RESUMEN

BACKGROUND/OBJECTIVE: To reproduce the methods and results of the study by Alobeid et al. (2018) in which the efficacy of tooth alignment using conventional labial and lingual orthodontic bracket systems was assessed. MATERIALS/METHODS: We used the identical experimental protocol and tested (i) regular twin bracket (GAC-Twin [Dentsply]) and lingual twin bracket systems (Incognito [3M]), (ii) together with NiTi 0.014" wires (RMO), and (iii) a simulated malocclusion with a displaced maxillary central incisor in the x-axis (2 mm gingivally) and in the z-axis (2 mm labially). RESULTS: The method described by Alobeid et al. (2018) is not reproducible, and cannot be used to assess the efficacy of tooth alignment in labial or lingual orthodontic treatment. Major flaws concern the anteroposterior return of the Thermaloy-NiTi wire ligated with stainless steel ligatures. The reproduced experimental setting showed that a deflected Thermaloy-NiTi wire DOES NOT move back at all to its initial stage (= 0 per cent correction) because of friction and binding (see supplemented video), neither with the tested labial nor with the lingual brackets. Furthermore, an overcorrection of up to 138 per cent, which the authors indicate for some labial bracket-wire combinations and which deserves the characterization "irreal", stresses the inappropriateness of the method of measurement.Further flaws include: a) incorrect interpretation of the measurement results, where a tooth tripping around (overcorrection) is interpreted as a better outcome than a perfect 100 per cent correction; b) using a statistical test in an inappropriate and misleading way; c) uncritical copying of text passages from older publications to describe the method, which do not correspond to this experimental protocol and lead to calculation errors; d) wrong citations; e)differences in table and bar graph values of the same variable; f) using a lingual mushroom shaped 0.013" Thermaloy-NiTi wire which does not exist; g) drawing uncritical conclusions of so called "clinical relevance" from a very limited in vitro testing. CONCLUSIONS: Clinical recommendations based on in vitro measurements using the Orthodontic Measurement and Simulation System (OMSS) should be read with caution.

Asunto(s)

Diseño de Aparato Ortodóncico , Soportes Ortodóncicos , Alambres para Ortodoncia , Análisis del Estrés Dental , Ensayo de Materiales , Acero Inoxidable , Estrés Mecánico , Titanio , Técnicas de Movimiento Dental

RESUMEN

This study aims to analyze the clinical performance of two loading concepts on second-generation palatal implants (Orthosystem, Straumann, Basel, Switzerland) in a prospective multicenter randomized controlled clinical trial. At the time of this interim analysis, 41 patients have been randomized on a 1:1 basis to one of two treatment groups. Group 1 underwent conventional loading of palatal implants after a healing period of 12 weeks (gold standard) while group 2 underwent immediate implant loading within 1 week after implant insertion. We report initial results at 6 months after functional loading. The primary outcome parameter was implant success (no implant mobility, no implant loss). The implants in both groups were initially stable at the time of insertion, and all were eligible for randomization. Twenty-two patients (group 1) were subjected to conventional implant loading after 12 weeks while 19 patients (group 2) received immediate functional loading within the first week after insertion. Direct (e.g. distal jet appliances) as well as indirect forms of anchorage (conventional or modified transpalatal arch) were used. The magnitude of orthodontic forces ranged between 1 and 4 N for the immediate loading group and between 1 and 5 N for the conventional loading group. One implant in group 1 was lost during the healing phase. One dropout was registered in group 2. Thirty-nine implants were functionally loaded for over 6 months now. These preliminary data provide first evidence of the fact that immediate loading of palatal implants yields equivalent success rates as conventional loading to 4 N after 6 months.

Asunto(s)

Implantes Dentales , Carga Inmediata del Implante Dental/métodos , Métodos de Anclaje en Ortodoncia/métodos , Paladar Duro/cirugía , Grabado Ácido Dental/métodos , Adolescente , Adulto , Anciano , Niño , Grabado Dental/métodos , Diseño de Prótesis Dental , Femenino , Estudios de Seguimiento , Humanos , Masculino , Maloclusión/clasificación , Maloclusión/terapia , Persona de Mediana Edad , Métodos de Anclaje en Ortodoncia/instrumentación , Diseño de Aparato Ortodóncico , Aparatos Ortodóncicos , Oseointegración/fisiología , Estudios Prospectivos , Estrés Mecánico , Propiedades de Superficie , Técnicas de Movimiento Dental/instrumentación , Técnicas de Movimiento Dental/métodos , Resultado del Tratamiento , Adulto Joven

