Objective: To evaluate the effects of nonextraction and all first premolar extraction modalities of orthodontic treatment on oral health-related quality of life (OHRQoL) among adolescents. Materials and Methods: Sixty-eight adolescents of aged 12-18 years were chosen. Subjects who required nonextraction orthodontic treatment were included in group I, and those who required all first premolar extractions for orthodontic treatment were included in group II. Baseline OHRQoL data (T 0 ) were recorded before the start of treatment. To evaluate the impact of orthodontic treatment on OHRQoL, the Oral Health Impact Profile-14 (OHIP-14) questionnaire was presented to all subjects for retrospective evaluation at 1 month (T 1 ), 3 months (T 2 ), 6 months (T 3 ) and 1 year (T 4 ) after the start of orthodontic treatment and 1 week after completion of orthodontic treatment (T 5 ). Results: At T 1 and T 2 , the physical pain and physical disability domains of OHIP-14 were impacted significantly by comprehensive orthodontic treatment in both groups (P , .001). The negative impact of orthodontic treatment on OHRQoL was maximum at T 1 and then slowly recovered to the pretreatment level at T 3 in both groups. Recovery of OHIP-14 scores was relatively faster in group I subjects compared to group II subjects. At T 1 and T 2 , social disability and handicap domains were deteriorated significantly in group II subjects compared to group I subjects (P , .01). Conclusions: The severity of OHRQoL deterioration was similar in both modalities of orthodontic treatment, but recovery from negative impacts was relatively slower in the first premolar extraction subjects. (Angle Orthod. 2020;90:578-586.)