Comparison of Skeletal Changes in the Temporomandibular Joint between the Twin Block Appliance and Fixed Functional Appliance: A Longitudinal Follow-up Study

Aim

This current study evaluated and compared the skeletal changes in the head of the condyle, glenoid fossa, and articular space between the twin block appliance and PowerScope™ a fixed functional appliance.

Materials and methods

This study was a pilot, randomized, single-blinded, assessing the skeletal changes in the components of the temporomandibular joint (TMJ) using cone-beam computed tomography (CBCT). The study was conducted in 20 subjects in the age range of 11-14 years with class II division 1 malocclusion. These subjects were distributed randomly between two groups with an allocation ratio of 1:1 (group I-twin block and group I-PowerScope™). Follow-ups of both groups were done till desirable skeletal correction was attained (clinical edge-to-edge incisor relation).

Results

Condylar parameters such as position, height, and length were evaluated bilaterally in the CBCT scans. After using both devices, there was an increase in all condylar qualities; however, the twin block appliance showed a more noticeable difference, which has been determined to be statistically significant. In the twin block group, there was an average decrease of 0.56 mm in the anterior articular space and an increase of 1.2 and 2.64 mm in the middle and posterior articular spaces, respectively. In the PowerScope™ group, there was an average decrease of 0.23 mm in the anterior articular space and an increase of 2.55 and 1.85 mm in the middle and posterior articular spaces, respectively. In the case of the twin block device, the change in glenoid fossa angle was observed to be 6.1 mm on both sides and a mean difference of 1.25 mm on the right-side and 1.75 mm on the left-side was observed in the case of PowerScope™. The difference was established to be significant with a p < 0.05 in all cases.

Conclusion

Condylar attributes increased after the application of both devices but the difference was more pronounced in the case of twin block appliances. The difference in articular space (middle and posterior) between the twin block group and PowerScope™ group, was not significant statistically. In the present study, the remodeling in the glenoid fossa was greater in the twin block group compared to the PowerScope™ group.

How to cite this article

Halapanavar B, MN P, Deshmukh S, et al. Comparison of Skeletal Changes in the Temporomandibular Joint between the Twin Block Appliance and Fixed Functional Appliance: A Longitudinal Follow-up Study. Int J Clin Pediatr Dent 2024;17(1):7-14.

Cephalometric changes in pharyngeal airway dimensions after functional treatment with twin block versus myobrace appliances in developing skeletal class II patients: a randomized clinical trial

BACKGROUND

Several appliances have been used for correction of developing skeletal Class II, including different myofunctional appliances as Twin block (TB)as well as the new pre-fabricated Myobrace (MB) appliance. However, the effects of these devices on the pharyngeal airways have not been compared in the literature. Thus, the aim of this study was to compare the effects of two Class II correction appliances; TB and MB on the sagittal pharyngeal airway dimension (SPAD), including the nasopharyngeal airway area (NPAA), the oropharyngeal airway area (OPAA), and the laryngopharyngeal airway area (LPAA).

METHODS

This is a two parallel arms randomized comparative clinical trial. Twenty-six children of 9-12 years with Skeletal Class II malocclusion due to mandibular deficiency and normal maxillary growth as confirmed by lateral cephalometric X-ray readings (ANB angle > 4° and SNB angle < 78) and Cervical vertebral maturational index (CVMI) 1 or 2 were randomly assigned into two equal groups. Group I: TB, Group II: MB (prefabricated functional appliance, Myofunctional Research Co., Australia). Lateral cephalograms were taken for all patients in both groups before treatment (T1) and after treatment (6 months later) (T2). The primary aim was to assess pre and post treatment changes in the SPAD in each group, and compare between the two study groups. The secondary aim was to evaluate the sagittal skeletal measurements such as the SNA, SNB, ANB, Wits appraisal, as well as vertical skeletal measurements represented by the Frankfurt-mandibular plane angle (FMA) measured pre- and post-treatment. The independent samples t-test was used to compare the two study groups, and the mean difference and 95% confidence intervals (CI) were computed. The paired samples t-test was used to compare various parameters between T1 and T2 within each group. The cutoff for significance was p-value < 0.05. Data were analyzed using IBM SPSS for Windows (Version 26.0).

