Prospective comparative study of affects of two functional appliances

INTERVENTION: 2 appliance systems (Twin Block and Dynamax) CONDITION: Oral Health ; Oral Health PRIMARY OUTCOME: 1. Hard tissue changes from lateral cephalo mexric radiograph taken at start and end of treatment. ; 2. Soft tissue changes from 3D laser scans taken during treatment SECONDARY OUTCOME: Not provided at time of registration INCLUSION CRITERIA: 200 patients awaiting treatment on orthodontic waiting lists to be allocated into one of the two groups. INCLUSION CRITERIA: 1. Class II division 1 malocclusion on a skeletal II base 2. Madibular retrongnathia contributing to the skeletal II base 3. Minimum overjet of 7mm 4. Male caucasians aged 12‐14 years by Jan 1st 2003 5. Female caucasians aged 10‐13 years by Jan 1st 2003 6. No history of orthodontic treatment 7. No permanent tooth extractions 8. No relevant medical history