Intermaxillary Elastics Research Articles

Effect of various active reminders via mobile phone on cooperation of orthodontic teenage patients regarding oral hygiene and ClassII elastics use : Athree-month follow-up prospective cohort study.

The purpose of this prospective cohort study was to assess the impact of reminders via mobile phone, such as text messages or video/multimedia images, on orthodontic patients' cooperation with regard to oral hygiene and the use of ClassII intermaxillary elastics. The study included 124 orthodontic patients aged 12-20years (mean age14.06 ± 2.0 years, 63females and 61males). The patients were divided into two groups: group1 (n = 56) was evaluated for oral hygiene, while group2 (n = 68) was evaluated for the use of ClassII intermaxillary elastics. Each main group was divided into three subgroups: text message group, video message group, and control group. Specific messages were sent to the participants in the study groups twice aweek for 12weeks. Data were collected at the beginning of the study (T0), after 6weeks (T1), and 12weeks (T2) and compared to determine the impact of the reminders. Oral hygiene was evaluated using plaque and gingival index scores, and the use of ClassII elastics was evaluated using digital model measurements. Between-subject comparisons were performed using Kruskal-Wallis or one-way analysis of variance (ANOVA). For within-subject comparisons (T0-T1, T1-T2, and T0-T2 time intervals), one-way repeated measures ANOVA or Friedman test was performed. There was no significant difference between the control group (1.49 ± 0.22) and the message groups (video: 1.58 ± 0.34 and text: 1.51 ± 0.28) in terms of plaque index scores and gingival index (control: 1.56 ± 0.26, text: 1.51 ± 0.36, video: 1.52 ± 0.26) scores. However, in the intragroup comparison, it was observed that both plaque index scores and gingival index scores at T0, T1, and T2 increased for both the study and control groups. While there was no difference between the subgroups in overjet measurement at T0 (control: 3.46 ± 1.20, video: 3.34 ± 1.20, text: 2.73 ± 1.03; p = 0.51), there was asignificant difference at T2 (control: 2.62 ± 0.85, video: 2.32 ± 1.41, text: 1.48 ± 0.72, p < 0.01). Mobile active reminders had no effect on improving oral hygiene. Despite repeated reminders, hygiene worsened over time. The use of ClassII elastics seemed to have increased as aresult of the mobile reminders.

Evaluation of the Best Method for Orthodontic Correction of Skeletal Deep Bites in Growing Patients: A Systematic Review.

This review aimed to evaluate the currently available evidence regarding the best method of correcting deep bites in growing patients. In September 2023, a search was conducted electronically across the following databases: PubMed®, Web of Science™, Scopus®, Embase®, Google™ Scholar, and Cochrane Library. In this systematic review, randomized control trials (RCTs), controlled clinical trials (CCTs), and cohort studies of growing patients with deep bite malocclusion who received treatment with the primary objective of treating the deep bite were included. Risk of bias of the included studies was assessed using two different tools; one tool was applied for RCTs and the other one for the CCTs and cohort studies. One RCT, one CCT, and one cohort study were included (85 patients). The flat fixed acrylic bite plane was superior in terms of duration of treatment when compared to the inclined fixed acrylic bite plane and the utility arch with posterior intermaxillary elastics. Limited evidence indicates that the inclined fixed acrylic bite plane causes a significant increase in the lower incisor inclination and a significant increase in the angle between the mandible and the anterior cranial base (SNB). However, limited evidence indicates that the utility arch with posterior intermaxillary elastics causes a significant decrease in the angle between the maxilla and the anterior cranial base (SNA). Regarding the vertical skeletal changes, it was found that the three methods were comparable; in each case, the vertical dimension of the face increased because of a significant increase in the lower first molar height. There is a need for further studies to strengthen the evidence of the treatment efficacy of the employed methods, with more RCTs to be conducted in this regard.

