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BACKGROUND: The minimal important difference (MID) is defined as the smallest difference that the patient perceives as important. Furthermore, the smallest worthwhile effect (SWE) is the important change measured with the benefit-harm trade-off method. The aim of this study was to evaluate the MID in orthodontic treatment duration to inform the decision regarding seeking procedures to accelerate orthodontic tooth movement and reduce treatment duration. METHODS: We constructed a survey eliciting views of the MID from adult participants from four countries undergoing orthodontic treatment. Ten questions addressed reduction in the treatment duration for both durations 12 and 24 months, and four questions were related to the reduction in treatment duration that the patients would require to undergo surgical or non-surgical adjunctive procedures. We applied a univariable random effects logistic regression model to examine the association between the participants' characteristics and the MID. Then, we fitted a multivariable logistic random effects regression including significant predictors. RESULTS: Four hundred and fifty adults, with a median age of 21 (interquartile range: 19-24), undergoing orthodontic treatment participated in the survey. Of the respondents, 60% considered 15 days as a trivial reduction from 12 months duration of therapy and 70% considered 15 days a trivial reduction from 24 months. Of the respondents, 48% considered the period of 2 months a moderate reduction from 12 months, and 60% considered 2 months a moderate reduction from 24 months. From these results, we inferred that patients considered reductions of approximately 1 month as the MID in the treatment duration for both 12 and 24 months. However, SWE was considerably more than the MID for most of the participants to decide undergoing surgical adjunctive procedures to reduce the time of therapy. The participants required smaller SWE to undergo non-surgical procedures compared to surgical procedures. CONCLUSION: The MID in the treatment duration is one month for both treatment durations 12 and 24 months. Patients require a greater SWE than the MID to undergo adjunctive procedures to shorten the duration, particularly for surgical procedures.
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Ortodoncia Correctiva , Humanos , Femenino , Masculino , Factores de Tiempo , Adulto Joven , Ortodoncia Correctiva/métodos , Encuestas y Cuestionarios , Adulto , Técnicas de Movimiento Dental/métodosRESUMEN
OBJECTIVE: Fixed orthodontic appliances might result in dental adverse effects, if sufficient oral hygiene is not maintained. Since recommendations on toothbrushing times are lacking scientific justification in orthodontic populations, the aim of the present study was to comparatively quantify the duration of toothbrushing with a manual and a powered toothbrush in two distinct age groups. TRIAL DESIGN: Two-centre, two-period crossover balanced randomized clinical trial with computer-generated numbers and blinding at the outcome-assessing level. METHODS: Children and adults with fixed appliances with at least 22 aligned teeth were recruited at a university clinic and private practice in Bavaria, Germany. Plaque was disclosed with staining tablets and participants brushed their teeth with their habitual technique in front of a mirror and without interference until staining was, to their own satisfaction, completely removed. The primary outcome was duration of toothbrushing in seconds. Secondary outcomes were percentage plaque reduction and questionnaire data on dental attitudes and behaviours. Data were analysed with linear mixed models. RESULTS: Twenty-eight participants were randomized to the first and 27 to the second toothbrush sequence. The combined effect of age and toothbrush on the duration of toothbrushing was evident (n = 52, F(1, 50.8) = 5.1, P = 0.028). Children brushed 14.5 seconds less [n = 28, 95% confidence interval (CI) = -31.3 to 2.3, P = 0.090], yet adults 13.3 seconds more (n = 24, 95% CI = -4.6 to 31.3, P = 0.143) with the manual than powered toothbrush. Brushing times ranged from 2 minutes and 45 seconds to 3 minutes and 17 seconds with plaque reduction at 76% and good dental attitudes and behaviours. CONCLUSIONS: Both children and adults with fixed appliances might equally reach an effective plaque reduction with either manual or powered toothbrushes and their habitual brushing technique in around three minutes, if plaque is visible. REGISTRATION: DRKS-German Clinical Trials Register ID: DRKS00012463. FUNDING: Oral-B Procter & Gamble.
