Evaluation of Morphological Variations in Pars Tympanica of Temporal Bone in Dogs

Abstract

In this study, it was aimed to examine the relationship between the morphometric-geometric features of the meatus acusticus externus, bulla tympanica and tuba auditiva and the cranium shape, age, gender and race characteristics in the os temporale region in terms of the clinical-anatomical approach to the outer ear and middle ear regions of the dogs’ skull. In the study, a total of 110 dog's cranium were studied. The bones were photographed in three different views with the camera. The morphometric data on the head, angle measurements and index values related to them were calculated in obtained images. Tuba auditiva angle and meatus acusticus externus angle were found to differ statistically between the age groups. In addition, it was determined that the index values of bulla tympanica, except for the height index, showed statistical differences among age groups. When the angle measurements and index values of the skulls of male and female animals are examined it was determined that other index values did not differ between female and male animals, except for the meatus acusticus externus angle. As a result, it can be said that age and skull type is more effective than gender in the position of the tympanic region in dogs. The results of this research are supportive information that can be used in both clinical and zooarchaeological studies on the bulla tympanica region in dogs.

Full text

Evaluaon of Morphological Variaons in Tympanic Poron of Temporal Bone in
Dogs
Semra ÇINAR1* , Figen SEVİL-KİLİMCİ1, Mehmet Erkut KARA1
1Department of Anatomy, Faculty of Veterinary Medicine, Aydin Adnan Menderes University, Aydin, Turkey
ABSTRACT
In this study, it was aimed to examine the relaonship between the morphometric-geometric features of the external
acousc meatus, tympanic bulla, and auditory tube and the cranium shape, age, gender, and race characteriscs in
the os temporale region in terms of the clinical-anatomical approach to the outer ear and middle ear regions of the
dog’s skull. A total of 110 dogs’ skulls were used. The bones were photographed in three dierent views with the
camera. The morphometric data on the skull, angle measurements, and index values related to them were calculated
in obtained images. Auditory tube angle and external acousc meatus angle were found to dier stascally among
the age groups. In addion, it was determined that the index values of bulla tympanica, except for the height index,
showed stascal dierences among age groups. When the angle measurements and index values of the skulls of
male and female animals were examined, it was determined that other index values did not dier between female
and male dogs, except for the external acousc meatus angle. As a result, it can be said that age and skull type is more
eecve than gender in the posioning of the tympanic region in dogs. The results of this research are supporve
informaon that can be used in both clinical and zooarchaeological studies on the tympanic bulla region on dogs.
Keywords: Bulla tympanica, dog, morphometry, temporal bone, tuba audiva
Köpeklerde Temporal Kemiğin Pars Tympanica’sındaki Morfolojik Varyasyonların
Değerlendirilmesi
ÖZET
Bu çalışmada, köpeklerin kafatasının dış kulak ve orta kulak bölgelerine anatomik yaklaşım ve klinik açıdan meatus
acuscus externus, bulla mpanica ve tuba audiva’nın morfometrik-geometrik özellikleri ile os temporale
bölgesindeki kafatası şekli, yaş, cinsiyet ve ırk özellikleri arasındaki ilişkinin incelenmesi amaçlanmışr. Çalışmada
toplam 110 adet köpek kafatası üzerinde çalışılmıştır. Kemiklerin üç farklı yönde fotoğraarı çekildi. Elde edilen
görüntülerde kafa ile ilgili bazı morfometrik veriler, açı ölçümleri ve bunlara ilişkin indeks değerleri hesaplandı. Tuba
audiva açısı ve meatus acuscus externus açısı yaş grupları arasında istasksel olarak farklılık görüldü. Ayrıca bulla
mpanika indeks değerlerinin boy indeksi dışında yaş grupları arasında istasksel olarak farklılık gösterdiği belirlendi.
Dişi ve erkek hayvanların kafataslarının açı ölçümleri ve indeks değerleri incelendiğinde, meatus acuscus externus
açısı dışındaki diğer indeks değerlerinin dişi ve erkek hayvanlar arasında farklılık göstermediği belirlendi. Sonuç
olarak köpeklerde mpanik bölgenin pozisyonunda, yaş ve kafa pinin cinsiyeen daha etkili olduğu söylenebilir.
Bu araşrmanın sonuçları köpeklerde bulla mpanica bölgesi ile ilgili hem klinik hem de zooarkeolojik çalışmalarda
kullanılabilecek destekleyici bilgilerdir.
Anahtar kelimeler: Bulla tympanica, köpek, morphome, temporal kemik, tuba audiva
*Corresponding Author: Semra ÇINAR, Department of Anatomy, Faculty of Veterinary Medicine, Aydin Adnan Menderes University, Aydin,
Turkey. e-mail: veterinariansemra@gmail.com
Received Date: 05.10.2021 Accepted Date: 24.11.2021
DOI: 10.53913/aduveterinary.1005009
Animal Health Prod and Hyg (2021) 10 (2) : 39 - 44
Research Arcle
Research Arcle

