Abstract
Objective
To test if placing a Southend clasp on the upper and lower incisors during Twin-block appliance treatment will control their angulation and enhance skeletal correction.
Design
Prospective, randomized, controlled clinical trial (ISRTCTN 45965219).
Setting
Orthodontic Department, Royal Preston District General Hospital, Preston, UK.
Participants
Fifty-two consecutive patients aged 9–30 years undergoing treatment for Class II division 1 malocclusion (ANB>5°, OJ>6 mm).
Method
Two alternative designs of Twin-block appliance were allocated randomly. One with a Southend clasp on the upper and lower central incisors and one without. The appliances were identical in all other aspects.
Outcomes
Skeletal and dental changes measured on before and after treatment lateral cephalometric radiographs.
Results
There was a statistically significant change in ANB angle between the Southend group (−3·5°) and the Non-Southend group (−2·6°) (P = 0·004). The change in upper incisor angulation was −6·1° for the Southend group and −12·0° for the Non-Southend group, which was statistically significant (P = 0·005). The change in lower incisor angulation was 3·0° for the Southend group and 6·9° for the Non-Southend group, which was statistically significant (P = 0·005).
Conclusions
The presence of a Southend clasp on the upper and lower incisors during Twin-block treatment limited their tipping which enhanced the skeletal correction.
Get full access to this article
View all access options for this article.