RESUMEN

AIM: To analyze the spectrum of indications for second-generation palatal implants in relation to two different loading concepts in a prospective, multicenter, randomized controlled trial (RCT). PATIENTS AND METHODS: Forty-one patients were recruited to the study from 2006 to 2009. All implants (Orthosystem, Straumann, Basel, Switzerland; dimensions: 4.1 mm x 4.2 mm) were inserted in the median or paramedian region of the anterior palate, and each patient was randomized to one of two loading groups (immediate loading within the first week after insertion versus conventional loading after a 12-week healing phase). In this interim evaluation, we report preliminary results obtained six months after functional loading. RESULTS: All palatal implants were primarily stable at the time of insertion. One implant loss (12 weeks after surgical insertion) was documented in the cohort subjected to conventional loading, and one patient dropped out of the immediate-loading group. At the time of this investigation, 39 palatal implants are experiencing functional loads. Using both loading concepts, we had various orthodontic objectives, such as intrusion of anterior and/or posterior teeth, and the mesialization and distalization of posterior teeth. Both loading groups presented nearly identical indications, and the distribution of direct vs. indirect anchorage forms was also very similar during the active treatment. CONCLUSION: Comparison of the two treatment concepts revealed no clinical differences in implant stability. Patients undergoing immediate-loading therapy were subject to no limitations regarding indications at 6 months after functional loading compared with the patients who experienced conventional loading.

Asunto(s)

Implantes Dentales , Arcada Edéntula/cirugía , Hueso Paladar/cirugía , Adolescente , Adulto , Anciano , Niño , Diseño de Prótesis Dental , Análisis de Falla de Equipo , Femenino , Alemania , Humanos , Arcada Edéntula/diagnóstico por imagen , Masculino , Persona de Mediana Edad , Radiografía , Resultado del Tratamiento , Adulto Joven

RESUMEN

OBJECTIVE: The aim of this clinical trial was to investigate and compare outcomes after treating a skeletal Class II malocclusion with two fixed functional orthodontic appliances, the Herbst appliance and the Functional Mandibular Advancer, by evaluating their skeletal and dentoalveolar effects and the repercussion on the profile in relation to patient age. PATIENTS AND METHODS: The sample population comprised 42 subjects with skeletal Class II malocclusion. They were divided into two groups depending on age. Group A (n = 21) included nine female subjects aged up to 12 years and twelve male subjects aged up to 14 years. Group B (n = 21) comprised twelve females older than 12 years and nine males older than 14 years. Treatment course was documented cephalometricly. The net therapeutic effects were calculated with reference to the control group. RESULTS: A significant reduction of the overjet was achieved in both treatment groups. Within the two groups there were no significant sagittal effects in terms of mandibular advancement. However, there was an inhibiting effect on the maxilla, which counteracted the natural growth process. Significant changes in vertical direction were detected mainly in the younger patients in the sense of lengthening of the lower face. Significant dental changes were predominantly found in the group of older patients. For instance, treatment with fixed functional orthodontic appliances led to retrusion of the upper incisors by a mean of 2.21 mm +/- 2.66 mm (p = 0.0015), protrusion of the lower incisors by a mean of 2.28 mm +/- 2.39 mm (p =

Asunto(s)

Cefalometría , Maloclusión Clase II de Angle/diagnóstico , Maloclusión Clase II de Angle/rehabilitación , Aparatos Ortodóncicos , Adolescente , Niño , Diseño de Prótesis Dental , Análisis de Falla de Equipo , Femenino , Humanos , Masculino , Pubertad , Resultado del Tratamiento

RESUMEN

INTRODUCTION: Conventional anchorage appliances rely exclusively on intraoral anchorage for noncompliance molar distalization. The partial coverage of the palate, in particular, often results in compromised oral hygiene. An innovative alternative combines a skeletonized distal jet appliance with 2 paramedian miniscrews for additional anchorage. The objectives of this study were to investigate the suitability of the skeletonized distal jet for translatory molar distalization and to check the quality of the supporting anchorage setup. METHODS: Two paramedian miniscrews (length, 8-9 mm; diameter, 1.6 mm) were placed into the anterior area of the palate in 10 patients. Skeletonized distal jet appliances fitted with composite to the first premolars and the collars of the miniscrews were used for bilateral molar distalization, and the coil springs were activated with a distalization force of 200 cN on each side. RESULTS: The study confirmed the suitability of the appliance for translatory molar distalization (3.92 +/- 0.53 mm) with slight mesial inward rotation (on average, 8.35 degrees +/- 7.66 degrees and 7.88 degrees +/- 5.50 degrees ). The forces acting reciprocally on the anchorage setup were largely absorbed by the anchorage unit involving 2 anchorage teeth and 2 miniscrews. Significant anchorage loss, in the form of first premolar mesialization of 0.72 +/- 0.78 mm, was found. CONCLUSIONS: The skeletonized distal jet appliance supported by additional miniscrew anchorage allows translatory molar distalization. Although the anchorage design combining 2 miniscrews at a paramedian location and the periodontium of 2 anchorage teeth does not offer the quality of stationary anchorage, it achieves greater molar distalization in total sagittal movement than conventional anchorage designs with an acrylic button.