Çınar et al Morphological Variaons in Tympanic Poron of Temporal Bone in Dogs
.
40
Introducon
Morphometric studies of the skull can be done to
determine species, race or sex characteriscs (Onar,
1999; Onar and Gunes, 2003; Schmidt et al., 2011), as
well as to form the basis of clinical approaches in various
regions (Fox, 1964; Schmidt et al., 2011; Schmidt et al.,
2013) is important. One of the most common ailments
of dogs seen in veterinary medicine is ear disease. About
15%-20% of all canine paents have ear problems, which
can range from mild erythema to severe os media
(Louis, 2004). The temporal bone, which parcipates in
the formaon of a part of the lateral and base wall of the
cavum cranii, is an important bone in terms of clinical
applicaons, as some important vessels and nerves pass
through it, arculates with the mandible, and forms the
bony roof of the ear. In the middle of pars tympanica of
the os temporale external hole of the meatus acouscs
externus osseous is located. External acousc meatus
(external ear canal) is a tubular path which it is extending
from concha auriculare to membrana tympanica and
obliquely in dog (Evans, 1993; König, 2007; Njaa et al.,
2012). The membrana tympanica at the end of external
acousc meatus is located at an angle of approximately
45 degrees to the horizontal central axis of the external
acousc meatus in dogs, however, this angle may dier
according to dog breeds (Njaa et al., 2012). External
acousc meatus is closed in newborn kiens and
puppies. For this reason, although newborn puppies can
perceive some sounds, they cannot hear them properly.
Generally, the external ear canal opens between the 6th
and 14th days and the puppies begin to hear in the 3rd
week aer they are born (Samsar and Akın, 2006). Bony
enlargement called tympanic bulla located on the ventral
aspect of the pars tympanica is a structure that contains
the middle ear (Bahadır and Yıldız, 2004). The space in
the middle ear is called tympanic cavity and this space
is in conjuncon with the pharynx through the auditory
tube (Eustachian tube). Since the posion of the osseous
roof of the external auditory canal, mastoid part of
middle ear, and auditory tube, which is the funconal
unit of the ear, is related to various clinical approaches.
Many studies are conducted on the morphometric and
geometric features of the region (Mann et al., 1979;
Albiin, 1984; Djeric and Savic, 1985; Sadler-Kimes et
al., 1989; Kemaloğlu et al., 1996; Judkins and Li, 1997;
Sırıkçı et al., 2001). In clinical applicaons, posion of
the external auditory canal for otoscope applicaon and
locaon of the tympanic membrane during cleaning of
the ear canal must be taken into account (Njaa et al.,
2012). For example, the dorso-rostral border of the
external acousc meatus and the shape of the zygomac
process of the os temporale and the angle of the skull
to the long axis may show variaons in dierent skull
types of dogs. This is important in terms of placing the
autoendoscope deeper during video otoscope use in
procedures such as myringotomy (Njaa et al., 2012). In
addion, regarding the angle of the external auditory
canal with the tympanic annulus; provides an advantage
in washing the external ear, inserng and passing the
catheter into the horizontal ear canal, and collecng
the washing soluon and serum physiology without
damaging the tympanic membrane (Njaa et al., 2012).
Auditory tubeposion is considered to be the main cause
of middle ear inammaons (Mawson, 1974; Kemaloğlu
et al., 1996). The po sion of the Tympanic bulla and
auditory tube changes depending on age (Takeuchi ve
ark., 1980; Bluestone and Doyle, 1988; Kemaloğlu et al.,
1996)
Due to the common middle ear inammaons in
children, there are many studies on this subject both in
humans and animals (Sadler-Kimes, 1989; Judkins and
Li, 1997). For this reason, os temporale measurements
and their raos to ossa cranii measurements have gained
importance. Considering the changes in development
process of the studied measurements, it is seen that the
os temporale connues to develop together with the
ossa faciei unl it reaches maturity (Takeuchi ve ark.,
1980) and it has been revealed that the growth process
of the skull signicantly aects funcon of the auditory
tube (Mann et al., 1979). In these studies, change in the
shape, size and posion of the auditory tube with age
was also invesgated (Mann et al., 1979; Takeuchi et al.,
1980; Todd and Marn, 1988).
In literature review on the subject, detailed data
on various ear diseases in dogs and temporal bone
morphometry, which is important in terms of
examinaon, and variaons of this region depending on
race, age, gender, and skull shape were not found. In this
study, it was aimed to examine the relaonship between
the morphometric and geometric features of the external
acousc meatus, tympanic bulla and auditory tube and
the cranium shape, age, and gender characteriscs in the
os temporale region in terms of the clinical-anatomical
approaches to the outer ear and middle ear regions of
the dog’s skull.
Materials and Methods
In this study, dog skull bones obtained from the archive of
Adnan Menderes University Veterinary Faculty Anatomy
Department Osteometry Laboratory were used. A total
of 110 dogs (48 female, 59 male, 3 non-gendered)
were studied. In the absence of age records of the
animals (n:16), the approximate age of the animals was
determined according to the condion of their teeth and
sutures (Dyce et al. 2002; Thrall and Robertson, 2011;
Mihelic et al., 2013; Schmidt et al., 2013). Accordingly,
animals with an approximate age range of 1.5 months to
168 months were used.
In order to demonstrate the reliability of the method, the
cranium of a randomly selected dog was photographed
ve mes and all measurements were taken repeatedly
on these ve images of the same skull to calculate the
coecients of variaon (Özdamar, 2004).
Aer checking the validity and reliability of the
measurement method, photographic images of the
bones, which were placed on a at plaorm with the

