RESUMEN
BACKGROUND: The objective of this study was to evaluate the treatment effects of Forsus™ Fatigue Resistant Device (FRD; 3M Unitek, Monrovia, CA, USA) in growing patients with Class II non-extraction malocclusions. METHODS: A retrospective sample of 24 class II patients treated consecutively with the FRD followed by comprehensive orthodontic treatment was compared to a sample of untreated control subjects from the Bolton Brush Study who was matched in age, sex, and craniofacial morphology. Lateral cephalometric radiographs were taken before treatment (T1) and after removal of fixed appliances (T2). Growth changes were subtracted from the treatment changes to obtain the treatment effects of the appliance. Data were analyzed using ANOVA and a match paired t test. RESULTS: Significant differences were found between the treated and control groups for 12 of the 29 measured variables (Co-Gn minus Co-Apt, Wits, Is-OLp, Ii-OLp, overjet, Mi-OLp, molar relationship, overbite, Mic-ML, SNA, ANB, and Ii-ML). With 27.8 months of treatment, all patients were corrected to a class I dental arch relationship. Overjet and molar relationships were improved by an average of 4.7 and 3.1 mm, respectively. This was contributed by a 1.2 mm of restraint in forward maxillary growth, 0.7 mm of forward movement of the mandible, 1.5 mm of backward movement of the maxillary incisors, 1.3 mm forward movement of the mandibular incisors, 0.5 mm backward movement of the maxillary molars, and 1.3 mm of forward movement of the mandibular molars. The overbite was decreased by 2 mm with no significant change in the occlusal, palatal, or mandibular plane. Individual variations in response to the FRD treatment were large for most of the parameters tested. Significant differences in treatment changes between male and female subjects were found only in a few parameters measured. CONCLUSIONS: These results demonstrate that significant overjet and overbite corrections can be obtained with the Forsus FRD in conjunction with comprehensive orthodontic treatment.
Asunto(s)
Maloclusión Clase II de Angle/terapia , Diseño de Aparato Ortodóncico , Aparatos Ortodóncicos Funcionales , Puntos Anatómicos de Referencia/patología , Estudios de Casos y Controles , Cefalometría/métodos , Vértebras Cervicales/crecimiento & desarrollo , Niño , Femenino , Estudios de Seguimiento , Humanos , Incisivo/patología , Masculino , Mandíbula/patología , Maxilar/crecimiento & desarrollo , Maxilar/patología , Desarrollo Maxilofacial/fisiología , Diente Molar/patología , Hueso Nasal/patología , Sobremordida/terapia , Pubertad/fisiología , Estudios Retrospectivos , Silla Turca/patologíaRESUMEN
BACKGROUND: A retrospective study was conducted to determine the cephalometric changes in a group of Class III patients treated with the inter-arch spring-loaded module (CS2000®, Dynaflex, St. Ann, MO, USA). METHODS: Thirty Caucasian patients (15 males, 15 females) with an average pre-treatment age of 9.6 years were treated consecutively with this appliance and compared with a control group of subjects from the Bolton-Brush Study who were matched in age, gender, and craniofacial morphology to the treatment group. Lateral cephalograms were taken before treatment and after removal of the CS2000® appliance. The treatment effects of the CS2000® appliance were calculated by subtracting the changes due to growth (control group) from the treatment changes. RESULTS: All patients were improved to a Class I dental arch relationship with a positive overjet. Significant sagittal, vertical, and angular changes were found between the pre- and post-treatment radiographs. With an average treatment time of 1.3 years, the maxillary base moved forward by 0.8 mm, while the mandibular base moved backward by 2.8 mm together with improvements in the ANB and Wits measurements. The maxillary incisor moved forward by 1.3 mm and the mandibular incisor moved forward by 1.0 mm. The maxillary molar moved forward by 1.0 mm while the mandibular molar moved backward by 0.6 mm. The average overjet correction was 3.9 mm and 92% of the correction was due to skeletal contribution and 8% was due to dental contribution. The average molar correction was 5.2 mm and 69% of the correction was due to skeletal contribution and 31% was due to dental contribution. CONCLUSIONS: Mild to moderate Class III malocclusion can be corrected using the inter-arch spring-loaded appliance with minimal patient compliance. The overjet correction was contributed by forward movement of the maxilla, backward and downward movement of the mandible, and proclination of the maxillary incisors. The molar relationship was corrected by mesialization of the maxillary molars, distalization of the mandibular molars together with a rotation of the occlusal plane.
