Intermaxillary Elastics Research Articles

顎間ゴム装着時の外側翼突筋下頭の筋電図学的研究(大阪歯科大学大学院歯学研究科博士(歯学)学位論文内容要旨および論文審査結果要旨の公表)

顎間ゴム装着時の外側翼突筋下頭の筋電図学的研究(大阪歯科大学大学院歯学研究科博士(歯学)学位論文内容要旨および論文審査結果要旨の公表)

Simultaneous maxillomandibular distraction osteogenesis in hemifacial microsomia: Report of 7 cases

IntroductionThe goal in treating Hemifacial microsomia (HFM) is to improve facial symmetry, allow functional jaw movement, obtain stable occlusion, and achieve patient satisfaction. This study was planned with an aim to assess the outcome of simultaneous maxillomandibular distraction osteogenesis in hemifacial microsomia. Material & methodsSeven patients with hemifacial microsomia were included in this study and demographic data was obtained. Simultaneous maxillo-mandibular distraction was planned for correction of maxillary cant, vertical ramal lengthening and midline, by performing unilateral mandibular osteotomy in ramus and distractor fixation, a Le Fort I osteotomy, with fixation at contralateral zygomatic buttress and intermaxillary elastics. Derriford Appearance Scale was used to measure individual responses to address problems of appearance. Results6 males and 1 female, with age range 18–26 years, mean 22.14 were included in the study. Maxillary occlusal cant varied from 4–16°, mean 9.85° and distraction achieved ranged from 12–19mm, mean 15.57. Preoperatively DAS score ranged from 42–61, mean 51.7 and improved to 10–27, mean 18.4. 100% success was achieved in 5 cases, while other two showed 96% and 99% success. ConclusionSimultaneous maxillomandibular distraction osteogenesis improves facial esthetics and obviates the need for postoperative orthodontics, minimizing the treatment period.

Force degradation of orthodontic latex elastics: An in-vivo study

Our objectives were to assess the force degradation of orthodontic latex elastics over 48hours invivo and to study the relationship between the amount of mouth opening and the degree of force decay. Fifty-two orthodontic patients wearing fixed appliances using Class II elastics were asked to wear premeasured-force 3/16-in heavy and medium intermaxillary elastics. The force amounts were measured and compared at different time intervals. Fifty percent of theforce was lost after 3.9hours for the medium elastics and after 4.9hours for the heavy elastics. A continuous significant force drop in all elastics was seen at all time intervals (P<0.05, P<0.001). There was greater force loss in the heavy elastics compared with the medium elastics invivo at all time intervals (P<0.001); the rates of force loss, however, were similar. Fifty percent of force degradation occurred in the first 4 to 5hours. Because of breakage and for oral hygiene purposes, orthodontic elastics should be changed daily; otherwise, elastics can be used for 48hours. Force decay of the elastics was correlated to the lateral distance between the maxillary canine and the mandibular first molar in occlusion.

Effects of hybrid-Hyrax, Alt-RAMEC and miniscrew reinforced heavy Class III elastics in growing maxillary retrusive patients. A four-year follow-up pilot study

