Quantification of temporomandibular joint space in patients with juvenile idiopathic arthritis assessed by cone beam computerized tomography.

OBJECTIVE: To describe a method to calculate the total intra-articular volume (inter-osseous space) of the temporomandibular joint (TMJ) determined by cone-beam computed tomography (CBCT). This could be used as a marker of tissue proliferation and different degrees of soft tissue hyperplasia in juvenile idiopathic arthritis (JIA) patients. MATERIALS AND METHODS: Axial single-slice CBCT images of cross-sections of the TMJs of 11 JIA patients and 11 controls were employed. From the top of the glenoid fossa, in the caudal direction, an average of 26 slices were defined in each joint (N = 44). The interosseous space was manually delimited from each slice by using dedicated software that includes a graphic interface. TMJ volumes were calculated by adding the areas measured in each slice. Two volumes were defined: Ve-i and Vi , where Ve-i is the inter-osseous space, volume defined by the borders of the fossa and Vi is the internal volume defined by the condyle. An intra-articular volume filling index (IF) was defined as Ve-i /Vi , which represents the filling of the space. RESULTS: The measured space of the intra-articular volume, corresponding to the intra-articular soft tissue and synovial fluid, was more than twice as large in the JIA group as in the control group. CONCLUSION: The presented method, based on CBCT, is feasible for assessing inter-osseus joint volume of the TMJ and delimits a threshold of intra-articular changes related to intra-articular soft tissue proliferation, based on differences in volumes. Intra-articular soft tissue is found to be enlarged in JIA patients.

Force Systems Produced by Different Cantilever Configurations during Deactivation.

Intrusion with a three-piece arch is routinely achieved during orthodontic treatment. This study aimed to experimentally determine how the cantilever design influences the generated force system. Both straight and arch-formed cantilever designs: tip-back (TB), flat curve (FC) deep curve (DC), and 3 mm and 6 mm high utility arch (UA3; UA6) were activated for 5 mm and 10 mm. Force systems were determined by a hexapod. Typodonts simulating a three piece-intrusion arch were scanned using an intraoral scanner (3Shape, TRIOS, Denmark) before (T0) and after (T1) the experiment and superimposed with Mimics software (Materialise, Leuven, Belgium). Data were analyzed. All straight designs displayed an extrusive force in the vertical plane, and all arch-formed an intrusive force. DC and TB showed a retrusive force in the sagittal plane and UA6 a protrusive. For the medial/lateral forces, DC and TB displayed a medial, and UA6 a lateral force. Configurations can be distinctively ranked from DC, FC, TB to UA3, and UA6 according to the increasing protrusive nature of the generated sagittal forces. A DC or TB configuration should be used for intrusion and retraction, while for an intrusion and a protrusion, a UA6 configuration. All straight configurations showed a higher force level than the arch-formed configurations.

Cantilevers: Multi-Tool in Orthodontic Treatment.

This review aims to discuss and illustrate various uses of cantilevers to solve multiple clinical issues and prove their versatility. Cantilevers are commonly used in the segmented arch technique, and they can be designed to solve various clinical problems with highly predictable results. Its design and shape can modify the various combinations of vertical and horizontal forces. The novel trend is to combine cantilevers with skeletal anchorage. Cantilevers offer a very simple and statically determined force system. The advantage is the control over side effects, which normally occur on the anchor teeth and the occlusion. The disadvantages include possible side effects on the anchorage unit, when the anchorage is poorly controlled. The review highlights the clear benefits of cantilever use in complex corrections of single teeth, segments, and entire arch with a diminished effect on the dentition, also with the use of skeletal anchorage. With their simple and easily tailored design, these springs can be called an orthodontic multi-tool.

The Effect of Ligature Type on Lateral Tooth Movement during Orthodontic Treatment with Lingual Appliances-An In Vitro Study.