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Maloclusión de Angle Clase III/terapia , Diseño de Aparato Ortodóncico , Ortodoncia Correctiva/instrumentación , Adolescente , Estudios de Casos y Controles , Cefalometría/métodos , Niño , Aleaciones Dentales/química , Femenino , Estudios de Seguimiento , Humanos , Incisivo/patología , Masculino , Mandíbula/patología , Maxilar/patología , Diente Molar/patología , Níquel/química , Alambres para Ortodoncia , Técnica de Expansión Palatina/instrumentación , Estudios Retrospectivos , Rotación , Titanio/química , Técnicas de Movimiento Dental/instrumentaciónRESUMEN
OBJECTIVES: To evaluate the length and orientation of masseter in different types of malocclusions using Cone Beam Computed Tomography (CBCT). METHODS: Samples of 180 patients seeking orthodontic treatment at the University of Nevada, Las Vegas School of Dentistry, were included in the study. Pre-treatment multi-slice CBCT scans of these patients were divided into three anteroposterior groups: Class I subjects with ANB angle 0° to 5°; Class II subjects with ANB angle >5°; and Class III subjects with ANB angle <0°. CBCT scans were also divided into three vertical groups: normodivergent subjects with mandibular plane angle 22° to 30°; hyperdivergent subjects with mandibular plane angle >30°, hypodivergent subjects with mandibular plane angle <22°. The masseter was identified and landmarks were placed on the anterior border, at the origin and insertion of the muscle in 3-D mode of the Dolphin Imaging 10.5 Premium software. The Frankfort Horizontal Plane was used as a reference plane and an angular measurement was obtained by intersection of a line produced by the masseter landmarks to calculate the orientation of the muscles. The length of the masseter was measured and data were analyzed using ANOVA and matched pairs test. RESULTS: ANOVA found significant differences in muscle length among the three vertical groups for both the left and right muscles. Paired t test showed significantly shorter muscle length for the hypodivergent group (43.3 ± 4.0 mm) compared to the normodivergent group (45.6 ± 4.5 mm, P < 0.05) and shorter muscle length for the hyperdivergent group (42.3 ± 4.7 mm) compared to the hypodivergent group, P < 0.05. No significant differences were found in muscle length among the three anteroposterior groups. However, significant differences in muscle orientation angle were found among the three anteroposterior groups (P < 0.05). Class II subjects were found to have the most acute orientation angle (67.2 ± 6.6°) and Class III had the most obtuse orientation angle (81.6 ± 6.8°). CONCLUSIONS: These results suggest that certain types of malocclusion may have different masseter lengths and orientations and these differences may have implications for the mechanical advantage in bite force. For example, Class III individuals may have greater bite force than Class II individuals because the muscle fibers are oriented more along the arch of closure.
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Tomografía Computarizada de Haz Cónico/métodos , Maloclusión/diagnóstico por imagen , Músculo Masetero/diagnóstico por imagen , Puntos Anatómicos de Referencia/diagnóstico por imagen , Cefalometría/métodos , Oclusión Dental , Humanos , Procesamiento de Imagen Asistido por Computador/métodos , Imagenología Tridimensional/métodos , Maloclusión Clase II de Angle/diagnóstico por imagen , Maloclusión de Angle Clase III/diagnóstico por imagen , Mandíbula/diagnóstico por imagen , Maxilar/diagnóstico por imagen , Tomografía Computarizada Multidetector/métodos , Hueso Nasal/diagnóstico por imagen , Reproducibilidad de los Resultados , Dimensión VerticalRESUMEN
AIM: To evaluate and compare the anteroposterior relationship of the maxillary central incisors to the forehead in white male adults with harmonious profiles and white male adult orthodontic patients. METHODS: Photographs of 101 white male adults with good facial harmony (control sample) were compared with photographs of 97 white male adults seeking orthodontic treatment (study sample). All were profile images with the maxillary central incisors and foreheads in full view. The images were imported into an image editing software program, resized, and rotated to the upright head position. Reference lines were constructed to assess the anteroposterior positions of the maxillary central incisors and forehead inclinations. RESULTS: In the control sample, the maxillary central incisors were positioned between the forehead facial axis (FFA) point and glabella in 91%, posterior to the FFA point in 8%, and anterior to the glabella in <1%. The position of the maxillary central incisors was moderately correlated with forehead inclination (r² = 0.37). In the study sample, the maxillary central incisors were positioned between the FFA point and glabella in 34%, posterior to the FFA point in 59%, and anterior to the glabella in 7%. Maxillary central incisor position and forehead inclination were strongly correlated (r² = 0.53). The anteroposterior maxillary incisor position relative to the forehead between the control and study groups was significantly different (P < .0001). In addition, the forehead inclination between the control and study group was significantly different (P < .05). CONCLUSION: The forehead is an important landmark for anteroposterior maxillary incisor positioning for adult white male patients seeking improved facial harmony.