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Placa Dental , Cepillado Dental , Adulto , Niño , Placa Dental/etiología , Placa Dental/prevención & control , Índice de Placa Dental , Diseño de Equipo , Humanos , Aparatos Ortodóncicos Fijos , Método Simple Ciego , Cepillado Dental/métodosRESUMEN
OBJECTIVE: To investigate if orthodontic model analysis with a digital caliper can be interchangeably performed between plaster and printed dental models. MATERIALS AND METHODS: Forty-eight plaster models were digitized with orthoX®scan (DENTAURUM) and 48 counterparts were printed with Objet30 Dental Prime (Stratasys). One examiner performed five repeated orthodontic model analyses (41 outcomes) with a digital caliper in each plaster and the corresponding printed model and was externally validated by a second examiner. Inter- and intra-examiner reliability and error were evaluated with intraclass correlation coefficients (ICCs) and Dahlberg's formula, intra-examiner agreement with Bland-Altman analyses and Lin's correlation coefficients (CCCs), and changing bias with regression analyses. RESULTS: Inter- and intra-examiner ICCs and Dahlberg's error were ≥ 0.75 and ≤ 0.5 mm, respectively, for most outcomes in both plaster and printed models. Intra-examiner agreement (systematic bias) between plaster and printed models ranged from - 0.45 to 0.45 mm. Ranges of limits of agreement were wide for cumulative outcomes, such as crowding maxilla and mandible (2.69 mm and 3.07 mm around zero, respectively). Tooth widths were measured slightly larger in printed models. Lin's CCCs were ≥ 0.87 for all the outcomes between plaster and printed models, while no changing bias was detected. CONCLUSION: If orthodontic model analyses are consistently performed, plaster casts and their corresponding printed models obtained with orthoX®scan and Objet30 Dental Prime can be interchangeably used for clinical purposes in orthodontics. CLINICAL RELEVANCE: Orthodontic model analysis is important in treatment planning and printed dental models need to be validated regarding this diagnostic procedure.
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Maloclusión , Modelos Dentales , Ortodoncia , Femenino , Humanos , Imagenología Tridimensional , Masculino , Impresión Tridimensional , Reproducibilidad de los ResultadosRESUMEN
Background and aim: Digital orthodontic model analysis is gaining acceptance in orthodontics, but its reliability is dependent on the digitalisation hardware and software used. We thus investigated intra-observer reliability and agreement / conformity of a particular digital model analysis work-flow in relation to traditional manual plaster model analysis. Materials and methods: Forty-eight plaster casts of the upper/lower dentition were collected. Virtual models were obtained with orthoX®scan (Dentaurum) and analysed with ivoris®analyze3D (Computer konkret). Manual model analyses were done with a dial caliper (0.1 mm). Common parameters were measured on each plaster cast and its virtual counterpart five times each by an experienced observer. We assessed intra-observer reliability within method (ICC), agreement/conformity between methods (Bland-Altman analyses and Lin's concordance correlation), and changing bias (regression analyses). Results: Intra-observer reliability was substantial within each method (ICC ≥ 0.7), except for five manual outcomes (12.8 per cent). Bias between methods was statistically significant, but less than 0.5 mm for 87.2 per cent of the outcomes. In general, larger tooth sizes were measured digitally. Total difference maxilla and mandible had wide limits of agreement (-3.25/6.15 and -2.31/4.57 mm), but bias between methods was mostly smaller than intra-observer variation within each method with substantial conformity of manual and digital measurements in general. No changing bias was detected. Conclusions: Although both work-flows were reliable, the investigated digital work-flow proved to be more reliable and yielded on average larger tooth sizes. Averaged differences between methods were within 0.5 mm for directly measured outcomes but wide ranges are expected for some computed space parameters due to cumulative error.
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Técnica de Colado Dental , Diagnóstico por Computador/métodos , Maloclusión/diagnóstico , Modelos Dentales , Moldes Quirúrgicos , Cefalometría/métodos , Dentición , Humanos , Maloclusión/patología , Mandíbula/diagnóstico por imagen , Mandíbula/patología , Maxilar/diagnóstico por imagen , Maxilar/patología , Variaciones Dependientes del Observador , Ortodoncia/métodos , Reproducibilidad de los Resultados , Programas InformáticosRESUMEN
AIM: The validity of meta-analysis is dependent upon the quality of included studies. Here, we investigated whether the design of untreated control groups (i.e. source and timing of data collection) influences the results of clinical trials in orthodontic research. MATERIALS AND METHODS: This meta-epidemiological study used unrestricted literature searching for meta-analyses in orthodontics including clinical trials with untreated control groups. Differences in standardized mean differences (ΔSMD) and their 95% confidence intervals (CIs) were calculated according to the untreated control group through multivariable random-effects meta-regression controlling for nature of the interventional group and study sample size. Effects were pooled with random-effects synthesis, followed by mixed-effect subgroup and sensitivity analyses. RESULTS: Studies with historical control groups reported deflated treatment effects compared to studies with concurrent control groups (13 meta-analyses; ΔSMD = -0.31; 95% CI = -0.53, -0.10; P = 0.004). Significant differences were found according to the type of historical control group (based either on growth study or clinical archive; 11 meta-analyses; ΔSMD = 0.40; 95% CI = 0.21, 0.59; P < 0.001). CONCLUSIONS: The use of historical control groups in orthodontic clinical research was associated with deflation of treatment effects, which was independent from whether the interventional group was prospective or retrospective and from the study's sample size. Caution is warranted when interpreting clinical studies with historical untreated control groups or when interpreting systematic reviews that include such studies. REGISTRATION: PROSPERO (CRD42015024179). CONFLICT OF INTEREST: None.
