LAUSR

Abstract Background/purpose Idiopathic osteosclerosis (IO) is an intraosseous lesion of asymptomatic, non-expansive, radiopaque. The study aimed to investigate the prevalence and morphometric parameters of IO in orthodontic patients and variations in longitudinal observations and to assess the relationship between IO and orthodontic treatment. Materials and methods Five hundred and seventy-one orthodontically-treated patients were reviewed. A cross-sectional study was performed with the evaluated parameters, including the age and sex of patients, as well as the number, shape, location and morphometric data of IO observed in panoramic radiography. Long-term behaviour of IO and orthodontic tooth movement were also observed. Also, a control group was set up for comparisons. Results Sixty-eight (11.3%) patients had 78 lesions all in the mandible with premolar/molar preference and no sex predilection. Lesions were located more commonly at apical and separate sites related to teeth. A large majority of lesions enlarged in the 10–19 years old group, while most lesions had no change in the 30–39 years old group. Hindrances of tooth movement and external root resorption around IO were not found in affected patients. Conclusion IO is labile lesion that may develop in early stages of life, with little change occurring once the affected individual is mature and being relatively stable in the middle stage of life. Our study supports the hypothesis that IO may be developmental anatomic variations of normal bone. However, no obvious association between IO and orthodontic treatment was found in patients, which may be due to the limitations of two-dimensional shooting of panoramic radiography and the sample size.