A periodontal examination and probing is one way your general dentist or dental specialist can evaluate the health of your gums and teeth. They help your dentist diagnose the gum diseases gingivitis and periodontitis and also check for receding gums, exposed roots, tooth grinding (bruxism), and other problems.

Periodontal measurements can be taken by any dentist or dental specialist, as well as by dental hygienists. If you are referred to a periodontist (gum-disease specialist) for evaluation, these measurements will be taken during your first visit.

Here's what your dentist will evaluate during a periodontal examination and what to expect:

• Any lumps or lesions in the mouth or changes in color of the gums, inner cheeks or tongue — Changes such as these can indicate oral cancer or a precancerous condition. Some infections also cause these changes. Your dentist may be able to diagnose your condition in the office, or you may be referred to a specialist.
• Whether any of your teeth are missing or loose, and how loose they are — Loose teeth can indicate periodontal disease. Loose teeth also can be the result of a problem with your bite (the way your teeth come together) or tooth grinding (bruxism).
• The color, texture, size and shape of your gums — Healthy gums are firm and pink. Reddish or bluish-red gums, or puffy or spongy gums can indicate disease. Enlarged or swollen gums and gums that are shaped differently than normal also can indicate problems.
• Whether you have any restorations, such as fillings, crowns, bridges, dentures or implants
• How much plaque is on your teeth — Plaque is the coating that forms on your teeth and contains large numbers of bacteria that can cause decay and/or periodontal disease. The amount of plaque gives your dentist an idea of your oral hygiene habits. You may be missing certain areas of your mouth when you brush and floss.
• The depth of the space between your tooth and gum (called the sulcus) — Spaces, or pockets, that are deeper than normal indicate gum disease: either gingivitis (the early stage) or periodontitis (more advanced disease). To measure these spaces, the dentist uses a periodontal probe, which is nothing more than a tiny millimeter ruler with a blunt tip. Your dentist slides the probe between the tooth and gums at various places around each tooth to measure the depth of the spot where the gum attaches to the tooth. Healthy gums adhere tightly to the tooth so that the probe penetrates only 1 to 3 millimeters. Diseased gums tend to swell and detach from the tooth, forming what are known as pockets. In advanced forms of periodontitis, the pocket can be more than 10 millimeters deep, so the probe reaches all the way to the tip of the root of the tooth. This means that much of the soft tissue and bone anchoring the tooth in place has been lost.
• Whether your gums bleed during probing — After your dentist has measured the depths of the gum tissue around your teeth, he or she will look to see whether the probing caused bleeding. Bleeding after probing is an indicator of gum disease.
• Gum recession — Normally, the roots of your teeth are covered by gum tissue. Numerous factors, however, may cause the gums to recede. These include inflammation, teeth that are badly positioned, and overly aggressive tooth brushing. Once the roots of the teeth have been exposed, the teeth may become sensitive to changes in temperature, are more susceptible to decay, and may not appear cosmetically pleasing. Dentists use periodontal probes to measure the extent of gum recession by measuring the distance between the crown of the teeth and the gum margin.
• How your teeth come together when you bite (also called occlusion or bite) — Too much tooth-on-tooth force can affect your teeth and gums. This can result from the way your teeth come together when you bite down, or from habits such as grinding and clenching your teeth. Your dentist will be able to identify some problems simply by looking at your teeth because excessive force can cause tooth wear. He or she may use special wax or a special blue paper to evaluate your bite. The wax or paper is placed on the biting surface of your teeth and you tap your teeth together or grind them slightly. The wax shows an imprint of your teeth, and the paper leaves marks on your teeth that help your dentist see where your teeth may be meeting with too much force.

In addition to the periodontal examination, you also may need X-rays of your teeth. A type of X-ray called a periapical X-ray helps the dentist or periodontist determine the extent and pattern of bone loss around each tooth. These X-rays show the entire tooth from the crown (top) to the end of the root, which anchors the tooth in your jaw. You also may need an X-ray of your entire head, known as a panoramic radiograph. This type of picture provides information about other important structures in your skull, such as the maxillary sinuses and jaw joints (temporomandibular joints or TMJs).

Many dentists check all of these factors at every dental visit, but don't write down the results unless something has changed from the previous visit. Repeating these measurements helps your dentist track the progress of treatment. For example, if you need scaling and root planing, your dentist will chart these measurements before the treatment and again several weeks or months later to see if the treatment was effective.

Each dentist has his or her own method for keeping track of periodontal measurements, although most charting methods probably look similar. Many offices today use computers to keep track of the measurements.