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Ortodoncia , Sesgo , Grupos Control , Humanos , Estudios Prospectivos , Estudios Retrospectivos , Tamaño de la MuestraRESUMEN
OBJECTIVE: To assess the treatment effects of fixed functional appliances (FFAs) in treated versus untreated Class II patients by means of lateral cephalometric radiographs. SEARCH METHODS: Unrestricted electronic search of 18 databases and additional manual searches up to October 2014. SELECTION CRITERIA: Prospective randomized and non-randomized controlled trials reporting on cephalometric angular measurements of Class II patients treated with FFAs and their matched untreated controls. DATA COLLECTION AND ANALYSIS: Skeletal, dental, and soft tissue cephalometric data were annualized and stratified according to the time of evaluation in effects. Following risk of bias evaluation, the mean differences (MDs) and 95 % confidence intervals (CIs) were calculated with random-effects models. Patient- and appliance-related subgroup analyses and sensitivity analyses were performed with mixed-effects models. RESULTS: Nine studies were included (244 patients; mean age: 13.5 years and 174 untreated controls; mean age: 12.8 years) reporting on cephalometric effects directly after the removal of FFAs. FFAs were found to induce a small reduction of SNA angle (MD = -0.83 degree/year, 95 % CI: -1.17 to -0.48), a small increase of SNB angle (MD = 0.87 degree/year, 95 % CI: 0.30-1.43), and moderate decrease of ANB angle (MD = -1.74 degree/year, 95 % CI: -2.50 to -0.98) compared to untreated Class II patients. FFA treatment resulted in significant dentoalveolar and soft tissue changes. Several patient- or appliance-related factors seem to affect the treatment outcome. Long-term effectiveness of FFAs could not be assessed due to limited evidence. CONCLUSIONS: According to existing evidence, FFAs seem to be effective in improving Class II malocclusion in the short term, although their effects seem to be mainly dentoalveolar rather than skeletal.
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Cefalometría/métodos , Maloclusión Clase II de Angle/terapia , Aparatos Ortodóncicos Funcionales , Proceso Alveolar/patología , Humanos , Mandíbula/patología , Maxilar/patología , Diente/patología , Resultado del TratamientoRESUMEN
BACKGROUND/OBJECTIVE: Chondrogenesis is an integral part of endochondral bone formation, by which the midline cranial base is developed. Reactive oxygen species (ROS) are required in chondrogenic differentiation and antioxidant enzymes regulate their levels. The aim of this study was to localize the antioxidant enzyme glutathione peroxidase 1 (Gpx1) at the spheno-occipital synchondrosis, as well as its effect on ROS challenge and its expression pattern in the course of differentiation. MATERIALS AND METHODS: Gpx1 was semiquantified in immunohistochemically stained sections of spheno-occipital synchondroses of rats. The effect of Gpx1 on ROS-induced apoptosis was investigated by manipulating the expression of Gpx1 in ATDC5 cells. The temporal pattern of Gpx1 expression was determined during chondrocyte differentiation for 21 days in vitro. RESULTS: Proliferating chondrocytes exhibited the greatest Gpx1 immunoreactivity and hypertrophic ones the lowest (P = 0.02). Cells transfected with Gpx1-siRNA had the highest apoptotic rate, while cells overexpressing Gpx1 the lowest one (P < 0.001). Gpx1 was significantly increased on days 10 (P = 0.02) and 14 (P = 0.01). CONCLUSIONS: Hypertrophic chondrocytes have the lowest Gpx1 activity in the spheno-occipital synchondrosis. Gpx1 is implicated in the ROS-induced apoptosis in chondrocytes. Its expression was not constitutive during chondrogenic differentiation.
