Twin Block Research Articles

Study on the changes of soft and hard tissue before and after early treatment of ClassIIskeletal malocclusion with Twin-block appliance

PURPOSE To investigate the effect of early correction with Twin-block appliance on soft and hard tissues of patients with Class Ⅱ skeletal malocclusion. METHODS Sixty patients with Angle Class Ⅱ skeletal malocclusion were prospectively selected. The patients were divided into 2 groups, 30 cases in each group, by random number table method. Patients in the experimental group were treated with a Twin-block appliance combined with straight wire appliance, while patients in the control group were treated with a straight wire appliance. The soft and hard tissue indexes(SNA, SNB, ANB, U1-NA angle, U1-NA distance, L1-NB distance, L1-NB angle, U1-L1) before, and 12 months after treatment were measured. Soft tissue measurement indicators included UL-U1, LL-L1, over jet, overbite, E-upper-lip from the upper lip to the E-line, and the lower lip to the E-line, changes in the vertical distance (E-lower-lip), the dip angle of the sulcus, and the thickness of the soft tissue. SPSS 25.0 software package was used for statistical analysis of the data. RESULTS U1-NA, U1-NA, L1-NB, L1-NB, overjet, overbite, E-upper-lip, and E-lower-lip were significantly less than the control group at 12 months and 36 months after treatment in the experimental group(P<0.05). U1-L1, nasolabial angle, sulcus angle, and soft tissue thickness of the experimental group were significantly greater than those of the control group(P<0.05). CONCLUSIONS Twin-block appliance combined with straight wire appliance can significantly improve the relationship between the jaw and the soft and hard tissues of patients with Class Ⅱ skeletal malocclusion, and the long-term effect is good.

Predictors of patient compliance during Class II division 1 malocclusion functional orthodontic treatment

To determine factors that could predict Class II/1 malocclusion patient compliance during functional treatment. The sample consisted of 77 subjects (aged 11-13 years; 47% girls) presenting with Class II/1 malocclusion. Inclusion criteria were distal molar relationship, overjet greater than 5 mm, and confirmed pubertal growth spurt. Removable functional appliances (62% Twin Block [TB], 38% Sander Bite Jumping [BJ]) with built-in maxillary expansion screws were used. Follow-up period was 1 year. Patients and parents independently filled out the Child Perception Questionnaire, Parental/Caregiver Perception Questionnaire, and Family Impact Scale to assess emotional and social well-being, oral symptoms, functional limitations, parental emotions, family activities, conflicts, and financial burden as possible predictors of compliance during treatment. Sex, overjet, and appliance type were also analyzed. There were more noncompliant than compliant patients (55% vs 45%). Parental perception of altered emotional well-being of their children was the strongest predictor, increasing compliance odds 3.4 times (95% confidence interval [CI], 1.2-9.4; P = .017). Patients were 3.2 times (95% CI, 1.1-9.3; P = .033) more likely to cooperate with TB compared with BJ appliance. OJ ≥ 8 mm increased compliance odds 3.1 times (95% CI, 1.0-9.4; P = .044). Parental perception of child's emotional well-being alteration, severity of malocclusion, and type of appliance are major predictors of compliance. Psychosocial issues and oral function limitations reported by children and family impact are of negligible influence.

Evaluation of skeletal changes in mandibular ramus height, corpus length, and mandibular angle changes following twin block appliance therapy using cone-beam computed tomography: A clinical prospective study

Aim and Objectives: This study aims to evaluate the skeletal changes in mandibular ramus height, corpus length, and mandibular angles changes following twin block (TB) functional appliance therapy using cone-beam computed tomography (CBCT).Methodology: Fifteen patients with skeletal Class II, growing of 9–14 years of age with mandibular retrognathism, were treated with TB functional appliance treatment. Pretreatment CBCT and posttreatment CBCT were taken (T0) before treatment and (T1) at the end of the 12 months following TB therapy. The data obtained are analyzed and compared for the skeletal changes in ramus height, corpus length, and mandibular angle changes following therapy. Student's paired t-test was used compare the pre- and post-treatment periods.Results: The test results demonstrate that the Ramus height (mm) in posttreatment period was significantly increased as compared to pretreatment period. The mean increase of 1.23 mm in the ramus height between pre- and post-treatment period was statistically significant at P < 0.001, and that the corpus length (mm) in posttreatment period was significantly increased as compared to pretreatment period. The mean increase of 3.35 mm in the corpus length between pre- and post-treatment period was statistically significant at P < 0.001, and demonstrate that the mean gonial angle (degrees) in posttreatment period was significantly increased as compared to pretreatment period. This mean increase of 3.18° in the gonial angle between pre- and post-treatment period was statistically significant at P < 0.001.Conclusion: TB appliance therapy increases the ramus height, and corpus length stimulating the growth of condyle in backward and upward direction and increases the gonial angle by backward rotation of mandible.

