To stimulate condylar growth by twin-block is an appropriate way to treat Angle class Ⅱ malocclusion associated with mandibular skeletal retrusion. The adaptation of condylar cartilage to mandibular forward positioning
constitutes the fundamental rationale for orthodontic functional therapy, which partially contributes to the correction of jaw discrepancies by achieving mandibular growth modification. However, functional appliance therapy
delivers more stable results when used at or after the peak of pubertal period while its effect is more equivocal and controversial on adult patients. In this article, the treatment principle of twin-block appliance, adaptable rebuilding
in condylar process and glenoid fossa of the temporomandibular joint were reviewed, which help orthodontists to comprehend the mechanism of adaptable rebuilding of the temporomandibular joint induced by functional
appliance. This review also provides a basic theory, treatment opportunity and indication to recognize, diagnose, and treat patients with mandibular retrusion of Angle class Ⅱ malocclusion.