Class II malocclusion correction by two different intermaxillary elastics protocols: a randomized clinical trial

Class II malocclusion correction by two different intermaxillary elastics protocols: a randomized clinical trial

Orthodontic camouflage treatment of a hyperdivergent adolescent patient with anterior open bite and TMD: a case report

BackgroundIn orthodontics, anterior open bite is a common malocclusion that recurs frequently. Because the causes of anterior open bite are so varied, medical professionals must create customized treatment programs for each patient based on their unique etiology. Through the lowering of the posterior teeth, closure of the anterior teeth gap, and cooperation with intermaxillary traction, the treatment plan outlined in this case study sought to achieve a stable occlusion.Case presentationThis case report aims to describe an orthodontic camouflage treatment of a 15-year-old female patient with anterior open bite, arch width discrepancy and a history of temporomandibular joint disorder. The patient was treated with intermaxillary vertical elastics and the multiple edgewise arch wire (MEAW) approach. A satisfactory occlusion with a neutral molar relationship was attained after 29 months of orthodontic therapy. The condylography recording showed that this patient’s occlusion tended to be more stable both before and after our treatment. The purpose of this case study is to provide an overview of an orthodontic camouflage treatment for a female patient, who had a history of temporomandibular joint disease, anterior open bite, and arch width disparity.ConclusionsOur results demonstrated that more attention should be paid to levelling the occlusal plane, intrusion of the molars, decompression of temporomandibular joints and the etiology factors of malocclusion during the orthodontic period for those patients with anterior open bite.

Clinical Experience With a Less Invasive Surgical Transparotid Approach and Trapezoidal Plate for Neck and Base Condylar Fractures: A Retrospective Study.

This is a retrospective observational study. To evaluate the clinical outcomes after an open reduction and internal fixation (ORIF) of condylar neck and base fractures (CNBFs) with a trapezoidal shape plate in patients using a less invasive transparotid approach. Fifteen patients with condylar fractures were classified according to the Arbeitsgemeinschaft für Osteosynthesefragen Craniomaxillofacial (AOCMF) classification system, treated by ORIF with a trapezoidal plate. All patients were evaluated by clinical examination (pain, occlusion, and mandibular dynamics) and imaging through computed axial tomography. Postoperative evaluations considered a favourable clinical outcome of fragment stability, stable occlusion, absence of pain, and regular mouth opening ranges. In addition, any signs of local infection, malocclusion, facial nerve damage, or failure of the fixation system were recorded. According to the AOCMF classification for condylar fractures, eight fractures affected the condylar base and seven involved the condylar neck. No patients presented pain or joint sounds in the TMJ. All patients obtained a buccal opening greater than or equal to 35mm. Two patients showed postoperative malocclusion which was corrected by intermaxillary elastics therapy. In addition, two patients had transient paresis during the postoperative period. One of them had paresis of the frontal and buccal branches of the facial nerve while the second patient had paresis of the zygomatic and buccal branches. Using trapezoidal miniplates provides functionally stable fixation for neck and base condylar fractures and allows for a less invasive surgical transparotid approach (2cm extension). They also reduce the amount of osteosynthesis material and are easier to adapt and fix in the author's opinion.

Elastické tahy v Ortodoncii

Aim: The work assesses force characteristics of one type and size of elastics, specifically 3/16“ medium elastics, of five different manufacturers. We compared initial forces, and particularly the relationship between their force degradation over aɸperiod of time. Material and method: 500 latex elastics 3/16“ medium from Dentaurum, American Orthodontics, 3M, Ortho Organizers and G &amp; H Orthodontics (100 of each) were tested. Force was measured with dynamometer at time 0, 2, 8, 24 and 48 hours. Elastics were stretched to triple of their original diameter and they were placed onto the plate manufactured by us. The plate was produced with 3D printer. Then everything was put into an incubator at the temperature of 37 °C and constant humidity. Shapiro-Wilk normality tests, ANOVA and Bonferroni’sɸpost-hoc tests were used for statistical evaluation. Individual manufacturers were asked whether they know in which plants exactly the elastic tractions are produced. Unfortunately, they did not answer the question. Results: The average initial force was between 1.109 N and 1.550 N; elastics made by Dentaurum were closest to the declared force of 1.255 N. The force decreased most during the first two hours. Between the individual producers the decrease of elastic tractions during 24 hours oscillated between 20 and 33%. The greatest drop in force was recorded for American Orthodontics products. The smallest decrease was recorded between 2nd and 8th hour for 3M, and between 24th and 48th hour for OrthoOrganizers products. Conclusion: Intermaxillary elastics of 3/16“ medium measured in vitro differ both in the amount of their initial force and in force degradation. Orthodontists should know the basic parameters of elastic tractions. To secure maximum care aɸdoctor should measure initial force of elastic tractions with dynamometer intraorally.