RESULTS

By Comparing changes in airway measurements within each group, it was found that NPAA, OPAA, and LPAA increased significantly after treatment within each group of MB and TB. TB group showed significantly higher mean difference (T2-T1) in both NPAA and OPAA than MB group with 28.39 (± 56.75) and 40.46 (± 52.16) respectively. The increase in LPAA values was not statistically significant at (T2-T1) between both groups. Regarding skeletal changes, there was a significant increase in the SNB values between T1 and T2 within each group with 2.82 (± 3.32) for MB group and 3.79 (± 3.06) for TB group Moreover, there was a significant decrease in the ANB values between T1 and T2 within each group by 2.42 (± 2.70) for MB group and 3.06 (± 1.14) for TB group. Similarly, there was a significant decrease in the ANB values between T1 and T2 within each group by -2.13 (± 0.62) for MB group and - 2.46 (± 0.72) for TB group. No significant differences were found between both groups in SNA, SNB, ANB and Wits appraisal at p = 0.06, p = 0.45, p = 0.43 and p = 0.22 respectively. FMA did not show significant difference between T1 and T2 within each group, nor showed a significant mean difference between both groups at T2-T1.

CONCLUSIONS

TB was more effective than MB in improving the upper (NPAA) and middle (OPAA) airways, while no difference was found regarding the lower airway (LPAA). Both TB and MB reduced the severity of developing skeletal class II due to mandibular retrognathism by forward posturing of the mandible. Thus, patients with airway problems would benefit more from TB than MB.

Effects of twin-block appliance on upper airway parameters in OSA children with class II malocclusion and mandibular retrognathia: a CBCT study

Twin-block appliance had been advocated as a potential treatment option in paediatric obstructive sleep apnoea (OSA) due to their favourable effect in enhancing upper airway parameters and improving OSA symptoms. The aim of this study was to evaluate the effect of twin-block appliance therapy on upper airway parameters/dimensions and the apnoea-hypopnea indexes (AHIs) in OSA children with class II mandibular retrognathic skeletal malocclusion using cone-beam computed tomography. This prospective longitudinal study comprised 34 polysomnography-proven OSA growing children with class II mandibular retrognathic skeletal malocclusion between the ages of 8 and 12 years who had completed myofunctional twin-block therapy and matched corresponding controls. The upper airway was segmented into the nasopharynx, oropharynx, and hypopharynx, and the effect of twin-bock treatment on upper airway parameters/dimensions was assessed pre- and posttreatment using CBCT analysis, while a second standard overnight PSG was performed to determine changes in the AHI. At the nasopharynx level, minimal (nonsignificant) increases in all variables were observed within the twin-block group and between the groups (P > 0.05). At the level of the oropharynx, all variables increased significantly in the treatment group and between groups (P < 0.001), but these increases were nonsignificant in the control group. At the level of the hypopharynx, only the minimum cross-sectional area (MCA) increased significantly in the treatment group (P = 0.003). The change in MCA was also significant between the groups (P = 0.041). In addition, the upper airway length increased significantly in the twin-block group (P = 0.0154), and the AHI decreased by 74.8% (P < 0.001).

CONCLUSION

Correction of class II mandibular retrognathic skeletal malocclusion with twin-block appliance resulted in a significant increase in upper airway volume, MCA, anteroposterior and lateral distances of the MCA at the level of the oropharynx, MCA at the level of the hypopharynx and upper airway length, and a significant decrease in AHI, but it had no effect on nasopharynx parameters.

WHAT IS KNOWN

• CBCT imaging has been shown to be an effective and precise diagnostic tool for analyzing the upper airways and craniofacial structures. • Twin block appliance may be an effective treatment modality in children with OSA.

WHAT IS NEW

• Minimal cross-sectional area of upper ways may be the most relevant potential parameter when explaining how the upper airway anatomy plays role of in the pathogenesis of pediatric OSA. • Twin block appliance induced favorable changes in upper airway morphology (oropharynx area mainly) and respiratory parameters in OSA children with class II malocclusion.

Evaluation of changes in tongue pressure with twin-block appliance therapy in growing Class II Div 1 malocclusion. An in vivo study

INTRODUCTION

Twin-block appliance therapy in patients with Class II Div 1 malocclusion positions the mandible anteroinferior leading to possible alterations in tongue pressure, tongue length, and the oropharynx.

OBJECTIVES

To evaluate the changes in tongue pressure, tongue length and dimension of the pharyngeal airway in Class II Division 1 subjects before and after twin-block therapy.

