Abstract
A 4-year old boy was referred to Osaka University Dental Hospital by his mother with complaints of tongue chewing and buccal mucosa while eating. His face was asymmetrical, and a mandibular shift and anterior crossbite were found. A lingual crossbite from the mandibular first primary molar on the left side to the lateral incisor on the right side was also observed. His mother reported that he had habits of chewing unilaterally and sleeping on the right side of his face. A lateral cephalometric analysis showed that he presented a potential skeletal Class III malocculusion and it could be pr edicted that his mandible would grow excessively as he matures. A frontal cephalometric analysis showed a skeletal crossdite and positional maxillo-mandibular aymmetry. Orthodontic treatment was initiated with the lingual arch soldered with springs. The springs were activated for 6 months and then retained for 6 months. Tooth interference was eliminated by grinding or equibration. His mother was told that he had to stop sleeping on his face. By means of this treatment, the patient was able to r egain a correct bite and showed improvement in his facial asymmetry.