(1) Background: One of the most challenging parts in lingual orthodontics is the control and correction of the tip of anterior teeth, due to the occlusal open vertical slot of the incisors in lingual systems. The presented experimental in-vitro study was performed to determine the maximal tipping moment of the anterior teeth between two types of lingual brackets, the Incognito™ Appliance System (Incognito, TOP-Service, Bad Essen, Germany) and Tip-Bar™ system (Incognito, TOP-Service, Bad Essen, Germany). Furthermore, twelve different ligation methods and two different ligature materials were investigated. (2) Methods: The measurement was performed by assessing the stiffness and ultimate strength of the ligature in a uniaxial material testing machine (Instron, Norwood, MA, USA) using a 0.025 × 0.018 inch stainless steel wire. (3) The results showed that the highest precision for control tipping of anterior teeth was determined for the 0.010 inch Stainless Steel Tie (Pelz and Partner). Furthermore, the Tip-Bar™ brackets increased the maximal moment by 33.8% for elastic and steel ligatures. (4) Conclusions: The lateral tooth movement is highly dependent on the type of ligature and applied material during orthodontic treatment with lingual appliances. The use of 0.010 inch steel ligatures and the Tip-Bar™ bracket design results in better alignment in the anterior teeth segment.

The Effect of Symmetric and Asymmetric Loading of Frontal Segment with Two Curved Cantilevers: An In Vitro Study.

Cantilevers generate statically determined force systems. The frontal segment loading with symmetric and asymmetric cantilevers in a three-piece intrusion base arch can be used to correct midline asymmetry. Three types of 0.017″ × 0.025″ beta-titanium cantilevers: tip-back (TB), deep curve (DC), utility arch (UA) were tested on typodonts simulating intrusion of the maxillary anterior segment. Typodonts with symmetric and asymmetric cantilevers were scanned with intraoral scanner (3Shape, TRIOS, Copenhagen, Denmark) before (T0) and after (T1) the experiment, scans were superimposed using Mimics software (Materialise, Leuven, Belgium). Data were analysed with qualitative analysis. All cantilevers generated vertical and horizontal forces. For symmetric design, the DC and TB displayed intrusive force with retrusive component, UA intrusion and protrusion. The asymmetric cantilevers produced transverse displacement of anterior segment. DC created lateral, UA medial force, the anterior segment displacement was consistent with the used configuration. The movement of an anterior segment with TB is smaller compared to DC and UA. Symmetric cantilevers configurations can achieve simultaneous intrusion and retrusion or protrusion of the anterior segment. The asymmetric design with transversal force can clinically aid the correction of midline discrepancies. The effect of the cantilever configuration on delivered force direction was confirmed.

In Vitro Comparison of Different Invisalign® and 3Shape® Attachment Shapes to Control Premolar Rotation.

Aim: To evaluate in vitro the differences of various Invisalign® attachments in their effectiveness during derotation of an upper second premolar in terms of forces and moments created and compare them to the 3Shape® box attachment as well as to no attachment at all. Materials and Methods: A Force System Identification (FSI) machine, comprising two load sensors, was used in this study. Sensor 1 was connected to the test tooth (i.e. upper second premolar) carrying a different attachment design, and the fixed sensor (Sensor 2) was connected to the base model. Once the corresponding aligner was passively seated on the teeth, 12 different setups (i.e. 11 different attachments and one setup with no attachment at all) were tested by rotating the test tooth 4.5° mesially and 4.5° distally, in increments of 0.45°. Results: The vertical rectangular attachments were able to generate the highest derotational moment on both mesial and distal rotations but also received the most side effects (intrusive force, torque, and tipping). The no-attachment setup performed least favorably in terms of derotational ability but exhibited the least side effects. In the y-axis, all attachments received a buccal root torque with a lingual force during disto-rotation and a lingual root torque with a buccal force during mesio-rotation. Conclusion: Attachments are necessary for derotating an upper second premolar. An aligner incremental change of more than 1° derotation can generate high moments. The vertical rectangular attachments perform best in derotations; however, they exhibit the most side effects. Finally, despite presenting the least side effects, derotation of a premolar with no attachment is not as efficient.

Image quality assessment of three cone beam computed tomography scanners-an analysis of the visibility of anatomical landmarks.

