To investigate the correlation between mandibular Bonwill - Hawley arch and base bone archshape.

CBCT and Mimics10.01 software were used to locate and measure the mandibular arch of 32 patients with type Ⅰ malocclusion. The individualized Bonwill-Hawley arch was drawn and the length and width of the arch and base arch were measured, and the data were compared and analyzed by SPSS 16.0 software.

Pearson correlation analysis results showed significant correlation between Bonwill - Hawley arch and base bone arch in both length and width (r＞0.5). Compared with base bone arch, anterior (t = 0.81, P = 0.25) and medium (t = 0.69, P = 0.50) Bonwill - Hawley arch showed no statistical difference in both length and width (P＞0.05), while posterior Bonwill-Hawley arch showed significant statistical difference in length (t = 2.21, P = 0.03) and width (t = 2.42, P = 0.02).

There was significant correlation between Bonwill-Hawley arch and base bone arch in both length and width.