MATERIALS AND METHODS

Twenty-four subjects were selected, in the range of 10-14 years (mean-12 years). The tongue pressure was recorded at three regions with sensors placed at the incisive papilla and bilaterally at the molar region of the palate for four minutes. The root mean square (RMS) values were recorded and used for further analysis. Evaluation of tongue length and pharyngeal airway dimension was done using a lateral cephalogram. All the measurements were done before and after twin-block appliance therapy. The paired t-test was performed to compare the changes.

RESULTS

Resting tongue pressures decreased from pre-treatment levels to post-treatment at all three regions. Change in ANB angle was found to have a significant negative correlation with tongue length, and pharyngeal airway dimension, a significant positive correlation with pressure at incisive papilla and left molar region and no correlation at right molar region.

CONCLUSION

There was a decrease in resting tongue pressure as the malocclusion was corrected from Class II to Class I. Hence, this decrease in pressure could be a contributory factor in the maintenance of the dental equilibrium as lighter forces exist in the oral cavity.

Dentoskeletal effects of clear aligner vs twin block-a short-term study of functional appliances

PURPOSE

The twin block (TB) is one of the most widely used functional appliances for the correction of class II malocclusions. Align Technology (San Jose, CA, USA) developed the Invisalign® mandibular advancement (MA) that replicates the mechanism of action of a functional appliance. The aim of this study was to compare the changes produced by the TB versus those by MA.

METHODS

The records of 56 class II patients treated with the TB (TB group: n = 35) or the MA (MA group: n = 21) were compared to a control sample of 15 untreated class II subjects (UC2).

RESULTS

The TB and MA groups showed a significant reduction of the ANB angle, compared to the controls (TB group: -1.5°; MA group: -1.5°; UC2 group: +0.2°). For the Co-Gn values, the TB and MA groups showed significant differences when compared with the UC2 group with an increase of 8.4 mm in TB patients and of 8.3 mm in MA patients. The increase of the distance of Pg to the true vertical line (TVL) was the only measurement where significant differences between the three groups were found with a greater advancement of the soft tissue pogonion in the TB group compared with the MA group and the UC2 group (TB group: +3 mm; MA group: +0.9 mm; UC2 group: -1.6 mm). The angle between the palatal plane and mandibular plane revealed a more relevant reduction in the TB and MA groups. Both appliances were able to reduce overjet and vertical overbite values.

CONCLUSIONS

Treatment with the MA and TB appliances produced a significant elongation of the mandible with an improvement in sagittal relationship, overjet, and vertical overbite and with good control of the vertical relationship. TB subjects showed a greater advancement of the soft tissue chin.

Second Class Functional Treatment: Andreasen Activator vs Twin Block

Aim

The purpose of this research is to analyze and compare the dental and skeletal changes induced by two functional devices, Andreasen Activator and Clark's twin block, on the sagittal and vertical plane, by means of cephalometric analysis, of the lateral cephalograms prescribed at the beginning and at the end of the treatment for a second skeletal class, first division with normal or deep bite.

Materials and methods

Twenty patients, 8 females and 12 males, fulfilling criteria for inclusion, were divided randomly into two groups: group I was treated with Andreasen activator, the second group with Clark's twin block. The duration of the therapy was about 18 months plus less 2 months. Pretreatment and posttreatment cephalometric radiographs were analyzed using angular (SNA, SNB, ANB, SnaSnp–GoGn angles), linear (Sna–Snp, Co–Gn, Co–Go, Go–Gn) skeletal parameters and dental one (U1–SnaSnp angle, L1–GoGn angle, Overjet and Overbite). To evaluate the posttreatment changes in the single groups and between them, paired and unpaired t-test was used.

Results

In both of the two groups analyzed, all the sagittal and vertical, angular and linear, skeletal measurements appear to be increased in a statistically significant way, except SNA angle and the distance Sna–Snp. Regarding the dental parameters, in the group treated with Andreasen activator, only Overjet and Overbite showed statistically significant differences. On the other hand, twin block induced statistical changes about Overjet, Overbite and also U1/SnaSnp, but not about L1/GoGn. The advancement of the mandible determines a greater prominence of the chin and lower lip, an increment of the labial mental angle and a reduction of the convexity of the profile. Also, the decrease of the overjet and, consequently, of the dental exposure improve the esthetic appearance of the patient's face.