BACKGROUND/OBJECTIVES: The aim of this study was to evaluate large field of view (FoV) subjective image quality of three cone-beam computed tomography (CBCT) machines to assess the threshold for reliable diagnostic perceptibility when lowering exposure settings. MATERIALS AND METHODS: One entire cadaver's head was scanned using three CBCT scanners. The largest available FoV of each device, imaging orthodontic relevant structures, was applied. CBCT datasets with different image quality based on standard to minimum scanning parameters were acquired. Five dentists evaluated the visibility of selected anatomical structures of the upper and lower jaw using a 5-point rating scale. RESULTS: Image quality depends on parameters such as a minimum voxel size of 0.2 to 0.4mm or a minimum of 4mA. A reduction in number of images (scanning protocol) reduces image quality. Visualization of different anatomical structures for orthodontic treatment planning requires distinct scanning protocols to support adequate perception of these structures. LIMITATIONS: This study does not account for the evaluation of paediatric anatomical structures due to the availability of cadaver's head. CONCLUSIONS: CBCT scans performed for orthodontic purposes using a large FoV with reduced parameters (400 µm, 2 to 4 mA and low dose protocols) are acceptable for visualization of large anatomical structures. Further lowering these parameters will not be sufficient to view small anatomical structures. Orthodontic indications will have to define specific anatomical structures to choose adequate scanning protocols to reduce dose and ensure reliable diagnostic visibility.

Validity and Reproducibility of the Peer Assessment Rating Index Scored on Digital Models Using a Software Compared with Traditional Manual Scoring.

The aim of this study was to assess the validity and reproducibility of digital scoring of the Peer Assessment Rating (PAR) index and its components using a software, compared with conventional manual scoring on printed model equivalents. The PAR index was scored on 15 cases at pre- and post-treatment stages by two operators using two methods: first, digitally, on direct digital models using Ortho Analyzer software; and second, manually, on printed model equivalents using a digital caliper. All measurements were repeated at a one-week interval. Paired sample t-tests were used to compare PAR scores and its components between both methods and raters. Intra-class correlation coefficients (ICC) were used to compute intra- and inter-rater reproducibility. The error of the method was calculated. The agreement between both methods was analyzed using Bland-Altman plots. There were no significant differences in the mean PAR scores between both methods and both raters. ICC for intra- and inter-rater reproducibility was excellent (≥0.95). All error-of-the-method values were smaller than the associated minimum standard deviation. Bland-Altman plots confirmed the validity of the measurements. PAR scoring on digital models showed excellent validity and reproducibility compared with manual scoring on printed model equivalents by means of a digital caliper.

Orthodontically induced root resorption: A critical analysis of finite element studies' input and output.

INTRODUCTION: Orthodontically induced inflammatory root resorption (OIIRR) constitutes an undesirable risk connected to orthodontic treatment. Finite element analysis (FEA) is a powerful tool to study the risk of OIIRR. However, its efficiency in predicting OIIRR depends on the insertion of the correct inputs and the selection of an output coherent with the clinical failure mechanism. METHODS: By combining a systematic review with a 3-dimensional FEA, this article discusses which are the implications of using certain periodontal ligament (PDL) properties (linear and nonlinear models) and failure criteria. Six orthodontic loading regimes were simulated in a maxillary premolar: pure intrusion, buccal tipping, and their combination applied with either a light (25 cN) or a heavy (225 cN) force. Three stress parameters in the PDL were compared: von Mises stress, minimum principal stress, and hydrostatic stress (σH). RESULTS: The comparison between linear and nonlinear models showed notable differences in stress distribution patterns and magnitudes. For the nonlinear PDL, none of the light-force models reached the critical compressive hydrostatic stress of 4.7 kPa, whereas all the heavy-force models reached it. In addition, the regions of critical compressive σH matched with the regions with resorption craters in clinical studies. In linear models, the σH critical value of 4.7 kPa was reached even in the light-force scenario. CONCLUSIONS: Only compressive hydrostatic stress in PDL satisfied the requirements to be used as an FEA indicator of OIIRR. However, the requirements were satisfied only when a nonlinear PDL model was considered.

Individualization of the three-piece base arch mechanics according to various periodontal support levels: A finite element analysis.