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Cefalometría/métodos , Frente/anatomía & histología , Incisivo/anatomía & histología , Maxilar/anatomía & histología , Adulto , Puntos Anatómicos de Referencia/anatomía & histología , Estética , Hueso Frontal/anatomía & histología , Humanos , Procesamiento de Imagen Asistido por Computador/métodos , Masculino , Maloclusión/patología , Fotograbar/métodos , Sonrisa , Población BlancaRESUMEN
AIM: Enamel demineralization is considered to be the most prevalent and significant iatrogenic effect associated with fixed orthodontic treatment and can seriously jeopardize both tooth longevity and dental esthetics. This in vitro study was undertaken to compare the effectiveness of four different commercially available surface treatment medicaments for the inhibition of enamel demineralization. METHODS: Seventy-five intact maxillary premolars extracted from patients undergoing orthodontic treatment were divided into five equal groups and were subjected to one of the following protocols: no treatment (control group) or treatment with one of the following four medicaments: fluoride varnish (Fluor Protector [FP]), casein phosphopeptide-amorphous calcium phosphate (GC Tooth Mousse [TM]), calcium sodium phosphosilicate (SHY-NM), and casein phosphopeptide-amorphous calcium phosphate with fluoride (GC Tooth Mousse Plus [TMP]). All the teeth were subjected to ten Cate demineralization solution?for 96 hours and subsequently evaluated under polarized light microscopy to obtain the mean depths of enamel demineralization. One-way analysis of variance and Bonferroni comparison tests were used to obtain statistically significant differences between the five different groups at P < .05. RESULTS: All four surface treatment medicaments provided statistically significant reduction in the depths of enamel demineralization as compared with the control group. FP provided the greatest protection of enamel surface in terms of reduction of lesion depth, followed by TMP, SHY-NM, and TM. CONCLUSIONS: The use of these commercially available medicaments could prove to be beneficial for patients undergoing orthodontic treatment and who are at a risk for developing enamel decalcification.
Asunto(s)
Cariostáticos/uso terapéutico , Esmalte Dental/efectos de los fármacos , Aparatos Ortodóncicos/efectos adversos , Desmineralización Dental/prevención & control , Diente Premolar/efectos de los fármacos , Caseínas/uso terapéutico , Esmalte Dental/patología , Combinación de Medicamentos , Fluoruros/uso terapéutico , Fluoruros Tópicos/uso terapéutico , Vidrio , Humanos , Enfermedad Iatrogénica , Procesamiento de Imagen Asistido por Computador/métodos , Microscopía de Polarización/métodos , Poliuretanos/uso terapéutico , Silanos/uso terapéutico , Desmineralización Dental/patologíaRESUMEN
INTRODUCTION: The objectives of this research were to assess skeletal and dental changes in patients with Class II malocclusion treated with the edgewise crowned Herbst appliance in the early mixed dentition and to measure the stability of treatment after a second phase of fixed appliance therapy. METHODS: Twenty-two patients (ages, 8.4 ± 1.0 years) with Class II Division 1 malocclusion treated consecutively with the edgewise crowned Herbst appliance in the early mixed dentition were studied. Lateral cephalograms were taken before Herbst treatment, immediately after Herbst treatment, and after a second phase of fixed appliance therapy. The results were compared with a control group of untreated Class II subjects selected from the Bolton-Brush study, matched by age, sex, and craniofacial morphology. A total of 37 sagittal, vertical, and angular cephalometric variables were evaluated. Changes in overjet and molar relationship were calculated. Changes due to growth were subtracted to obtain the net changes due to treatment. The data were analyzed by using analysis of variance (ANOVA) and the t tests. RESULTS: Overcorrection with the Herbst appliance resulted in an average reduction in overjet of 7.0 mm and a change in molar relationship of 6.6 mm. Several factors contributed to the change in overjet: restraint of the forward movement of the maxilla (0.4 mm), forward movement of the mandible (2.0 mm), backward movement of the maxillary incisors (3.7 mm), and forward movement of the mandibular incisors (0.9 mm). Skeletal changes together with a 3.1-mm backward movement of the maxillary molars and a 1.1-mm forward movement of the mandibular molars contributed to the changes in molar relationship. After the second phase of fixed appliance therapy, the change in overjet was reduced to 2.8 mm. Most of the remaining overjet corrections were contributed by the restraint of maxillary growth (2.8 mm). The mandible moved posteriorly by 1.6 mm, and the mandibular incisors moved forward by 0.2 mm. Change in molar relationship was reduced to 2.2 mm. The maxillary molars moved backward by 0.2 mm, and the mandibular molars moved forward by 0.8 mm. CONCLUSIONS: Overcorrection of Class II malocclusion with the edgewise crowned Herbst appliance in the early mixed dentition resulted in a significant reduction in overjet and correction of the molar relationship. A portion of the correction was maintained after a second phase of fixed appliance therapy because of the continuous restraint of maxillary growth and the dentoalveolar adaptations.
