Patients with root resorption and malocclusion can benefit from orthodontic treatment with or without surgery. However, orthodontics has a risk of inducing or aggravating root resorption, therefore the duration of the treatment is of utmost importance. In this paper, a surgery-first protocol with lower jaw advancement and precise interdental alveolar osteotomies was conducted to accelerate the treatment of a 14-year-old female patient who presented with a Class II division 2 malocclusion, anterior dental crowding and idiopathic root resorption. One week after the surgery, the patient received postoperative orthodontic treatment for 6 months with weekly activation the first month. The clinical outcome was satisfactory with complete clinical resolution and no tooth loss. This surgery approach allowed an ‘en bloc’ tooth movement and induced an increased bone remodelling, which resulted in an accelerated tooth movement. The reduction of treatment time was beneficial and no aggravation of the root resorption was seen.