Skeletal and Dentoalveolar changes concurrent to use of Twin Block appliance in Class II division I cases with a deficient mandible: A cephalometric study

Abstract

Most of Class II malocclusions are due to underdeveloped mandible with increased overjet and overbite. Lack of incisal contact results in the extrusion of the upper and lower anterior dentoalveolar complex, which helps to lock the mandible and prevent its normal growth and development, and this abnormality, is exaggerated by soft tissue imbalance. The purpose of present study was to cephalometrically evaluate skeletal and dentoalveolar changes following the use of Twin-Block appliance in 10 growing children of age group 9-13 years (mean 11.1 year ± SD 1.37) of Class II division 1 malocclusion with a deficient mandible. Cephalometric pre- and post-functional treatment measurements (angular and linear) were done and statistically analyzed using student's paired t-test. The results of the present study showed that maxilla (SNA) was restricted sagittally (head gear effect) with marked maxillary dental retraction. Significant mandible sagittal advancement (SNB) with minimum dental protraction was observed with significant increase in the mandibular length. The maxillomandibular skeletal relation (ANB and WITS appraisal) reduced considerably which improved the profile and facial esthetics. Pronounced correction of overjet and overbite was seen. The present study concluded that Class II correction occurs by both skeletal and dentoalveolar changes.

The Assessment of Sagittal Changes with Twin Block Appliance in Patients with Decelerating Growth Phase

“…It correlates with the findings with the that of Tiziano and Lorenzo [13] and Kevin and Jean [14]. The skeletal and dental effects of Twin block therapy on Indian population were done by Sharma et al, [15]. The subjects selected in that study are all in mixed dentition period with active growth potential.…”

Dentoalveolar changes in post-twin block appliance orthodontic treatment class II dentoskeletal malocclusion

“…Such findings are in line with a study performed by Sharma et al 20 that indicated a significant increase in the interincisal angle in cases of orthodontic treatment utilising twin block appliances.…”

“…Several studies reported significant proclination of mandibular incisors after treatment with twin block appliances, while the mandibular incisors remain stable in their position. 20 This result may be explained by the design of the twin block appliance. The use of an acrylic cover on mandibular incisors and the eyelet clasps produce rigid retention on the labial lower jaw, as well as the use of sounthend clasps by Tarvade.…”

“…15 Within a Steiner analysis, several angles are used as the reference for measuring the relationships between the maxillary first incisor and the maxilla, the mandibular first incisor and the mandible, and the maxillary and mandibular teeth. 20 According to the Steiner analysis, the results of measuring the average change in the dentoalveolar before and after treatment by means of a Twin Block appliance showed that there was a statistically significant change in I-NA angle, I-NA distance, I-NB distance, and interincisal angle. The greatest reduction was seen in I-NA distance.…”

Versatile functional appliance- Twin block

“…But some studies observed some headgear effect resulting in slight inhibition of forward maxillary growth. 16, 21 Singh and Hodge also concluded that Twin block appliances along with extra oral traction causes growth modulation in specific regions of midfacial complex and changes position of mandible. 25 Lower facial height also increased with twin block therapy, 16,17,19 but Nicole et al demonstrated good vertical control on mandibular plane angle with twin block appliance therapy as compared to Herbst, Bionator and MARA appliances.…”