INTRODUCTION: The orthodontic correction of periodontally compromised dentitions constitutes a huge challenge in the clinical practice of adult orthodontics. The biological and physical distinct features of these conditions require a carefully designed mechanical plan for the successful treatment of these complex cases. SETTING AND SAMPLE POPULATION: A segment of a human maxilla containing the central and lateral incisors, obtained from autopsy, was scanned with microcomputed tomography, and a finite element (FE) model was generated to represent an intact periodontal dentition. Based on this model, three additional models simulating a mild, moderate and severe bone alveolar loss were created as well. MATERIALS AND METHODS: Two loading scenarios for the application of intrusive and retraction mechanics with a three-piece base arch appliance were evaluated in a series of FE analyses. The tooth displacements and strains in the periodontal ligament (PDL) were calculated and compared for the four FE models. RESULTS: The periodontal reduced dentitions exhibited a similar axis of resistance for intrusive mechanics, but the axis of resistance for retraction movements was significantly dependent on the degree of alveolar bone loss. The tooth displacements and PDL loads were higher in the reduced dentitions for both intrusive and retraction mechanics. CONCLUSIONS: A reduction in the force levels applied to periodontal reduced dentitions is indicated, and a customized selection of appropriate points of force application is needed according to the specific amount of alveolar bone loss.

In vitro comparison of the torsional load transfer of various commercially available stainless-steel wires used for fixed retainers in orthodontics.

OBJECTIVE: To assess the torsional load transfer of various commercially available stainless-steel wires used for fixed retainers. DESIGN: An in vitro study using a robotic device. SETTING: Department of Pediatric Oral Health and Orthodontics, University of Basel. METHODS: A 10° proclination of a maxillary lateral incisor of a 2-2 retainer was simulated with a robotic device. Eight stainless-steel wires with different shapes (round or rectangular), types (plain, braided, coaxial or chain) and dimensions were selected to measure the torsional load transfer at the adjacent central incisor. The influence of annealing was also tested. RESULTS: The 0.016 × 0.016 and Bond-A-Braid™ wires (0.02645 × 0.01055-inch, 8-stranded, braided) showed the largest relative torsional load transfer (3.7% and 3.3%, respectively). The two multistranded wires - Triple Flex™ and Respond® - showed the smallest values of 1.0% and 0.7%, respectively. The spiral direction of these two multistranded wires affected the load transfer, the twisting showing larger torsional load transfer than the untwisting one. CONCLUSION: The effective torsional load transfer depends on the dimension, shape and type of a wire. Plain and braided retainers were more predictable in torsional load transfer than multistranded retainers, which may have stored more energy in the area between the composite bonding sites. This may explain the unexpected complications reported in multistranded retainers.

The biomechanical evaluation of magnetic forces to drive osteogenesis in newborn's with cleft lip and palate.

This study examined the potential for dental magnets to act as a driving force for osteogenesis in the palate of newborns with a unilateral cleft lip and palate. In the first part of the study dental magnets were arranged in a set up mimicking a distraction device and the curves of the magnetic attraction force versus gap distance curves generated, with and without the presence of palatal rugae tissue in between both sides of the distraction device. The attraction forces ranged from 1 to 12 N depending on the gap distance and the presence of soft tissue in the gap. In the second part of the study these forces were used as input for a 3D finite element model of the palate of a newborn affected by unilateral cleft lip and palate. In the analysis of load transfer, it was found that the strains generated by a magnetically induced distraction exceed 1,500 µstrain suggesting that bone locally is submitted to mild overload leading to bone apposition.

Influence of different storage temperatures on the mechanical properties of NiTi, Cu-NiTi and SS orthodontic archwires: An in vitro study.

OBJECTIVE: Due to their exceptional temperature sensitivity, the mechanical properties of Nickel-titanium and Copper Nickel-titanium wires may be influenced by their storage temperature. This in turn may have clinical implications and may also affect the outcomes. This study analyzed the influence of storage temperatures on the mechanical properties of orthodontic wires in a laboratory setting. MATERIALS AND METHODS: Stainless steel (SS), Nickel-Titanium (NiTi), and three variants of Copper-NiTi (Cu-NiTi 27°C, 35°C and 40°C), 0.017×0.025 inches in size were analysed using a three-point bending test in a pre-heated chamber at 36°C. The orthodontic wires were stored for twenty-four hours before the mechanical testing at four different temperatures (5°, 22°, 36° and 60°C). RESULTS: The obtained results showed that the mechanical forces exerted by 27°C Copper-NiTi exhibit the most stable behaviour after having been stored at different temperatures, whereas 35°C Copper-NiTi showed the highest variability. As to be expected, Stainless steel shows no changes in its bending mechanical properties. CONCLUSION: Furthermore, the results of this investigation reflect the importance of controlling the storage temperature of orthodontic NiTi and Copper-NiTi wires tested in a research environment in order to avoid unexpected bias.

