Failure Rate of Infra-Zygomatic Orthodontic Mini-Screws

Researchers will evaluate the influence of mini-screw length, diameter, oral hygiene status, age, sex, and loading time on the failure rate of infra-zygomatic mini-screws. Mini-screw failure will be assessed clinically by the presence of mobility or loss of stability.

Participants will:

• Receive fixed orthodontic treatment with a pre-adjusted edgewise appliance system.
• Receive infra-zygomatic mini-screws bilaterally for maxillary anchorage reinforcement.
• Receive a 10 mm × 1.8 mm mini-screw on one side with immediate loading.
• Receive a 12 mm × 2.0 mm mini-screw on the contralateral side with delayed loading.
• Receive standardized orthodontic force using elastic power chain.
• Undergo CBCT assessment to evaluate the position of the inserted mini-screws.
• Be evaluated at baseline and at one-month intervals for three consecutive months to assess mini-screw mobility or failure.

Inclusion criteria

• Participants aged 19 to 35 years.
• Both male and female participants.
• Patients requiring absolute anchorage for maxillary arch and orthodontic tooth movement.
• Patients undergoing fixed orthodontic treatment.
• Patients in whom infra-zygomatic mini-screws are indicated for anchorage reinforcement.
• Participants whose oral hygiene status can be clinically assessed.
• Participants willing to provide written informed consent.

Exclusion criteria

• Patients with incomplete history or records
• Patients with a history of previous orthodontic treatment.
• Patients with a history of maxillofacial surgery.
• Patients with a history of head or facial trauma.
• Patients with temporomandibular joint disorder.
• Medically compromised patients.
• Patients with diagnosed syndromes, congenital defects, or facial deformities.