IntroductionThe prevalence of hypodontia in the permanent dentition is estimated to be 3.5-6% in the United Kingdom (Brook, 1974), with a 1.22 times more likely chance of hypodontia occurring in females than in males (Khalaf et al. 2014). The aetiology is complex, with genetics, the environment and developmental timing all believed to be factors which play a role (Cobourne, 2007; Fleischmannova et al., 2008).Patients with hypodontia commonly present complaining of spacing between their teeth and poor dental aesthetics (Hobkirk et al., 1995). Missing anterior teeth are considered to be one of the most unattractive dental traits (Shaw, 1981). Individuals who have a less aesthetic dental appearance, such as conspicuous spacing, may also attract unfavourable social responses and become targets for nicknames and teasing from other children (Shaw et al., 1980; Seehra et al., 2011). Hypodontia has been proven to affect social and emotional well-being, although this does not appear to be related to the number of teeth missing (Kotecha et al., 2013).Hypodontia is often treated by a multi-discplinary team approach, with input from orthodontics, paediatric dentistry, and prosthodontics. A multi-disciplinary approach meets the needs of the patients and their families by reducing the number of appointments required and by providing an opportunity for patients to meet all relevant specialties at the outset (Tams and Ashley, 2013), however, as yet there are no defined care pathways in place for hypodontia patients within the UK National Health Service. Ideally patients 4 would make predictable transitions through each stage of the pathway and this would result in them receiving timely and optimal levels of care.Part of the care pathway process also involves assessing outcomes and until relatively recently measuring orthodontic outcomes was primarily clinician led, using tools such as PAR scores or cephalometric outcomes. To date there are few tools in place to measure outcome from a patient perspective. Keles and Bos (2013) carried out a study in the Netherlands to identify specific factors that influenced patient satisfaction with orthodontic treatment and showed that the patient-doctor relationship was the most important factor contributing to patient satisfaction. Feldman (2014) carried out a similar study in Sweden and found that care and attention were the factors that showed the highest correlation with satisfaction. Neither of these studies investigated hypodontia specifically but it is likely that these findings are of importance to all orthodontic patients. Patients' perceptions of outcomes have been identified as a valuable source of information that can be used to improve services and Lord Darzi's report (2008) "High Quality of Care for All" highlighted the need for the success of a treatment intervention to include patient's views. A validated, hypodontia specific questionnaire has been designed to assess the impact of the condition on quality of life (QoL) and to investigate the effects of treatment (Akram et a...