Strategic Intervention: Ectopic Premolar Management for Preventing Molar-Premolar Transposition in Class III Malocclusion.

Class III malocclusion often leads to the ectopic eruption of premolars in the upper arch, posing unique challenges for orthodontic practitioners. This case report explores the clinical implications of ectopic maxillary premolars in a Class III malocclusion patient, emphasizing the importance of early intervention and comprehensive treatment strategies. Factors contributing to ectopic eruption, including genetic predisposition and anatomical variations, are discussed, guiding orthodontists in effective diagnosis and management. A 14-year-old patient with Class III malocclusion, anterior crossbite, and ectopic maxillary premolars sought orthodontic consultation. The treatment plan involved extracting the deciduous second molar, realigning the ectopic premolar, and addressing arch length discrepancies. Utilizing fixed orthodontic appliances and strategic force application, the patient achieved Class I molar and canine relationships, resolving the ectopic premolar alignment within 10 months. Ectopic eruption of maxillary premolars, especially in Class III malocclusion, is a critical concern for oral health. Genetic predisposition, arch crowding, and developmental disturbances contribute to this condition. Early intervention, as demonstrated in this case, plays a pivotal role in restoring dentoskeletal harmony. The study underscores the need for a multidisciplinary approach, combining orthodontic, surgical, and restorative interventions for optimal outcomes. Thus, this case report highlights the successful management of ectopic maxillary premolars in a Class III malocclusion patient through strategic orthodontic intervention. Understanding the etiological factors and employing a comprehensive treatment approach facilitate timely diagnosis and prevent complications. Orthodontists must navigate the complexities of ectopic eruption, considering occlusal effects and collaborating with other specialists for holistic patient care.

Effects of eruption guidance appliance in the early treatment of Class III malocclusion.

OBJECTIVES: To evaluate the dentoskeletal effects and effectiveness of the eruption guidance appliance in Class III patients in the mixed dentition. MATERIALS AND METHODS: The experimental group comprised 22 patients with Class III malocclusion and anterior cross-bite (12 males, 10 females, mean age 7.63 ± 0.96 years) treated with the eruption guidance appliance over a mean period of 1.72 ± 0.48 years. The control group comprised 22 untreated subjects (12 males, 10 females, mean age 7.21 ± 0.60 years) with Class III malocclusion. Lateral cephalometric radiographs were obtained at pretreatment (T1) and posttreatment (T2). Intergroup comparisons were performed with Mann-Whitney and t-tests (P < .05). RESULTS: In the experimental and control groups, the anteroposterior relationship between the maxilla and mandible (ANB angle) remained stable during the treatment period (T1 to T2). The mandibular plane angle decreased in the experimental group and increased in the control group. In the experimental group, the lower anterior face height increase and maxillary molar vertical development were significantly smaller compared to controls. Positive overjet was achieved in 54% of the experimental group. CONCLUSIONS: The eruption guidance appliance produced no change in the skeletal anteroposterior relationship. The anterior cross-bite/edge-to-edge relationship was corrected in only about half of the treated subjects.

Activated omega loops for anterior crossbite correction in transitional dentition.

Key Clinical Message: Several approaches can correct pseudo-Class III anterior crossbite. 2 × 4 appliance, compressed open-coil springs, Class III elastics, etc. All cause either soft tissue lacerations, smile line flattening, or upper incisor overproclination. This paper describes a novel method to tip lower incisors into a normal overjet without compromising the upper dentition. Abstract: In pseudo-class III cases, a "two by four" multibracketed appliance has been utilized to put the incisors into a typical overjet during transitional dentition. Compressing a rectangular super elastic archwire creates continuous force, but its length restricts activation and risks cheek impingement. Open-coil springs on rigid archwires advance incisors labially, although a 4-5 mm of wire distal to the molar tube may injure soft tissue. Reciprocally anchored Class III intermaxillary elastics restore anterior overjet through lower incisor lingual tipping and upper incisor proclination. Class III elastics extrude maxillary molars and mandibular incisors, rotating the dental occlusal plane counterclockwise and reducing maxillary incisor exposure and aesthetics. A unique method is reported in this report to tip the lower incisors back into normal overjet without affecting the upper dentition.

