Change of Mandibular Position during Two-Phase Orthodontic Treatment of Skeletal Class II in the Chinese Population

Figure 1

Cephalometric landmarks (for details please see [2, 19]). Cephalometric reference lines are OL: maxillary occlusal plane, the line joining the distobuccal cusp tip of the maxillary permanent first molar and the upper incisor tip, is, and OLp: occlusal plane perpendicular to OL through S. Sagittal variables: overjet (mm): is-OLp minus ii-OLp; mandibular length (mm): Ar-Gn; maxillary prognathism: A-OLp (mm) and S-N-A (°); mandibular prognathism: Pg-OLp (mm) and S-N-B (°); jaw base relationship: A-Pg (mm), A-N-B (°), and A, B on functional occlusal plane (mm); upper and lower incisor changes: is-A (mm), is-OLp minus A-OLp and ii-Pg (mm), ii-OLp minus Pg-OLp; upper and lower first molar changes: ms-A (mm), ms-OLp minus A-OLp and mi-Pg (mm), mi-OLp minus Pg-OLp; and molar relationship: ms-mi (mm), ms-OLp minus mi-OLp. Vertical variables: overbite (mm): ii-OL; upper face height (mm): N-NL; lower face height (mm): NL-Me; total face height (mm): NSL-Me; upper and lower incisor changes (mm): is-NL and ii-ML; upper and lower first molar changes (mm): msc-NL and mic-ML. Rotational changes (°): NSL/NL and NSL/ML.