Çınar et al Morphological Variaons in Tympanic Poron of Temporal Bone in Dogs
.
41
help of play dough, were taken from the dorsal, lateral
and basal face with a Canon EOS 350D camera. A ruler
was placed during photographing for calibraon of the
images. Photographs were taken perpendicular to the
bone and focusing on the midpoint of the bone for all
posions. All obtained photos were transferred to the
computer in “.jpeg” format. Aer calibraon of the
transferred images in the “ImageJ” program, all the
measurements of skull bones were taken using necessary
commands in the “ImageJ” program”,
whose reference points were already
dened. (Figure 1-3, Table 1).
Stascal analyzes were performed
with the SPSS 19.0 program, and
normal distribuon of the data was
checked with the “Shapiro-Wilk
test”. In age and gender groups, an
intergroup comparison was checked
for independent variables by t-test.
The results were checked with the
Mann-Whitney test, which is a non-
parametric test for parameters that
did not show normal distribuon,
and the signicant (p) values were
wrien according to the results of
this test. Pearson correlaon analysis
method was used to determine
whether there was a correlaon
between the cranium index values
in the bones used and the index
and angle values obtained from the
pars tympanica region the data were
presented as the number of animals
in the group (n), mean value (MV),
and standard deviaon (SD) in tables.
The signicance level in the study
was accepted as p<0.05. Checking
the reliability of the measurement
method, the coecient of variaon
(%CV) of measurements was
calculated using the formula,
“(standard deviaon/mean value) x
100” (Özdamar, 2004).
Results
When the coecients of variaon
calculated for the measurement
method in the study were examined,
the lowest coecient of variaon
was found to be 0.18% in facial length
and skull width measurements, and
the highest coecient of variaon
was 1.96% in the measurement of
auditory tube angle.
Angle measurements and index
values of the young and adult age
groups are presented in Table 2.
Auditory tube angle and external
acousc meatus angle were found
to dier stascally between two
groups. In addion, it was determined that the index
values of bulla tympanica, except for the height index,
showed stascal dierences among age groups.
Angle measurements and index values of the skulls
of male and female animals are presented in Table 3.
According to these results, it was determined that other
index values did not dier between female and male
animals, except for the external acousc meatus angle.
Figure 1. Dorsal view of the skull and the measurements
Figure 2. Lateral view of the skull and the measurements
Figure 3. Basal view of the skull and the measurements