Chemokine Regulation in Temporomandibular Joint Disease: A Comprehensive Review.

Temporomandibular joint disorders (TMDs) are conditions that affect the muscles of mastication and joints that connect the mandible to the base of the skull. Although TMJ disorders are associated with symptoms, the causes are not well proven. Chemokines play an important role in the pathogenesis of TMJ disease by promoting chemotaxis inflammatory cells to destroy the joint synovium, cartilage, subchondral bone, and other structures. Therefore, enhancing our understanding of chemokines is critical for developing appropriate treatment of TMJ. In this review, we discuss chemokines including MCP-1, MIP-1α, MIP-3a, RANTES, IL-8, SDF-1, and fractalkine that are known to be involved in TMJ diseases. In addition, we present novel findings that CCL2 is involved in ß-catenin-mediated TMJ osteoarthritis (OA) and potential molecular targets for the development of effective therapies. The effects of common inflammatory factors, IL-1ß and TNF-α, on chemotaxis are also described. In conclusion, this review aims to provide a theoretical basis for future chemokine-targeted therapies for TMJ OA.

Deep learning-based prediction of mandibular growth trend in children with anterior crossbite using cephalometric radiographs.

BACKGROUND: It is difficult for orthodontists to accurately predict the growth trend of the mandible in children with anterior crossbite. This study aims to develop a deep learning model to automatically predict the mandibular growth result into normal or overdeveloped using cephalometric radiographs. METHODS: A deep convolutional neural network (CNN) model was constructed based on the algorithm ResNet50 and trained on the basis of 256 cephalometric radiographs. The prediction behavior of the model was tested on 40 cephalograms and visualized by equipped with Grad-CAM. The prediction performance of the CNN model was compared with that of three junior orthodontists. RESULTS: The deep-learning model showed a good prediction accuracy about 85%, much higher when compared with the 54.2% of the junior orthodontists. The sensitivity and specificity of the model was 0.95 and 0.75 respectively, higher than that of the junior orthodontists (0.62 and 0.47 respectively). The area under the curve value of the deep-learning model was 0.9775. Visual inspection showed that the model mainly focused on the characteristics of special regions including chin, lower edge of the mandible, incisor teeth, airway and condyle to conduct the prediction. CONCLUSIONS: The deep-learning CNN model could predict the growth trend of the mandible in anterior crossbite children with relatively high accuracy using cephalometric images. The deep learning model made the prediction decision mainly by identifying the characteristics of the regions of chin, lower edge of the mandible, incisor teeth area, airway and condyle in cephalometric images.

Clear aligner treatment for a four-year-old patient with anterior cross-bite and facial asymmetry: A case report.

BACKGROUND: Clear aligners have been widely used to treat malocclusions from crowding, extraction cases to orthodontic-orthognathic cases, and practitioners are exploring the border of it. For the first time, clear aligners were used to early intervene anterior cross-bite and facial asymmetry. CASE SUMMARY: This case report described a four-year-old child presented with anterior cross-bite and facial asymmetry associated with functional mandibular shift, who had undergone a failed treatment with conventional appliances. The total treatment time was 18 weeks, and a stable outcome was obtained. CONCLUSION: The increasing need in early treatment highlights the need for clinicians to thoroughly investigate for the patient regarding clinical manifestation as well as patient compliance. We hope that our case will be contemplated by clinicians when seeking for treatment alternatives.

miR-132-3p participates in the pathological mechanism of temporomandibular joint osteoarthritis by targeting PTEN.

