Describe the proper hole placement for the posterior anchor tooth of a rubber dam placement from #18 – 28.
To determine the proper location for the anchor hole when the rubber dam is applied to the mandibular teeth, mentally divide the rubber dam into three vertical sections: left, middle, and right. Although the anchor tooth is tooth #18, the second molar, first consider a situation where the first mandibular molar, or #19, is the anchor tooth. You would punch the hole for this tooth at a point halfway from the superior edge to the inferior edge and at the junction of the right (or left) and middle thirds. However, since the anchor tooth is the second molar, the position for the hole moves toward the inferior border and slightly toward the center of the rubber dam, as compared to the first molar hole just described.