Asunto(s)

Tornillos Óseos , Diente Molar/patología , Métodos de Anclaje en Ortodoncia/instrumentación , Diseño de Aparato Ortodóncico , Técnicas de Movimiento Dental/instrumentación , Diente Premolar/patología , Cefalometría , Niño , Resinas Compuestas/química , Arco Dental/patología , Materiales Dentales/química , Femenino , Humanos , Incisivo/patología , Masculino , Maloclusión Clase II de Angle/terapia , Maxilar/patología , Alambres para Ortodoncia , Hueso Paladar/patología , Rotación , Estrés Mecánico , Propiedades de Superficie , Resultado del Tratamiento

RESUMEN

AIM: Recent papers have discussed genetic predisposition for root resorption. The aim of this study was to investigate this kind of relationship as dependent on the EARR phenotype. Alleles from IL-1A and IL-1B gene polymorphisms are discussed as genetically predisposing factors. MATERIAL AND METHODS: Orthopantomograms (OPG) exhibiting EARR (n = 96) were metrically and statistically analyzed for expression and were compared to a control group (n = 162). Additionally, the percentage of affected teeth per individual was determined. A subgroup of the EARR patient sample (n = 49) was assessed, based on blood analyses, for an association with genomic IL-1A (-889) and IL-1B (+3954) polymorphism. RESULTS: In the case of the IL-1A variation, a significant difference of genotype distribution was found between EARR patients and the control group: genotype 2-2 could be seen significantly more frequently in the EARR group. Furthermore, the extent of resorption grades seemed to be influenced by the genetic constitution. The genotype distribution of the IL-1B polymorphism was comparable to the distribution in the control sample. In particular, allele 1 of the IL-1B polymorphism, which has been described as being associated with family histories of EARR, was observed less frequently in the patient cohort than in the control group. CONCLUSIONS: The available data of the IL-1A polymorphism point to an association of the genotype 2-2 with EARR. As analyses of individual subgroups showed, with the increase in the extent of EARR there was a recognizable correlation with genotype 2-2. The genotype distribution of the IL-1B polymorphism in patients and control cohorts revealed no indication of a predisposition. Despite the low number of cases in the own cohort, the data collected revealed that the allele 1 of the IL-1B polymorphism in patients with sporadic EARR did not contribute to predisposition, in contrast to familial cases. The results are an initial basis for pre-orthodontic genetic EARR risk analyses.

Asunto(s)

Interleucina-1alfa/genética , Interleucina-1beta/genética , Resorción Radicular/epidemiología , Resorción Radicular/genética , Ápice del Diente , Predisposición Genética a la Enfermedad/epidemiología , Predisposición Genética a la Enfermedad/genética , Alemania/epidemiología , Humanos , Incidencia , Medición de Riesgo/métodos , Factores de Riesgo

RESUMEN

AIM: It was the aim of this clinical study to compare the skeletal and dentoalveolar effects as well as those on the profile of three different treatment approaches in Class II patients (camouflage orthodontics, dentofacial orthopedics, and combined orthodontic and surgical treatment). PATIENTS AND METHOD: Our study cohort consisted of 60 young adults presenting a skeletal Class II, Division 1 malocclusion: 20 patients whose overjet was reduced by camouflage following premolar extraction, 20 patients whose occlusions were corrected by placement of a fixed functional orthopedic appliance, and 20 who underwent orthognathic surgery (bilateral sagittal split osteotomy of the mandible without genioplasty). We documented the therapeutic progress using cephalometry. RESULTS: Each patient group achieved a reduction in overjet via their respective treatment. While no treatment-related changes in the maxillary area were assessable, the effects on the mandible differed. We observed advancement of the bony chin and an increase in mandibular length in the sagittal-diagonal dimension in the surgical and functional orthopedic groups. However, the extent of the treatment-related changes was significant only in the group of patients that had undergone orthognathic surgery. Only the surgical group presented changes in vertical relationships. Incisor repositioning as an outcome of the respective treatments differed fundamentally, with those in the surgical group revealing significant protrusion of the upper incisors. The maxillary incisors were retruded and mandibular incisors proclined in the functional orthopedic group, whereas the upper and lower incisors both retruded significantly in the extraction group. Soft-tissue remodeling bore no linear relationship to treatment-induced skeletal and dental effects. Still, orthognathic surgery led to the most marked profile changes. Treatment using fixed functional orthopedic appliances reduced the convexity of the soft-tissue profile at least moderately. Camouflage orthodontics, on the other hand, resulted in an increase in the nasolabial angle. CONCLUSIONS: In young adults fixed functional appliances are a treatment alternative to extraction therapy but to a lesser extent to orthognathic surgery. Because of their limited skeletal effects and minor changes in the profile they are indicated only in patients with a moderately severe Class II malocclusion. Pre-treatment proclined mandibular incisors limit the scope of indications for fixed functional appliances, as they can cause an increase in lower incisor proclination. Significant reductions in profile convexity are achievable only by combined orthodontic and surgical treatment of the malocclusion. When performing camouflage orthodontics in conjunction with maxillary premolar extractions in adults, an increase in the nasolabial angle, which is often esthetically undesirable, has to be discussed as a potential side effect and has to be taken into account when considering the different therapeutic approaches.