Three-Dimensional Morphological Changes of the True Cleft under Passive Presurgical Orthopaedics in Unilateral Cleft Lip and Palate: A Retrospective Cohort Study.

The aim of this cohort study was to quantify the morphological changes in the palatal cleft and true cleft areas with passive plate therapy using a new analysis method based on three-dimensional standardized reproducible landmarks. Forty-five casts of 15 consecutive patients with complete unilateral cleft lip and palate were laser scanned and investigated retrospectively. The landmarks and the coordinate system were defined, and the interrater and intrarater measurement errors were within 1.0 mm. The morphological changes of the cleft palate area after a period of 8 months of passive plate therapy without prior lip surgery are presented graphically. The median decrease in cleft width was 38.0% for the palatal cleft, whereas it was 44.5% for the true cleft. The width of the true and palatal cleft decreased significantly over a period of 8 months. The true cleft area decreased by 34.7% from a median of 185.4 mm2 (interquartile range, IQR = 151.5-220.1) to 121.1 mm2 (IQR = 100.2-144.6). The palatal cleft area decreased by 31.5% from a median of 334 mm2 (IQR = 294.9-349.8) to 228.8 mm2. The most important clinical considerations are the reproducibility and reliability of the anatomical points, as well as the associated morphological changes. We propose using the vomer edge to establish a validated measuring method for the width, area, and height of the true cleft.

Condylar changes in patients with idiopathic condylar resorption: retrospective 2-year follow-up CBCT-based case-control study.

OBJECTIVES: To compare condylar development and changes in condylar radiological appearance in patients with idiopathic condylar resorption (ICR) to a healthy, age- and gender matched, control group. MATERIALS AND METHODS: This case-control study included 16 ICR patients [mean age: 15years, 9 months; standard deviation (SD): 4 years) and 16 controls (mean age: 16 years, 8 months; SD: 4 years, 7 months), with diagnostic (T0) and 2-year follow-up (T1) CBCT examinations. Condylar changes were evaluated through changes in condylar neck angle (CNA), and the transversal, vertical and anteroposterior displacement of five condylar points between T0 and T1. The magnitude and direction of condylar changes were evaluated using vector analyses. A qualitative radiological evaluation of the TMJ was performed based on healthy, erosive and repaired morphological appearance. Linear and angular measurements were assessed using ANOVA and a Tukey post-hoc test, and vectors were tested using an independent-sample 2-tailed t-test. Fisher's exact test was used for the qualitative evaluation. RESULTS: At T0, ICR patients exhibited decreased condylar height, smaller condylar width and posteriorly inclined CNA compared with the control group (P < 0.05). During observation, condylar vertical growth was smaller in the ICR group than in the control group (P < 0.05). Vector analysis showed an upward direction of vertical displacement for all condylar points in the control group; the ICR group showed a downward direction (P < 0.003). The radiological appearance of 75% of the ICR condyles and 94% of the control condyles did not change during the 2-year follow-up period. CONCLUSIONS: ICR condyles displayed reduced vertical development compared with control condyles. The radiological appearance remained unchanged for most joints. Observed changes in radiological appearance did not always follow a progressive model of degenerative joint disease.

Evaluation of a Fluorescence-aided Identification Technique (FIT) to assist clean-up after orthodontic bracket debonding.

OBJECTIVES: To compare a fluorescence-aided identification technique (FIT) with a conventional light source (CLS) for removing composite during debonding of brackets with respect to time needed, composite remnants, and tooth substance loss. MATERIALS AND METHODS: Twelve maxillary models with 10 bovine teeth each were digitally surface-scanned and metal brackets were bonded on each tooth with Opal Seal and Opal Bond. Two operators: an experienced orthodontist (A) and an undergraduate student (B) received six models each and were asked to remove the composite remnants with a tungsten carbide bur and Sof-Lex discs by both a conventional light source (CLS group, n = 3), and fluorescent inducing light (FIT group, n = 3). The time taken was recorded, and a postoperative scan was digitally superimposed on the preoperative scan to quantify number of teeth with composite remnants and volume and thickness of enamel loss and composite remnants. Chi-square test and independent t-tests were performed to compare methods with a significance level of 5%. RESULTS: Compared to CLS, both operators needed significantly less time when using the FIT method and degree of enamel loss, height, and volume of composite remnants and total remaining composite remnants were significantly reduced. By FIT, the volume of enamel loss was significantly reduced for operator A only. Operator B removed the same enamel volume with either method. CONCLUSIONS: Cleanup after orthodontic debonding with the FIT was superior regarding time needed and removal of composite remnants. Total enamel loss reduction was operator-dependent.

