Pterygoid Plate Fractures Associated with Mandible Fractures
Anh Q. Truong,
a
M.D. ,
E. Bradley Strong,
a
M.D. ,
a
Neck
Arthur Dublin,
b
M.D.
b
Radiology ,
Department of Otolaryngology Head and
Surgery and
University of California – Davis Medical Center, Sacramento, CA, U.S.A.
INTRODUCTION
RESULTS
DISCUSSIONS/FUTURE WORK
Classically, pterygoid plate fractures noted on computed
tomography (CT) images are a component of midface
fractures1-3. Pterygoid plate fractures noted on CT without
associated Le Fort fractures may present a confusing
clinical picture. Currently, there are no descriptions of
isolated lateral pterygoid plate fractures (i.e. without an
associated medial pterygoid plate fracture or a Le Fort
fracture) associated with mandible fractures. This
retrospective case series will review the relevant anatomy
and propose a mechanism of isolate pterygoid plate
fractures associated with mandible fractures.
Seven patients between 2006 and 2012 with facial trauma
had lateral pterygoid plate fractures without Le Fort
fractures. Subsequent maxillofacial CT scans demonstrated
associated mandible fractures. All the patients were male
with an average age of 37 years. All seven patients had an
ipsilateral subcondylar fracture, two had symphyseal
fractures, one had a body fracture, one had a
parasymphyseal, and one had a coronoid fracture (Table 1).
- An isolated lateral pterygoid plate fracture suggests the
presence of a mandible fracture.
- CT features of isolate pterygoid fracture:
A
Fig. 1: Attachments of lateral and
medial pterygoid muscle4.
B
•
•
Unilateral + no involvement of medial plate
Vertical fracture of lateral pterygoid plate
- Proposed mechanism:
• Force transduction through the pterygoid muscles
during acute displacing force on the mandible
• Pterygoid muscles contraction during acute injury
- A dedicated CT of the mandible may reveal mandible
fractures with findings of an isolated lateral pterygoid
fracture
- A more extensive retrospective chart review of all facial
fractures will be performed to strengthen the association
between the fractures
Fig. 2: Le-Fort III fracture
w/bilateral medial & lateral
pterygoid plates fracture.
C
C
OBJECTIVES
1. To evaluate CT scans with evidence of isolate lateral
pterytoid plate fractures with concomitant mandible
fractures.
2. To propose a mechanism of lateral pterygoid plate
fractures associated with mandible fractures
MATERIALS & METHOD
After IRB approval was obtained, the electronic medical
records of a series of seven patients with pterygoid plate
fractures treated at UC Davis Medical Center between
2006 to and 2012. Demographic information was extracted.
Available CT images were evaluated by the lead author for
all facial fractures.
C
D
Fig. 3: A) CT head with lateral pterygoid fracture. Mandible
fracture not visible. B) CT face with pterygoid + mandible
fracture visible. C) Coronal view. D) Sagittal view.
Pt Age/Sex Associated Fractures
1
42M Left subcondylar, left pterygoid, left body, right
parasymphyseal, left anterior maxillary wall
2
22M Left subcondylar, left lateral ptyergoid, symphaseal
3
33M Left subcondylar, left lateral pterygoid, left zygomatic arch,
left inferior orbital rim
4
40M Left subcondylar, left lateral pterygoid, left anterior
maxillary wall, nasal bones
5
38M Left subcondylar, left lateral pterygoid
6
53M Left subcondylar, left lateral pterygoid, left tripod fracture,
left coronoid
7
34M Right subcondylar, right lateral pterygoid, symphaseal, left
zygomatic arch
Table 1: Associated facial fractures [classification of mandible fractures5]
Fig. 5: Proposed mechanism of lateral pterygoid
plate fracture. * = external force. C = contraction.
REFERENCES
1. Rhea JT, Novelline RA. How to simplify the CT diagnosis of Le Fort fractures. AJR Am J
Roentgenol. 2005 May;184(5):1700-5.
2. Tessier P. The classic reprint. Experimental study of fractures of the upper jaw. I and II.
René Le Fort, M.D. Plast Reconstr Surg. 1972 Nov;50(5):497-506
3. Tessier P. The classic reprint: experimental study of fractures of the upper jaw. III. René Le
Fort, M.D., Lille, France. Plast Reconstr Surg. 1972 Dec;50(6):600-7.
4. Gray, Henry, and Warren Harmon. Lewis. Anatomy of the human body. Philadelphia: Lea
& Febiger, 1918. 07 Jul. 2012 <http://www.bartleby.com/107/109.html>.
5. Myers, E. et. al. (2008). Operative Otolaryngology: Head and Neck Surgery. Philadelphia,
PA: Saunders.
DISCLOSURE/ACKNOWLEDGEMENTS
All electronic medical records and CT images were viewed
with UC Davis Medical Center equipments.