Severity
	 Interdental CAL	
1 – 2 mm	 3 – 4 mm	 ≥5 mm	 ≥5 mm
	
	 (at site of greatest loss)	
	
RBL
	 Coronal third	 Coronal third	 Extending to middle	 Extending to middle
		 (<15%)	 (15% - 33%)	 third of root and beyond	 third of root and beyond
	 Tooth loss	
No tooth loss 			 ≤4 teeth	 ≥5 teeth
	 (due to periodontitis)	
Complexity
	 Local	 •	 Max. probing depth	 •	 Max. probing depth	 In addition to	 In addition to
			 ≤4 mm		 ≤5 mm	 Stage II complexity:	 Stage III complexity:
		 •	 Mostly horizontal	 •	 Mostly horizontal	 •	 Probing depths 	 •	 Need for complex
			bone loss		bone loss		 ≥6 mm		 rehabilitation due to:
		 		 		 •	 Vertical bone loss		 –	 Masticatory dysfunction	
							 ≥3 mm		 –	 Secondary occlusal trauma	
						 •	 Furcation involvement			 (tooth mobility degree ≥2)	
							 Class II or III		 –	 Severe ridge defects 	
						 •	 Moderate ridge defects		 –	 Bite collapse, drifting, flaring
									 –	 < 20 remaining teeth 		
										 (10 opposing pairs)
Extent and
	 Add to stage as	 For each stage, describe extent as:
distribution
	 descriptor	 •	 Localized (<30% of teeth involved);
		 •	 Generalized; or
		 •	 Molar/incisor pattern
PERIODONTITIS: STAGING
Staging intends to classify the severity and extent of a patient’s disease based on the measurable amount of destroyed and/or damaged tissue as a result
of periodontitis and to assess the specific factors that may attribute to the complexity of long-term case management.
Initial stage should be determined using clinical attachment loss (CAL). If CAL is not available, radiographic bone loss (RBL) should be used. Tooth loss due to
periodontitis may modify stage definition. One or more complexity factors may shift the stage to a higher level. See perio.org/2017wwdc for additional information.
	 Periodontitis	 Stage I	 Stage II	 Stage III	 Stage IV
Staging and Grading Periodontitis
The 2017 World Workshop on the Classification of Periodontal and Peri-Implant Diseases and Conditions resulted in a new
classification of periodontitis characterized by a multidimensional staging and grading system. The charts below provide an
overview. Please visit perio.org/2017wwdc for the complete suite of reviews, case definition papers, and consensus reports.
The 2017 World Workshop on the Classification of Periodontal and Peri-Implant Diseases and Conditions was co-presented by the
American Academy of Periodontology (AAP) and the European Federation of Periodontology (EFP).
	
Progression
		 Grade A: 	 Grade B: 	 Grade C:
			 Slow rate	 Moderate rate	 Rapid rate
Primary	 Direct evidence of 	 Radiographic	 No loss over 5 years	 <2 mm over 5 years	 ≥2 mm over 5 years
criteria	 progression	 bone loss or CAL	 	
	 Indirect evidence	 % bone loss / age	 <0.25	 0.25 to 1.0	 >1.0
	of progression				
			 Case phenotype	 Heavy biofilm deposits 	 Destruction commensurate	 Destruction exceeds 	
							 with low levels of	 with biofilm deposits 	 expectations given biofilm 		
							 destruction		 deposits; specific clinical 		
									 patterns suggestive of periods
									 of rapid progression and/or 		
									 early onset disease			
														
	
Grade	 Risk factors	 Smoking	 Non-smoker	 <10 cigarettes/day	 ≥10 cigarettes/day
modifiers
	 	
			 Diabetes	 Normoglycemic/no	 HbA1c <7.0% in patients	 HbA1c ≥7.0% in patients	 	
							 diagnosis of diabetes	 with diabetes	 with diabetes				
Whenever
available,
direct evidence
should be used.
Tables from Tonetti, Greenwell, Kornman. J Periodontol 2018;89 (Suppl 1): S159-S172.
PERIODONTITIS: GRADING
Grading aims to indicate the rate of periodontitis progression, responsiveness to standard therapy, and potential impact on systemic health.
Clinicians should initially assume grade B disease and seek specific evidence to shift to grade A or C.
See perio.org/2017wwdc for additional information.