OBJECTIVE: This study aimed to investigate the role of miR-132-3p in the progression of temporomandibular joint osteoarthritis (TMJOA) and its potential pathological mechanism. DESIGN: A TMJOA model was established using six rats via the unilateral anterior crossbite method. The differential expression of miR-132-3p in the TMJOA (n = 6) and control groups (n = 6) was detected via miRNA sequencing and verified via PCR. The chondrocytes in the condylar cartilage of the temporomandibular joint were cultured and stimulated with IL-1ß to simulate TMJOA in vitro. The changes in the proliferation, apoptosis, inflammation and extracellular matrix of these chondrocytes were detected after the upregulation of miR-132-3p expression. The targeted relationship of miR-132-3p and PTEN in TMJOA was verified, and rescue experiments were conducted via co-upregulation of the expression of both miR-132-3p and PTEN. RESULTS: Compared with that in the control group, miR-132-3p expression was lower in the cartilage tissues of TMJOA rats and IL-1ß-induced TMJ chondrocytes. After upregulating the expression of miR-132-3p, the cell proliferation activity and expression levels of aggrecan and type II collagen of IL-1ß-induced TMJ chondrocytes were increased, and the apoptosis rate and levels of inflammatory factors were decreased. miR-132-3p can regulate PTEN expression in a targeted manner, and upregulating PTEN expression could reverse the influences of the upregulation of miR-132-3p expression on TMJOA cells. CONCLUSION: miR-132-3p is less expressed in TMJOA, and it regulates the proliferation, extracellular matrix, and inflammatory response of TMJOA chondrocytes and participates in TMJOA progression by targeting PTEN.

Age-related variations in position and morphology of the temporomandibular joint in individuals with anterior openbite and crossbite: a multi-cross-sectional comparative study.

BACKGROUND: This study aimed to compare the age-related positional and morphological characteristics of the temporomandibular joint (TMJ) between individuals with anterior openbite or crossbite and controls. METHODS: This multi-cross-sectional comparative study analysed cone-beam computed tomography images of 750 participants, equally divided into the openbite, crossbite, and control groups (OBG, CBG, and CG, respectively). Each group was further divided into five subgroups (8-11 years, 12-15 years, 16-19 years, 20-24 years, and 25-30 years). Measurements of the TMJ included the position of the condyles in their respective fossae and morphology of the condyles and fossae. Data were submitted to statistical analysis. The study adhered to the STROBE Statement checklist for reporting of cross-sectional studies. RESULTS: Condyles were positioned more posteriorly with increasing age in all groups, and the condylar position was more posterior in the OBG than in the CBG. The articular eminence inclination increased with age in all the groups. There were significant differences in the articular eminence inclination among the three major groups at the age of > 15 years, and the condylar path was flatter in the CBG than in the OBG. CONCLUSIONS: Age-related morphological and positional characteristics of the TMJ differed considerably among OBG, CBG and CG. Contrary to CBG, OBG was found to have relatively posterior condylar position and steeper condylar path.

MicroRNA-26b regulates BMSC osteogenic differentiation of TMJ subchondral bone through ß-catenin in osteoarthritis.

