Background: In recent years, as the demand for orthodontic treatment has increased, the need to thoroughly investigate the causes of dental and skeletal malocclusions has become more important. In skeletal Class II malocclusion, mandibular deficiency prevalence for 70–80% of cases, maxillary excess for 10–20%, and a combination of both for approximately 15% (Figure 1). In cases associated with mandibular deficiency, clinical features include severe dental crowding, deep overbite, and reduced lower facial height. These conditions negatively affect facial profile, occlusion, masticatory function, and airway. Therefore, accurate diagnosis and appropriate treatment planning are essential. Diagnosis: Skeletal Class II malocclusion, deepbite, and severe crowding. Treatment: in August 2025, using self-ligating brackets with posterior bite up placed on the molars. After 4 months, a temporary anchorage device (TAD) was inserted, and anterior retraction was performed along with vertical elastics. Within 7 months, the overjet was decreased from 7 mm to 3 mm, and the overbite decreased from 7.5 mm to 4.5 mm. Midline deviation and arch form were corrected, and molar and canine relationships improved to Angle Class I. The facial profile also showed noticeable improvement. Conclusion Within a relatively short period after treatment initiation, severe crowding was resolved, and both sagittal and vertical relationships of the anterior teeth improved to normal values. Molar and canine relationships were significantly improved, along with facial esthetics. This case demonstrates that with proper planning, TAD-supported orthodontic treatment can be an effective non-extraction approach for certain cases of skeletal Class II malocclusion with severe crowding.