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Apoptosis/fisiología , Suturas Craneales/enzimología , Glutatión Peroxidasa/análisis , Hueso Occipital/enzimología , Especies Reactivas de Oxígeno/análisis , Hueso Esfenoides/enzimología , Animales , Animales Recién Nacidos , Técnicas de Cultivo de Célula , Diferenciación Celular/fisiología , Línea Celular , Proliferación Celular , Condrocitos/enzimología , Condrocitos/fisiología , Condrogénesis/fisiología , Suturas Craneales/citología , Técnicas de Silenciamiento del Gen , Glutatión Peroxidasa/genética , Glutatión Peroxidasa/fisiología , Hipertrofia , Hueso Occipital/citología , Osteogénesis/fisiología , ARN Interferente Pequeño/genética , Ratas , Ratas Wistar , Especies Reactivas de Oxígeno/farmacología , Base del Cráneo/citología , Hueso Esfenoides/citología , Factores de Tiempo , Glutatión Peroxidasa GPX1RESUMEN
OBJECTIVE: To assess the treatment effects of removable functional appliances (RFAs) in treated versus untreated patients with Class II malocclusion by means of lateral cephalometric radiographs. SEARCH METHODS: Unrestricted electronic search of 18 databases and manual searches up to October 2013. SELECTION CRITERIA: Prospective randomized and non-randomized controlled trials reporting on cephalometric angular measurements of Class II patients treated with RFAs and their matched controls. DATA COLLECTION AND ANALYSIS: Skeletal, dental, and soft tissue changes were annualized and stratified to short- and long-term effects. Methodological limitations were evaluated with the Cochrane Risk of Bias tool and the Downs and Black checklist. Mean differences (MDs) with their 95% confidence intervals (CIs) were calculated from random-effects meta-analyses. Patient- or appliance-related subgroup analyses and sensitivity analyses were performed with mixed-effects models. RESULTS: Seventeen studies were included (1031 patients; mean age: 10.6 years), with most of them originating from university clinics and reporting short-term effects (directly after the removal of RFAs). Treatment was associated with minimal reduction of SNA angle (11 studies, MD = -0.28 degree/year, 95% CI: -0.44 to -0.12 degree/year), minimal increase of SNB angle (11 studies, MD = 0.62 degree/year, 95% CI: 0.36-0.88 degree/year), and small decrease of ANB angle (10 studies, MD = -1.14 degree/year, 95% CI: -1.52 to -0.77 degree/year) compared to untreated Class II patients. RFAs caused significant dentoalveolar changes (predominantly retroclination of the upper incisors) and significant soft tissue changes. Skeletal changes were more pronounced with the Twin Block appliance. Various patient- or appliance-related factors influenced the results of the subgroup analyses, while the sensitivity analyses indicated robustness. Existing evidence was inadequate to assess the long-term effectiveness of RFAs. CONCLUSIONS: The short-term evidence indicates that RFAs are effective in improving Class II malocclusion, although their effects are mainly dentoalveolar, rather than skeletal.
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Maloclusión Clase II de Angle/terapia , Aparatos Ortodóncicos Funcionales , Aparatos Ortodóncicos Removibles , Cefalometría/métodos , Humanos , Mandíbula/patología , Maxilar/patología , Resultado del TratamientoRESUMEN
AIM: Two-phase treatment for children with Class II malocclusion with several functional appliances is still performed by many orthodontists, while the Activator and the Bionator appliances are two of the most popular ones. Aim of this study was to compare the skeletal and dentoalveolar effects of treatment with these two appliances. METHODS: Class II children treated with Activator or Bionator in the first phase, followed by a phase of fixed appliances were included. Skeletal and dentoalveolar parameters were assessed from lateral cephalograms and analysed with linear regressions at 5%. RESULTS: A total of 89 patients (mean age 10.0 years; 47% female) were included. During the first phase, Bionator increased less the SNB (difference in mean treatment-induced changes [MD] -0.7°; 95% confidence interval [CI] -1.3 to -0.2°; P=0.01) and decreased less the ANB angle (MD 0.6°; 95% CI 0 to 1.1°; P=0.03) compared to Activator. Activator slightly increased the facial axis and Bionator reduced it (MD -1.6°; 95% CI -2.3 to -0.8°; P<0.001). Compared to Activator, the Bionator retroclined more the upper incisors (MD -2.4°; 95% CI -4.6 to -0.2°; P=0.03) and increased more the interincisal angle (MD 2.9°; 95% CI 0.5 to 5.4°; P=0.02). After the second phase (6.2 years after baseline), the only differences were a reduced facial axis (MD -1.3°; 95% CI -2.2 to -0.3°; P=0.008) and an increased maxillary rotation (MD 0.9°; 95% CI 0 to 1.8°; P=0.04) with Bionator compared to Activator. CONCLUSION: Similar dentoalveolar effects were seen overall with two-phase treatment with either appliance, with Bionator being associated with more vertical increase compared to Activator.
