Comparison between Classic Twin-block and a Modified Clear Twin-block in Class II, Division 1 Malocclusions: A Randomized Clinical Trial.

AIM: The aim of this study was to compare dentoskeletal effects and patient's satisfaction with a modified twin-block (clear twin-block) and classic twin-block. MATERIALS AND METHODS: A total of 62 patients with skeletal class II malocclusion contributing to mandibular retrognathism with a minimum of 4 mm overjet, the FMA angle between 20 to 25 degree and being in stage 2 to 3 of cervical vertebral maturation participated in this study. Subjects were randomized in 1:1 ratio to classic and clear twin-block. Lateral cephalograms were taken at two stages-Pre- and post-treatment (when the overjet reduced to 1 to 0 mm). All the measurements were done with Dolphin software version 10.5. Four months after the start of the treatment the patients were asked to fill the questioners regarding their compliance from the appliances. RESULTS: Both classic and clear twin-block groups showed mandibular advancement without statistically significant difference between them. However, SNB angle increased slightly more in clear group than the classic one. "Headgear effect" is not statistically noticeable in both groups. However, SNA angle decreased slightly more in classic group. Increased in lower incisors proclination was happening in both groups, but in a clear group, this increase was significantly less. Overbite reduction could be seen in both groups with significantly more reduction in the classic group. CONCLUSION: Increase in lower incisors proclination was less in clear group than the classic one. Overbite reduction was more in the classic group than the classic one. CLINICAL SIGNIFICANCE: Clear twin-block is more beneficial in skeletal class II patients with proclined lower incisors and vertical growth pattern.

Effect of removable functional appliances on mandibular length in patients with class II with retrognathism: systematic review and meta-analysis.

BACKGROUND: Orthopedic functional devices, are used to improve mandibular length in skeletal class II patients. However, the orthopedic functional device with the best effect to increasing the mandibular length, has not been identified before. Thus, the aim of the present investigation was to evaluate Randomized Controlled Trials (RCT), to determine the best functional appliance improving mandibular length in subjects with retrognathism. METHODS: A systematic review and meta-analysis was performed, including studies published and indexed in databases between 1966 and 2016. RCTs evaluating functional appliances' effects on mandibular length (Condilion-Gnation (Co-Gn) and Condilion-Pogonion (Co-Po)), were included. Reports' structure was evaluated according to 2010 CONSORT guide. The outcome measure was distance between Co-Gn and/or Co-Po after treatment. Data were analyzed with Cochran Q Test and random effects model. RESULTS: Five studies were included in the meta-analysis. The overall difference in mandibular length was 1.53 mm (Confidence Interval (CI) 95% 1.15-1.92) in comparison to non-treated group. The Sander Bite Jumping reported the greatest increase in mandibular length (3.40 mm; CI 95% 1.69-5.11), followed by Twin Block, Bionator, Harvold Activator and Frankel devices. CONCLUSIONS: All removable functional appliances, aiming to increase mandibular length, are useful. Sander Bite Jumping was observed to be the most effective device to improve the mandibular length.

A hinged two-part partial denture used in conjunction with severely tilted teeth: a case report.

A two-part sectional denture can be a useful treatment option when the presence of severe hard tissue undercuts compromises the provision of a satisfactory conventional prosthesis. This article presents a case report illustrating the effective use of a hinged two-part denture in restoring a mandibular Kennedy Class IV edentulous area. A sectional denture approach was selected because of severe proximal and lingual undercuts.

Virtual surgical planning for treatment of severe mandibular retrognathia with collapsed occlusion using contemporary surgical and prosthodontic protocols.

PURPOSE: To meet functional and esthetic needs in an older adult for treatment of complex skeletal and dentoalveolar deformities using contemporary surgical and prosthodontic protocols. METHODS: An older adult with dentoalveolar complex and skeletal deformity (mandibular retrognathia) was treated by a combination of virtual planning and current surgical and prosthodontic protocols. Treatment planning steps and sequencing are presented. RESULTS: Skeletal, soft tissue, and dental harmonies were attained without biological or mechanical complications. Definitive oral rehabilitation was completed with a maxillary complete denture and a mandibular metal ceramic fixed implant-retained prosthesis. CONCLUSIONS: A surgical and prosthodontic team approach in combination with technologic advances can predictably optimize esthetic and functional outcomes for patients with complex skeletal and dentoalveolar deformities.

