Abstract: Objective: To investigate the adjustment of the asymmetry of the anterior and middle part of the lower arch by using fixed lingual arch as anchorage. Methods:6 patients with asymmetrical mandibular arch was treated by using fixed lingual arch as anchorage, plaster models before and after adjustment were collected, scanned and measured after the establishment of the three-dimensional digital model by Dolphin 11.0 software. Results: 6 patients were treated with mandibular fixed lingual arch for average 1-3 months, nearly symmetry of the mandibular arch were achieved, and difference between the distance from bilateral second premolar buccal cusps, canine cusps, midpoints of lateral incisal edge to the sagittal plane significantly reduced, and there was statistical significance（P<0.05）, while the difference between the distance from bilateral mesial buccal cusp of first molar to sagittal plane was not significant, and there was no significant difference in the width of first molar（P>0.05）. Conclusion: The fixed lingual arch can effectively adjust the asymmetry of the anterior and middle part of the lower arch, to establish normal occlusal relationship.

Key words: Key words: mandibular dental arch, asymmetry, lingual arch, anchorage, three-dimensional reconstruction