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severe, mixed hearing losses. Although OCS fractures are often
associated with no measureable hearing loss, those that are tend
to be associated with mild, conductive losses. Hearing losses,
especially conductive losses, associated with OCS fractures tend
to resolve over the course of about 6 weeks (
Table 2
).
In this study, most fractures were unilateral and OCS
(
Table 1
). In adult population reports, 9% to 20% of tem-
poral bone fractures are bilateral.
2
The bilateral prevalence
is lower here (3%). In the same vein, the prevalence of all
skull base and maxillofacial fractures seems to be lower in
children than adults.
1,3,12
Though speculation, this may be
related to greater skull flexibility and impact absorption in
children.
3
Pediatric craniofacial anatomy is fundamentally
different, with developing paranasal sinuses and prominent
buccal fat pads. Varying fracture rates between pediatric
and adult populations may also relate to a different mechan-
ism of injury pattern in children.
12
The mechanism of injury distribution in this study was
similar to that seen in prior pediatric skull base trauma liter-
ature, with falls as the leading cause (
Figure 3
).
1,3,6
A
majority of patients in this study were Caucasian males,
reflecting a possible tendency for males to engage in more
active and reckless behavior (
Table 1
). Motor vehicle acci-
dents are still the leading cause of adult temporal bone frac-
tures, but that prevalence is decreasing.
2,3,13
It has been
postulated that this decrease may be related to stricter safety
regulations involving airbags and seatbelts.
1
There may be a
similar and stronger effect in the pediatric population given
rigorous standards for car seats and child restraint devices.
Similar to this study, a previous work showed that most
hearing losses associated with OCS fractures were conduc-
tive.
6
Whereas a majority of OCV fracture-associated hear-
ing losses were classified as sensorineural in a prior study,
we found that most classifiable losses in OCV fractures are
mixed (
Table 2
,
Figure 4
).
6
The difference here may be
Table 2.
Initial and Follow-up Audiometric Outcomes Based on Fracture Pattern.
a
All
OCS
OCV
P
Value
Fracture
60
56 (93)
4 (7)
—
Abnormal audio
34 (57)
30 (54)
4 (100)
.1258
Type of hearing loss
Conductive
14 (41)
14 (47)
—
.1261
Sensorineural
3 (9)
3 (10)
—
1.000
Mixed
3 (9)
1 (3)
2 (50)
.0307
Unclassified
14 (41)
12 (40)
b
2 (50)
b
1.000
Hearing loss severity
Mild
23 (68)
22 (73)
1 (25)
.0889
Moderate
3 (9)
3 (10)
—
1.000
Severe
4 (12)
1 (3)
3 (75)
.0026
Unclassified
4 (12)
4 (13)
c
—
1.000
Follow-up audio available
25 (42)
23 (41)
2 (50)
1.000
Improvement from abnormal to normal on follow-up
d
13 of 20 (65)
13 of 18 (72)
0 of 2 (0)
.1105
Conductive losses
10 of 12 (83)
10 of 12 (83)
—
Other types
3 of 8 (38)
3 of 6 (50)
0 of 2 (0)
Abbreviations: OCS, otic capsule–sparing; OCV, otic capsule–violating.
a
Values presented as n (%).
b
Otoacoustic emissions or due to lack of bone lines.
c
Otoacoustic emissions.
d
Improvements occurred at a mean of 46
6
15.9 days.
Figure 4.
Severity and type of hearing loss (HL) based on fracture
pattern. OCS, otic capsule–sparing; OCV, otic capsule–violating.
Otolaryngology–Head and Neck Surgery 154(1)
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