An implant-supported overdenture design with a horizontal path of insertion.

The rehabilitation of the atrophic maxilla by means of implant-supported prostheses cannot always be achieved with fixed prostheses because of anatomic, esthetic, or economic issues, so for some patients the treatment of choice is a removable prosthesis. This article analyzes a new design for implant-supported overdentures with horizontal or faciolingual insertion. Its retention system is based on frictional forces or stepped interlocking horizontal surfaces and is appropriate for patients with skeletal Class II or III relationships with severe maxillary atrophies. The design facilitates implant-prosthetic hygiene and improved esthetics in patients with nonparallel implants by hiding abutment screws.

Complex prosthodontic treatment with dental implants for a patient with polymyalgia rheumatica: a clinical report.

Prosthodontic and implant treatment for a patient with polymyalgia rheumatica can be complicated not only by its symptoms, but also by the side effects of long-term use of certain medications, particularly systemic glucocorticoids. This clinical report presents a polymyalgia rheumatica patient who required full-mouth rehabilitation with dental implants. The patient had a sensitive gag reflex and refused the use of any removable prostheses. She presented clinically with a skeletal Class II malocclusion with severe overbite and overjet. All her remaining dentition was determined to be unrestorable. Full-mouth extractions and immediate placement of implants followed by early implant loading were performed. The use of systemic glucocorticoids might have exacerbated her type 4 maxillary bone and compromised her healing capacity and consequently made implant surgery challenging. Her treatment with full-arch fixed implant-supported dentures to correct her severe overbite and overjet and manage misaligned dental implants is summarized here. The effects of polymyalgia rheumatica in prosthodontic and dental implant treatments are reviewed and discussed.

Static magnetic field combined with functional appliances: a new approach to enhance mandibular growth in Class II malocclusion.

Class II malocclusion is one of the most common orthodontic problems. The main aetiology of Class II malocclusion is mandibular retrognathia. A variety of functional appliances have been used to stimulate mandibular growth in adolescence, however, the effects remain unsatisfactory. Therefore, new approaches are in need to strengthen the effects of functional appliances. Static magnetic field (SMF), created by permanent magnets, has long been proven to be clinically safe and is well accepted as a practical and non-invasive therapy. Numerous experimental and clinical data suggest that exogenous SMF can make profound effects on a large variety of biological systems. There has been increasing interest in curing bone injuries with SMF. More recently, literatures shed light on the chondrogenic and osteogenic effects of SMF. SMF and functional appliances may well have a synergistic effect in mandibular growth promotion. Based on experimental results and theoretical analysis, it is hypothesized that SMF combined with functional appliances can enhance mandibular growth in Class II malocclusion. A practical clinical design is also put forward.

Correlation- and covariance-supported normalization method for estimating orthodontic trainer treatment for clenching activity.

In this study, electromyography signals sampled from children undergoing orthodontic treatment were used to estimate the effect of an orthodontic trainer on the anterior temporal muscle. A novel data normalization method, called the correlation- and covariance-supported normalization method (CCSNM), based on correlation and covariance between features in a data set, is proposed to provide predictive guidance to the orthodontic technique. The method was tested in two stages: first, data normalization using the CCSNM; second, prediction of normalized values of anterior temporal muscles using an artificial neural network (ANN) with a Levenberg-Marquardt learning algorithm. The data set consists of electromyography signals from right anterior temporal muscles, recorded from 20 children aged 8-13 years with class II malocclusion. The signals were recorded at the start and end of a 6-month treatment. In order to train and test the ANN, two-fold cross-validation was used. The CCSNM was compared with four normalization methods: minimum-maximum normalization, z score, decimal scaling, and line base normalization. In order to demonstrate the performance of the proposed method, prevalent performance-measuring methods, and the mean square error and mean absolute error as mathematical methods, the statistical relation factor R2 and the average deviation have been examined. The results show that the CCSNM was the best normalization method among other normalization methods for estimating the effect of the trainer.

Pharyngeal dimensional changes in class II malocclusion treatment when using Forsus® or intermaxillary elastics - An exploratory study.

