Secondary fractures of Le Fort I osteotomy.
OBJECTIVE
To report the ophthalmic complications of Le Fort I osteotomy for the correction of dentofacial deformities and to determine the maximal compressive loads applied during pterygomaxillary separation in a cadaver model.


METHODS
Two cases of ophthalmic complications arising after Le Fort I osteotomy are reported. Le Fort I osteotomy was performed on five cadavers. The maximal compressive load applied during pterygomaxillary separation was recorded with a 10 kN (3,000 lbf) load cell of a MTS Mini-Bionix servo-hydraulic machine (MTS, Eden Prairie, MN, U.S.A.). A paired t test was used to compare forces applied to the right and left sides. Computed tomography scans of each specimen were obtained after Le Fort I osteotomy to document secondary fractures. The skulls were subsequently stained with 1% fuschin red to highlight secondary fractures.


RESULTS
Maximum compressive loads during pterygomaxillary separation ranged from 22 N (5.0 lbf) to 162 N (36.5 lbf), with an average of 106 N (23.8 lbf) (SD 47.6 N [10.7 lbf]). Forces applied on the first operative side were significantly greater than forces applied on the second operative side (p = 0.0034). Secondary fractures were found in three specimens by computed tomography and in two specimens by 1% fuschin red. All secondary fractures occurred on the second operative side.


CONCLUSIONS
Secondary fractures in the Le Fort I osteotomy procedures occurred on the side opposite the greater maximal compressive load and on the second operative side.
Department of Ophthalmology, University of Tennessee, Memphis, College of Medicine, 38163, USA.
M W
MW
Wilson
P
P
Maheshwari
K
K
Stokes
M J
MJ
Wheatley
S
S
McLoughlin
M
M
Talbot
W T
WT
Shults
R A
RA
Dailey
J L
JL
Wobig
D000328:Adult; D000368:Aged; D001696:Biomechanical Phenomena; D002102:Cadaver; D006801:Humans; D008297:Male; D008439:Maxillary Diseases / Q000601:surgery*; D008875:Middle Aged; D009886:Ophthalmoplegia / Q000209:etiology*; D019340:Osteotomy, Le Fort / Q000009:adverse effects*; D011681:Pupil Disorders / Q000209:etiology*; D012887:Skull Fractures / Q000000981:diagnostic imaging / Q000209:etiology* / Q000503:physiopathology; D013100:Sphenoid Bone / Q000000981:diagnostic imaging / Q000293:injuries*; D014057:Tomography, X-Ray Computed; D014786:Vision Disorders / Q000209:etiology*