John J. Moorhead
1922 Journal of the American Medical Association (JAMA)  
when the anterior edge of the canvas chin piece rested in the open mouth during a prolonged suboccipital craniotomy. An objection may be found in that the canvas piece (Fig. 1 B and Fig. 2 C) covers the eyes, preventing examination of them during the anesthetic. We have not found this a disadvantage; but if this is found undesirable, a metal piece (Fig. I A) may be inserted into the head rest at b and the same range of movements and adjustments obtained, or additional holes for the eyes may be
more » ... ut in the canvas. The head piece permits of two movements, flexion or extension at the joint, a, and a backward or forward movement by sliding the face piece through b. The relative height of the head piece to the table may be altered by sliding c through c. In order to obtain the proper degree of flexion, the backward and forward movement is essential, since the head in relation to the trunk varies with each angle of flexion, and proper adjustment of this variation must be made. As the head piece is attached to the table, the position of the table may be changed without altering the head piece.
doi:10.1001/jama.1922.26420100003014b fatcat:yzndtwkqtzfxbjcuwkluiwl7dy