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Maloclusión Clase II de Angle/terapia , Desarrollo Maxilofacial , Aparatos Ortodóncicos Funcionales , Ortodoncia Correctiva/instrumentación , Análisis de Varianza , Estudios de Casos y Controles , Cefalometría/estadística & datos numéricos , Niño , Dentición Mixta , Femenino , Humanos , Masculino , Análisis por Apareamiento , Soportes Ortodóncicos , Ortodoncia Correctiva/métodos , Prevención Secundaria , Resultado del TratamientoRESUMEN
INTRODUCTION: The purpose of this study was to determine the skeletal, dental, and soft-tissue changes in response to camouflage Class III treatment. METHODS: Thirty patients (average age, 12.4 + or - 1.0 years) with skeletal Class III malocclusions who completed comprehensive nonextraction orthodontic treatment were studied. Skeletal, dental, and soft-tissue changes were determined by using published cephalometric analyses. The quality of orthodontic treatment was standardized by registering the peer assessment rating index on the pretreatment and posttreatment study models. The change in the level of gingival attachment with treatment was determined on the study casts. The results were compared with a group of untreated subjects. Data were analyzed with repeated measures analysis and paired t tests. RESULTS: The average change in the Wits appraisal was greater in the treated group (1.2 + or - 0.1 mm) than in the control group (-0.5 + or - 0.3 mm). The average peer assessment rating index score improved from 33.5 to 4.1. No significant differences were found for the level of gingival attachments between the treatment and control groups. The sagittal jaw relationship (ANB angle) did not improve with camouflage treatment. A wide range of tooth movements compensated for the skeletal changes in both groups. The upper and lower limits for incisal movement to compensate for Class III skeletal changes were 120 degrees to the sella-nasion line and 80 degrees to the mandibular plane, respectively. Greater increases in the angle of convexity were found in the treated group, indicating improved facial profiles. Greater increases in length of the upper lip were found in the treated group, corresponding to the changes in the hard tissues with treatment. CONCLUSIONS: Significant dental and soft-tissue changes can be expected in young Class III patients treated with camouflage orthodontic tooth movement. A wide range of skeletal dysplasias can be camouflaged with tooth movement without deleterious effects to the periodontium. However, proper diagnosis and realistic treatment objectives are necessary to prevent undesirable sequelae.
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Técnicas Cosméticas , Maloclusión de Angle Clase III/terapia , Técnicas de Movimiento Dental , Cefalometría/estadística & datos numéricos , Niño , Cara/anatomía & histología , Femenino , Recesión Gingival/etiología , Humanos , Incisivo , Masculino , Revisión por Expertos de la Atención de Salud , Estudios Retrospectivos , Técnicas de Movimiento Dental/efectos adversos , Resultado del Tratamiento , Dimensión VerticalRESUMEN
INTRODUCTION: Technological advances have attempted to improve the standard of traditional x-ray imaging. ImageIQ software (LumenIQ, Bellingham, Wash) enhances conventional radiography by producing a computer-generated, enhanced 2-dimensional (2D) image, adding depth and detail. The software converts the scales of gray to topographic height values, which are easier for the eye to see. The purpose of this study was to determine whether the enhanced 2D renderings are as sensitive as traditional 2D radiographs for detecting periodontal defects in cadaver mandibles. METHODS: Periodontal defects were located and classified on 20 cadaver mandibles. These defects were radiographed, and computer-generated, enhanced 2D topographic renderings were made with ImageIQ software. A panel of evaluators was shown the 2D radiographs and the enhanced 2D renderings in random order. The evaluators classified the defects from these images. RESULTS: Significantly better agreement by the evaluators with the intrasurgical classification was found with the enhanced 2D rendering to view periodontal defects vs the traditional 2D x-ray. Enhanced 2D renderings improved the accuracy of radiographic periodontal defect classification by 14.3% over traditional 2D radiographs. CONCLUSIONS: Computer generated, enhanced 2D renderings of conventional radiographs might provide a reliable diagnostic alternative to conventional 2D radiographs when attempting to classify periodontal defects.