Abstract Introduction The aim of this study was to evaluate the short- and long-term effects of hybrid-Hyrax, Alt-RAMEC and applied, miniscrew reinforced, heavy intermaxillary elastics on a modified lingual arch in growing skeletal Class III patients. Methods Fifteen subjects (seven male, eight female) were included, with an average age of 12.52 ± 0.94 years, of cervical vertebrae maturation (CVM) stage CS2-CS4 and skeletal Class III malocclusions due to a retrognathic maxilla. Nine weeks of Alt-RAMEC were followed by eight to nine weeks of maxillary protraction with heavy 400 gm Class III elastics worn 24 h/day. Treatment was finalised with orthodontic fixed appliances. Cone beam computed tomographic (CBCT) scans were taken initially (T1), at the end of maxillary protraction (T2) and four years after active orthopaedic treatment (T3). Cephalometric measurements were performed on reconstructed lateral cephalograms and the differences between time intervals were calculated using an analysis of variance (ANOVA). Results A positive overjet was achieved in all but one subject. From T1 to T2, A point advanced 3.12 ± 3.42 mm and from T2 to T3 advanced a further 2.21 ± 3.49 mm. Significant initial increases in SNA of 1.05° ± 1.10° (p = 0.004), ANB of 2.71° ± 1.01° (p = 0.00), Wits of 4.49 ± 2.21 mm (p = 0.00) and overjet of 4.90 ± 1.66 mm (p = 0.00) were accomplished and maintained without significant changes in the vertical dimension. Upper and lower incisor inclinations were not affected by the protraction protocol but significantly increased (U1-PP: 8.39° ± 5.59°) between T2 and T3. SNB decreased initially by 1.67° ± 1.34° (p = 0.00) but relapsed due to residual mandibular growth and a counterclockwise rotation of the mandibular plane. Conclusion The hybrid-Hyrax Alt-RAMEC combined with miniscrew reinforced heavy Class III elastics resulted in a favourable and stable Class III correction.

Efficiency of compensatory orthodontic treatment of mild Class III malocclusion with two different bracket systems.

ABSTRACTObjective: The purpose of this study was to assess the efficiency of compensatory orthodontic treatment of patients with mild Class III malocclusion with two preadjusted bracket systems. Method: Fifty-six matched patients consecutively treated for mild Class III malocclusion through compensatory dentoalveolar movements were retrospectively evaluated after analysis of orthodontic records. The sample was divided into two groups according to the brackets used: Group 1 = non-Class III compensated preadjusted brackets, Roth prescription (n = 28); Group 2 = compensated Class III preadjusted brackets, Capelozza III prescription (n = 28). Cephalometric analysis, number of appointments and missed appointments, months using Class III elastics, and bond/band failures were considered. Treatment time, Peer Assessment Rating (PAR) index at the beginning (PAR T1) and end of treatment (PAR T2) were used to calculate treatment efficiency. Comparison was performed using a MANOVA at p< 0.05. Results: Missed appointments, bond or band failures, number of months using the Class III intermaxillary elastics, and cephalometric measurements showed no statistically significant difference (p> 0.05) between groups. Patients treated with Roth brackets had a treatment time 7 months longer (p= 0.01). Significant improvement in the patient’s occlusion (PAR T2-T1) was observed for both groups without difference (p= 0.22). Conclusions: Orthodontic brackets designed for compensation of mild Class III malocclusions appear to be more efficient than non-compensated straight-wire prescription brackets. Treatment time for Class III patients treated with brackets designed for compensation was shorter than with Roth prescription and no difference in the quality of the occlusal outcome was observed. A prospective randomized study is suggested to provide a deeper look into this subject.

Maxillary protraction through skeletal anchorage in growing patients. Literature review

Early treatment of skeletal Class III patients is usually handled with the use of maxillary protraction face mask. The results of this orthopedic therapy are often accompanied by adverse dentoalveolar effects. An alternative treatment is skeletal anchorage comprised of temporary anchorage devices (TADs), which uses two titanium plates fixed with mini implants placed in the zygomatic process of the maxilla and two side plates between the lower canine and right and left and the use of intermaxillary elastics. This results in maxillary advancement and improvement of facial aesthetics while reducing dentoalveolar adverse effects.

Fixed multibracket dental therapy has challenges but can be successfully performed in young persons with Down syndrome

