No abstract

This study was conducted in 533 children with 1,634 treated teeth who visited the Pediatric Dentistry Department at the Chiba Hospital of Tokyo Dental College between January and December, 2003. Restorations on deciduous tooth were categorized by age of patient and tooth type. The following observations were made: Children aged 4 (17.9%) visited the clinic most frequently and this group had the highest number of deciduous restorations (21.3%). Among the 1,634 deciduous teeth restored, metal inlays were provided in 29.4% of total teeth restored, composite resin restorations in 27.2%, stainless-steel crowns in 25.7%, composite resin full crowns in 7.7%, glass-ionomer cement restorations in 6.6%, and amalgam restorations in 3.4%. By age, composite resin was most frequently used in children aged 1 to 3. In children aged 5 to 9, metal inlay was most frequently used. Those aged 4 received mostly stainless-steel crowns. Composite resin restorations were used mostly in anterior deciduous teeth, and metal inlays mostly in deciduous molars. Previous research indicated an increasing trend towards composite resin restorations and composite resin full crowns. The present study also confirmed such a trend. While the use of metal inlays and stainless-steel crowns tended to increase until 1987, the present study indicated a trend to decrease.

During the period of the growth and development of the dental arch, anteriorposterior and medial-lateral changes in the maxillary deciduous and permanent canines were longitudinally studied in children. A longitudinal series of dental casts were obtained from 50 children at 2-month intervals from the completion of deciduous dentition to the stable period of permanent dentition. Subjects were divided into two groups according to the arrangement of the permanent teeth: a normal dental arch group and a crowded dental arch group. The mesial and distal points of the deciduous and permanent canines and the most prominent points on the labial and lingual contours were observed longitudinally. The results indicated that the measurement points of the deciduous canines in the normal and crowded groups moved in the anterior and lateral direction. When the amount of movement in the normal group was compared to that in the crowded group, the normal group showed greater movement than the crowded group. The permanent canines in both groups moved in the anterior and medial directions. When the amount of movement in the normal group was compared to that in the crowded group, the normal group showed more anterior movement than the crowded group, and the crowded group showed more medial movement than the normal group. When the distal point of the permanent canine was compared with the point of the deciduous canine at the exfoliation period in the normal arch group, the permanent canine was in almost the same position or was in a more anterior position than the deciduous canine. In the crowded arch group, the permanent canine tended to drift posteriorly.