PubMed | Royal Preston Hospital Preston
Type: Journal Article | Journal: Journal of orthodontics | Year: 2012
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.Prospective, randomized, controlled clinical trial (ISRTCTN 45965219).Orthodontic Department, Royal Preston District General Hospital, Preston, UK.Fifty-two consecutive patients aged 9-30 years undergoing treatment for Class II division 1 malocclusion (ANB>5, OJ>6 mm).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.Skeletal and dental changes measured on before and after treatment lateral cephalometric radiographs.There was a statistically significant change in ANB angle between the Southend group (-35) and the Non-Southend group (-26) (P=0004). The change in upper incisor angulation was -61 for the Southend group and -120 for the Non-Southend group, which was statistically significant (P=0005). The change in lower incisor angulation was 30 for the Southend group and 69 for the Non-Southend group, which was statistically significant (P=0005).The presence of a Southend clasp on the upper and lower incisors during Twin-block treatment limited their tipping which enhanced the skeletal correction.