Temporomandibular joint osteoarthritis (TMJ-OA) is a degenerative disease of the joint. The early manifestations of TMJ-OA are abnormal remodeling of condylar subchondral bone. In bone tissue, bone marrow mesenchymal stem cells (BMSCs) and osteoblasts play important roles in the differentiation and maturation of most hematopoietic cells. MicroRNA-26b (miR-26b) is upregulated during the osteogenesis of BMSCs, and miR-26b overexpression leads to the activation of ß-catenin and the enhancement of osteogenesis and cartilage formation. However, the pathologic mechanism remains unclear. In the present study, we used a rat model with OA-like changes in the TMJ induced by experimental unilateral anterior crossbite (UAC) and found that the level of miR-26b was markedly lower in BMSCs from the subchondral bones of UAC rats than in those from sham control rats. MiR-26b overexpression by agomiR-26b increased condylar subchondral bone osteogenesis in UAC rats. Notably, although agomiR-26b primarily affected miR-26b levels in the subchondral bone (but not in cartilage or the synovium), the overexpression of miR-26b in BMSCs in UAC rats largely rescued OA-like cartilage degradation, while the inhibition of miR-26b in BMSCs exacerbated cartilage degradation in UAC rats. We measured the expression levels of ß-catenin and related osteogenic and osteoclastic factors after using miR-26b mimics and inhibitors in vivo. Moreover, BMSCs were treated with the ß-catenin blocker Wnt-C59 and then transfected with miR-26b mimics or inhibitors. Then, we examined the expression of ß-catenin as the direct target of miR-26b. The results of the present study indicate that miR-26b may modulate subchondral bone loss induced by abnormal occlusion and influence the osteogenic differentiation of subchondral BMSCs through ß-catenin in the context of TMJ-OA progression.

Activation of the VpdmVGLUT1-VPM pathway contributes to anxiety-like behaviors induced by malocclusion.

Occlusal disharmony has a negative impact on emotion. The mesencephalic trigeminal nucleus (Vme) neurons are the primary afferent nuclei that convey proprioceptive information from proprioceptors and low-threshold mechanoreceptors in the periodontal ligament and jaw muscles in the cranio-oro-facial regions. The dorsomedial part of the principal sensory trigeminal nucleus (Vpdm) and the ventral posteromedial nucleus (VPM) of thalamus have been proven to be crucial relay stations in ascending pathway of proprioception. The VPM sends numerous projections to primary somatosensory areas (SI), which modulate emotion processing. The present study aimed to demonstrate the ascending trigeminal-thalamic-cortex pathway which would mediate malocclusion-induced negative emotion. Unilateral anterior crossbite (UAC) model created by disturbing the dental occlusion was applied. Tract-tracing techniques were used to identify the existence of Vme-Vpdm-VPM pathway and Vpdm-VPM-SI pathway. Chemogenetic and optogenetic methods were taken to modulate the activation of VpdmVGLUT1 neurons and the Vpdm-VPM pathway. Morphological evidence indicated the involvement of the Vme-Vpdm-VPM pathway, Vpdm-VPM-SI pathway and VpdmVGLUT1-VPM pathway in orofacial proprioception in wild-type mice and vesicular glutamate transporter 1 (VGLUT1): tdTomato mice, respectively. Furthermore, chemogenetic inhibition of VpdmVGLUT1 neurons and the Vpdm-VPM pathway alleviated anxiety-like behaviors in a unilateral anterior crossbite (UAC) model, whereas chemogenetic activation induced anxiety-like behaviors in controls and did not aggravate these behaviors in UAC mice. Finally, optogenetic inhibition of the VpdmVGLUT1-VPM pathway in VGLUT1-IRES-Cre mice reversed UAC-induced anxiety comorbidity. In conclusion, these results suggest that the VpdmVGLUT1-VPM neural pathway participates in the modulation of malocclusion-induced anxiety comorbidity. These findings provide new insights into the links between occlusion and emotion and deepen our understanding of the impact of occlusal disharmony on brain dysfunction.

Comparison and applicability of three induction methods of temporomandibular joint osteoarthritis in murine models.

