Participants are orthodontic patients with anterior open bite (AOB) malocclusion. These patients will be treated by molar intrusion achieved using one of two interventions, either orthodontic fixed appliances incorporating a single palatal Temporary Anchorage Device (TAD) or orthodontic fixed appliances incorporating two buccal TADs

Participants will be recruited from those attending Dundee Dental Hospital Orthodontic Department and those currently awaiting treatment. Those that meet the inclusion and exclusion criteria will be invited to participate. After obtaining consent they will be allocated to receive one of the two interventions. The two interventions represent the currently available options for treatment of mild - moderate (1-6mm) anterior open bite in the Orthodontic Department and as such patients will be receiving routine treatment regardless of the arm they are randomised to. In order to assess the more effective intervention additional records will be taken during the treatment involving additional cephalometric radiographs, additional intra-oral scans or dental impressions (See later for details). Primary outcome is at the end of intrusion with TADs after 9-12 months, but participants will be followed until completion of treatment for the secondary outcome of stability of intrusion and overbite correction

Inclusion Criteria:

• Patients with AOB of 1-6mm
• Aged between (12 and 40 years).
• Able to consent.
• Patient due to undergo orthodontic treatment with fixed orthodontic braces.

Exclusion Criteria:

• Patient has previously had upper first permanent molar extraction.
• Patient with congenital cleft of lip and/or palate or any other craniofacial anomalies.
• Patient with bone disease or taking medications that affect the bone quality or nature.
• Patient with an active digit sucking habit.
• Pregnant or breastfeeding women

Outcome assessor will be blind to allocation