Palatal morphology in unilateral cleft lip and palate patients: Association with infant cleft dimensions and timing of hard palate repair.

OBJECTIVES: To assess the impact of cleft severity and timing of hard palate repair on palatal dimensions in unilateral cleft lip and palate (UCLP) children. SETTING AND SAMPLE POPULATION: Single-centre analysis within a multicenter RCT of primary surgery; 122 UCLP randomized to early hard palate closure (EHPC) at 12 months or delayed hard palate closure (DHPC) at 36 months; 28 frequency-matched controls. METHODS: Linear measurements of palatal height, width and length were performed on 116 digital models of UCLP subjects (8.21 years, SD = 0.53) and 28 models of non-cleft individuals (8.44 years SD = 0.72). Cleft dimensions at infancy (mean 1.8 months) were considered. In a pilot study, shell-to-shell distances between the 3D cleft palate objects and a reference mesh were calculated and differences between the groups assessed. Morphological differences were visualized using colour mapping. RESULTS: Compared to controls, UCLP subjects presented a higher palate at the level of the anterior scar (P = 0.002), but generally a lower palate in the middle region (P < 0.001). Comparing UCLP subgroups, the DHPC subjects showed a flatter palate posteriorly (P = 0.048) and the EHPC group exhibited more transversal constriction (P = 0.003 at M1 level). 3D analysis revealed a shallower palate in the DHPC group both in the middle (P = 0.002) and the posterior part (P = 0.008). Anterior cleft severity correlated negatively with palatal height (P = 0.01). CONCLUSIONS: Unilateral cleft lip and palate palates differ from controls in width and height. DHPC may represent an advantage for the transversal dimension, but a disadvantage for palatal height. Infant cleft dimensions partially explain differences in palatal height.

Reposicionamento mandibular em pacientes adultos ­ uma alternativa à cirurgia? Um acompanhamento de dois anos / Is mandibular repositioning in adult patients an alternative to surgery? Two-year follow-up

Muitos pacientes adultos com discrepâncias esqueléticas não aceitam a proposta de intervenção cirúrgica para corrigi-las. O objetivo desse trabalho é verificar a resposta ao reposicionamento mandibular, simulando a correção esquelética nesses pacientes. Trinta e dois pacientes sem sinais de disfunção temporomandibular (DTM) foram indicados para o reposicionamento mandibular, sendo essa uma técnica não invasiva. Foi explicado para eles que essa abordagem estava baseada em resultados descritos em relatos de casos clínicos. Antes do início de qualquer tratamento, foi feita a documentação inicial (teleradiografia , radiografia PA, modelos de estudo e fotografias) (T0). Após, a mandíbula foi reposicionada para camuflar a discrepância esquelética através de um levante de mordida feito em Triad® Gel. Três meses mais tarde (T1), 23 pacientes mostraram-se adaptados a nova oclusão, com ausência de problemas funcionais e sem nenhuma quebra no levante de mordida. As mudanças esqueléticas que ocorreram durante o reposicionamento foram verificadas em radiografias sagitais e frontais, enquanto as alterações intra-articulares que ocorreram durante os dois anos de acompanhamento (T2) foram avaliadas em imagens tomográficas. Nenhuma alteração significativa foi observada nesses acompanhamentos de dois anos, tanto para a recidiva quanto para a sobrecorreção. O reposicionamento é uma abordagem não invasiva e deve ser considerada como uma alternativa válida à cirurgia em alguns pacientes. Variações morfológicas observadas nas radiografias feitas em T0 e nos resultados dos exames clínicos iniciais das avaliações de disfunção mostraram apenas indicativos vagos ou insignificantes sobre a previsibilidade da adaptação ao reposicionamento.(AU)