Çınar et al Morphological Variaons in Tympanic Poron of Temporal Bone in Dogs
.
42
The correlaon coecients between cranial index values
and angle values measured from the pars tympanica
region are presented in Table 4. In parcular, it was
observed that there was a correlaon between the angle
of the auditory tube and the all skull indices. External
acousc meatus angle was found to have correlaon
only with bulla tympanica indices
Discussion
Before starng the study, ve images were taken from
the skull of an animal to the demonstrate reliability of
the method used and the measurements taken, and all
measurements were taken again from these images. It is
seen that the highest coecient of variaon was 1.96%
in the angle of Tuba audiva. According to these data,
since all coecients were below 5% value, it was seen
that the measurement method used in the study was
reliable (Özdamar 2004).
When index values of the tympanic bulla measurements
were examined, it was noted that the width and length of
the bulla were larger compared to the skull size in young
animals, but the height rao did not change with age. In
addion, it was determined that the angle of the auditory
Parameter Method Source
Lenght Values (mm)
Facial length FL Between nasion and prosthion EVANS (1993)
Cranial length CL Between Inion and nasion EVANS (1993)
Cranial width CW The widest interparietal width EVANS (1993)
Cranial height CH Lateral side from base of occipital condyle to highest point
of head EVANS (1993)
Skull width SW The widest interzygomac distance EVANS (1993)
Skull length SL FL+CL EVANS (1993)
Width of Bulla tympanica 1 BTW1 The largest diamater of the Bulla tympanica DRIESCH
(1976)
Width of Bulla tympanica 2 BTW2 The narrowest diamater of Bulla tympanica DRIESCH
(1976)
Heigth of Bulla tympanica BTH
The distance between the upper border of the porus acus-
cus externus and the ground contacng part of the bulla
tympanica
-
Angle
Values
(o)
Angle of tuba audiva TAA Angle of tuba audiva with transversal plane -
Angle of meatus acuscus externus MEA The angle between ventral border of porus acuscus exter-
nus and the transversal axis ALBIIN (1984)
Index Values (%)
Skull index SI SW x 100 /SL EVANS (1993)
Cranial index CI CW x 100 /CL EVANS (1993)
Facial index FI SW x 100 /FL EVANS (1993)
Width of Bulla tympanica 1 index BWI1 BTW1x100/SL -
Width of Bulla tympanica 2 index BWI2 BTW2x100/SW -
Heigth of Bulla tympanica index BHI BTHx100/CH -
Table 1. Idencaon of abbreviaons in the study
Young Adult p
Angular values (o) N MV±SD NMV±SD
Angle of tuba audiva 39 43.81±7.38 69 53.50±5.65 0.000***
Angle of meatus acuscus externus 39 48.34±5.32 69 45.75±5.86 0.021*
Index values (%)
Skull index 41 57.90±4.09 69 56.38±9.51 0.004**
Cranial index 41 75.69±10.02 69 57.90±10.67 0.000***
Facial index 41 156.67±27.05 69 126.69±26.80 0.000***
Width of bulla tympanica 1 index 41 16.86±4.411 69 12.28±1.34 0.000***
Width of bulla tympanica 2 index 41 13.44±4.02 69 8.93±1.10 0.000***
Heigth of bulla tympanica index 41 19.17±4.76 69 20.92±2.09 0.114
Table 2: Angular measurements and calculated index values of the skulls of animals in dierent age groups
p<0.05 * , p<0.01** , p<0.001***