Purpose The objective of this study was to analyze the feasibility of orthodontic treatment with fixed multibracket dental appliances (FMAs) in patients with Down syndrome (DS). Methods The study sample was formed of 25 patients with DS who underwent orthodontic treatment with FMAs. Dental and skeletal characteristics, aspects of FMA treatment, retainer use and recurrences were analyzed. Results were compared with a control group of healthy, age-, sex- and PAR index-matched individuals. Results All the controls underwent a single desensitization session, whereas 2–3 sessions were necessary in 11 patients with DS (p < 0.001). All the controls underwent bimaxillary treatment, compared with 11 patients with DS (p < 0.001). Only 8 patients with DS wore intermaxillary elastics, compared with 19 controls (p = 0.004). Complications were more common in patients with DS than in controls (p = 0.003), due particularly to traumatic ulcers development. There were more failures during the maintenance phase in patients with DS than in controls (p = 0.001). The mean duration of treatment was 37 months in patients with DS and 23 months in controls. More cemented retainers were used in the controls than in patients with DS (p = 0.050). Conclusions It is possible to perform orthodontic treatment with FMAs in patients with DS, although treatment may take longer than usual and the frequency of complications is higher than in controls.Implications for RehabilitationCertain dental characteristics of Down syndrome (DS) make these children firm candidates for orthodontic intervention.There is little literature available on orthodontic treatment in patients with DS, particularly with regard to the use of fixed appliances.This case–control study shows that it is possible to perform orthodontic treatment with fixed appliances in adequately selected patients with DS.However, in patients with DS orthodontic treatment may take longer than usual and the frequency of complications is higher than in the general population.

Integrating posture into orthodontic–surgical treatment

The correction of large inter-maxillary or craniofacial elastics often suggests orthognathic surgery, as a complement to orthodontic preparation. This depends on cephalic extremity, which generates important bone movement, affecting the centre of gravity of the head and muscular and articular activities. Many receptors act on main body balance and lead to distant lesions, when affected, just like better coordination of the jaws can help to reduce associated postural imbalance. Literature is poor in this field. We are therefore presenting some concepts of general posture and means to assess the initial postural context of our patients to optimize the integration and orientation of our ortho-surgical treatment. Overall care of patients and interdisciplinarity are factors of success and treatment stability.

The Removable Mandibular Retractor vs the Bone-anchored Intermaxillary Traction in the Correction of skeletal class III Malocclusion in children: A Randomized Controlled Trial.

No randomized controlled trial has tried to compare early class III treatment outcomes between the removable mandibular retractor (RMR) and the bone-anchored intermaxillary traction (BAIMT). The objective of this study was to evaluate skeletal, dental, and soft-tissue changes following early class III treatment with these two treatment modalities. A parallel group randomized controlled trial was conducted on patients with class III malocclusion, treated at the University ofAl-Baath Dental School in Hamah, Syria. Ninety-three children with skeletal class III malocclusion were evaluated and 41 children fulfilled the inclusion criteria. Randomization was performed using computer-generated tables; allocation was concealed using sequentially numbered opaque and sealed envelopes. Thirty-eight participants were analyzed (mean age 11.46 ± 1.28 years). They were randomly distributed into two groups receiving either the RMR or the BAIMT technique with 19 children in each (1:1 allocation ratio). The primary outcome measure was the horizontal movement of points A, B, and Pogonion. Point A showed greater anterior movement in the BAIMT group (x = 1.69 mm) than in the RMR group (x = 1.05 mm; p < 0.001). Points B and Pog showed posterior movement in the BAIMT group (x=-3.01 and -2.51 mm respectively) and anterior movements in the RMR group (x = 0.22 and 0.78 mm respectively). The BAIMT appeared to be more effective than the RMR in the correction of mild to moderate class III malocclusion in growing patients. Bone-anchored intermaxillary elastics appears to be a promising solution for class III growing patients with mild to moderate degrees of skeletal discrepancy.

Improved Superelastic NiTi wire for the Treatment of Adult Skeletal Class III Malocclusion in a Surgery-first Case

ABSTRACT A 19-year-old female came to our department with the chief complaint of facial asymmetry. Clinical examination showed skeletal class III relationship with mandibular prognathism, large reverse overjet, lower right mild crowding, and left hemimandibular elongation. After a thorough discussion with the patient, she accepted the proposal of orthognathic surgery and mandibular setback by bilateral sagittal split osteotomy (BSSRO), and therefore, tooth extraction was performed for 18, 28, 38, and 48 before the surgery. An improved superelastic Ti-Ni alloy wire (ISW wire), developed by Tokyo Medical and Dental University, was then used to facilitate the correction of lower crowding. Involved mechanism included intermaxillary elastics for a better interdigitation and jaw relationships. Adequate overbite and overjet were achieved after treatment completion. How to cite this article Fang C-Y, Tsai Y-Y, Yu J-H. Improved Superelastic NiTi wire for the Treatment of Adult Skeletal Class III Malocclusion in a Surgery-first Case. Int J Experiment Dent Sci 2016;5(2):133-138.