Asunto(s)

Cefalometría , Estética , Maloclusión de Angle Clase III/terapia , Procedimientos Quirúrgicos Orales/instrumentación , Procedimientos Quirúrgicos Orales/métodos , Aparatos Ortodóncicos , Adolescente , Adulto , Femenino , Humanos , Masculino , Resultado del Tratamiento , Adulto Joven

RESUMEN

Since the end of the 1970s, various appliances with intramaxillary anchorage for distalization of the upper molars have been described as an alternative to headgear. The major advantages of these innovative appliances are that they act permanently and are independent of patient compliance. The purpose of this study was to compare the efficiency, both quantitatively and qualitatively, of various appliance types with intramaxillary anchorage for non-compliance molar distalization. Eighty-five papers were reviewed, and 22 were identified as being suitable for inclusion. The selection was based on compliance with the following criteria: treatment group with at least 10 non-syndromal patients, conventional intraoral anchorage design using a palatal button and anchorage teeth, consistent cephalometric measurements in clinical-epidemiological studies, exact data on the course of treatment, and statistical presentation of the measured outcomes and their standard deviations. The results show that non-compliance molar distalization is possible with numerous different appliances. While molar distalization with standard pendulum appliances exhibited the largest values for dental-linear distalization, it also resulted in concurrent, substantial therapeutically undesirable distal tipping. However, specific modifications to the pendulum appliance allow achievement of almost bodily molar distalization. Different outcomes are quoted in the studies for the efficiency of loaded spring systems for distal molar movement, but it seems that the first class appliance and the palatal distal jet are more efficient than the vestibular Jones Jig. The studies identify anchorage loss as being found in the area of the incisors rather than the area of the first premolars. There was a trend for more substantial reciprocal side-effects to occur when only two teeth were included in the anchorage unit. Vertical components acting on the molars, premolars, and incisors, such as intrusion and extrusion, tended to be of secondary importance and, therefore, may be disregarded.

Asunto(s)

Maloclusión/terapia , Métodos de Anclaje en Ortodoncia/instrumentación , Técnicas de Movimiento Dental/instrumentación , Humanos , Maxilar , Diente Molar , Aparatos Ortodóncicos , Ortodoncia Correctiva/instrumentación , Cooperación del Paciente , Técnicas de Movimiento Dental/métodos , Resultado del Tratamiento

RESUMEN

AIM: As a clinical pilot study using the skeletonized, periodontally/miniscrew-anchored Distal Jet appliance, this study aimed to verify the positional stability of the palatally-inserted paramedian miniscrews when subjected to loading for several months, hence to assess the efficacy of the supporting anchorage design. MATERIAL AND METHOD: Sixteen miniscrews (8-9 mm in length, 1.6 mm in diameter, polished surface) were inserted in the anterior region of the palate at paramedian locations. Once they had been in place for 1 week, skeletonized Distal Jets for bilateral molar distalization were anchored to the first premolars and necks of the miniscrews using composite. The appliances' coil spring systems were activated to a distalization force of 200-240 cN. The miniscrews were processed histologically after minimally-invasive explantation. RESULTS: Forces acting reciprocally on the anchorage unit result in significant anchorage loss in the palatally-inserted titanium miniscrews used for added anchorage support: we observed ventral movement in the vicinity of the miniscrew heads of 0.95+/-0.82 mm (the mean; p = 0.005), and extrusion of 0.21+/-0.28 mm (p = 0.040). In the process they tipped 2.65 degrees +/-6.23 degrees in relation to the palatal plane and 2.15 degrees +/-5.76 degrees in relation to the anterior cranial base. We observed no evidence of direct screw-to-bone contact in any of the explanted miniscrews. CONCLUSIONS: Titanium miniscrews with a polished surface, 1.6 mm in diameter and 8-9 mm long, do not provide stationary anchorage in molar distalization with the periodontally/miniscrew-anchored Distal Jet. When subjected for several months to load from forces that act in reciprocity to the force systems occurring during molar distalization, they fail to remain completely stationary in position in the palatal locations in which they were inserted. However, the combined anchorage setup is sufficient, intraorally and regardless of patient compliance, to largely compensate for the mesially-acting forces that occur reciprocal to molar distalization.

