Abstract: Objective To investigate the changes of occlusal relationship during the treatment of the second molar scissors bite with modified fixed inclined biteplate. Methods 24 cases (9males,15females,aged from 12~15 years,with the average age of 13.5 years old) were treated with modified fixed inclined biteplate. Cephalometric analysis was carried out before and after treatment.Results After 3 to 4 months′ treatment,the scissors bite of the second maxillary molars was corrected. The mandible showed forward movement. Occlusal relationship came to class I,and the soft tissue profile has improved greatly. The clinical crown height of mandibular molars grew significantly while the growth of upper molars was unobvious. Conclusions Modified fixed inclined plate is a simple but effective intraoral device in treatment of the second maxillary molar with buccal crossbite. It did not cause the clinical crown height of maxillary molar to grow,and the hard and soft tissue changes are satisfactory. This kind of device especially applies to the treatment of the lowangle patients.

Key words: modified fixed inclined plate, second molar, scissors bite