뇌졸중 환자에서 재발성 턱관절 탈구의 관리 : 증례보고

Temporomandibular joint dislocation causes considerable pain, discomfort, and swelling. The anatomic construction of the articular fossa and the eminentia articularis may predispose to dislocation, and weakness of the connective tissue forming the capsule is believed to be a predisposing factor. The capsule may be stretched and, more rarely, torn. Dislocation may be unilateral or bilateral and may occur spontaneously after stretching of the mouth to its extreme open position, such as during a yawn or during a routine dental operation. Manual reduction with the patient under muscle-relaxing condition or anesthesia is recommended method. After the reduction of an acute dislocation, immobilization of the jaw is recommended to allow the stretched and sometimes torn capsule to heal, thus preventing recurrence. A Barton's bandage may be applied for 2 to 3 weeks to prevent the patient from opening the jaw too wide. But, it results in recurrent dislocation in the neurologically disabled patient, because of loose intermaxillary fixation. This is a case report about management of recurrent temporomandibular joint dislocation by multiple loop wirings and intermaxillary elastics in cerebrovascular accident patient.

Force decay of latex and non-latex intermaxillary elastics: a clinical study

To evaluate force decay between intermaxillary orthodontic elastics with and without latex in the oral medium at different time intervals. Intermaxillary orthodontic elastics with and without latex [1/8″ (3.2mm), 1/4″ (6.35mm), and 5/16″ (7.94mm) in diameter] were evaluated 'clinically'. For this purpose, 26 patients served as hosts for the elastics during the evaluation period. Initially, 52 thermoplasticized plates 1mm thick were made according to the patients' mould. Then, the orthodontic accessories were bonded to the plates, which kept the elastics distended throughout the experimental period. The force released by the elastics at this distance was evaluated at 0, 12, and 24 hours. Statistical analyses were performed using the Friedman, Wilcoxon, and Mann-Whitney tests (significance set at 5 per cent). Elastics with and without latex presented with permanent deformation and increasing internal diameter throughout the entire period. Elastics with latex, 1/8″ (3.2mm) in diameter, sustained higher levels of force than those without latex. Elastics measuring 1/4″ (6.35mm) and 5/16″ (7.94mm) in diameter without latex sustained higher levels of force at 0 and 12 hours compared to those with latex. At the end of the experiment (24 hours), no significant difference was observed between the elastics (P > 0.05). This study only evaluated three time intervals: 0, 12, and 24 hours. If the behaviour was evaluated at different time intervals, different behaviours of these materials might be revealed. Elastics with latex 1/8″ in diameter sustained a higher level of final force than the corresponding type without latex. The 1/4 and 5/16 elastics with and without latex were not different at the end of the evaluation period.

Comparison of two types of biomecanics for deep overbite correction

Aim: To compare two types of treatment for Class II deep overbite malocclusion assessing maxillary and mandibular arches behavior in subjects submitted to full orthodontic treatment with standard edgewise appliance and those who used straight wire appliance. Methods: The sample consisted of 50 patients treated with full fixed appliances either with edgewise appliance (n=25, Group 1), or with straight wire appliance (n=25, Group 2). In both groups lateral cephalometric radiographs were compared with those done at the beginning of treatment and at its end, in order to quantify the cephalometric measures (8 linear and 6 angular) presenting the maxillary and mandibular arches behavior in the anteroposterior and vertical directions. All patients were treated without extraction or use of Class II intermaxillary elastics during the full orthodontic treatment. Results: In both groups the treatment of malocclusion contributed for mandibular forward displacement, reduction of deep overbite and overjet, reduction of mandibular plane with anti-clockwise rotation and labial projection of maxillary incisors. Conclusions: In both groups the sample showed favorable mandibular displacement, reduction of facial convexity, and profile improvement with anti-clockwise rotation. The correction of deep overbite was due to labial projection and intrusion of maxillary incisors.