OBJECTIVE: Pharyngeal airway obstruction can facilitate some forms of sleep disorder breathing (SDB) in susceptible children, especially in those having class II malocclusion. Changes in the anatomic areas surrounding the pharyngeal region during orthodontic treatment could hypothetically impact the pharyngeal airway dimensions. Management of a class II malocclusion on a growing individual with either intermaxillary elastics or different removable or fixed class II appliance designs have been proposed over the last century. The objective of this retrospective exploratory cohort study is to investigate to what extent the class II malocclusion treatment with either intermaxillary elastics (IME) or Forsus® fatigue resistance device (FFRD) leads to changes in oropharyngeal airway dimensions. MATERIALS AND METHODS: Twenty-nine patients diagnosed as class II with an average age of 12.7years were included in this study, (11 males, 18 females). The sample was divided into group 1: IME and group 2: FFRD. CBCT's scans before (T1) and after treatment (T2) were obtained and analysed using Dolphin software. Reliability was obtained using Intraclass Correlation Coefficient (ICC). Descriptive statistics, ANOVA and paired t-test were used for analysis. RESULTS: Intra-rater reliability test was excellent in all measurements for both groups. There were no statistically significant differences in pharyngeal airway dimensions between both groups (P=0.919). A statistically significant correlation was found for sex, where male patients had the highest increase in oro-space area (ORS), and in oropharyngeal volume. Children under 14-year-old in IME group showed statistically negative correlation for sub-mandibular (SM) and for ORS, meaning the younger the greatest increase. Additionally, individuals younger than 14years had a statistically significant increase in the vertical dimension. CONCLUSIONS: Both orthodontic treatment approaches appear to be associated with a similar increase in oropharyngeal airway dimensions. Male patients under 14-year-old had a greater significant increase compared to female patients and older children. Normal pharyngeal dimensions changes were not accounted for.

[Orthodontics in general dental practice 6. Treatment of Angle Class II/1 malocclusions]. / Orthodontie in de algemene tandartspraktijk 6. Behandeling van Angle klasse II/1-malocclusies.

Four patients with a Class II/1 malocclusion were treated. Despite their common malocclusion, the 4 patients had a different skeletal and dentofacial structure, which resulted in four different treatments. Whether treatment is indicated and which treatment is preferable depends on many factors, such as expected jaw growth, the possibility of jaw adaptation, the motivation of the patient and his or her parents and psychological factors. In the case of children and young adolescents a Class II/1 malocclusion can be treated with orthopaedic appliances, in which case natural growth and adaptation mechanisms of the face and jaw are exercised in the correction. In treating these 4 patients, both functional and extra-oral orthopaedic appliances were used.

[Cervical headgear treatment and growth patterns: analysis by lateral cephalometry].

OBJECTIVE: Retrospective cephalometric study of changes in vertical and sagittal relations after headgear treatment depending on preexisting growth patterns. MATERIALS AND METHODS: Lateral cephalograms obtained from 119 patients before and after headgear treatment were analyzed. All patients were treated with headgears exclusively. Only cases were included that showed bilateral improvement of least 4 mm in Class II occlusion after headgear treatment lasting at least 6 months. Patients were assigned to six groups based on y-axis values obtained at baseline. RESULTS: Almost all groups revealed substantial improvements in skeletal Class II relations, including 1.38 degrees-1.72 degrees reductions in ANB angles and 0.62-0.81 mm reductions in Wits values. SNA values fell by 0.51-1.25 degrees. SNB angle values increased by 0.21 degrees-0.95 degrees. SN-MeGo angles and mandibular angles were reduced, while y-axis values remained essentially unchanged during headgear treatment. Different results were only obtained in the group with the most pronounced horizontal growth pattern. Those patients revealed lower SNB angle values (-0.93 degrees ) and increased vertical relations (y-axis: +1.39 degrees ; SN-MeGo angle: +1.22 degrees; mandibular angle: +0.01 degrees) after headgear treatment. All groups showed a reduction in basal plane angles and maxillary retroinclination after treatment. CONCLUSION: Our results do not support the conventional recommendation that cervical headgears should not be used in the presence of vertical growth patterns.

