Premolar Extraction Crossbite of Individual Teeth

Female, aged 29. Chief complaint: Teeth misalignment, requiring correction.

Crowding and misalignment of maxillary and mandibular teeth, crossbite of tooth 12 and 22, and midline misalignment.

Smartee clear aligner was employed. Four maxillary and mandibular first premolars were extracted, and retraction was performed to align the upper and lower teeth, relieve overbite and overjet of the anterior teeth area and align the upper and lower

midline.

Orthodontic Treatment Steps and Cycle

• Steps: 36+20+8 sets

• Cycle: 27 months