Patent ID: 7331781

Claim:
An orthodontic expander for increasing maxillary transverse dimension, comprising: a first body and an opposing second body that each define a threaded bore, a pair of guide bores, and a guide pin fixed to and extends from one of the guide bores in the body, the threads of the threaded bores turn in opposing directions, and the guide pins extending from the respective body for being slidably received in the aligned one of the guide bores of the opposing body; a threaded member having a first portion threaded in a first direction for engaging the threaded bore of the first body and a second portion threaded in an opposing second direction for engaging the threaded bore of the opposing second body, whereby rotation of the threaded member moves the opposing first and second bodies together or apart selectively; a rotation member rigidly attached to the threaded member medial opposing distal ends and defining a plurality of openings in a perimeter surface of the rotation member for engaging by a tool to rotate the threaded member selectively in a first direction and in a second opposing direction; a jam nut defining on a side face a plurality of laterally projecting lugs and threadably received on the first portion of the threaded member and selectively movable against the first body to fix the opposing bodies in a selected spaced-apart relation; the first body having an engaging surface that defines a plurality of detents spaced apart about the opening for receiving the lugs when the jam nut is threaded against the body, the receipt of the lugs within the detents restricting threaded member from rotation; and means for connecting the opposing bodies to a respective tooth for applying lateral force to a palate.