Maxillary Protraction Via Bone Anchorage: A Straightforward Strategy for Complex Dilemmas - An Illustrative Case Report

Class III malocclusion is one of the most challenging malocclusions to treat. Approximately 40 of skeletal Class III malocclusion is caused due to maxillary retrognathism. Various treatment approaches have been mentioned in the literature concerning the management of skeletal Class III malocclusion in growing patients. Conventional treatment for young Class III patients often involves reverse-pull headgear which is extraoral in nature and heavily depends on patient acceptance and compliance. Moreover the limitation of this approach is that the forces are directly applied to teeth resulting in unpredictable skeletal and frequently unwanted dentoalveolar effects which are ultimately prone to relapse. Bone Anchored Maxillary Protraction BAMP employs intra-oral skeletal plates and intermaxillary elastics to bring about true skeletal changes without dentoalveolar side-effect. It is also found to be effective when implemented at a later age. This case report attempts to present the case of a 15 year old female patient with skeletal class III malocclusion who was successfully treated with Bone anchored maxillary protraction

Prevalence of temporomandibular disorders in clear aligner patients using orthodontic intermaxillary elastics assessed with diagnostic criteria for temporomandibular disorders (DC/TMD) axis II evaluation: A cross-sectional study.

The objective of this investigation is to assess the relationship between the utilisation of orthodontic intermaxillary elastics and temporomandibular disorder (TMD) symptoms in clear aligner patients and to examine the correlation between the elastic usage time with the Diagnostic Criteria for Temporomandibular Disorders (DC/TMD)-Axis II Evaluation Forms. This study was carried out on a total of 40 clear aligner patients using intermaxillary elastics in the experimental group and 30 clear aligner patients who did not use any intermaxillary elastics in the control group. The data were evaluated using the Mann-Whitney U, chi-square, Fisher's exact chi-square, and Fisher Freeman Halton exact chi-square tests. The characteristic pain intensity, mastication, mobility, communication, global and PHQ-9 scores of the experimental group were significantly higher than those of the control group (p < .05). The characteristic pain intensity score, interference score and chronic pain grade score of patients using Class III elastics were statistically significantly higher than those of patients using Class II elastics (p < .05). Patients who used elastics for less than 6 months had statistically significantly higher PHQ-9 scores than those who used elastics for more than 6 months (p < .05). Orthodontic treatment may affect occlusion, bite force and jaw movement, which may cause or worsen TMD symptoms, and the DC/TMD questionnaires can determine if orthodontic patients acquire TMD by assessing their psychosocial state and pain-related problems.

Clear aligners for Class III malocclusion and severe open bite camouflage: A case report