Asunto(s)

Tornillos Óseos , Diente Molar , Métodos de Anclaje en Ortodoncia/instrumentación , Diseño de Aparato Ortodóncico , Hueso Paladar/cirugía , Periodoncio/cirugía , Titanio , Técnicas de Movimiento Dental/instrumentación , Cefalometría , Niño , Análisis del Estrés Dental , Femenino , Humanos , Masculino

RESUMEN

OBJECTIVE: To analyze the forces and moments acting in the first molar region, induced by the Distal Jet appliance for maxillary molar distalization. MATERIALS AND METHODS: Over a working section of 3 mm with reactivation of the loaded spring systems, the force systems of three laboratory-fabricated appliances of identical design were analyzed with a 3D metering device. RESULTS: The force systems registered in vitro exhibited complex biomechanics. Regular reactivation of the loaded coils resulted in consistent distalizing forces and uprighting moments, in forces and moments toward buccal as well as slightly intrusive forces, and mesial-inwardly rotating moments. In the sagittal dimension, the Distal Jet appliance allows almost translatory molar distalization. Accordingly, applying uprighting activation is not necessary for treatment. Because of the application of the force palatal to the center of resistance of the molars, the teeth experience undesired mesial-palatal and distal-facial rotation. CONCLUSIONS: The Distal Jet appliance allows almost translatory distal molar movement, and uprighting activation is not necessary for treatment. The force applied palatal to the center of resistance of the molars produces an undesired mesial-palatal and distal-facial rotation. Regular intraoral coil spring reactivation is needed.

Asunto(s)

Análisis del Estrés Dental , Diente Molar/fisiología , Aparatos Ortodóncicos/efectos adversos , Técnicas de Movimiento Dental/instrumentación , Fenómenos Biomecánicos , Humanos , Movimiento Mesial de los Dientes/etiología

RESUMEN

AIM: The aim of this in-vitro study was to analyze the forces and moments acting in the first molar region induced by the Keles Slider appliance for maxillary molar distalization, thereby investigating this appliance's suitability for translatory distalization of the upper molars. MATERIAL AND METHODS: Over a working section of 3 mm with reactivation of the loaded spring systems, we analyzed the force systems of three laboratory-fabricated appliances of identical design using 3D measuring equipment. RESULTS: The force systems registered in-vitro exhibited complex biomechanics. Regular reactivation of the loaded coils resulted in consistent distalizing forces and uprighting moments, in forces and moments toward buccal and weak extrusive forces, and increasing mesial-inward rotating moments. CONCLUSIONS: The Keles Slider nearly achieves translatory molar distalization on a typodont in the sagittal plane. As a result, no uprighting activation is necessary for treatment. Because force application occurs palatally from the molars' center of resistance, there is a mesial-inward rotating moment that increases as distalization progresses, and this may lead to unwanted friction during clinical application. This is why regular reactivation of the coil spring systems, as well as subsequent measures for molar derotation, are indispensable. In the vertical plane, the molars are exposed to weak extrusive forces combined with moderate buccal rotating moments. These effects confirm that this appliance is indicated in patients with deep overbite.

Asunto(s)

Análisis del Estrés Dental , Maxilar/fisiología , Diseño de Aparato Ortodóncico , Técnicas de Movimiento Dental/instrumentación , Fenómenos Biomecánicos , Humanos , Técnicas In Vitro

