SIXES: Should I eXtract Every Six? A Study of the Extraction of Permanent Molar Teeth in Children.

SIXES: Should I eXtract Every Six? A Randomized Clinical Trial of the Extraction of First Permanent Molar Teeth in Children

This clinical trial investigates relative benefits (clinical effectiveness and quality of life) of two extraction patterns when lower first permanent molars (FPM) are extracted in children The study objectives are to determine whether compensating extraction of upper FPMs following loss of lower FPMs in children is of benefit. The particular benefits being investigated are related to the resulting occlusion, patient experience and oral health related quality of life. The follow up will extend over a period of 5 years or until the patient is 14 years of age - whichever is earlier.

The study has been designed as a randomised controlled clinical trial. The control group will have the normal standard intervention receiving routine patient care with the normal practice of upper and lower extractions, whilst the intervention group will have removal of the lower tooth but no upper extraction. Study recruitment will take place over an 18 month period and will be based in the Dundee Dental Hospital Orthodontic and Paediatric Dentistry Departments. Patients are referred to this department from their General Dental Practitioner.

Consent of the patients will be carried out by the attending dentists who will have received training on the study design and protocol, including RGF and consenting patients for clinical trials.

Data will be collected contemporaneously using the Case Report Forms. Additional data which will be collected for the purposes of the study will include COHQoL questionnaires and measurements from 3D images of models of the teeth.

At subsequent 1 year and five year review visits dental study 3D models will be repeated, and the CRF completed together with the COHQoL questionnaire for that visit.

Inclusion Criteria:

• Age: 7 -11 years
• Dental History: Able to co-operate with dental treatment
• Regular attender or considered likely to return for follow-up Social History
• Child and carer able to understand study documentation and give consent to participate in study

Dental condition:

• One or two lower FPMs requiring extraction
• Upper FPMs are sound or restorable/ restored with good long term prognosis (i.e. has or requires a single surface restoration with caries less than half-way into dentine, restoration with a simple restoration)
• Confirmed presence of all second premolars and all second molars

Exclusion Criteria

• Medical History: Medical contraindication to dental extractions
• Dental condition: Poor prognosis of premolars or permanent second molar teeth
• All four upper incisors in crossbite
• Poor prognosis of upper FPM
• Confirmed absence of one or more second premolars and second molars
• Declines to have impressions taken