Perception of pain due to various orthodontic procedures.

To investigate five orthodontic procedures, namely separator placement, banding, initial arch wire ligation (0.016 NiTi), T-loop activation, and use of intermaxillary elastics with respect to intensity of peak pain, time of peak pain, need of medication for pain relief, and effect on routine life due to pain. One hundred patients (52 males, 48 females) selected for comprehensive orthodontic therapy were included in the study. They were divided into five study groups, namely the separator group, banding group, initial NiTi group, T-loop activation group, and intermaxillary elastics group. Each patient was given a previously prepared questionnaire regarding the following: time of peak pain, intensity of peak pain, need for analgesic consumption, and effect on routine life. Consumption of medication for pain relief was found to be highest in the separator and the initial NiTi groups. Routine life was affected most in the intermaxillary elastics and the initial NiTi groups, but it was not statistically significant. Statistically significant differences were found between the T-loop activation and the banding groups and also between the banding and the intermaxillary elastic groups with respect to perception of intensity of peak pain. In the separator group, the time of peak pain was experienced at the 24th hour and in the rest of the groups it was at the 6th hour with most patients, although the values were not statistically significant. Peak pain intensity varies from one procedure to another. It was significantly more due to T-loop activation and wear of intermaxillary elastics than banding.

Functional treatment of skeletal Class II malocclusion using bone-anchored devices and intermaxillary elastics

Introduction: Dentofacial functional appliances used for the treatment of skeletal Class II malocclusion are divided into two groups: Removable appliances and fixed (bonded) appliances, each with certain advantages and disadvantages. Considering the problems related to functional appliances such as high volume in the oral cavity, patient noncompliance, esthetics, tissue irritation or ulceration, speech or breathing difficulties, etc., there is considerable demand to develop a new appliance that can overcome these issues. Thus, the aim of the current study is to present a hypothesis regarding a new functional treatment technique. The hypothesis: We hypothesize that by fixing mini-plates or -implants in the posterior region of the mandible and the anterior part of the infrazygomatic crest region of the maxilla using intermaxillary elastics, we can expect a forward growth of the mandible in a growing child. Using this technique, the force vector will be in the oblique (forward-upward) direction. By installing mini-plates with a long connecting bar in the infrazygomatic crest region (with the orthodontic attachment head approximating the level of the occlusal plane), and mini-plates or -implants in the most posterior and superior regions of the mandible, such as the retromolar region, the force vector can be placed in the most horizontal direction possible. Evaluation of the hypothesis: In the literature, significant growth modification results were reported in skeletal Class III patients using intermaxillary elastics and bone-anchored devices fixed in both jaws, when compared with those in the nontreatment group. Therefore, in practice, intermaxillary elastics can produce enough traction to stimulate the bone to change and grow. Thus, we presume that inverting the direction of the force vector (i.e., posterior-anterior force) may have similar growth effects on the mandibles of growing children.

Maxillary protraction using skeletal anchorage and intermaxillary elastics in Skeletal Class III patients.

The aim of this case report is to describe the treatment of a patient with skeletal Class III malocclusion with maxillary retrognathia using skeletal anchorage devices and intermaxillary elastics. Miniplates were inserted between the mandibular lateral incisor and canine teeth on both sides in a male patient aged 14 years 5 months. Self-drilling mini-implants (1.6 mm diameter, 10 mm length) were installed between the maxillary second premolar and molar teeth, and Class III elastics were used between the miniplates and miniscrews. On treatment completion, an increase in the projection of the maxilla relative to the cranial base (2.7 mm) and significant improvement of the facial profile were observed. Slight maxillary counterclockwise (1°) and mandibular clockwise (3.3°) rotations were also observed. Maxillary protraction with skeletal anchorage and intermaxillary elastics was effective in correcting a case of Skeletal Class III malocclusion without dentoalveolar side effects.