RESUMEN

BACKGROUND: In orthodontic treatment, anchorage control is a fundamental aspect. Usually conventional mechanism for orthodontic anchorage control can be either extraoral or intraoral that is headgear or intermaxillary elastics. Their use are combined with various side effects such as tipping of occlusal plane or undesirable movements of teeth. Especially in cases, where key-teeth are missing, conventional anchorage defined as tooth-borne anchorage will meet limitations. Therefore, the use of endosseous implants for anchorage purposes are increasingly used to achieve positional stability and maximum anchorage. METHODS/DESIGN: The intended study is designed as a prospective, multicenter randomized controlled trial (RCT), comparing and contrasting the effect of early loading of palatal implant therapy versus implant loading after 12 weeks post implantation using the new ortho-implant type II anchor system device (Orthosystem Straumann, Basel, Switzerland). 124 participants, mainly adult males or females, whose diagnoses require temporary stationary implant-based anchorage treatment will be randomized 1:1 to one of two treatment groups: group 1 will receive a loading of implant standard therapy after a healing period of 12 week (gold standard), whereas group 2 will receive an early loading of orthodontic implants within 1 week after implant insertion. Participants will be at least followed for 12 months after implant placement. The primary endpoint is to investigate the behavior of early loaded palatal implants in order to find out if shorter healing periods might be justified to accelerate active orthodontic treatment. Secondary outcomes will focus e.g. on achievement of orthodontic treatment goals and quantity of direct implant-bone interface of removed bone specimens. As tertiary objective, a histologic and microtomography evaluation of all retrieved implants will be performed to obtain data on the performance of the SLA surface in human bone evaluation of all retrieved implants. Additionally, resonance frequency analysis (RFA, Osstell mentor) will be used at different times for clinically monitoring the implant stability and for histological comparison in order to measure the reliability of the resonance frequency measuring device. TRIAL REGISTRATION: Current Controlled Trials ISRCTN97142521.

RESUMEN

BACKGROUND AND AIM: Fixed functional orthopedic appliances used in 6 to 9 month-long treatments to correct distoclusion keep the mandible permanently in the therapeutically-desired protruded position. The principal aim of this approach is to achieve an increase in length of the lower jaw by stimulating mandibular growth. Ideally, adaptive mechanisms in adolescents and young adults result in condylar remodeling. Alternatively, however, therapeutically-undesirable alterations in the condyle position within the articular fossa may also occur. Thus the aim of this magnetic resonance imaging (MRI) study was twofold: 1) to verify the effects that the treatment with a fixed functional orthopedic appliance used to correct distoclusion has on the topographic relationship of mandibular condyle and glenoid fossa, and 2) to analyze morphologic changes in the condyle. PATIENTS AND METHODS: Treatment progress in 20 patients was monitored by MRI at four defined points in time. Visual inspection and metric analysis were performed in three planes (axial, frontal, parasagittal) shown on the MRIs. 3D-reconstruction of the condyle surfaces based on the MRI data sets at hand was done in selected cases. RESULTS: Upon assuming the therapeutically-desired position, the condyles were caudally and ventrally displaced from their centric position within the fossa. At the end of treatment, they had returned to their original position. When assessed laterally, statistical analysis revealed no significant differences between the joints on the right and left sides. Neither the anterior nor posterior joint space among all 40 joints exhibited significant changes in width compared to the baseline findings. Visual inspection in the axial, frontal, and sagittal planes revealed changes in the exterior form of 31 of the 40 condyles analyzed. On the whole, while morphologic changes were observed in all three planes, they were most marked in the axial plane. Metric analysis of the 2D-MRIs, on the other hand, revealed no significant changes in width, depth, or height in the plane in question. This is why we reconstructed the condyle structure three-dimensionally on a trial basis. For purposes of analysis, we super imposed the reconstructions of the condyle surfaces at the various control points on each other. By processing the data in this manner, an alternative approach for evaluating morphologic changes was created. CONCLUSIONS AND PROSPECTS: In patients treated with a rigid, fixed functional orthopedic appliance (FMA) for skeletal Class II malocclusion, both joints returned to a physiologic condyle-fossa relationship post-treatment. The improved occlusion was not achieved at the price of unphysiologic repositioning in the temporomandibular joint. Visual inspection suggested that morphologic changes in the condyle may have occurred as treatment progressed, but this was not confirmed by 2D metric analysis. However, by means of 3D-reconstruction of the condylar surfaces and their superposition, detailed visualization of adaptive mechanisms and their non-invasive evaluation in 3D may become feasible in clinical routine.

Asunto(s)

Imagen por Resonancia Magnética/métodos , Maloclusión/patología , Maloclusión/rehabilitación , Avance Mandibular/instrumentación , Cóndilo Mandibular/patología , Aparatos Ortodóncicos Funcionales , Adolescente , Adulto , Niño , Femenino , Humanos , Masculino , Avance Mandibular/métodos , Pronóstico , Resultado del Tratamiento

