How Does a Dentist Diagnose Gum Disease?

Gum disease is diagnosed by both clinical (hands-on) and radiographic (x-ray) examinations. During a clinical exam, the dentist uses an instrument called a probe to measure the gums. A probe is like a small metal ruler using millimeter increments. The dentist probes the gum around the tooth and takes a series of measurements (usually six). If the gum bleeds when the dentist gently probes it, this often indicates the presence of gum disease.

Visual examination of a person with gum disease may reveal red, puffy, swollen or receding gums. Large deposits of plaque and calculus (tartar) are often visible in people with gum disease, especially those who have not seen a dentist in years. The teeth may be mobile, that is, the dentist is able to move the tooth a millimeter or two within the socket. A healthy tooth will not budge! The dentist may detect pus when putting gentle pressure on a puffy area of the gums. Foul mouth odor (bad breath) is also commonly associated gum disease.

X-rays are also helpful in the diagnosis of gum disease. The dentist will usually require a full mouth series of x-rays (18 films) to document the approximate level of the bone around the teeth. (Dentists often take a full mouth series of x-rays even if the patient does not have gum disease to serve as a baseline for future use.) Bone loss appearing on the x-ray can be uniform (horizontal bone loss), uneven (vertical bone loss), or a combination of both.

There are several stages of gum disease. In most cases, gum disease begins as gingivitis, an inflammation of the gums. People with gingivitis have red, puffy gums that often bleed after brushing their teeth. They may wake up and have blood on their pillow in the morning. Ironically, some people whose gums bleed after brushing decide to brush less or avoid brushing out of fear- this avoidance of brushing often leads to more advanced gum disease.

The first non-reversible stage of the disease is early periodontal disease. Early periodontal disease is confirmed when the dentist can probe a periodontal pocket depth of four or five millimeters (healthy gums measure one to three millimeters). Moderate periodontal disease has five to seven millimeter probe readings, and advanced periodontal disease is generally any probe reading greater than seven millimeters. As the disease progresses from early to advanced, the gums will often become more swollen and inflamed, the teeth may become loose, and people who wear partial dentures may notice a change in how they fit. The dentist will often be able to probe between the tooth roots (furcation) in people with moderate or advanced periodontal disease. All three stages of periodontal disease commonly affect adults.

One rare form of gum disease affects children, at or slightly before adolescence. It is called Juvenile Periodontitis, and is characterized by bone loss around the child's front teeth (central incisors) and first molars.