follow-up than cases of other Angle classes. The results indicate that 67% of the achieved orthodontic treatment result was maintained 10 years postretention. About half of the total relapse (as measured with the PAR index) takes place in the first 2 years after retention. All occlusal traits relapsed gradually over time but remained stable from 5 years postretention with the exception of the lower anterior contact point displacement, which showed a fast and continuous increase even exceeding the initial score. The presence of a fixed retainer had a positive effect on the PAR score. In cases with fixed retention, the relapse was 3.6 PAR points less at 5 years postretention and 4.6 points less at 10 years postretention. The results of this type of studies enable clinicians to inform their patients about treatment limitations in order to better meet their expectations.