The early treatment of skeletal Class III malocclusion is one of the most challenging problems that orthodontists may encounter. These patients often combine maxillary deficiency with anterior crossbite. In this report, an 8-year-old female patient with Class III malocclusion, anterior crossbite and protrusive lower lip. (SNA: 83.5°, SNB: 83°, ANB: 0.5°, overjet: -1.5mm, overbite: +2.5mm, mandibular plane to SN: 26.7°), received orthodontic treatment with rapid maxillary expansion and chin cup appliance. We used RME 2 turns (0.5mm) per day, and wore the chin cup at least 21 hours per day, to force mouth closure and enhance nasal breathing. Active orthodontic treatment time was 4 weeks. The retention period of RME was 3 months. The treatment results showed that maxilla was pushed forward by RME. and mandibular clockwise rotation, which improve anterior crossbite and facial profile. The treatment outcome were stable after 3 years follow up.

Creative Commons License

Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License.