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Aparatos Activadores , Cefalometría , Maloclusión Clase II de Angle , Maxilar , Aparatos Ortodóncicos Fijos , Humanos , Maloclusión Clase II de Angle/terapia , Femenino , Masculino , Niño , Estudios Retrospectivos , Mandíbula , Resultado del Tratamiento , Diseño de Aparato Ortodóncico , Aparatos Ortodóncicos Funcionales , Incisivo , Silla Turca , Hueso Nasal , Ortodoncia Correctiva/instrumentación , Ortodoncia Correctiva/métodosRESUMEN
OBJECTIVE: This study aims to demonstrate in vitro the synergistic effect of orthodontic forces and periodontal pathogens on cyclooxygenase-2 regulation and the subsequent receptor activator of nuclear factor kappa-B ligand (RANKL) production from periodontal ligament (PDL) cells. MATERIALS AND METHODS: In comparison to a control group, three experimental groups were formed from human primary PDL cells stressed with compressive forces, bacterial endotoxins, or a combination of both. Gene expression of cyclooxygenase-2 and RANKL was analysed with RT real-time PCR. The prostaglandin E2 production was determined with ELISA. A co-culture of PDL cells and an osteoclast-progenitor cell line was used in order to demonstrate the osteoclast formation effect caused by the simultaneous combined stress. RESULTS: The simultaneous combined stress resulted in a 56-fold up-regulation of cyclooxygenase-2 gene expression with a subsequent noticeable rise in the prostaglandin E2 in the culture medium. The RANKL/osteoprotegerin gene expression ratio was 50-fold up-regulated and the osteoclast formation assay revealed 153.5 ± 15.7 tartrate-resistant acid phosphatase (TRAP)-positive cells per well compared with 42.3 ± 3.8 TRAP-positive cells per well of the control group. CONCLUSION: The synergistic action of periodontal pathogens and orthodontic forces leads to an increased expression of cyclooxygenase-2 from PDL cells that intensify the RANKL production which in turn induces osteoclast differentiation and subsequent osteoclastogenesis. CLINICAL RELEVANCE: The present study puts an emphasis on the detrimental effect of orthodontic forces on patients with an active periodontal disease by underlining the significance of cyclooxygenase-2 activity and RANKL binding on the osteoclastogenesis process.
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Ciclooxigenasa 2/metabolismo , Endotoxinas/farmacología , Ligamento Periodontal/efectos de los fármacos , Ligando RANK/metabolismo , Adolescente , Adulto , Secuencia de Bases , Células Cultivadas , Ciclooxigenasa 2/genética , Cartilla de ADN , Dinoprostona/metabolismo , Ensayo de Inmunoadsorción Enzimática , Humanos , Masculino , Ligamento Periodontal/citología , Ligamento Periodontal/metabolismo , Ligando RANK/genética , Reacción en Cadena en Tiempo Real de la Polimerasa , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Adulto JovenRESUMEN
Objective: The growth and development of the mandible strongly depend on modeling changes occurring at its ramus. Here, we investigated covariance patterns between the morphology of the ramus and the rest of the face. Methods: Lateral cephalograms of 159 adults (55 males and 104 females) with no history of orthodontic treatment were collected. Geometric morphometrics with sliding semi-landmarks was used. The covariance between the ramus and face was investigated using a two-block partial least squares analysis (PLS). Sexual dimorphism and allometry were also assessed. Results: Differences in the divergence of the face and anteroposterior relationship of the jaws accounted for 24.1% and 21.6% of shape variation in the sample, respectively. Shape variation was greater in the sagittal plane for males than for females (30.7% vs. 17.4%), whereas variation in the vertical plane was similar for both sexes (23.7% for males and 25.4% for females). Size-related allometric differences between the sexes accounted for the shape variation to a maximum of 6% regarding the face. Regarding the covariation between the shapes of the ramus and the rest of the face, wider and shorter rami were associated with a decreased lower anterior facial height as well as a prognathic mandible and maxilla (PLS 1, 45.5% of the covariance). Additionally, a more posteriorly inclined ramus in the lower region was correlated with a Class II pattern and flat mandibular plane. Conclusions: The width, height, and inclination of the ramus were correlated with facial shape changes in the vertical and sagittal planes.
