Abstract:

Objective To guide the orthodontic diagnosis, treatment planning and prognosis by analyzing the craniofacial morphology and reimbursement mechanism of young patients with mandibular retrusion in Chongqing territory by Delaire cephalometric analysis. Methods Both conventional cephalometric analysis and Delaire cephalometric analysis were conducted on the basis of the lateral cephalograms from 56 young mandibular retrusion patients and 40 teenagers with normal occlusion. Results Decreases in ∠SNB, Co-Go, Co-Pog, U1-L1 and increases in ∠ANB, ∠SN -MP, L1 -MP were seen in mandibular retrusion group by conventional cephalometric analysis. Decreases in ∠1, ∠5, （Cp-Oi）/C2 and increases in ∠2, （M-Cp）/C2, ∠3, ∠4 were seen in mandibular retrusion group by Delaire cephalometric analysis. Me-F1 and Me-Met were -8.70 mm±2.48 mm and 5.74 mm±2.58 mm respectively. Conclusion Delaire cephalometric analysis could evaluate cranio -maxillofacial architectural features of mandibular retrusion patients more visually and quantitatively, which suggests that mandibular retrusion is usually caused by the retrusion of mandibular position and the hypodevelopment of mandibule.

Key words: Angle′s Class Ⅱ malocclusion, mandibular retrusion, Delaire cephalometric analysis