Agreement analysis of three mandibular third molar retention classifications

Area of Science:

• Oral and Maxillofacial Surgery
• Radiodontology
• Dental Anatomy

Background:

• Pell & Gregory and Winter classifications are standard for third molar categorization.
• The Sánchez-Torres classification is utilized in Mexico but lacks prior evaluation.
• Accurate classification of impacted mandibular third molars is crucial for treatment planning.

Purpose of the Study:

• To evaluate the inter-observer agreement of three classifications for impacted mandibular third molars: Pell & Gregory, Winter, and Sánchez-Torres.
• To compare the reliability of these classifications in radiographic evaluations.

Main Methods:

• An observational, descriptive study assessed inter-observer agreement.
• Ten oral and maxillofacial surgeons and ten training residents evaluated impacted mandibular third molars.
• Classifications used were Pell & Gregory, Sánchez-Torres, and Winter.
• Fleiss' kappa test was employed to measure inter-observer agreement.

Main Results:

• The Pell & Gregory classification showed the lowest agreement (kappa = 0.05 and 0.185).
• The Sánchez-Torres classification yielded moderate agreement (kappa = 0.125 and 0.326).
• The Winter classification exhibited the highest agreement (kappa = 0.28 for surgeons, 0.636 for residents).

Conclusions:

• The Winter classification demonstrated the best inter-observer agreement among the evaluated methods.
• Winter classification showed acceptable, moderate agreement for training residents in classifying mandibular third molars.
• Further research may explore refining existing classifications or developing new ones for improved consistency.