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BACKGROUND: High-pull headgear with fixed appliances is a common therapeutic plan in class II growing individuals, especially in those with a tendency to hyperdivergence. The stability of this approach has not been adequately assessed in the long-term. The aim of this retrospective study was to assess that long-term stability by means of lateral cephalograms. Seventy-four consecutive patients were included and examined at three time-points: pre-treatment (T1), end of treatment (T2), and at least five years post-treatment (T3). RESULTS: The average initial age of the sample was 9.3 years (standard deviation, SD: 1.6). At T1, the mean ANB was 5.1 degrees (SD: 1.6), the mean SN-PP 5.6 (SD: 3.0) and the mean MP-PP 28.7 degrees (SD: 4.0). The median follow-up time was 8.6 years with an interquartile range of 2.7. A statistically significant, but of small magnitude increase in the SNA angle was noted at T3 compared to T2 after adjusting for the pre-treatment SNA value (mean difference (MD): 0.75; 95% CI: 0.34, 1.15; P<0.001). The inclination of the palatal plane appeared stable in the post-treatment period, while the MP-PP angle showed scarce evidence of decrease during the post-treatment period after adjusting for sex, pre-treatment SNA and SN-PP angles (MD: -2.29; 95% CI: -2.85, -1.74; P<0.001). CONCLUSIONS: The sagittal position of the maxilla and the inclination of the palatal plane appeared to be stable after treatment with high-pull headgear and fixed appliances in the long-term. Continuous mandibular growth, both sagittaly and vertically, contributed to the stability of class II correction.
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Maloclusión Clase II de Angle , Humanos , Niño , Estudios Retrospectivos , Maloclusión Clase II de Angle/diagnóstico por imagen , Maloclusión Clase II de Angle/terapia , Aparatos Ortodóncicos Fijos , Maxilar , Mandíbula , Cefalometría , Aparatos de Tracción Extraoral , Resultado del TratamientoRESUMEN
PURPOSE: Orthodontic treatment involving premolar extractions might improve the angulation of lower third molars, which are the teeth most often impacted. This study analyzes the impact of first/second lower premolar extraction during orthodontic therapy on the angulation of mandibular third molars. METHODS: A total of 120 patients treated non-extraction (nâ¯= 40), with extraction of first (nâ¯= 40), or second lower premolars (nâ¯= 40) were included. The mesiodistal angulation of lower third molars relative to the adjacent tooth and their developmental stage were evaluated from posttreatment orthopantomograms. Between-group differences were statistically evaluated at a significance level of 0.05. RESULTS: The orthopantomograms of 120 patients (51% female) with a median age of 15.2 years at the time of debonding were evaluated after a mean treatment duration time of 2.9 years. No difference (Pâ¯> 0.05) was seen between the average angulation of the lower third molars of the right (meanâ¯= 24.4°, standard deviation [SD] 13.6°) and the left side (meanâ¯= 23.6°, SD 14.1°). No differences in the angulation of the lower third molar were found between the non-extraction and extraction groups for the right (Pâ¯= 0.44) or the left side (Pâ¯= 0.22). Likewise, no differences were found when comparing the first and second premolars for the right (Pâ¯= 0.26) or the left side (Pâ¯= 0.10). Premolar extraction was associated with an advanced root development stage of the right third molar (odds ratio 7.1; 95% confidence interval 1.1-48.1; Pâ¯= 0.04), with no differences between extraction of the first or second premolar (Pâ¯= 0.10). CONCLUSION: Orthodontic treatment involving premolars extractions might be associated with a small acceleration in root development, but not with the angulation, of lower third molars.