BACKGROUND: Temporomandibular joint osteoarthritis (TMJ-OA) causes severe symptoms such as chewing difficulties, acute pain and even maxillofacial deformity. However, there is hardly any effective disease-curing strategy because of uncertainty in aetiology. Animal model is an excellent tool to investigate the mechanism, prevention and treatment on diseases. Currently, although several TMJ-OA animal models have been established, there are almost no comparative studies on different models, which poses a great challenge for selecting suitable models. OBJECTIVE: To compare three TMJ-OA induction methods and assess their applicability considering pathological changes in the cartilage, subchondral bone, osteoclasts, and synovium. METHODS: Murine models were employed and followed for 3 and 6 weeks after experimental procedures (surgery, injection, crossbite). The TMJ changes were evaluated by Safranin-O/Fast green staining, immunofluorescence staining, micro-CT, TRAP staining, and HE staining. RESULTS: In the Surgery group, a pronounced drop in bone volume fraction was observed. In the Injection group, chondrocytes were mostly disordered or arranged in clusters and a substantial increase in the OARSI score and osteoclasts was found. The OARSI score and osteoclasts also increased significantly in the Crossbite group, although to a lower extent compared with injection. CONCLUSION: Osteoarthritis-like changes were observed in all models. Concerning the applicability of the different induction methods, surgery might be an important resource for the assessment of post-traumatic TMJ-OA and subchondral bone changes in early stages. Injection induces a severe end-stage osteoarthritis in a short time and provides model basis for advanced TMJ-OA. Crossbite might be more reasonable model to explore the pathogenesis mechanism of temporomandibular arthritis due to occlusal disorders.

Early Management of Class III Malocclusion in Mixed Dentition.

AIM: Skeletal class III malocclusion are the most challenging orthodontic problem to treat. Diagnosis and treatment in early stage was important to boost self-esteem of patient. Our aim was to correct skeletal relationship and anterior crossbite to enhance the growth of maxilla. BACKGROUND: Class III malocclusion can be due to retrognathic maxilla, prognathic mandible or combination. Complexity of class III malocclusion depends upon abnormal growth pattern of maxilla and mandible. Maxilla growth ceases around 8-10 years and mandible continue till 16 years. Early intervention boosts self-esteem of the patient. CASE DESCRIPTION: This case presents with clinical feature of retrognathic maxilla at the age of six years. The patient had concave profile with incompetent lips. The mentolabial sulcus was normal and obtuse nasolabial angle with high clinical Frankfurt mandibular angle (FMA). There was reverse overjet of 1 mm. Cephalometric analysis showed a class III skeletal pattern with retrognathic maxilla and orthognathic mandible with increase in lower facial height and increases in gonial angle. The rapid maxillary expansion (RME) with reverse pull face mask was planned. The expansion screw was activated to loosen the circumaxillary suture. CONCLUSION: After active treatment anterior crossbite was corrected. The patient sagittal discrepancy was improved. Early mixed dentition period is the best time to begin class III treatment. CLINICAL SIGNIFICANCE: Early treatment with maxillary protraction and palatal expansion can correct most anterior-posterior skeletal discrepancy. HOW TO CITE THIS ARTICLE: Jha AK, Chandra S. Early Management of Class III Malocclusion in Mixed Dentition. Int J Clin Pediatr Dent 2021;14(2):331-334.

Excitatory Impact of Dental Occlusion on Dorsal Motor Nucleus of Vagus.

Neurons in the trigeminal mesencephalic nucleus (Vme) have axons that branch peripherally to innervate the orofacial region and project centrally to several motor nuclei in brainstem. The dorsal motor nucleus of vagus nerve (DMV) resides in the brainstem and takes a role in visceral motor function such as pancreatic exocrine secretion. The present study aimed to demonstrate the presence of Vme-DMV circuit, activation of which would elicit a trigeminal neuroendocrine response. A masticatory dysfunctional animal model termed unilateral anterior crossbite (UAC) model created by disturbing the dental occlusion was used. Cholera toxin B subunit (CTb) was injected into the inferior alveolar nerve of rats to help identify the central axon terminals of Vme neurons around the choline acetyltransferase (ChAT) positive motor neurons in the DMV. The level of vesicular glutamate transporter 1 (VGLUT1) expressed in DMV, the level of acetylcholinesterase (AChE) expressed in pancreas, the level of glucagon and insulin expression in islets and serum, and the blood glucose level were detected and compared between UAC and the age matched sham-operation control mice. Data indicated that compared with the controls, there were more CTb/VGLUT1 double labeled axon endings around the ChAT positive neurons in the DMV of UAC groups. Mice in UAC group expressed a higher VGLUT1 protein level in DMV, AChE protein level in pancreas, glucagon and insulin level in islet and serum, and higher postprandial blood glucose level, but lower fasting blood glucose level. All these were reversed at 15-weeks when UAC cessation was performed from 11-weeks (all, P < 0.05). Our findings demonstrated Vme-DMV circuit via which the aberrant occlusion elicited a trigeminal neuroendocrine response such as alteration in the postprandial blood glucose level. Dental occlusion is proposed as a potential therapeutic target for reversing the increased postprandial glucose level.

