Soft tissue profile changes after bilateral sagittal split osteotomy for mandibular setback: a systematic review.
OBJECTIVE
To evaluate the ratio of soft tissue to hard tissue in bilateral sagittal split setback osteotomy with rigid internal fixation or wire fixation.


METHODS
A literature search was performed using PubMed, Medline, CINAHL, Web of Science, the Cochrane Library, and Google Scholar Beta. From the original 766 articles identified, 8 articles were included. Two articles were prospective and 6 retrospective. The follow-up period ranged from 1 year to 12.7 years for rigid internal fixation. Two articles on wire fixation were found to be appropriate for inclusion.


RESULTS
The differences between short- and long-term ratios of the lower lip to lower incisors for bilateral sagittal split setback osteotomy with rigid internal fixation or wire fixation were quite small. The ratio was 1:1 in the long term and by trend slightly lower in the short term. No distinction was seen between the short- and long-term ratios for mentolabial fold. The ratio was found to be 1:1 for the mentolabial fold to point B. In the short term, the ratio of the soft tissue pogonion to the pogonion showed a 1:1 ratio, with a trend to be lower in the long term. The upper lip showed mainly protrusion, but the amount was highly variable.


CONCLUSIONS
This systematic review shows that evidence-based conclusions on soft tissue changes are difficult to draw. This is mostly because of inherent problems of retrospective studies, inferior study designs, and the lack of standardized outcome measurements. Well-designed prospective studies with sufficient samples and excluding additional surgery, ie, genioplasty or maxillary surgery, are needed.
Joss
Christof Urs
CU
Department of Orthodontics and Oral Biology, Radboud University Nijmegen Medical Center, Nijmegen, The Netherlands. christofjoss@hotmail.com
Joss-Vassalli
Isabella Maria
IM
Bergé
Stefaan J
SJ
Kuijpers-Jagtman
Anne Marie
AM
D001864:Bone Wires; D002680:Chin / Q000473:pathology; D005145:Face; D005500:Follow-Up Studies; D006801:Humans; D007180:Incisor / Q000473:pathology; D016268:Internal Fixators; D008046:Lip / Q000473:pathology; D008334:Mandible / Q000473:pathology / Q000601:surgery*; D056948:Orthognathic Surgical Procedures / Q000295:instrumentation / Q000379:methods*; D010027:Osteotomy / Q000295:instrumentation / Q000379:methods*; D011446:Prospective Studies; D012189:Retrospective Studies