The Perio Perspective
The Perio Perspective
What’s In a Name?
Periodontal disease is an enigma. Its exact causes are not known, although many of its risk factors are. Its progress in each individual is unpredictable. It depends as much on the behavior of the patient as on treatment. It tends to be episodic, with erratic patterns of activity and inactivity. It tends to recur. Sometimes teeth that appear to have a poor prognosis survive for many years, while others with an apparently better prognosis fail sooner. It affects implants, even if all the teeth have been removed first. Formulating a rational approach to treatment is difficult when every tooth and every patient seem to have a unique pattern of disease and response to therapy.
The American Academy of Periodontology recently redefined its classification of periodontitis (Tonetti, M et al, J Perio 89: S159-172, 2018). Its motivation was to make diagnosis more closely correlated with the rate of disease progress, difficulty of treatment, and prognosis, and to make research guiding our treatment more closely tied to these factors. We and our patients deserve to know which treatment modalities work best at each stage of disease, and to assign prognosis with and without treatment of each type. At present these assessments are approximate at best.
The new classification is complicated. It defines severity (staging) and then modifies it with prognosis (grading), similar to the system used for cancer. It will eventually replace the current classification used by general dentists, hygienists, specialists, and insurance carriers. We hope that it will lead to a more rational algorithm for treatment. Here is our simplified description.
There are 4 severity stages. They correspond approximately to the old categories, listed in parentheses below.
Stage I (Mild): pockets 4 mm or less, slight bone loss (1-2 mm), no tooth loss due to periodontitis
Stage II (Moderate): pockets 5 mm or less, moderate bone loss (3-4 mm), no tooth loss
Stage III (Severe): pockets >5mm, severe bone loss (>4 mm), furcation involvements, up to 4 teeth lost
Stage IV (Severe): same as Stage III with added complexity due to >4 lost teeth, Class 2-3 mobility, bite collapse, and/or loss of chewing function
Stages are modified by 3 grades based on rate of progression as well as presence of systemic risk factors (diabetes and smoking). Grading can be generalized, localized (<30% of teeth) or molar/incisor (formerly Localized Aggressive Periodontitis). Grades roughly correspond to the old modifiers listed below in parentheses.
Grade A (Chronic): no bone loss in past 5 years, heavy plaque and calculus deposits (“For this much calculus, where is the disease?”), no smoking or diabetes
Grade B (Chronic): <2 mm bone loss in past 5 years, moderate deposits, smoking <10/day, controlled diabetes
Grade C (Aggressive): >2 mm bone loss in past 5 years, minimal deposits (“For this much disease, where is all the calculus?”), smoking >10/day, poorly controlled diabetes
This was a laudable effort by the AAP. But there are two glaring omissions. First, patient compliance is not included. Abundant research and decades of clinical experience have shown that this is a critical determinant of success or failure. Oral hygiene and recall attendance matter. Second, there is no research-based guidance to more accurately determine prognosis and treatment using the new classification. We will still root plane pretty much all periodontal patients, perform osseous or regenerative surgery for residual pockets 5 mm or greater, and institute a 3-month supportive periodontal therapy schedule. We will still extract teeth with severe mobility or unmanageable infection. We already knew that heavy smokers and poorly-controlled diabetics respond poorly to treatment of any type.
So periodontal disease remains enigmatic. Perhaps new research will offer better guidance based on the new classification. This will take years at best. We hope it proves to be more than just an academic exercise.