The application of a new clear removable appliance with an occlusal splint in early anterior crossbite.

BACKGROUND: The effectiveness of anterior crossbite treatment in preschool-aged children depends on the treatment design and patient compliance. Common early treatment appliances with steel wires and acrylic resin can bring about numerous problems, such as toothache, sore gums and mucous membrane injury. The aim of this study was to propose a new clear removable appliance to provide preschool-age children with an improved experience of early occlusal interference treatment. METHODS: Appliances were designed with the help of 3-dimensional (3D) digital reconstruction oral models and fabricated using 3D printing technology and the pressed film method. Then, the mechanical properties of the original dental coping sheet and thermoformed aligners were assessed in a simulated intraoral environment. Preschool-age participants who displayed anterior crossbite were recruited in this study. Records (photographs and impressions) were taken before the treatment (T1), during the treatment (T2) and at the end of the treatment (T3). The effects of treatment were evaluated by clinical examination and questionnaires. RESULTS: Normal degrees of overbite and overjet in the primary dentition were achieved using this new appliance. Dental and soft tissue relationships were improved. Questionnaires showed that the safety evaluation, degree of comfort and convenience grades of the appliance were all relatively high. CONCLUSION: This explorative study demonstrates that our new clear removable appliance is able to correct early-stage anterior crossbite in a safe, comfortable, convenient and efficient way. Thus, it is a promising method to correct a certain type of malocclusion, and its clinical use should be promoted in the future.

Simplified Fixed Technique for Correction of Anterior Crossbite: A Case Series

ABSTRACT@#Anterior crossbites would normally require early intervention, especially when associated with mandibular displacements. The intervention would usually commence in children around the age of eight and nine, where treatment could be a challenge at this age. Therefore, a simple and quick treatment to this malocclusion would be desirable. This case series illustrates two cases of anterior crossbite with a functional shift that were successfully corrected using a simplified fixed technique, which involved a short-span nickel-titanium (Ni-Ti) aligning round archwire, composite resin and glass ionomer cement (GIC).

Comparison Between Removable and Fixed Devices for Nonskeletal Anterior Crossbite Correction in Children and Adolescents: A Systematic Review.

OBJECTIVE: To compare removable and fixed orthodontic devices in the correction of non-skeletal anterior crossbite in children and adolescents in the mixed dentition. MATERIALS AND METHODS: Electronic searches were conducted in the following databases: PubMed, Web of Science, Scopus, Medline Ovid, Lilacs, US Clinical Trials, and Proquest. A hand search of the reference lists of the included articles and a Google Scholar search were also conducted. References were evaluated by 2 review authors. Articles that met the eligibility criteria were included. Data extraction, methodological quality assessment (Cochrane tool), and strength of the evidence evaluation (GRADE) were also carried out. RESULTS: Seven articles were included. The results showed that removable and fixed devices were equally efficacious for overjet correction. Removable and fixed devices can also present inconveniences regarding pain and discomfort levels, the accomplishment of everyday activities (leisure and school), and the performance of functions, such as chewing and speech. However, treatment time and costs were significantly lower in orthodontic therapy with fixed appliances. Sequence generation, allocation concealment, and complete outcome data were not a concern. Blinding of participants or personnel was not reported in any article, and blinding of the assessor was a concern in 2 articles. Selective reporting was a concern in 2 articles. The certainty of the evidence for overjet correction was very low. CONCLUSION: Removable and fixed orthodontic devices are efficacious for overjet correction in non-skeletal anterior crossbite. However, treatment time and costs are lower for cases treated with fixed devices.