Mandibular advancement with clear aligners in the treatment of skeletal Class II. A retrospective controlled study.

The current study aimed to analyse the dentoskeletal effects of the Invisalign mandibular advancement (MA) device in the treatment of skeletal Class II malocclusions. Pre-treatment and post-treatment lateral skull radiographs from patients treated with MA versus TB (Twin-Block Appliance) at the Department of Orthodontics of the University of L'Aquila, Italy, were traced. Eligibility criteria included SNB<78; ANB>4; no previous orthodontic treatments; and vertebral maturation stage (CVM) CS3. Radiographs from patients with craniofacial anomalies, or who underwent extraction treatments, were excluded. Totally, 20 patients were examined, 10 of whom treated with MA and 10 treated with TB. All the radiographs were traced by one expert operator, blind to the groups. A preliminary method error study was performed to exclude intra-operator differences. Baseline characteristics of the participants were similar between the groups. Both appliances demonstrated a reduction of SNB and ANB angle, and a decrease in overjet. TB demonstrated a higher efficacy in increasing mandibular dimensions. A significant retroinclination of the upper incisive was observed in the TB group, where a decrease of SNA angles was additionally observed. The resulting differences between the two groups could be attributed to the different design of the appliances. The present data show the effectiveness of both TB and MA in the management of skeletal Class II malocclusions due to mandibular retrusion. But some differences exist in the dentoalveolar effect of the two appliances. MA seems indicated in Class II cases where a control of the upper frontal teeth position is needed.

Management of skeletal class II malocclusion with twinblock and headgear followed by fixed orthodontic appliance: Case report

A 12 year old boy presented with class II skeletal and dental relationship due to prognathic maxilla and retrognathic mandible with excessive overjet and 100% deepbite. He was treated with 2 phase treatment by phase 1 growth modification therapy using twinblock appliance with combination pull headgear to improve his profile followed by phase II fixed mechanotheraphy to settle his occlusion. Pretreatment, postfunctional and posttreatment records are shown and treatment stability after 2 years are also shown.

Myofunctional Therapy Using Twin Block Appliance in a Class II Malocclusion Patient with ADHD Author(s)Yufita Fitriani, Mega Moeharyono Puteri, Sindy Cornelia Nelwan, Nur Masyitah Iskandar Putri

A 9-year-old male ADHD patient with class II dentoskeletal malocclusion came to the Pediatric Department of Universitas Airlangga, Surabaya, with a chief complaint of a protrusive look. The patient had a behavior disorder of ADHD (Attention Deficit Hyperactivity Disorder), in which its symptoms may be challenging in dental treatment since it heavily depends on the patient’s obedience and case selection. References and similar studies of myofunctional therapy in Class II Malocclusion Patients with ADHD are still scarce. Most patients with class II malocclusion present with hyperactive perioral muscle and altered tongue position. Hence, myofunctional appliance is a reliable treatment choice. A special rule where the patient was asked to focus on the operator’s instruction for 10 minutes and then a 5-minute break, was applied to this patient to overcome ADHD symptoms as a behavior management strategy. This is in line with a theory stating that children with ADHD are prone to distraction, causing them to have a shorter duration of focus, limited sustained attention span, poor impulse control, and motor overactivity compared to normal children. This strategy gave a positive result in maintaining the cooperation of the patient using the twin block for 6 months which is lead to positive progress in malocclusion correction.