Many adult patients with skeletal discrepancies refuse surgical intervention for their correction. The aim of this research was to assess the reaction to mandibular repositioning in simulating a skeletal correction in such patients. Thirty-two patients without any signs of temporomandibular dysfunction (TMD) were offered mandibular repositioning, as a non-invasive alternative. It was explained to them that the approach was based on the results described in case reports. Before starting any treatment initial records, headfilms, study casts, and photos were taken (T0). The mandible was then repositioned to camouflage the skeletal discrepancy by means of an occlusal built-up in Triad® Gel. Three months later (T1), 23 patients had adapted to the new occlusion what was reflected in functional problems absence and lack of built-up fracture. In these patients, the mandibular position was maintained by orthodontic adjusting of occlusion to the built-up position (T1). Skeletal changes that occurred during repositioning were assessed on sagittal and frontal headfilms while intra-articular changes occurring during a 2-year follow-up period (T2) were evaluated on images constructed from CBCT images. No significant changes were observed during the follow-up period, neither in the direction of relapse nor in the direction of further normalization of the condylar positioning were observed during the 2-year observation. Repositioning is a non-invasive intervention and may be considered a valid alternative to surgery in some patients. Morphological variables from the radiographs taken at T0 and the results of the initial clinical evaluation of dysfunction yielded only vague and insignificant indications regarding the predictability of adaptation to the repositioning. (AU)

[Mandibular repositioning in adult patients. An alternative to surgery in some patients? A two-year follow-up]. / Le repositionnement mandibulaire : une alternative à la chirurgie chez des patients adultes ? Un suivi sur deux ans.

INTRODUCTION: A number of adult patients with skeletal discrepancies refuse surgical intervention. AIMS: The aim was to assess the reaction to mandibular repositioning in simulating a skeletal correction in such patients. MATERIALS AND METHODS: 32 consecutive patients without any signs of temporo-mandibular dysfunction (TMD) were offered mandibular repositioning, as a non-invasive alternative and it was explained to them that the approach was based on the results described in case reports. Before initiating any treatment initial records, headfilms, study casts and photos were taken (T0) and the mandible was repositioned to camouflage the skeletal discrepancy by means of an occlusal built-up in Triad® Gel. RESULTS: Three months later (T1) 23 patients had adapted to the new occlusion reflected in absence of functional problems and lack of fracture of the built-up. In these patients the mandibular position was maintained by orthodontics adjusting the occlusion to the built-up position (T1). The skeletal changes occurring during repositioning were assessed on sagittal and frontal head films while intra-articular changes occurring during a 2-year follow-up period (T2) were evaluated on images constructed from CBCT images. No significant changes, neither in the direction of a relapse nor in the direction of further normalization of the condylar positioning, were observed during the 2-year observation period. CONCLUSIONS: Repositioning is a non-invasive intervention and may be considered a valid alternative to surgery in some patients. Morphological variables from the radiographs taken at T0 and the results of the initial clinical evaluation of dysfunction yielded only vague and insignificant indications regarding the predictability of adaptation to the repositioning.

Evaluation of facial asymmetry in patients with juvenile idiopathic arthritis: Correlation between hard tissue and soft tissue landmarks.

INTRODUCTION: The aims of this study were to assess the correlation between facial hard and soft tissue asymmetry in patients with juvenile idiopathic arthritis, to identify valid soft tissue points for clinical examination, and to assess the smallest clinically detectable level of dentofacial asymmetry. METHODS: Full-face cone-beam computed tomography scans and 3-dimensional photographs were used to assess facial hard and soft tissue asymmetry in 21 patients with juvenile idiopathic arthritis. A survey was conducted to assess how asymmetry is perceived observationally based on cone-beam computed tomography scans and 3-dimensional photographs. RESULTS: Significant linear correlations were seen between the hard and soft tissue landmark deviations at both the transverse and vertical positions. Among medial soft tissue points, glabella had the smallest deviation and pogonion the largest deviation from the midsagittal plane. Professionals could identify facial asymmetry based on images beyond a cutoff threshold of 2 mm for both pogonion and gonion. CONCLUSIONS: Soft tissue pogonion and gonion were identified as the most appropriate landmarks to clinically predict hard tissue facial asymmetry. Facial asymmetries are most pronounced in the lower facial third in patients with juvenile idiopathic arthritis. Professionals can accurately identify asymmetry exceeding 2 mm.