Complications during Herbst appliance treatment with reduced mandibular cast splints : a prospective, clinical multicenter study.

OBJECTIVE: To assess and compare the prevalence, type and frequency of complications during Herbst treatment with reduced (canine to 2nd premolars) and total (canine to molars) mandibular cast splints. SUBJECTS AND METHODS: Fifty consecutive Herbst patients treated with reduced mandibular splints (RMS) were compared to 182 consecutively treated Herbst patients with total mandibular splints (TMS). The prevalence, type and frequency of complications were analyzed. RESULTS: The prevalence of patients with complications did not differ significantly between the groups, and amounted to 58% in the RMS- and 60% in the TMS-group. The most frequent type of complication in both groups was maxillary splint loosening, making up 56.3% of all complications in the RMS- and 66.9% in the TMS-group. The second most frequent complication was mandibular splint loosening, which amounted to 32.5% of the complications in the RMS- and 26.8% in the TMS-group. We observed telescope breakage twice as often (8.8%) in the RMS- as in the TMS-group (4.3%). CONCLUSIONS: Loosening of the maxillary splints is the main complication during Herbst treatment with RMS and TMS. A reduction in mandibular splint length does not increase the prevalence of complications, but it does reduce expenses, and can thus be recommended for further use.

Preparation guidelines for less-invasive cosmetic restorations.

This article discusses the trend toward less-invasive restorative procedures. Two cases that required different approaches to similar restorations are documented. Understanding a systematic preparation philosophy allows clinicians to be consistent regarding both their approach and the expected results. The use of wax-ups and preparation guides to achieve predictable esthetic restorations is shown, both visually and technically.

Treatment outcome in angle class II, division 1 patients in pre-puberty and puberty after jumping-the-bite appliance.

AIM: The aim of this study was to investigate whether, and if so, to what extent, skeletal and dento-alveolar developments of the stomatognathic system take a different course due to influence of Tränkmann's jumping-the-bite appliance (JTB) in pre-pubertal and pubertal patients in comparison to untreated control groups presenting the same conditions at baseline. We aim to discover whether the results are better when the device is used on prepubertal children, or those in puberty. PATIENTS AND METHODS: Two lateral cephalograms were scanned in treated children presenting Angle Class II, Division 1 malocclusion; they were scanned in untreated children with the same distoclusion at intervals between at least 11 months and at most 25 months. The same procedure was taken in children in pre-puberty (female, min. = 8.6 yrs, max. = 11 yrs; male, min. = 9 yrs, max. = 12.6 yrs) and in puberty (female, min. = 11 yrs, max. = 14 yrs; male, min. = 12.6 yrs, max. = 15 yrs). The cephalometric analysis was made with the orthodontics-PC-program Onyx Ceph (Image Instruments, Chemnitz, Germany) using a modified Bergen/Hasund analysis [7, 8]. RESULTS: The Angle Class II, Division 1 malocclusion of all treated patients evolved into an Angle Class I occlusion via Tränkmann's JTB design. The location of this transformation was mainly dento-alveolar in both pre-puberty and puberty. The differences between the control and JTB groups concerning the development of cephalometric values in pre-pubertal age were unremarkable if one considers the range of reading error. The exception to this was with angleUP1-NA, which increased more in the control group than in the treated group. angleSNB, arB (mm), angleANB and angleML-NSL showed greater change in the targeted direction in the control group than in the JTB group in pubertal patients. The increase in the arA length (mm) was clearly, but not statistically significantly, inhibited by the JTB in puberty. Comparing both treated groups, one can conclude that cephalometric values developed more favorably in the pre-pubertal than in the pubertal patients, with the exception of angleSNA.

Treating Class II patients with removable plates and functional orthopedic appliances-the importance of anterior tooth inclination and direction of growth on treatment outcome.

OBJECTIVE: To determine the influence of physiological growth pattern and anterior tooth inclination on the outcome in Class II patients treated with removable orthodontic plates and functional orthodontic appliances. PATIENTS AND METHODS: After recruiting 50 patients with an upper anterior proclination of 1-SN >or= 107 degrees for this retrospective study, another 50 patients with a retroclination of 1-SN

Disc-condyle Relationships during Class II Treatment with the Functional Mandibular Advancer (FMA).