Pharyngeal airway, hyoid bone, and soft palate changes after Class II treatment with Twin-block and Forsus appliances during the postpeak growth period

This study aimed to compare cephalometrically the pharyngeal airway, hyoid bone, and soft palate (SP) changes after Class II malocclusion treatments using Twin-block (TWB) and Forsus Fatigue Resistant Device (FFRD) (3M UnitekCorp, 3M Dental Products, Monrovia, Calif) during the postpeak growth period. Forty-two patients with Class II malocclusion treated during the postpeak growth period were randomly and retrospectively included in this study. These patients were divided into 2 treatment groups: TWB and FFRD. The skeletal, dental, pharyngeal airway, hyoid bone position, and SP measurements were obtained from the lateral cephalometric radiographs taken at the beginning and at the end of the treatment. Paired-samples and independent-samples t tests were used for the intragroup and intergroup comparisons, respectively. In the TWB group, the SNB (°), Md1-NB (mm), Md1-NB (°), and McNamara upper and lower pharyngeal airway dimensions significantly increased, whereas the ANB (°), AD1-Ba (mm), AD2-H (mm), adenoidal nasopharyngeal area, and SP angle decreased (P<0.05). In the FFRD group, the SNB (°), Md1-NB (mm), Md1-NB (°), Ptm-Ba (mm), and McNamara upper airway dimensions significantly increased, whereas the ANB (°), AD2-H (mm), and interincisor angle decreased (P<0.05). Moreover, there were statistically significant differences in the Md1-NB angles and SP thicknesses between the 2 groups (P<0.05). The effects of TWB and FFRD treatment on the airway during the postpeak growth period were similar. However, the FFRD caused a greater mandibular incisor protrusion.

Treatment with Twin-block appliance followed by fixed appliance therapy in a growing Class II Class II Div 1 patient – A case report

Intraoral examination revealed poor oral hygiene He was in late mixed dentition. He had Class II Div I malocclusion with excessive overjet&#x0D; Overjet 9mm ,Overbite: 8mm which is represent 100% of lower incisors overlapped by upper incisors ,Mandibular to maxillary midline is deviated to the left by 2 mm. left Molars: full unit Class II , Canines: N.A Right Molars: 3/4 unit Class II , Mild crowdng upper : - 5 mm and lower : - 6 mm ,overlapped upper central incisors ,Proclined upper incisors .There was no transverse discrepancy . However, during TMJ evaluation, he did not report any muscle pain, joint pain, or other symptoms typically associated with temporomandibular disease.

The efficacy of twin block in increasing the mandibular length: A cephalometric study

Introduction: Angle’s Class II Div 1 malocclusion is one of the most common malocclusions in orthodontics. In cases of Angle’s Class II Div 1 malocclusion with mandibular deficiency, myofunctional appliances are often used with the intent of stimulating mandibular growth. Twin block is one of the most popular myofunctional appliances. Aim: The aim of this study was to find out “Does the length of mandible increase with Twin Block appliances” using cephalometric radiograph. Materials and Methods: Cephalometric radiographs of 15 patients who had Class II Div I malocclusion, before and after treatment were examined. The mean changes after Twin Block were compared with pre-treatment parameters using independent‘t’ test. Results: There were statistically significant differences in Pre and Post-treatment mandibular length. Patients treated with twin block appliance showed a mean increase of 4 mm in the mandibular length. Conclusion: Twin Block is an effective myofunctional appliance which can be used to increase the effective mandibular length in patients with skeletal Class II Div I malocclusion. Keywords: Functional appliance, Class II malocclusion, Twin block

Effects of functional therapy on hyoid bone, pharyngeal airway and tongue position in class II patients

Aim: The aim of this study is to evaluate the change in the position of hyoid bone, pharyngeal airway, and tongue position in subjects with skeletal Class II malocclusion treated with Twin block therapy. Materials and Methods: This study was performed on pre and post treatment lateral cephalograms of 21 patients with class II malocclusion treated with Twin block appliance, (mean age of (12.24± 1.22). Paired-t test was used to compare the amount of differences of mean value before and after treatment. A value of P

Evaluating the Agreement between the Twin-Block Appliance and a New Low-Cost Arch Development Appliance in Changing the Mandibular Length

