These descriptors are very indistinct and do not allow a precise estimation of the amount of Class II anteroposterior discrepancy. It was also observed that usually the experimental groups followed rigid occlusal anteroposterior discrepancy criteria while the control groups did not25.Therefore, results of these comparisons could be compromised. Omission in describing Class II malocclusion severity could explain why there are sometimes contrasting results. While some authors report significant effects, others fail in demonstrating them. Therefore, basic questions remain unanswered38.Studies that Demanded Occlusal Severity SpecificationPapers that did not specify the severity level were analyzed whether occlusal severity specification was mandatory based on the aim of the study. Among those classified as “Without Occlusal Severity Specification”, in 159 papers (55.40%) severity specification was judged to be crucial. This means that the results and conclusions of these works could be compromised by the unspecific anteroposterior severity description. As it is known, comparative studies and Class II investigations need matched samples to avoid bias. Furthermore, if a device or technique is being tested in a sample with mild Class II malocclusion occlusal severity description2010;18(4):397-402
J Appl Oral Sci.401severity, results naturally tend to praise the system being tested without considering the simplicity to correct the Class II malocclusion (Tables 2 and 3).Occlusal Severity Specification over the YearsThe results demonstrated that occlusal severity description has gained some attention through the years. Specification increased three times from 1986 to 2007. It seems that concerns in specifying Class II malocclusion severity reflects the improvement in malocclusion classification developed by Andrews, with his paper “The six keys to normal occlusion”, in 19724. His textbook also illustrates how cases from the American Board progressively improved at the end of treatment in the 1960's, 1970's and 1980's6. This improvement is certainly due to the consideration and attention on the final occlusal aspects of the cases to be judged, since the mission of the American Board of Orthodontics is to establish and maintain the highest standards of clinical excellence by evaluating clinical competence39. As concerns with detailed finishing increased, investigators and clinicians realized that greater specification of malocclusion severity, especially Class II malocclusion anteroposterior discrepancy, was necessary to satisfactorily describe treatment difficulty. However, although there have been an increasing number of papers describing Class II malocclusion occlusal severity (Table 4), the percentage of papers without specification in which it was mandatory increased (Table 5). This shows that the importance of malocclusion occlusal severity has been underestimated.