Purpose: The purpose of this study is to investigate the outcome and stability of combined surgical and orthodontic treatment of severe maxillary anterior teeth and dentoalveolar bone protrusion.
Methods: Twenty-eight adults with severe bimaxillary protrusion were included.Presurgical orthodontic treatment coordinated axis of upper anteriors and dentoalveolar bone.Maxilla was impacted and set back by Le Fort I osteotomy and maxillary anterior segmental osteotomy, while upper anteriors and dentoalveolar bone were uprighted and retracted. Post-surgical orthodontic treatment detailed the occlusion.Each patient underwent X ray examination at five time points including pre-treatment, pre-surgery, one month after surgery, three months after surgery and post-treatment. Hard tissue and soft tissue changes were investigated by cephalometric analysis. The data were analyzed by paired t tests with SPSS12.0 software package.
Results: It was observed that upper anteriors were uprighted and retracted (11.77+/-9.9) degrees (P<0.001) after treatment while dentoalveolar bone was uprighted (6.24+/-3.9) degrees (P<0.001). UI-LI angle increased (19.4+/-8.6) degrees (P<0.001), UI-Apog distance decreased (6.62+/-2.2)mm (P<0.001). The thickness of alveolus on anterior teeth labial side showed no change (P>0.05).The treatment outcome demonstrated a significant improvement in soft tissue profile. Nasolabial angle increased (11.06+/-11.8) degrees (P<0.001), upper and lower lips moved backward, and pog' moved forward. Most measurements showed no significant difference from surgery time to post treatment.
Conclusions: Combined surgical and orthodontic treatment is a very effective procedure in treatment of severe maxillary anterior teeth and dentoalveolar bone protrusion and gummy smile. It remains the thickness of alveolus on anterior teeth labial side. It shows big improvement in soft tissue profile and great stability.