Periodontal charting is a test that is performed to determine the health of the gums and bone that support the teeth. The test involves using a dental probe to slip between the teeth and the gums in order to measure the sulcus depth at six points. Healthy gums will have readings that range from 1 to 3 millimeters in depth. It also evaluates the following: bleeding during probing, plaque/calculus accumulation, furcation involvement ( bone loss between the roots), gingival recession, tooth mobility, and bad occlusion. Information gathered during the periodontal charting is then combined with the information available from the x-rays. For example a 5mm bleeding probe depth could be the result of the overhang on a restoration that traps food here. The correct treatment would be replacing the restoration with a properly contoured restoration and then perform localized scaling with localized antibiotic therapy. Or perhaps bone loss noted on an x-ray with 6 mm probing depths is due to the premolar that is crowded and out of correct position causing it to be pounded forcefully during chewing. In this case treatment would be to correct the occlusion and then perform any additional gum therapy needed afterwards. Both of these scenarios demonstrate how examining the x-rays alone would not tell the entire story, and without treatment these conditions can worsen until the tooth is vulnerable to being lost from the lack of gum and bone support. Due to all of the important information gathered from this exam it is important that it be performed annually during a dental hygiene visit.