The purpose of this study is to investigate rapidity of tooth alignment in a randomised clinical trial of orthodontic patients allocated randomly into two different appointment intervals groups. First group will be reviewed every two weeks to adjust their braces while the second group will be reviewed every 8 weeks.

Orthodontics is a branch of dentistry concerned primarily with the correction of dental crowding or tooth malalignment. The first phase of fixed appliance orthodontic treatment is concerned with tooth alignment and relies upon a rapid and predictable response of the appliance system to the forces applied by the aligning archwire. The appropriate length of time between orthodontic appointments, generally called the 'appointment interval', has been the subject of debate for many years. Doctors all have their own preferences, based either on what they were taught in their orthodontic specialty programs or on community norms. Little evidence has been presented in the orthodontic literature to support these biases. The appointment interval may influence tooth alignment rates and treatment time along with other variables, such as periodontal status. Accelerating orthodontic tooth movement can significantly reduce treatment duration and the risk of side-effects.

Inclusion Criteria:

Subjects should:

1. be aged 12-18 years old;
2. present with a crowded lower arch that requires orthodontic tooth alignment with a fixed appliance;
3. be medically fit and healthy (absence of systemic diseases);
4. have normal weight (according to body mass index measurements BMI);
5. have permanent dentition;
6. have lower incisor irregularity of 5-12 mm;
7. not having complete overbite;
8. be either extraction or non-extraction cases;
9. be able to give informed consent.

Exclusion Criteria:

1. Subjects who have received fixed orthodontic treatment before.
2. Subjects who will be participating in any other intervention trials.
3. Subjects with reported nickel allergy.
4. Subjects who have received antibiotic therapy in the previous six months, or who have any history of juvenile periodontal disease.
5. Subjects who have lower incisor extracted tooth.

Un-identified individual participant data for all primary and secondary outcome measures will be made available.

Data will be available within 6 months of study completion.

Zenodo (open-access repository).