Early Treatment of Anterior Crossbite with Eruption Guidance Appliance: A Case Report.

The purpose of this investigation was to show how to manage an anterior crossbite in early mixed dentition with an eruption guidance appliance (EGA). The analyzed clinical case reported an anterior crossbite, a bimaxillary retrusion tendency, and a horizontal growth pattern. The anterior crossbite was an unfavorable occlusal condition that could lead to a class III malocclusion growth pattern. An early treatment approach was suggested to reach a correct sagittal jaw relationship. Hence, the selected approach acted on the dentoalveolar sector, aiming to have effects on the posterior vertical dimension and to improve the sagittal jaw's relation. An EGA was selected to treat the patient in early mixed dentition. After 7 months of therapy with night-time use, the dental malocclusion was completely resolved. The patient continued to be treated with the same device, used as active retention. With the EGA treatment, the erupting forces, rather than the active forces, were used to resolve the dental malocclusion. This approach allowed a low compliance requirement and had a minimum psychosocial and psychological impact on the patient. The early treatment was essential to give a functional occlusion and a good balance of the soft perioral tissues and muscles.

Does the position of a bottle during infant feeding influence the jaw's postural position?

Early correction of anterior crossbite in the primary dentition can encourage proper growth and development of the maxilla and mandible, reducing the need for future orthodontic therapy. Correction is typically initiated after the age of 3 when a fixed or removable appliance can be fabricated and worn. This case study describes an instance of exceptionally early intervention without the use of an appliance. A bottle-fed 10-month-old boy presented with anterior crossbite, and a contributing factor may have been the position of the bottle's nipple during feeding. Correction of the anterior crossbite was achieved in 5 months by changing the bottle position to a counterbalancing angle. Although this technique warrants further investigation, it has the potential to reduce the need for and length of future procedures.

El quad-hélix, un aparato versátil / The quad-hélix, a versatile appliance

El quad-hélix (QH) es un aparato de expansión maxilar, fabricado con alambre de acero inoxidable soldado a bandas en molares, que dispone de espirales o hélices que aumentan la longitud de alambre del aparato, lo que lo hace muy elástico y aligera la magnitud de la fuerza sobre los dientes, es ampliamente usado tanto en dentición mixta como en permanente temprana, fácil de fabricar, higiénico y bien tolerado por los pacientes. Su principal acción es mover hacia vestibular los procesos dentoalveolares de la arcada maxilar, influyendo secundariamente en la expansión de la sutura palatina media en pacientes con dentición mixta o permanente temprana. El QH es muy práctico y tiene muchos usos y adaptaciones y se puede utilizar como auxiliar en el tratamiento de problemas de hábito de dedo o lengua, para abrir mordida, rotar y dar torque a molares permanentes o para mover sólo un diente en particular. En este artículo describimos una nueva aplicación del QH que consiste en la tracción, de dientes anteriores superiores permanentes retenidos, después del abordaje quirúrgico para localizarlos. También revisaremos las indicaciones, contraindicaciones, ventajas y desventajas del aparato QH soldado a bandas en molares así como su elaboración, variantes y forma de activación (AU)