Comparison of dentofacial effect of the Eureka Spring and intermaxillary elastics in the treatment of Class II malocclusions

Comparison of dentofacial effect of the Eureka Spring and intermaxillary elastics in the treatment of Class II malocclusions

Comparison of 2 types of treatment of skeletal Class II malocclusions: a 5-year post-retention analysis

Aim: To compare 2 types of treatment for Class II malocclusion assessing mandibular behavior in subjects submitted to full orthodontic treatment with standard edgewise appliance and cervical headgear (Kloehn appliance) and those who used cervical headgear in the first period and with full orthodontic appliance in the second period. Methods: The sample consisted of 80 children treated with either cervical headgear combined with full fixed appliances (n=40, group 1), or with cervical headgear at first (n=40, group 2). In both groups, lateral cephalometric radiographs were compared with those made at the beginning of treatment, at its end and at 5-year post-retention phase, in order to quantify the cephalometric measures (8 angular and 3 linear), presenting the mandibular behavior in the antero-posterior and vertical directions. All patients were treated with no extraction and no use of Class II intermaxillary elastics during the full orthodontic treatment. Results: In both groups, the effective treatment of skeletal Class II malocclusion did not interfere in the direction and amount of growth of mandibular condyles and remodeling at the lower border, with no influence on the anti-clockwise rotation of the mandible. The mandibular growth also was observed after the orthodontic treatment, suggesting that it is influenced by genetic factors. Conclusions: These observations may lead to the speculation that growing patients with skeletal Class II malocclusion and low mandibular plane are conducive to a good treatment and long-term stability with one or two periods of treatment.

Non-Osteotomy Treatment of Class III Skeletal Malocclusion Using Bollard Plates

A total of 14 patients were enrolled in the study at cervical vertebral maturation stage CVM2. Bilateral FDA approved miniplates (Bollard plates) were surgically inserted in the infrazygomatic crests of the maxilla and between the canine and the lateral incisor in the anterior mandible. The patients were treated by intermaxillary elastics for an average of 16 months. Cephalometric analysis was done before, during and at the end of the treatment. Intraoral and extraoral photographs were taken for comparisons. In this study, we analyze the effect of maxillary advancement in patients with class III skeletal malocclusions using a nonosteotomy technique that produces combined maxillary advancement and mandibular retraction using bone anchored Bollard plates (Tita-Link, Brussels, Belgium). We evaluate the change in WITS appraisal and ANB values for each patient before and after treatment. OMaxillary hypoplasia is frequently found in Class III Malocclusion patients O Traditional Treatment options include use of protraction face mask anchored to dentition or a more invasive Le Fort osteotomy OBone Anchored Maxillary Protraction devices provide skeletal anchorage O Requires active sutures in growth phase, skeletal anchorage buttress and remodeling of adjacent bone OLess invasive than osteomies

Therapeutic Outcomes in the Treatment of Unilateral Glenoid Fossa Fractures Using Intermaxillary Elastic Traction

This study aimed to evaluate the therapeutic outcomes of intermaxillary elastic traction in the treatment of unilateral glenoid fossa fractures. Five patients with traumatic unilateral glenoid fossa fractures were treated with intermaxillary elastic traction at the Sun Yat-Sen University Hospital of Stomatology during a 5-year period from 2006 to 2011. Pantomography and Schüller position radiographs were obtained at days 7, 28, and 90 to monitor glenoid fossa fracture healing. Removal of the intermaxillary elastic traction and the arch bar splint occurred at day 90, and the patients were advised to initiate mouth-opening exercises. Schüller position radiographs revealed a 100% reduction rate of the glenoid fossa fracture for all patients; morphologies of the glenoid fossa and mandibular condyle were normal. Follow-up ranged from 6 months to 2 years. The occlusal relationship (degree of mouth opening) was excellent in all cases. Patient recoveries were uneventful; no complications occurred such as pain, snapping, or limitations of mouth opening. Average mouth opening was measured at 3.6 cm at the last follow-up. Intermaxillary elastic traction is an effective, simple, and feasible method in the treatment of a glenoid fossa fracture. Accurate reduction and stable fixation may be achieved without significant complications.