[Early orthodontic treatment in the early permanent dentition].

The early orthodontic treatment of malocclusion includes the growth modification of skeletal discrepancy, preventive and interceptive orthodontic treatment of the dental malocclusion or oral habit. Therefore, early orthodontic treatment is to guide the normal dento-maxillafacial growth and development, eliminate the adverse effect on function of masticatory system and the health of dental and periodontal tissues. Most of the patients in the early permanent dentition are still in their pubertal growth period. Although all kind of comprehensive orthodontic treatment could be started from early permanent dentition, early orthodontic treatment can still be used in the cases such as class Ⅱ malocclusion caused by underdevelopment of mandible and crossbite caused by underdevelopment of maxilla in the early permanent dentition. The article will discuss class Ⅱ malocclusion caused by underdevelopment of mandible and anterior and posterior crossbite caused by underdevelopment of maxilla which are feasible for early orthodontic treatment.