The dental arch measuring device includes a first body, a first pivoting hole and a first positioning portion respectively disposed at two ends thereof, and an arc-shaped limiting hole is disposed above the first pivoting hole. Between the limiting hole and the first positioning portion, there is a horizontal and curved first scale meter and a longitudinal second scale meter； and a second body with a second pivotal connection at each end thereof a second positioning portion, a limiting member and an indicating member are disposed between the second pivoting hole and the second positioning portion, and the second system is superposed on the first body, the second pivot a receiving hole corresponding to the first pivoting hole, and providing a pivoting shaft, the limiting member is disposed in the limiting hole, the indicator is pointed to the first scale, thereby being the first The positioning portion and the second positioning portion are placed on the teeth, and the width and depth of the dental arch are respectively measured by the first scale and the second scale.本新型牙弓測量器，其包括：一第一本體，其兩端分別設有一第一樞接孔及一第一定位部，該第一樞接孔的上方設有一弧形的限位孔，該限位孔與該第一定位部之間具有設一橫向且弧形的第一刻度計及一縱向的第二刻度計；以及一第二本體，其兩端分別設有一第二樞接孔及一第二定位部，該第二樞接孔與該第二定位部之間設有一限位件及一指示件，該第二本體係疊合於該第一本體上，該第二樞接孔與該第一樞接孔對應，並提供插設一樞軸，該限位件係穿設於該限位孔中，使該指示件指向該第一刻度計，藉此將第一定位部與第二定位部放置於牙齒上，由第一刻度計與第二刻度計分別測得牙弓的寬度與深度。
