This clinical trial goal is to evaluate the difference in masticatory activities in adult patients treated with clear aligners compared to conventional fixed appliances treatment.

The aim of this study is to measure the changes of the activity of the anterior temporalis and masseter muscles in different treatment modality.

The activity of the muscles will be evaluated and measured using the surface electromyography (sEMG) BioRadio device before and after the beginning of each treatment modality.

Inclusion Criteria:

• Adult Participants aged 16 years old and above.
• Healthy growing Participants without any systemic diseases (assessed by taking a brief medical history ).
• Participants with skeletal Class I relationship.
• Participants with any other dental malocclusion referring to the Index of Orthodontic Treatment Need Index of orthodontic treatment needed (IOTN) .
• No active extensive caries and with healthy periodontal tissues.

Exclusion Criteria:

• Participants with any craniofacial anomalies, mental disabilities and/or neuropathic conditions.
• Participants with history of neuromuscular disease and/ or truma.
• Participants with the Presence of skeletal and/or diagnosed muscular asymmetries.
• Participants with History of any previous orthodontic treatment.
• Participants who have any signs of bruxism.
• Participants with history of use of muscle relaxants.
• Participants with true crossbites and/or with signs of Temporomandibular disorders (TMD) or condylar problems.
• Participants with skeletal CL II and/or CL III relationships.
• Participants with Hypodontia and/or with multiple missing posterior teeth (4 teeth and more).
• Participants with maxillary constriction and posterior cross-bite (unilateral or bilateral) with an indication for orthognathic surgery.
• Participants indicated for extraction orthodontic treatment.

Participants will be enrolled from Riyadh Elm University, Orthodontic Clinics, along with other private centers, Riyadh, Kingdom of Saudi Arabia.