Table 1 Study inclusion and exclusion criteria (PICOS)

Patients

Patients of any age, sex, ethnicity, and malocclusion

- Animal studies

- In vitro studies

- Patients with craniofacial syndromes or abnormalities

Intervention (exposure)

Phase I or Phase II orthodontic treatment with any type of fixed or removable appliance

Patient not receiving orthodontic treatment

Comparison

A. ortho-Tx vs no-Tx (No-Tx comprising data of other not treated patients)

B. ortho-Tx vs ortho Tx

C. pre ortho tx vs post ortho Tx

- Simulation of orthodontic treatment using software

- Does not test the effect of orthodontic treatment

- Tests only the effect of orthognathic surgery

Outcome

Qualitative and quantitative analysis of facial attractiveness as measured through standardized questionnaires and validated scales

- No clear mention of rating method

- Rating of esthetics or facial esthetics based on orthodontic objective criteria

Study design

Randomized controlled trials or non-randomized, prospective or retrospective, cohort studies and observational, exploratory studies will be included

- Case reports, Systematic reviews, Meta-analyses, Reviews