Objective: The aim of the study was to describe a clinical case of a Class III malocclusion and severe open bite approached with clear aligners (CAs) and intermaxillary elastics. Case Presentation: A 21-year-old male patient showed to the dental clinic asking for orthodontic treatment. His chief complaint was an unpleasant smile esthetics. The patient showed an oval face with increased length of the lower third of the face, slight mandibular asymmetry, and concave profile. On intraoral evaluation, a bilateral canine and molar Class III with reduced overbite could be seen. Pre-treatment panoramic radiograph showed good root parallelism and presence of all dental elements. Cephalometric values confirmed skeletal Class III (Wits Appraisal = −6.5 mm), increased vertical dimension (FMA = 34.3°), correctly inclined upper incisors and retroclined lower incisors. After discussing the treatment options with the patient, CAs (F22, Sweden and Martina, Due Carrare, Padova, Italy) were chosen to approach this malocclusion together with intermaxillary elastics. After 9 months of active treatment involving 18 sets of aligners, the patient showed correct overbite, bilateral canine e molar Class I, leveled and aligned dental arches, and no signs of radicular or bone resorption. Cephalometric parameters show control of vertical dimension (FMA = 34.4°), upper incisor flaring and lower incisor retroclination, and signs of a dentoalveolar compensation. Conclusion: Careful diagnosis, treatment planning, and clinical management of CAs and intermaxillary elastics led to a successful dentoalveolar compensation featured by good occlusal results, bilateral Class I relationship, and normal overbite which remained stable after 1 year from the end of treatment.

The Use of a CAD/CAM Thermoformed Splints System in Closed Reduction of Condylar Fractures.

(1) Background: Mandibular fractures are very common. Common indications of closed treatment for mandibular fractures are non-displaced or minimally displaced simple fractures in adult compliant patients with good dentition, the absence of occlusal disruption, and fractures in growing children. In closed treatment, the mandible is maintained in centric occlusion with a maxillomandibular fixation (MMF) with orthodontic elastics. Many methods of MMF have been described, often using orthodontic appliances. In recent years, CAD-CAM technology has improved many procedures used in maxillofacial surgery and orthodontics. The device we present is manufactured following a digital workflow, and was designed specifically for MMF. (2) Materials: Two patients with mandibular fractures were treated with an MMF method whose procedure comprised scanning of the dental arches, followed by construction of thermoformed splints on which buttons for the elastics and retention holes are made. The splints were fixed on the dental arches with composite resin at the level of the holes, and were kept in place for the period of healing of the fracture, with the intermaxillary elastics hooked to the buttons. (3) Results: The application time of the splints was very quick. The splints remained stable for the necessary time, without causing particular discomfort to the patients. (4) Conclusions: From our experience, this technique has proved to be reliable and reproducible and could represent a valid tool in the closed treatment of mandibular fractures.

Actual contribution ratio of maxillary and mandibular molars for total molar relationship correction during maxillary molar sequential distalization using clear aligners with Class II elastics: A finite element analysis

Class II elastics, in combination with clear aligners (CA), are efficient for molar distalization. However, the effects of this combination on intermaxillary molar relationship correction have yet to be investigated. This study aimed to investigate the actual contribution ratio of the maxillary and mandibular molars for total molar relationship correction during maxillary molar distalization using Class II elastics with CA and further explore therapeutic recommendations for clinical practice. Finite element models (FEMs) were established, including the distalization of the second molars (Set I), followed by the distalization of the first molars (Set II). Model A simulated elastics attached by precision cutting, whereas Model B simulated elastics attached to buttons. Force magnitudes of 100 g, 150 g, and 200 g of force were applied. We recorded the contribution ratio of the maxillary and mandibular molars for total molar relationship correction, effective distalizing distance in 0.25 mm step distance, tipping and rotation angles, and the hydrostatic stress in the periodontal ligament. During maxillary molar distalization, mesialization of the mandibular molar had a notable contribution ratio for molar relationship correction. The mandibular first molar was mesialized with mesiolingual rotation tendency. Approximately half of the 0.25 mm step distance was occupied by maxillary molar distalization; the remainder was occupied by anchorage teeth mesialization and tipping or rotation. When traction forces increased, the total molar relationship correction and effective distalization increased; the mandibular molars mesialization contribution ratio also increased, as did rotation and inclination tendency. Precision cutting had a higher total molar relationship correction and more effective distalization than a button but also had a larger contribution ratio of mandibular molar mesialization and inclination or rotation. Mandibular molar mesialization should be considered when correcting the molar relationship using CA with intermaxillary elastics during maxillary molar distalization. It is also important to consider the anchorage teeth mesialization and undesired tipping or rotation.