RESUMEN

The aim of this study was to analyse the acting forces and moments induced by a special orthodontic appliance, the Pendulum K, for molar distalization in the transverse and sagittal planes. The purpose-designed test set-up (artificial maxilla with anchorage unit and two electrothermodynamic molars, an electronic measuring unit, a unit with force-moment sensor, an analogue/digital converter, and a data read-out unit) allowed simulation of in vivo conditions on the one hand and precise determination of the force systems on the other. The appliances investigated were three specimens of the Pendulum K. In vitro measurement of the resulting force systems revealed that the forces and moments in the transverse and sagittal planes remained almost constant over a 3 mm measuring increment when the distal screw was continuously activated (10 activations/mm). Without reactivation of the incorporated distal screw, however, a marked decline in the force systems was recorded. The Pendulum K allows translatory distalization of the upper molars and thus dental arch expansion, dispensing with the need for permanent teeth to be extracted, subject to a corresponding indication. This is achieved by continuous adjustment of an incorporated distal screw and by specific pre-activations of the Pendulum springs.

Asunto(s)

Diseño de Aparato Ortodóncico , Aparatos Ortodóncicos , Técnicas de Movimiento Dental/instrumentación , Fenómenos Biomecánicos , Humanos , Técnicas de Movimiento Dental/métodos

RESUMEN

OBJECTIVE: The objective of this study was to verify the effects of treatment to correct Class II malocclusion with the Functional Mandibular Advancer (FMA) on the relative positions of the articular disc and mandibular condyle. In particular, we aimed to find out whether the disc-condyle relationship changed between baseline and post-treatment, in temporomandibular joints initially exhibiting a physiological relationship and alternatively, in temporomandibular joints initially presenting anterior displacement of the articular disc. PATIENTS AND METHODS: Treatment progress in 15 patients was monitored at defined points in time by manual structural analysis (MSA) and magnetic resonance (MR) imaging. The disc-condyle relationship was assessed by examining the parasagittal MR images made up of three slices each (lateral, central, medial) taken in habitual intercuspation and maximum-open mouth position. The MR images were metrically analyzed to determine the sagittal positional relationship of the articular disc and mandibular condyle using two methods on the central slices of the images taken in closed-mouth position. MSA was used in particular to determine the disc-condyle relationships and to metrically record the extent of active movement of the mandible during mouth opening, protrusion, laterotrusion, and retrusion. RESULTS: Comparison of baseline and post-treatment findings revealed that none of the joints exhibited a treatment-induced deterioration in the disc-condyle relationship, while the relationship improved in five joints. After categorization of the joints according to groups according to disc position, metric analysis of the MR images showed significantly-improved post-treatment disc positions in the joints that had initially exhibited anterior disc displacement. Post-treatment findings for maximum-open mouth position, protrusion, and laterotrusion corresponded to the baseline values recorded before bite-jumping, and the extent of maximum active retrusion increased significantly. CONCLUSIONS: Functional jaw orthopedics for correction of skeletal Class II with the rigid fixed FMA leads to side-effects reflected in the disc-condyle relationship in the temporomandibular joints: no adverse effects were observed in joints presenting an initial physiological disc-condyle relationship, whereas the disc position may improve in joints with initial partial or total anterior disc displacement. In comparison with the baseline findings, we observed no post-treatment restriction in the extent of maximum mouth opening, protrusion, and left and right laterotrusion. Maximum active retrusion increased due to the treatment. MR imaging and MSA only partly cover the same aspects of temporomandibular joint diagnostics.

Asunto(s)

Maloclusión Clase II de Angle/diagnóstico , Maloclusión Clase II de Angle/rehabilitación , Avance Mandibular/instrumentación , Cóndilo Mandibular/patología , Aparatos Ortodóncicos Funcionales , Disco de la Articulación Temporomandibular/patología , Trastornos de la Articulación Temporomandibular/rehabilitación , Adolescente , Niño , Femenino , Humanos , Masculino , Maloclusión Clase II de Angle/complicaciones , Avance Mandibular/métodos , Trastornos de la Articulación Temporomandibular/diagnóstico , Trastornos de la Articulación Temporomandibular/etiología , Resultado del Tratamiento

RESUMEN

La fase de nivelado prequirúrgica puede necesitar el distalamiento progresivo de los primeros y segundos molares. Si el mismo es realizado con aparatología que no requiera la colaboración del paciente y con anclaje dental exclusivamente, los molares deben ser distalados consecutivamente, para minimizar la pérdida de anclaje. El quad pendulum, péndulo modificado especialmente para poder tratar pacientes adultos, permite la distalación molar mediante el uso de cuatro resortes, cada uno de los cuales puede ser activado separadamente. Este péndulo modificaco puede ser anclado en un implante intraóseo

Asunto(s)

Humanos , Masculino , Adulto , Aparatos Ortodóncicos Removibles/normas , Diente Molar , Ortodoncia Correctiva , Cirugía Bucal , Técnicas de Movimiento Dental , Planificación de Atención al Paciente

