North Texas Dentistry Volume 9 Issue 6 2019 ISSUE 6 DE | Page 15

the genioglossus muscle. A CBCT scan was taken and models were
obtained of the current occlusion. The study models were used to set a
post-operative occlusion and this, along with the CBCT, was uploaded to
Medical Modeling, 3D Systems. A web design meeting took place where
clinical and cephalometric measurements were used to position the maxilla
and mandible in the ideal AP position. The virtual surgical planning allowed
us to correct any asymmetries, midline discrepancies, or occlusal cant prob-
lems. In the treatment plan, the maxilla was advanced and impacted verti-
cally to help improve the excessive gingival display. The mandible was
advanced to achieve an ideal Class I occlusion, and the maxillomandibular
complex was rotated counterclockwise to decrease the occlusal plane
angle. This counterclockwise movement allowed us to achieve better
advancement of the mandible and helped achieve better jawline definition.
The post-operative occlusion was confirmed and a multi-piece Le Fort was
planned to achieve expansion of the maxilla and better control of each seg-
ment. Finally, an advancement genioplasty with inclusion of the genioglos-
sus was planned. Surgical splints and positioning guides were fabricated
to allow mandible first surgery. This was especially important for her due to
difficulty of properly seating the condyles in centric relation during the pre-
surgical work-up.
RESULTS
The surgical results were excellent and post-surgically she was in orthodontic
treatment for 4 months to finalize the details of her occlusion. She is very
happy with her facial balance and occlusion. She has significant improve-
ment post-operatively and she subjectively feels less tired with more focus
and energy. A post-surgical polysomnogram revealed her AHI to be 7.
Lateral cephalometric measurements to evaluate airway include PSA, which
changed from 6.2 mm preoperatively to 11.8mm postoperatively. A 3D analy-
sis also showed a substantial increase in her airway volume starting at
27.3 cm 3 to 40.5 cm 3 , respectively. She initially had paresthesia of her lower
lip and mid-face, but this resolved during the first 3 months of recovery. She
is a great example of demonstrating how orthognathic surgery is an excellent
tool to achieve a better airway and a better occlusion without compromising
on facial balance and esthetics.
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