Management of Class III malocclusion by orthodontic clockwise rotation of maxillo-mandibular complex – A case report

Severe Skeletal Class III malocclusions in adult patients are managed by surgical orthodontic correction and orthodontic camouflage especially in borderline cases. An orthodontic camouflage is best opted in situations where the patient is either reluctant to have an invasive procedure or mitigate other ways to obtain an ideal interincisal relation, best esthetic outcome and function. There are many ways suggested to treat Class III malocclusions non-surgically like fixed appliance with class III intermaxillary elastics, extraction of mandibular first bicuspids, extraction of mandibular first and maxillary second bicuspids and enmasse distalization of mandibular arch using temporary anchorage devices. Clockwise rotation of maxillo-mandibular occlusal complex gives promising treatment outcome in selected cases with extrusion of upper arch and possible clockwise rotation of the mandible for improving mandibular prognathism. This case report aims to illustrate a Class III non-growing patient treated by clockwise rotation of maxillo-mandibular occlusal complex for achieving optimum facial esthetics and function.

Concept for the Treatment of Class III Anomalies with a Skeletally Anchored Appliance Fabricated in the CAD/CAM Process-The MIRA Appliance.

Intermaxillary elastics, anchored skeletally, represent a promising concept for treatment in adolescent patients with skeletal Class III anomalies. A challenge in existing concepts is the survival rate of the miniscrews in the mandible or the invasiveness of the bone anchors. A novel concept, the mandibular interradicular anchor (MIRA) appliance, for improving skeletal anchorage in the mandible, will be presented and discussed. In a ten-year-old female patient with a moderate skeletal Class III, the novel MIRA concept, combined with maxillary protraction, was applied. This involved the use of a CAD/CAM-fabricated indirect skeletal anchorage appliance in the mandible, with interradicularly placed miniscrews distal to each canine (MIRA appliance), and a hybrid hyrax in the maxilla with paramedian placed miniscrews. The modified alt-RAMEC protocol involved an intermittent weekly activation for five weeks. Class III elastics were worn for a period of seven months. This was followed by alignment with a multi-bracket appliance. The cephalometric analysis before and after therapy shows an improvement of the Wits value (+3.8 mm), SNA (+5°), and ANB (+3°). Dentally, a transversal postdevelopment in the maxilla (+4 mm) and a labial tip of the maxillary (+3.4°) and mandibular anterior teeth (+4.7°) with gap formation is observed. The MIRA appliance represents a less invasive and esthetic alternative to the existing concepts, especially with two miniscrews in the mandible per side. In addition, MIRA can be selected for complex orthodontic tasks, such as molar uprighting and mesialization.

Applications and effectiveness of teledentistry in orthodontic practice during the COVID-19 restrictions.

The aim of this study was to identify the areas of application for teledentistry and analyze its effectiveness in orthodontic practice during the COVID-19 pandemic. A total of 233 patients (159 women, 74 men) receiving orthodontic treatment were included. During the COVID-19 restriction period, patients were given teledentistry appointments. During these video conferences, remote orthodontic checkups were performed by one orthodontist, who asked the patients for photos or videos. The applications carried out during the interviews were recorded, classified, and analyzed. In addition, clinical emergency patients were identified. After the teledentistry consultations, two different questionnaires were presented to the patients, depending on their attendance at teledentistry appointments, and the results were statistically evaluated. In all, 21.25% of the patients were identified as having clinical emergencies, including injury because of damage from brackets and wires; 10% of them reported bracket breakage; 17.5% were encouraged to use intermaxillary elastics; and 3.75% were in pain. However, 50% of them were found to be unproblematic. A total of 91% of the participants in the survey reported that online checkups were sufficient to understand and resolve their symptoms. However, 28% wanted to communicate with orthodontists by video call or with photos instead of meeting face to face (65.5%) when unexpected problems arose during the COVID-19 pandemic. Teledentistry can be an effective method for motivating patients who are undergoing orthodontic treatments that require cooperation. It is also an effective way of understanding the patients' symptoms and reducing the risk of cross-infection by identifying patients who will require face-to-face emergency treatment during pandemics.

