Alteration of the mandibular plane during sagittal split advancement: short- and long-term stability.
OBJECTIVE
We investigated predictors of long- and short-term stability of surgical mandibular advancements with bilateral sagittal split osteotomy (BSSO).


METHODS
Class II patients (n = 127) received mandibular advancement through BSSO with either rigid internal fixation or wire osteosynthesis. We used multiple linear regression analysis to assess the association of predictor variables with post-treatment horizontal and vertical B-point movement through 2 years.


RESULTS
Counterclockwise rotation of the mandibular plane angulation (MPA) was associated with greater horizontal and vertical relapse at all time periods except 8 weeks. Wire osteosynthesis, larger advancements, younger age, and genioplasty were significantly associated with relapse.


CONCLUSIONS
Surgically closing the MPA is associated with late horizontal and vertical relapse, whereas fixation type is related to early B-point movement. Large advancements with forward and upward repositioning of the mandible, genioplasty, and young age also play a role in relapse after BSSO.
Frey
Daniela Rezende
DR
Department of Orthodontics, The University of Texas Health Science Center, San Antonio, Texas 78229-3900, USA.
Hatch
John P
JP
Van Sickels
Joseph E
JE
Dolce
Calogero
C
Rugh
John D
JD
D000328:Adult; D000367:Age Factors; D001863:Bone Screws; D001864:Bone Wires; D002508:Cephalometry; D002680:Chin / Q000601:surgery; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D019248:Jaw Fixation Techniques; D016014:Linear Models; D008297:Male; D008312:Malocclusion, Angle Class II / Q000601:surgery*; D008334:Mandible / Q000601:surgery*; D019186:Mandibular Advancement / Q000379:methods*; D015999:Multivariate Analysis; D011446:Prospective Studies; D012008:Recurrence