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

Kooperation von Kieferorthopädie, Kieferchirurgie und Prothetik bei der umfassenden Rehabilitation von DysgnathiepatientInnen. Teil 2: Fallbeispiel Klasse-II-Malokklusion, Tiefbiss, Hypodontie.

Dental aplasia of heterogenous etiology may cause jaw growth disturbance, malocclusion, esthetic discontent and psychosocial impairment. By a case report of a young patient suffering from hypodontia, class II malocclusion and a deep bite the intricate interdisciplinary diagnosis- and treatment-protocol targeting the functional and esthetic rehabilitation is illustrated.

Mouth opening and its influencing through the SII appliance during the night.

In twelve patients, 43 nocturnal sleep investigations were carried out telemetrically. These investigations were aimed at contributing towards answering the questions of how large the interocclusal distance is during the night, whether there is a correlation with the growth pattern, and whether this interocclusal distance can be changed by using Class II elastics. The treatment appliance chosen was the SII appliance. During nocturnal sleep, all patients slept with their mouth more or less open. The largest interocclusal distance was found in patients with a vertical growth pattern as well as in one patient in whom an allergic reaction to the house dust mite was later verified. The active phase during nocturnal sleep comprised between 200 and 800 biting actions during the entire sleeping period and corresponded to an activity of about 10 minutes. During nocturnal sleep there were rarely complete mouth closures, even during diverse swallowing actions. Patients with a horizontal growth pattern showed the smallest interocclusal distance, provided that nasal breathing was not obstructed. The additional application of Class II elastics had a positive effect on the interocclusal distance in all patients. A shortening of the protrusive bars must be avoided in all events; otherwise there may be no protrusion when biting together. The long bars of the SII appliance have an influence on the maxilla, because there is contact between maxilla and mandible up to mouth openings of about 14-16 mm.

The influence of functional therapy on facial and dental structures. Case presentation.

In the era of fixed appliances, some orthodontic practitioners seem to forget about functional therapy. Functional appliances are the only capable of orthopedically changes during the growth spurt. Activators of all types, classic or opened, are elected appliances in growing subjects with class II/1 anomalies. The appropriate case selection, along with patient compliance, lead to improved facial aesthetic and dental occlusion, at affordable prices. With this case presentation, we want to show our protocol in the management of these cases.

Class II division 2 treatment--does skeletal maturity influence success and stability?

AIM: To analyze the influence of skeletal maturity on Herbst multibracket (MB) treatment of Class II division 2 malocclusions and its stability. MATERIAL AND METHODS: A total of 37 patients fulfilled the inclusion criteria (Class II division 2, fully erupted premolars and canines, Class II molar relationship ≥1/2 cusp widths bilaterally or 1 cusp width unilaterally, retention period ≥24 months). According to pretreatment hand wrist skeletal maturity the subjects were assigned to the groups EARLY (n=9), LATE (n=14) and ADULT (n=14). Lateral headfilms (T1: before treatment, T2: after Herbst MB treatment, T3: after retention) were analyzed using the Sagittal-Occlusal analysis and standard cephalometrics. RESULTS: During Herbst MB treatment (T2-T1), significant (p<0.001) molar relationship improvement was seen in all groups (EARLY: 3.6 mm; LATE: 3.7 mm; ADULT: 3.2 mm). The amount of skeletal effects contributing to molar correction varied markedly between the groups (EARLY: 19%; LATE: 62%; ADULT: 31%). Improvement (p<0.01) was also seen for ssNB angle (EARLY: 1.8°; LATE: 1.8°; ADULT: 0.9°) and overbite (EARLY: 3.3 mm; LATE: 4.5 mm; ADULT: 4.3 mm). During retention (T3-T2), minimal changes of molar relationship (<0.2 mm) and ssNB angle (<0.5°) were seen in all groups. Also the overbite relapsed (EARLY: 0.5 mm; LATE: 1.0 mm; ADULT: 1.1 mm) only to a clinically irrelevant extent. CONCLUSION: Irrespective of skeletal maturity, Herbst MB treatment of Class II division 2 malocclusions showed to be successful and stable. However, the LATE group showed the highest amount of skeletal effects contributing to the correction of the molar relationship.