Camouflage Correction of Skeletal Class III Severe Open Bite with Tooth Ankylosis Treated by Temporary Anchorage Devices: A Case Report

Tooth ankylosis is a disorder characterized by the fusion of tooth and alveolar bone. This case report describes the treatment of a severe open bite due to tooth ankylosis. A 14-year-old female patient with a chief complaint of masticatory dysfunction was diagnosed with skeletal Class III severe anterior open bite and tooth ankylosis. She visited our university hospital with a chief complaint of an anterior open bite. After the surgical luxation of the ankylosed maxillary right central incisor, the tooth was orthodontically retracted using a nickel-titanium wire. The right mandibular lateral incisor and canine were luxated and retracted using intermaxillary elastics from a temporary anchorage device (TAD), which was inserted in the opposite jaw. During the treatment, skeletal Class III malocclusion deteriorated due to anterior growth of the mandible. Therefore, TADs were inserted into the retromolar pad on both sides of the mandible and retracted into the mandibular dental arch. Although the mandibular right canine was luxated several times, it could not be brought to the occlusal line, and was thus extracted; the extraction space was replaced with a prosthesis. Consequently, a normal overjet and overbite with a straight profile were achieved. Extrusion of ankylosed teeth by intermaxillary elastics from a TAD is a valid treatment option for patients with severe open bites.

Improved Super-elastic Ti-Ni Alloy Wire for Nonsurgical Treatment of Skeletal Class III Malocclusion Combined with Anterior Crowding and Anterior Crossbite Case

The article reported the use of improved super-elastic Ti-Ni alloy wire (ISW), which was developed by Tokyo Medical and Dental University, to correct a case of skeletal Class III malocclusion combined with anterior crowding and anterior crossbite. An 18-year-old male with a chief complaint of poor dental alignment and protruded lower incisors showed up in our clinic for treatment. Clinical examination revealed skeletal Class III facial profile. Anterior crowding and anterior crossbite could be also noted. Because the patient refused orthognathic surgery, we tried camouflage orthodontic treatment. First, we used ISW crossbite arch to eliminate the anterior interference in order to observe the change of the mandibular position. After that, we use ISW multiloop edgewise arch wire (MEAW) technique and intermaxillary elastics to achieve midline correction and adequate overjet with the bite raising process. The treatment was finished with the improvement of facial appearance and a stable occlusion.

Non-Surgical Camouflage Treatment of a Skeletal Class III Patient with Anterior Open Bite and Asymmetry Using Orthodontic Miniscrews and Intermaxillary Elastics

This case report presents the non-surgical orthodontic camouflage treatment of an 18-year-old male patient with skeletal Class III asymmetry and severe anterior open bite. The anterior open bite was corrected by extrusion of the maxillary and mandibular anterior teeth and clockwise and counterclockwise rotation of the maxillary and mandibular occlusal plane, respectively, using intermaxillary Class III elastics between the maxillary posterior buccal miniscrews and mandibular canines and anterior vertical elastics between the maxillary and mandibular canines. Class III dental relationships and dental asymmetry were corrected via unilateral distalization of the mandibular dentition on the left side using a closed coil spring between the buccal shelf screw and hook. The patient’s smile esthetics and dental relationship were improved with a more favorable facial profile, and facial asymmetry was slightly alleviated after orthodontic camouflage treatment. The total treatment time was 15 months. A modified wraparound retainer with a scalloped labial bow, tongue crib, and tooth positioner was used simultaneously to prevent the potential relapse.