Aim: The main objective of this study is to compare the development of mandibular length by comparing the effectiveness of a new low-cost arch development appliance in increasing the length of the mandible with the twin block appliance (Twin-B).&#x0D; Methodology: This analysis was performed on patients who attended the clinic in the Division of Orthodontics, Faculty of Dental Sciences, University of Peradeniya. The sample included 60 subjects treated with Twin-B (n=30) and new low-cost arch development (n=30) appliances and each appliance comprised 15 males and females. Intraclass Correlation Coefficient (ICC) and the Concordance Correlation Coefficient (CCC) were calculated to check the agreement between the two methods. A mixed-effects model was fitted to predict mandibular length, and Akaike Information Criterion (AIC), Bayesian Information Criterion (BIC), and log-likelihood were used for selecting the best model.&#x0D; Results: It was observed that the Concordance Correlation Coefficient (CCC) for after treatment as 0.9172 with a (0.8488, 0.9555) 95% confidence interval. Furthermore, it gives a Pearson correlation of 0.9609 and bias correlation factor of 0.9545. ICC values after treatment for both single measures and average measures are 0.9499 and 0.9743 with the 95% confidence intervals (0.8976, 0.9758) and (0.9460, 0.9878) respectively.&#x0D; Conclusion: Besides, both Twin-B and new low-cost arch development appliances have a better agreement and can be used interchangeably. Therefore, the new low-cost arch development appliance is more suitable as a treatment for malocclusion for Sri Lankan patients as it is less expensive, simpler and, less invasive.

Comparison of the effects of rapid maxillary expansion versus Twin Block appliance on mandibular growth in skeletal Class II patients

BackgroundThis is a retrospective study that compares mandibular growth changes in skeletal Class II patients treated by rapid maxillary expansion (RME) and following fixed appliance with those patients treated by Twin-Block (TB) and following fixed appliance.MethodsFourteen patients treated by RME and following fixed appliance were included into the RME group. Fifteen patients treated by Twin-Block and following fixed appliance were included into the TB group. Lateral cephalometric radiographs taken before treatment and immediately after fixed appliance treatment were used to evaluate mandibular growth effects.ResultsThe starting forms of the patients in the two groups were examined to be of good comparability. The mandibular length increased significantly in both groups as measured by Co-Gn, Go-Gn and Ar-Gn, but the TB group didn’t show more mandibular growth than the RME group (P > 0.05). Skeletal changes of the mandible in vertical dimension were different in the two groups. The change in FMA was 0.35° in the RME group, while the change was 2.65° in the TB group (P < 0.001). The change in LAFH was 5.14 mm in the RME group, significantly smaller than the change of 10.19 mm in the TB group (P < 0.001).ConclusionThe investigated Phase I treatment with RME followed by Phase II treatment of fixed appliance achieved the same increases in sagittal mandibular growth and facial profile improvements as the Twin-Block therapy. The treatment with RME followed by fixed appliance was better for vertical control, while the treatment with Twin-Block followed by fixed appliance significantly increased the mandibular plane angle.

Soft and Hard Tissue Changes Following Treatment of Class II Division 1 Malocclusion with Twin-Block and Myofunctional Appliance: A Pilot Study

ABSTRACT Background Many cases of Class II deformities have been reported to be treated with prefabricated appliances. The aim of this study was to distinguish the clinical effect of traditional custom-made appliances and prefabricated appliances in the treatment of Class II division 1 malocclusion. Therefore, soft and hard tissue changes following treatment of Class II division 1 malocclusion using the twin-block (TB) appliance was compared to that using the Myofunctional Research Company (MRC) appliance (K1 + K2) combined with oral myofunctional treatment (OMT) (MRC + OMT). Methods The study included 22 children (6 boys and 16 girls aged 9–11 years) with Class II division 1 malocclusion along with mandibular retrognathism with a 5–12 mm overjet, basic normal maxillary status, and stage 2 or 3 cervical vertebral maturation (CVM). Participants were randomly assigned into two groups, the TB group and the MRC + OMT group for 12 months. Standardized lateral cephalograms were used to assess skeletal, dental, and soft tissue changes from pre- to post-treatment. Independent t-tests were used to compare the initial and final cephalometric status and tissue changes between the groups. Results The TB and MRC + OMT groups resulted in different degrees of lateral changes; however, improvements of skeletal and soft tissue indices were significantly greater in the TB group than in the MRC + OMT group. Conclusion TB was more effective than MRC + OMT in treating children aged 9–11 years with Class II division 1 malocclusion. However, further research using custom-made appliances with OMT is recommended, and further investigations are needed to confirm these findings.