RESUMEN

La fase de nivelado prequirúrgica puede necesitar el distalamiento progresivo de los primeros y segundos molares. Si el mismo es realizado con aparatología que no requiera la colaboración del paciente y con anclaje dental exclusivamente, los molares deben ser distalados consecutivamente, para minimizar la pérdida de anclaje. El quad pendulum, péndulo modificado especialmente para poder tratar pacientes adultos, permite la distalación molar mediante el uso de cuatro resortes, cada uno de los cuales puede ser activado separadamente. Este péndulo modificaco puede ser anclado en un implante intraóseo(AU)

Asunto(s)

Humanos , Masculino , Adulto , Técnicas de Movimiento Dental/métodos , Ortodoncia Correctiva/métodos , Diente Molar/fisiología , Aparatos Ortodóncicos Removibles/normas , Cirugía Bucal , Planificación de Atención al Paciente

RESUMEN

INTRODUCTION: The pendulum appliance allows for rapid molar distalization without the need for patient compliance. Its efficiency has been confirmed in a number of clinical studies. However, the potential interactions and positional changes between the deciduous molars used for dental anchorage and the erupted and unerupted permanent teeth have yet to be clarified when this appliance is used for molar distalization in the mixed dentition. METHODS: Twenty-nine patients in the mixed dentition each received a modified pendulum appliance with a distal screw and a preactivated pendulum spring for bilateral distalization of the maxillary molars. The patients were divided into 4 groups based on dentition stages: patient group 1 (PG 1, n = 10) was in the early mixed dentition; patients had resorption of the distal root areas of the deciduous molars being used for dental anchorage, and the unerupted premolars were located at the distal margin of the deciduous molar root region. Based on radiographs taken before placement of the pendulum appliance, patient group 2 (PG 2, n = 10) was diagnosed as having a central location of the unerupted premolars. In the third group (PG 3, n = 4), the first premolars were already erupted and could be integrated into the dental anchorage, but the canines were not yet erupted. In the fourth group (PG 4, n = 5), the first premolars and both canines were fully erupted. RESULTS: Statistical analysis of the measured results showed significant differences in the side effects between PG 1 and PG 2. In patients being treated with pendulum appliances, the anchorage quality of the deciduous molars that were already partially resorbed in the distal root area was comparatively reduced. Consequently, the mesial drift of the deciduous molars and incisors was increased, without impairing the extent and quality of the molar distalization. Anchorage loss in the supporting area had no direct impact on the sagittal position of the unerupted premolars in the early mixed dentition. CONCLUSIONS: If permanent teeth have already started to erupt in the supporting area, additional space restrictions should be avoided in patients with critical topography, especially if there is little space for the unerupted canines. At this stage of the mixed dentition, premolar extraction or augmentation of the supporting area with extraoral headgear offers a therapeutic alternative to intraoral distalization appliances with exclusively dental anchorage.

Asunto(s)

Métodos de Anclaje en Ortodoncia/métodos , Aparatos Ortodóncicos , Técnicas de Movimiento Dental/instrumentación , Diente no Erupcionado/fisiopatología , Análisis de Varianza , Diente Premolar/fisiopatología , Cefalometría , Niño , Contraindicaciones , Diente Canino/fisiopatología , Análisis del Estrés Dental , Dentición Mixta , Dentición Permanente , Femenino , Humanos , Masculino , Maloclusión/etiología , Maxilar , Diente Molar , Aparatos Ortodóncicos/efectos adversos , Erupción Dental

RESUMEN

Titanium microscrews for orthodontic anchorage purposes have been developed in different designs and dimensions by a number of manufacturers. Whereas conventional implants need a relatively extensive bone supply and the insertion sites are limited, microscrews offer a more flexible range of applications. They also offer crucial advantages such as simple, atraumatic insertion and removal, a minimum patient stress and a favourable cost-benefit ratio. In the present case report the successful orthodontic uprighting of a tipped second lower molar using a microscrew demonstrated.

Asunto(s)

Diente Molar/fisiopatología , Métodos de Anclaje en Ortodoncia/instrumentación , Aparatos Ortodóncicos , Técnicas de Movimiento Dental/instrumentación , Adolescente , Tornillos Óseos , Implantes Dentales , Humanos , Masculino , Mandíbula , Miniaturización , Diseño de Aparato Ortodóncico

Asunto(s)

Maloclusión Clase II de Angle/terapia , Métodos de Anclaje en Ortodoncia/métodos , Aparatos Ortodóncicos , Técnicas de Movimiento Dental/instrumentación , Niño , Humanos , Masculino