The quad-helix (QH) is a maxillary expansion appliance, manufactured with stainless steel wire welded to bands in molars, which has spirals or helix to increase the length of wire of the device, which makes it very elastic and lightens the magnitude of the force on the teeth, is widely used both in mixed and in early permanent dentition, is easy to manufacture, hygienic and well tolerated by patients. Its major action is to move towards the dentoalveolar process of the maxillary arcade, secondarily influencing the expansion of the middle palatal suture in young patients with mixed or permanent early dentition. The QH is very practical and has many uses and adaptations as an aid in the treatment of problem of thumb sucking or tongue habit, to open bite, to rotate and torque permanent molars or to move only one particular tooth. In this article we describe a new application of the QH that consist of the traction or retained permanent upper teeth, after surgical approach to locate them. We will also review the indications, contraindications, advantages and disadvantages of the QH welded to molar bands, as well as its construction, variants and activation form (AU)

Impact of two early treatment protocols for anterior dental crossbite on children's quality of life

ABSTRACT Objective: To assess the impact of two early treatment protocols for anterior dental crossbite on children's quality of life. Methods: Thirty children, 8 to 10 years of age, with anterior dental crossbite, participated in this study. Individuals were divided into two groups: Group 1 - 15 children undergoing treatment with an upper removable appliance with digital springs; Group 2 - 15 children undergoing treatment with resin-reinforced glass ionomer cement bite pads on the lower first molars. Quality of life was evaluated using the Brazilian version of the Child Perceptions Questionnaire (CPQ8-10), which contains four subscales: oral symptoms (OS), functional limitations (FL), emotional well-being (EW), and social well-being (SW). A higher score denotes a greater negative impact on children's quality of life. Children answered the questionnaire before treatment (T1) and twelve months after orthodontic treatment onset (T2). Descriptive statistics, the Wilcoxon test and analysis of covariance (ANCOVA) were performed. Results: Children's mean age was 9.07 ± 0.79 years in Group 1 and 9.00 ± 0.84 years in Group 2. For Group 1, the FL and EW subscale scores and the overall CPQ8-10 were significantly higher in T1 as compared to T2 (p= 0.004, p= 0.012 and p= 0.015, respectively). For Group 2, there were no statistically significant differences. The ANCOVA showed no significant difference regarding quality of life at T2 between groups, after controlling for quality of life measures at T1. Conclusions: The difference regarding the impact on quality of life between groups is not related to the protocol used.

RESUMO Objetivo: avaliar o impacto de dois protocolos de tratamento precoce para a mordida cruzada anterior dentária na qualidade de vida de crianças. Métodos: trinta crianças de 8 a 10 anos de idade com mordida cruzada anterior dentária participaram desse estudo. Os indivíduos foram divididos em dois grupos: Grupo 1 - 15 crianças em tratamento com aparelho removível superior com molas digitais; Grupo 2 - 15 crianças em tratamento com batentes de cimento de ionômero de vidro resinoso nos primeiros molares permanentes inferiores. A qualidade de vida foi avaliada por meio da versão brasileira do Child Perceptions Questionnaire (CPQ8-10), o qual contém quatro subescalas: sintomas bucais (SB), limitações funcionais (LF), bem-estar emocional (BE) e bem-estar social (BS). Um escore mais alto indica um impacto mais negativo na qualidade de vida. As crianças responderam ao questionário antes do tratamento (T1) e 12 meses após o início do tratamento ortodôntico (T2). Estatística descritiva, o teste Wilcoxon e análise de covariância (ANCOVA) foram realizados. Resultados: a média de idade das crianças foi de 9,07 ± 0,79 anos no Grupo 1 e de 9,00 ± 0,84 no Grupo 2. Para o Grupo 1, os escores das subescalas LF e BE e o escore total do CPQ8-10 foram significativamente maiores em T1 do que em T2 (p= 0,004, p= 0,012 e p= 0,015, respectivamente). Para o Grupo 2, não houve diferença estatisticamente significativa. A ANCOVA não mostrou diferença significativa entre os grupos em relação à qualidade de vida em T2, após o controle para as medidas de qualidade de vida em T1. Conclusões: a diferença em relação ao impacto na qualidade de vida entre os grupos não foi relacionada ao protocolo de tratamento utilizado.