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PURPOSE: Adequate control of the vertical dimension is of great importance in orthodontic treatment. Although existing evidence is very limited, extraction of four premolars is thought to contribute towards improved control of anterior facial height compared with non-extraction treatment protocols. Thus, the aim of this retrospective cohort study was to compare the effect of fixed-appliance treatment with extraction of four premolars to non-extraction treatment on the skeletal vertical dimension. METHODS: A consecutive sample of 76 children with skeletal hyperdivergence (49% male; mean age 11.9 years) was divided into two groups for treatment with either non-extraction (nâ¯= 31) or extraction of four premolars (nâ¯= 45). Baseline characteristics were comparable: overjet 5.1⯱ 2.5â¯mm, overbite 2.4⯱ 1.9â¯mm, ANB angle 4.6⯱ 2.3°, and SN-ML angle 40.2⯱ 3.5°. Patients were treated with standard edgewise fixed appliances with closing loops/sliding mechanics. Vertical skeletal and dental outcomes were measured on lateral cephalograms before and after treatment. Data were analyzed with linear regression at 5%. RESULTS: Compared to non-extraction treatment, treatment with premolar extractions had no significant effect on the SN-ML angle (difference (Δ)â¯= 0.07°; 95% confidence interval -0.90 to 1.01°; Pâ¯= 0.88). Statistically significant changes between the extraction and non-extraction groups were only found for the parameters SNA (Δ -1.47°; Pâ¯= 0.003), ANB (Δ -1.17°; Pâ¯= 0.004), SN-OP (Δ -1.48°; Pâ¯= 0.04), and L1-ML (Δ -6.39°; Pâ¯< 0.001). CONCLUSION: Orthodontic treatment of children with skeletal hyperdivergence using systematic extraction of four premolars had minimal effects on the vertical facial dimension compared to non-extraction treatment.
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PURPOSE: To assess mandibular incisor inclination after leveling the curve of Spee (CoS) in patients treated with fixed appliances. MATERIALS AND METHODS: This was a retrospective study, which included 80 consecutive patients with a mild CoS treated without extraction but with various biomechanical approaches. The depth of CoS was digitally measured on scanned plaster casts and mandibular incisor inclination was assessed with lateral cephalograms pre- and posttreatment. Patients were treated with 0.018"-slot edgewise fixed appliances and cinched back wires. Data were analyzed using linear regression modeling at 5%. RESULTS: A total of 80 patients (40% female; mean age 13.8 years) were included with mean ANB = 4.4 ± 1.9°, mean SN/ML = 31.7 ± 4.7°, mean L1/ML = 95.0 ± 7.7°, and a mean depth of CoS = 1.1 ± 0.4 mm. The depth of CoS was leveled by -0.85 ± 0.39 mm to a post-treatment median of 0.18 mm (interquartile range = 0.09 to 0.35 mm). A small mandibular incisor proclination was observed through treatment (2.49 ± 9.1°), but this was not associated with the reduction in the depth of CoS (p > 0.05) and no statistically significant modifying effect from the different treatment mechanics was observed. CONCLUSION: Under the limitations of this study, leveling a mild CoS was not associated with mandibular incisor proclination during fixed-appliance treatment.
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Incisivo , Humanos , Femenino , Adolescente , Masculino , Estudios Retrospectivos , Modelos LinealesRESUMEN
OBJECTIVE: To investigate changes in dental arch configuration, relationship, and malocclusion directly after Class II malocclusion treatment with a Balters bionator modified by Ascher as well as 20 years after treatment. MATERIALS AND METHODS: Orthodontic dental cast analysis of 18 patients with skeletal Class II treated with a bionator without any additional fixed therapy was performed with a digital caliper at three stages: before (T0), after (T1) and 20 years after (T2) treatment. Arch perimeter and depth, intermolar and intercanine distance, overjet, overbite, sagittal molar and canine relationship, mandibular incisor irregularity (Little's index), and malocclusion (PAR index) were assessed. RESULTS: During treatment (T0-T1), upper arch perimeter significantly increased with a significant decrease in the upper and lower arch perimeter long-term (T1-T2), whereas corresponding arch depths changed only slightly in both periods. Transverse intermolar width increased significantly during treatment, remaining almost constant from T1 to T2. Lower intercanine distance remained fairly unchanged during treatment, but decreased significantly during follow-up. Lower incisor irregularity improved slightly during treatment but increased significantly long-term. After treatment, sagittal molar relationships on both sides were improved, overjet and overbite reduced; these significant changes remained stable long-term. The peer assessment rating (PAR) index was significantly lower after treatment and increased insignificantly during follow-up. CONCLUSIONS: 20 years after bionator treatment without additional fixed appliances, the improved sagittal relationship and the reduced overjet and PAR index remained fairly stable. Long-term changes are most likely due to physiological aging processes and are not associated with bionator treatment.
