A Case of Ectopic Eruption of the Left Mandibular Second Molar in a Child with Williams Syndrome Improved by Occlusal Guidance

<p>Clinical characteristics of Williams syndrome have been reported to include elf-like facial features, intellectual impairment, and cardiovascular lesions, which are primarily supravalvular aortic stenosis and peripheral pulmonary arterial stenosis. In addition, hyperacusis and anxiety/phobia are also considered to be characteristic of this syndrome. Occlusal guidance was performed for the management of ectopic eruption of left mandibular second molar in a child with this syndrome. The clinical course is reported.</p><p>The patient was a 10-year 3-month-old girl who presented with intellectual impairment, micrognathia, supravalvular aortic stenosis, ventricular septal defect, pulmonary valve stenosis, and elf-like facial features. She visited our clinic with the primary objectives of caries treatment and milk teeth extraction, and was treated under restriction of body movements and nitrous oxide inhaled anesthesia. Thereafter, she was followed up with periodic oral care. Since ectopic eruption of left mandibular second molar was observed 1 year and 4 months after the first examination, fenestration of left mandibular second molar and extraction of left mandibular third molar were performed under oral sedation in collaboration with the departments of dental anesthesia and oral surgery of our hospital. Lingual arches were placed about 1 year after fenestration, and left mandibular second molar was moved distally using an elastic chain. Then, brackets were applied and the appliances were removed after about 10 months. Presently, no relapse of left mandibular second molar or new caries is observed, and a satisfactory intraoral condition is maintained.</p><p>Occlusal guidance is occasionally difficult in patients with intellectual impairment because of poor cooperation. In the present case, however, continuation of regular oral care is considered to have mitigated the fear of dental treatment resulting in the management of ectopic eruption of left mandibular second molar by the use of simple appliances.</p>