Prevalence of non-cavitated lesions and progression, regression, and no change from age 9 to 23 years.

Non-cavitated lesions were more prevalent at age 17 than at ages 9, 13, and 23. The high rates of regression compared to progression or no change suggest that many non-cavitated lesions do not progress to cavitated lesions and could be reversed; therefore, surgical intervention should not be the treatment of choice for incipient lesions.