Conclusion

Both functional treatments showed a lower jaw advanced on the sagittal plane and increased in size. In the upper jaw no significant changes were observed. It was also evident a dental compensation both on sagittal and vertical planes.

Clinical significance

The functional devices studied, Andreasen activator and twin block, seem to obtain more skeletal than dental results when the patients were treated at the peak of pubertal growth.

How to cite this article

Baccaglione G, Rota E, Ferrari M, et al. Second Class Functional Treatment: Andreasen Activator vs Twin Block. Int J Clin Pediatr Dent 2020;13(2):144–149.

Twin Block in Myogenous Orofacial Pain: Applied Anatomy, Technique Update, and Safety

The twin block, introduced in 2014, has proven to be more advantageous for the management of myogenous orofacial pain than the masseteric nerve block, which was introduced in 2009. The twin block is an extraoral nerve block injection which passes through the temporal fossa to anesthetize both the masseteric and the deep temporal nerves as they exit the infratemporal fossa at the infratemporal crest. Similar to the masseteric nerve block, the twin block has demonstrated efficacy with expeditious and sustained relief of myogenous face pain originating from the masseter muscle. Furthermore, in a 6-month prospective treatment study, that has been accepted for publication, the twin block has been demonstrated as comparable to trigger point injections in the management of chronic myofascial pain of masseteric origin. The twin block's ability to mitigate myogenous pain from both the masseter and temporalis muscles and its ease of administration are the key advantages over the masseteric nerve block. Since its inception, we have refined the technique for administering the twin block and our clinical experience corroborates its safety and efficacy. This review describes the refined technique and its safety in the context of the region's applied anatomy.

Evaluation and quantification of airway changes in Class II division 1 patients undergoing myofunctional therapy using twin block appliance

Background

The purpose of the present study was to determine the airway changes in skeletal class II division 1 malocclusion patients with mandibular retrognathism, treated with Twin-Block (TB) appliance.

Methods

Airway assessment was carried for twelve patients (mean age 11.7 ± 1.1 years) who underwent myofunctional therapy using TB appliance for correction of skeletal class II division 1 malocclusion with mandibular retrognathism. Acoustic pharyngometry (AP) was used to assess and quantify the comparative changes in the upper airway, pretreatment and posttreatment.

Results

Data acquired was subjected to appropriate statistical analysis. The paired 't' test was used to compare pre-treatment (T0) and after the positive pterygoid response (T1). TB appliance increased mean minimum airway area by 0.28 ± 0.25 cm² and mean airway by 0.47 ± 0.44 cm² with 95% CI. Posttreatment minimum airway and mean area changes were found to be statistically significant (P-value<0.01).

Conclusion

TB appliance therapy has a positive effect on upper airway and is beneficial for the treatment of sleep-related disorders associated with Class II division 1 malocclusion for achieving positive functional changes, esthetics, and healthier quality of life.

Dentoskeletal Comparison of Changes Seen in Class II Cases Treated by Twin Block and Forsus

BACKGROUND

To evaluate skeletal and dentoalveolar effects of Forsus fatigue resistant devices (FRD) and twin-block (TB) appliance in Class II malocclusion cases.

MATERIALS AND METHODS

Twenty young adult patients (age 13-17 years, overjet 6-10 mm) with a Class II division 1 malocclusion were randomly divided into two groups: group I included 10 patients treated with TB, Group II included 10 patients treated with FRD. Dentoskeletal changes were analyzed on lateral cephalograms taken before (T1) and (T2) at the end of the treatment. Inter-group differences were evaluated with Wilcoxon signed rank test, and intra-group differences were assessed with Mann-Whitney test at the P < 0.05 level.

RESULTS

Both were useful in improving the esthetics. However, more AP skeletal changes were seen with TB appliances as compared with Forsus. Vertical skeletal measurements were increased after functional appliances. These results were more pronounced with Forsus appliance than TB. Increase in incisor mandibular plane angle was seen in both groups, but was found to be more pronounced with Forsus group. Similarly, extrusion of upper and lower molars and lower incisors was also seen in both groups.

CONCLUSION

In this study we found TB to have more mandibular lengthening effect as compared to Forsus, and thus was found to be more effective in treatment of Class II cases. How to cite the article: Tarvade SM, Chaudhari CV, Daokar SG, Biday SS, Ramkrishna S, Handa AS. Dentoskeletal comparison of changes seen in class II cases treated by Twin Block and Forsus. J Int Oral Health 2014;6(3):27-31.