Abstract: This paper reports the effect of a huge maxillary bone island on orthodontic tooth movement in a 19-year-old female. The three-dimensional relationship between the bone island and the root was assessed by cone beam computed tomography (CBCT), and the extraction and miniscrew anchorage technique combined with MBT straight wire arch treatment was used. The post-treatment profile was improved with gap closure, but the dense structure of the bone island caused poor root parallelism between the left maxillary lateral incisor and the first premolar, suggesting that the bone island restricted the physiological movement of the root. This case provides a reference for orthodontic patients with bone islands in the jaws who need to focus on the design of individualized treatment plans and treatment goals.

Key words: bone islands, CBCT, orthodontic tooth movement