Three-Dimensional Assessment of Mandibular Condylar Volume and Position Subsequent to Twin Block Functional Therapy of Skeletal Class II Malocclusion Accompanied by Low-Level Laser Therapy.

This study aimed to evaluate and compare the effect of low-level laser therapy (LLLT) on mandibular condylar volume and position following treatment of a Class II malocclusion with a twin block (TB) appliance employing cone beam computed tomography (CBCT). Twenty-four growing patients, aged 9–12 years, were randomly allocated into control and laser groups. All patients were treated with a TB appliance. The patients in the laser group were treated weekly with a gallium–aluminum–arsenide (GaAlAs) diode laser around the temporomandibular joint (TMJ) region for three months. CBCT images were obtained before and after TB therapy and the changes in TMJ and skeletal variables were evaluated and compared among and between the groups. In the laser group, the condylar volume of the right and left sides significantly increased by 213.3 mm3 and 231.2 mm3, respectively (p < 0.05), whereas in the control group it significantly increased by 225.2 mm3, and 244.2 mm3, respectively (p < 0.05), with forward and lateral positioning of both sides. Furthermore, effective mandibular, ramus, and corpus lengths were increased, which were not significant between the groups. Low-Level Laser therapy accomplished no considerable effect on mandibular condylar volume and position following the functional orthopedic treatment of skeletal Class II malocclusions using a TB appliance.

Twin Block and Its Modifications

Twin block, one of the most commonly used functional appliances has many advantages over other functional appliances like comfort, esthetics and function. But using the same appliances for all clinical situations limited its use in various cases. To overcome such limitations of twin block appliance, various researchers have come up with various modifications. This article gives an overview of the different modifications of twin block appliance.

Comparison of the effects of activator and twin block treatment on skeletal, dental and soft tissues

Background: The aim of this study was to evaluate the effects of activator and Twin Block appliances on the patient’s profile. To evaluate skeletal, dental and soft tissue changes after treatment of Class II division 1 malocclusion with activator and Twin block appliances. Methods: The study included 30 skeletal Class II patients, 15 girls and 15 boys, mean age: 10.5 ± 0.15 years who were randomly allocated to one of two functional appliance treatment groups. Pretreatment (T0) and post functional appliance therapy (T1) lateral cephalograms of 30 patients were evaluated. The skeletal, dentoalveolar and soft tissue changes were evaluated in both groups on standardized lateral cephalograms taken with the same cephalostat before (T0) and after (T1) functional appliance therapy. The groups were compared at T0 and T1 using analysis of variance, and treatment/observation differences (T1−T0) were evaluated with the Kruskal–Wallis test. The Student’s t test was used, with a significance level of P

Multistage Treatment of a Class II Division 1 Malocclusion With Severe Crowding

The improvement of facial aesthetics is one of the main reasons why patients with a class II division 1 malocclusion seek orthodontic treatment. There are various techniques available to treat class II malocclusions, one of which is a two-phase approach that includes functional jaw orthopedics as well as fixed orthodontic treatment. The following case report describes the case of a 12-year-old growing female patient AK with a severe class II division 1 malocclusion. The patient was treated initially with Haas-type rapid maxillary expansion. Pre-functional orthodontics was followed with a removable twin block functional appliance and a combination pull headgear for growth modification and correction of her overjet and profile. Thereafter, a fixed, pre-adjusted MBT (McLaughlin Bennet Trevsi) prescription orthodontic appliance was utilized following the extractions of the maxillary first premolars and two lower incisors in the final phase, to ensure well-aligned arches and improved aesthetics and function.

