Pressure Pain Threshold (PPT) is defined as the minimum force applied to an area that is perceived as pain. PPT is considered an objective measurement tool to assess pain levels. Studies have assessed the difference in pain levels between clear aligners and fixed appliances using subjective pain scales. No study has utilized PPT to evaluate the difference in pain between aligners and fixed braces at different time points. This study will aim to compare the self- reported and experimental pain perception between the clear aligner and fixed appliance therapies during the phase of crown alignment and to assess how long pain is perceived in the following five days from the adjustment of the appliance.

Inclusion Criteria:

• consecutive consented patients (> 14 years old) beginning an orthodontic treatment on both arches, either with aligners or fixed appliance at the Midwestern University, Multidisciplinary Clinic;
• patients in possession of an email address and Internet connection.

Exclusion Criteria:

• patients with generalized systemic conditions known to affect the overall body pain and pressure pain threshold assessment (e.g., fibromyalgia, autoimmune conditions such as multiple sclerosis, rheumatoid arthritis),
• untreated dental caries.

Patients starting an orthodontic treatment (clear aligners or fixed braces) at the Multispecialty Clinic of Midwestern University