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Interpretación de Imagen Asistida por Computador/métodos , Mandíbula/diagnóstico por imagen , Enfermedades Periodontales/diagnóstico por imagen , Intensificación de Imagen Radiográfica/métodos , Radiografía Dental/métodos , Análisis de Varianza , Cadáver , Humanos , Radiografía Dental/instrumentaciónRESUMEN
INTRODUCTION: The relationship between nasal airway resistance and the use of rapid palatal expansion appliances remains controversial. The purpose of this study was to use conventional tomography to determine the anatomical changes in the nasal cavity after maxillary expansion. METHODS: Nineteen patients (aged 8-15 years) were included in the study. Tomograms were taken before expansion (T1), immediately after expansion (T2), and 3 months after expansion (T3). Areas for the left and right anterior, middle, and posterior nasal cavity and total volume were calculated by using the computer software, AutoCAD LT 2005. Data were analyzed with paired t tests. RESULTS: Significant increases in area were found in the anterior nasal cavity from T1 to T2 (0.85 +/- 1.19 cm2, 11.7% increase), T2 to T3 (1.18 +/- 1.2 cm2, 22.2% increase), and T1 to T3 (2.6 +/- 1.7 cm2, 35.7% increase) (P <.05). Similar increases were found in the middle and posterior nasal cavity. Significant increases in volume were found from T1 to T2 (2.1 +/- 2.7 cm3, 10.7% increase), T2 to T3 (4.9 +/- 2.3 cm3, 22.6% increase), and T1 to T3 (6.99 +/- 2.45 cm3, 27.8% increase). No significant differences were found in the area or the volume of the left and right sides of the nasal cavity. Individual variations in response to maxillary expansion were large for most of the parameters tested. CONCLUSIONS: These data suggest that rapid palatal expansion is usually accompanied by increases in area and volume of the nasal cavity, and these changes remain stable 3 months after maxillary expansion.
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Cavidad Nasal/anatomía & histología , Técnica de Expansión Palatina , Radiografía Dental/métodos , Tomografía por Rayos X , Adolescente , Niño , Humanos , Cavidad Nasal/diagnóstico por imagenRESUMEN
INTRODUCTION: The crown Herbst appliance was introduced in the late 1980s because of shortcomings of the banded Herbst. In edgewise Herbst treatment, a fixed appliance is used with the crown Herbst to maximize the skeletal effects of treatment. Treatment response to the edgewise Herbst appliance has not been reported in the literature. Our objective was to investigate skeletal and dental changes in patients with Class II malocclusions treated with the edgewise Herbst appliance. METHODS: Fifty-two consecutive patients were treated with the edgewise Herbst appliance; 32 (18 girls, 14 boys) met the criterion of 16 months out of Herbst treatment and were included in the study. Mean treatment time with this appliance was 8.0 +/- 1.8 months. Patients in the mixed dentition received additional treatment with 2 x 4 appliances until proper overbite, overjet, and torque on the incisors and permanent first molars were achieved. Patients in the permanent dentition were treated with full appliances to finalize the occlusion. Cephalometric measurements were taken at pretreatment, posttreatment, and 16 months after removal of the Herbst appliance, and the results were compared with 32 untreated Class II subjects from the Bolton Brush Study, matched for sex, age, and cephalometric dentofacial morphology. Data were analyzed with ANOVA, Tukey-Kramer multiple comparison tests, and 2-tailed t tests. RESULTS: After 8 months of Herbst treatment, incisal relationship was overcorrected to an end-to-end incisal relationship and improved 8.4 mm, compared with the control group. The maxilla moved backward 1.4 mm at Point A, and the mandible moved forward 1.7 mm. The maxillary incisors moved lingually 1.7 mm, and the mandibular incisors were proclined 3.6 mm. The molars were corrected to a Class III relationship with a change of 7.2 mm compared with the control group. The mandible moved downward and forward. However, the condyle showed only 0.2 mm forward movement in the fossa. Sixteen months after appliance removal, the molars had relapsed into a Class I relationship, for a net change of 2.4 mm compared with the control group. Net overjet gain was 2.7 mm. Net restraint of maxillary growth was 1.3 mm, and net forward movement of the mandible was 1.0 mm. The maxillary incisors had no net movement, and the mandibular incisors had a net forward movement of 0.3 mm. Overall, skeletal change contributed 85% of the net overjet correction. CONCLUSIONS: Class II treatment with the edgewise Herbst appliance is accompanied by both skeletal and dental changes. The changes are stable, with significant skeletal differences remaining 16 months after appliance removal. The forward and downward movement of the mandible with minimal changes in the position of the condyles in the fossae suggests a combination of condylar growth and remodeling of the glenoid fossa with treatment.