Ortho-Surgical Management of An Adult Patient with Gummy Smile

Aim: This case report represents the clinical management of a Skeletal Class II adult patient with gummy smile treated by Orthognathic surgery. Background: Vertical maxillary excess (VME) is the most common skeletal deformity in Skeletal Class II which is treated by Anterior Maxillary Osteotomy (AMO) and Gummy Smile is the characteristic feature of VME in which the anterior part of maxilla is superiorly repositioned. Case Description: A 19-year-old patient reported our clinic with the complaint of forwardly placed upper front teeth. On extra oral examination, she had convex profile with posterior divergence and interlabial gap of 10mm and everted upper lip. The patient had a gummy smile of 8mm. Intra orally, she had Class II canine relationship on both sides with missing irt 16, 36, 46. Cephalometric values showed Class II skeletal base with protrusive upper and lower incisors and acute nasolabial angle. Initially orthodontic treatment was done and extraction of upper first premolars was planned during surgery. AMO was done with superior impaction of 4mm and posteriorly by 6mm. After 4 weeks of post surgery, the settling of occlusion using intermaxillary elastics was done. At the end of the treatment, the patient had Class I canine relationship on both sides with Skeletal Class I and overjet and overbite was 2mm. The patient gummy smile was reduced to 4mm which was accepted by the patient. Fixed retention was given in both the arches. The total treatment time was around 30 months. Conclusion: The proper diagnosis and appropriate treatment planning is the main key to achieve stable results in Orthodontics. An interdisciplinary approach with the orthodontist and surgeon will lead to achieve stable, functional and esthetic results.

Numerical investigation of the biomechanical effects of orthodontic intermaxillary elastics on the temporomandibular joint

Temporomandibular joint disorder (TMD) often coincides with malocclusion, and in some cases TMDs are reported after orthodontic treatment. Intermaxillary elastics (also known as orthodontic elastics, OE) are a common way to apply force during orthodontic treatment, and they might cause mechanical effects on the temporomandibular joint (TMJ), thereby lead to joint remodeling. It is still a controversial topic whether the adapted remodeling of the TMJ or of the alveolar bone is the main cause for the alteration of occlusion after treatment with OEs. It was the aim of this study to analyze whether variations of OEs would develop harmful effects on the healthy TMJ. A TMJ model with a masticatory system based on Hill-type muscle actuators was established. Mouth opening and closure with and without OEs were simulated, and maximum principal stresses in the disc and condylar cartilage as well as the displacement of the mandible were analyzed. We found no considerably difference in the mandibular movement without and with symmetrical OEs during mouth opening and closing. At full mouth opening, stresses in the disc and condylar cartilage of some models with OEs were much smaller than without OEs, but we did not find consistency in the results from the left and right sides of the same model (e.g. the lowest compressive stress on the left side of disc from the model with Class II OEs is much smaller than without OEs, −17.3 MPa compared with −28.2, while on the right side, there was no obvious difference). Hence, we could not conclude that OEs would develop deleterious effects on the healthy TMJ.

Class II and anterior open bite malocclusion treated with mini-implants, intermaxillary elastics, speech therapy, and retained with a night-wear palatal crib wraparound

The teeth position in anterior open bite malocclusion depends on a balance of pressure between the tongue and lips and the treatment planning should include such variables. The objective of this study was to report an orthodontic case of an adult with maxillary protrusion and anterior open bite treated with skeletal anchorage and intermaxillary elastics. The patient presented a Class II malocclusion with anterior open bite, without a history of non-nutritive habits, and mandibular missing teeth at 54 years old. Mini-implants were inserted in the maxillary molars region to produce distal movement of the maxillary dentition while controlling molar extrusion, and in the mandibular anterior region on the left side to produce mesial movement of posterior teeth. Up and down intermaxillary elastics were worn in the area of the incisors to treat the open bite together with Class II intermaxillary elastics. Cleats were bonded in the lingual surface of the anterior teeth as spurs to the tongue posture. However, the best result on the anterior open bite treatment was coincident with the speech therapy. Normal relationships between the maxillary and mandibular occlusal plane of cusps, correct anterior overbite, and adequate proximal relationships were obtained at the end of treatment. The retention modality to the maxillary arch was daily wear of a removable standard wraparound and a night-time wraparound with the palatal crib. The new technology allows for more effective treatment in adults and speech therapy was helpful to achieve balanced pressure between the tongue and lips.