Comparison of facial soft tissue changes after treatment with 3 different functional appliances

This study aimed to evaluate the effects of 3 different fixed or removable functional appliances on the soft tissue changes in patients with Class II Division 1 malocclusion using 3-dimensional images. A total of 60 patients with Class II Division 1 malocclusion (38 girls and 22 boys; mean age, 12.35±1.01years) were treated with 3 different functional appliances, namely, Twin-block (TB) (group TB, n=20), mono-block (MB) (group MB, n=20), or Herbst (H) (group H, n=20) for 9.55±1.46months. Three-dimensional photographs of each patient were taken at the baseline and the end of the therapy with a 3dMD Face system (3dMD, Atlanta, Ga). Statistical analyses were performed using the dependent samples t test, 1-way analysis of variance, Kruskal-Wallis, Mann-Whitney U, and Wilcoxon signed rank tests. No statistically significant differences were detected for soft tissue changes except for the lower facial width found, at least in group H (P<0.05). Volumetric differences in the mandible were similar between the groups (P>0.05). A statistically significant decrease in total facial height and an increase in convexity angle and facial depth were detected in all groups after treatment compared with the baseline (P<0.05). The upper and lower facial height, lower lip height, and nasal width were statistically significantly increased in the TB and MB groups after treatment compared with the baseline (P<0.05) and similar to those in group H (P>0.05). TB, MB, and H appliances may promote the facial soft tissue profile, including volumetric improvement, in the mandibular region.

Prevalence Of Removable Functional Appliance Usage In The Management Of Class II Malocclusion

A Removable functional appliance is composed of polished acrylic shields and stainless steel wires prescribed for patients with more pronounced class II malocclusion or open bite. These appliances work comfortably with a patient’s inherent growth to produce the desired Skeletal or Dental development. It can be achieved by dentoalveolar effects, alteration of soft tissue and utilisation of greater Mandibular growth potential. The commonly used Removable functional appliances are Twin Block appliance, Activator, Bionator, Frankel appliance, etc. This study aims to assess the frequency of the usage of removable functional appliances in a hospital based set up. The data of patients undergoing Removable functional appliance therapy was retrieved from the case sheets of the patients.The collected data was tabulated in Excel and statistically analysed with the help of SPSS software. From the results obtained, Twin block appliance was the most prevalent Removable functional appliance with a frequency of 60.6%. Frankel appliance and Activator each had a frequency of 9.1%. Twin block appliances were mostly preferred for males than females whereas Activator is preferred mostly for females. Based on the age, Twin block appliance was preferred for the age group 10-15 years, Frankel appliance for 5-10 years, Activator and Other appliances for 10-15 years. Therefore, within the limits of this study, we observed that Twin block appliance was the most preferred Removable functional appliance used in the management of Class II malocclusion and the most common age group receiving appliance therapy is 10-15 years.

Comparative Evaluation of Hyoid Bone Position and Tongue Area with Twin Block and Forsus: A Randomized Clinical Trial

Introduction: Class II div 1 malocclusion is most commonly presented with retruded mandible. This backward placement of mandible pushes the tongue posteriorly and inturn impairs the position of hyoid bone and total tongue area. Correction of retruded mandible with functional appliances is also considered to have positive effect on hyoid bone position and tongue area. Aim and Objectives: The objective of this study was to evaluate and compare the effects of Twin Block and Forsus on the hyoid bone position and tongue area in the treatment of Class II division 1 malocclusion.&#x0D; Materials &amp; Method: A 2-arm parallel, randomized controlled trial was designed consisting of 24 Class II division 1 malocclusion patients indicated for treatment with functional appliances. 24 patients were randomized and equally divided among Twin Block (Group A) and Forsus (Group B) group. Pre- and post functional lateral cephalograms of both groups were traced and statistically analysed using paired t-test and T test of Equality of Means. ‘p’ value of less than 0.05 was considered as statistically significant.&#x0D; Result: A significantly upward and forward movement of hyoid bone was found with both the appliances. Tongue area also improved with Twin Block and Forsus group. On intergroup comparison insignificant results were observed between both the appliances indicating similar effect on tongue area and hyoid bone position.&#x0D; Conclusion: Twin Block has more skeletal effect than Forsus, still both Twin Block and Forsus are effective in improving tongue area and forward and upward displacement of hyoid bone position while correcting Class II malocclusion.