Abstract: A tooth circumference measuring device is disclosed that device provides a strap that is placed around a dental patient's tooth and retracted into an at least generally conformal relationship (i.e., snuggly fit around the tooth) using a strap adjusting mechanism. The strap is operatively interconnected to a gage such that when the strap is secured about the tooth with a predetermined amount of tension, the gage indicates the circumference of that tooth. In one embodiment, the strap adjusting mechanism includes a reel that is interconnected to the strap. Upon rotation of the reel, a first portion of the strap is wound or unwound about a perimeter of the reel such that a second portion of the strap disposed about a tooth may be tensioned or loosened. In a further embodiment, the strap adjusting mechanism is operative to provide a consistent tension between measurements.