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Aparatos Activadores , Maxilar , Cefalometría , Arco Dental , Estudios de Seguimiento , Humanos , Mandíbula , Maxilar/anatomía & histología , Modelos Dentales , Estudios RetrospectivosRESUMEN
OBJECTIVES: Adults with fixed orthodontic appliances are increasing nowadays. Compared with adolescents, adults present biological differences that might influence treatment duration. Therefore, the aim of the study was to compare duration of treatment with fixed appliances between adults and adolescents. MATERIALS AND METHODS: Eight databases were searched up to September 2019 for randomized and non-randomized clinical studies comparing treatment duration with fixed appliances in adolescents and adult patients. After duplicate study selection, data extraction, and risk of bias assessment with the Cochrane ROBINS-I tool, random effects meta-analyses of mean differences (MD) and their 95% confidence intervals (CIs) were performed, followed by assessment of the quality of evidence with GRADE. RESULTS: A total of 11 unique studies (one prospective and 10 retrospective non-randomized) with 2969 adolescents and 1380 adult patients were finally included. Meta-analysis of 7 studies found no significant difference in the duration of comprehensive treatment with fixed appliances (MD = - 0.8 month; 95% CI = - 4.2 to 2.6 months; P = 0.65; I2 = 92%) between adults and adolescents. Similarly, both distalization of upper first molars with skeletal anchorage for class II correction and the retraction of canines into the premolar extraction spaces lasted similarly long among adults and adolescents. On the other hand, alignment of palatally displaced canines lasted considerably longer in adults compared to adolescents (1 study; MD = 3.8 months; 95% CI = 1.4 to 6.2 months; P = 0.002). The quality of evidence for the meta-analysis was low due to the inclusion of non-randomized studies with considerable risk of bias. CONCLUSIONS: While existing evidence does not indicate a difference in the overall duration of treatment with fixed appliances between adults and adolescents, the alignment of palatally displaced canines lasted significantly longer in adults. However, our confidence in these estimates is low due to the risk of bias in the included studies. TRIAL REGISTRATION: PROSPERO: ( CRD42019148169 ).
Asunto(s)
Diente Molar , Aparatos Ortodóncicos Fijos , Adolescente , Adulto , Duración de la Terapia , Humanos , Estudios Prospectivos , Estudios RetrospectivosRESUMEN
The aim of this systematic review is to compare the effect on the upper airways of orthopedic treatment for skeletal Class III malocclusion with untreated controls. Nine databases were searched up to August 2020 for randomized or nonrandomized clinical trials comparing orthopedic Class III treatment (facemask or chin-cup) to untreated Class III patients. After duplicate study selection, data extraction, and risk of bias assessment (Risk Of Bias In Non-randomized Studies - of Interventions [ROBINS-I]), random-effects meta-analyses of Mean Differences (MDs)/Standardized Mean Differences (SMD) and 95% Confidence Intervals (CIs) were performed, followed by the Grading of Recommendations Assessment, Development and Evaluation assessment evidence-quality. A total of 10 papers (9 unique nonrandomized studies) with 466 patients (42.7% male; average age 9.1 years) were finally included. Limited evidence indicated that compared to normal growth, maxillary protraction with facemask was associated with increases in total airway area (n = 1; MD = 222.9 mm2; 95% CI = 14.0-431.7 mm2), total nasopharyngeal area (n = 4; SMD = 1.6; 95% CI = 1.2-2.0), and individual airway dimensions (upper-airway MD = 2.5 mm; lower-airway MD = 2.1 mm; upper-pharynx MD = 1.6 mm; lower-pharynx MD = 1.0 mm; all n = 6). Subgroup/meta-regression analyses did not find any significant effect-modifiers, while the results were retained 2-5 years postretention. Our confidence in these estimates was, however, very low, due to the inclusion of nonrandomized studies with methodological issues. Limited data from 2 chin-cup studies indicated smaller benefits on airway dimensions. Existing evidence from controlled clinical studies on humans indicates that maxillary protraction for skeletal Class III treatment might be associated with increased airway dimensions, which are, however, mostly minor in magnitude.