Çınar et al Morphological Variaons in Tympanic Poron of Temporal Bone in Dogs
.
43
tube with the transversal plane was approximately 18%
higher in adults than in young animals. The angle that
the porus acuscus externus makes with the transversal
axis is approximately 5% greater in young animals
than in adults. In this case, it is seen that the long axis
of the tympanic bulla rotates more rostro-medially
in the horizontal plane depending on age. While the
suturae-shaped secons of the occipital bone, which
largely surround the tympanic bone secons in the
skull posteriorly and laterally, are mostly closed by the
age of six months, the sphenoid bone and associated
synchondrosis type juncons anteriorly close aer one
year of age (Evans, 1993; Thrall and Robertson, 2011;
Schmidt et al., 2013). Since the facial bones connue to
grow at the front during these periods, it can be said that
the posion of the tympanic bone may show age-related
changes in this way.
Studies of sexual dimorphism in the closure of skull
sutures have shown that dierences in suture closure
can be seen in both male and female (Sahni et al., 2005;
Vijay et al., 2013; Alhadi et al., 2019). Since dierences
between males and females occur at dierent points
in the life cycle, a gender-related dierence in the
posion of tympanic region can also be expected due to
dierences in suture closure. However, according to the
results of this study, it was determined that other angle
and index values did not dier between female and male
animals, except for a small dierence in the external
acousc meatus angle in the dog.
It has been stated that the closure me of synchondrosis
type unions, which has the most important eect on
the longitudinal growth of the skull-shape, may vary
according to the skull-shape type or race (Schmidt et
al., 2013). The auditory tube angle measurement is
approximately the angle of the tympanic bulla long axis
with the transversal plane. It can be said that the long
axis of tympanic bulla may be more medially oriented in
dogs with longer head type, as this angle has negave
correlaons with skull indices. In addion, the medial
posion of the tympanic bulla increases as the bulla
height increases.
The most important limitaon of this study is the
insucient exact age informaon of the animals. For
this reason, animals esmated under one year of age,
which are considered to be young, could not be divided
into subgroups. The neurocranium (cranium) region of
the skull, in which it is located in the temporal bone,
has largely completed its development and this region
changes less. However, the splanchnocranium (facies)
region adjacent to the temporal bone develops and
changes much more rapidly unl about one year of
age (Evans, 1993; Thrall and Robertson, 2011; Schmidt
et al., 2011). Therefore, if the younger group could be
further divided into subgroups, age-related changes
could be seen more prominently. In addion, due to the
lack of pedigree records of all dogs used, breed-related
evaluaons could not be made. Instead, skull indices
were used to evaluate head type-related changes.
In conclusion, it can be said that age and skull type
is more eecve than gender in the posion of the
tympanic region in dogs. The results of this research are
supporve informaon that can be used in both clinical
and zooarchaeological studies on the tympanic bulla
region in dogs.
Acknowledgement
This study is a part of the project supported by TUBITAK
(2209-University Students Research Projects Support
Table 3: Angular measurements and calculated index values of the skulls of animals of dierent sexes
p<0.05 *
FEMALE MALE
Angular values (o) NMV±SD NMV±SD p
Angle of tuba audiva 48 49.83±6.79 57 50.03±8.80 0.616
Angle of meatus acuscus externus 48 45.48±4.73 57 47.77±6.51 0.040*
Index values (%)
Skull index 48 57.22±10.94 59 56.77±4.63 0.608
Cranial index 48 66.57±15.02 59 62.92±12.37 0.201
Facial index 48 137.43±31.1 59 138.95±30.36 0.735
Width of bulla tympanica 1 index 48 14.21±2.51 59 13.87±4.41 0.066
Width of bulla tympanica 2 index 48 10.83±2.62 59 10.47±3.98 0.146
Heigth of bulla tympanica index 48 20.78±3.23 59 19.83±3.63 0.176
SI CI FI BWI1 BWI2 BHI
TAA -0,273** -0,581** -0,524** -0,454** -0,528** 0,265**
MEA -0,120 0,127 0,061 0,220*0,212* -0,110
Table 4: Correlaon coecients between cranial index values and the angle values on the pars tympanica
p<0.01**

Çınar et al Morphological Variaons in Tympanic Poron of Temporal Bone in Dogs
.
44
Program/1919B011301511)
The rst results of this study XVII. Presented at the
Internaonal Veterinary Medicine Students Scienc
Research Congress (Istanbul).
Conict of interest
The authors declare that they have no conict of interest
in this study.
References
Albiin, N. (1984). The anatomy of the eustachian tube. Acta-
Otolaryngologica (Stockh), suppl. 414, 34-37. hps://doi.
org/10.3109/00016488409122879
Alhadi, A., Issrani, R., Prabhu, N., & Alhadi, M. (2019). Observaon on
the closure of lambdoid suture in relaon to age, sex and populaon
variaons using a novel radiographic technique – a prospecve
study. Acta Odontologica Scandinavica, 77(1), 61-65. hps://doi.or
g/10.1080/00016357.2018.1503710
Bahadır, A., Yıldız, H. (2004). Veteriner Anatomi I (Hareket Sistemi). Ezgi
Kitabevi.
Bluestone, C.D., Doyle, W.J. (1988). Anatomy and physiology of
eustachian tube and middle ear related to os media. Journal of
Allergy and Clinical Immunology, May; 81, 997-1003. hps://doi.
org/10.1016/0091-6749(88)90168-6. PMID: 3286738
Djeric, D., Savic D. (1985). Anatomical variaons and relaons of the
bony poron of the eustachian tube. Acta Oto-Laryngologica, 99,
543-550. hps://doi.org/10.3109/00016488509182259
Driesch, A.V.D. (1976). Measurement of the Mammalian Skeleton in: A
Guide to The Measurement of Animal Bones from Archaeological
Sites. Peabody Museum of Archaelogy and Ethnology Harvard
University.
Dyce, K.M., Sack, W.O., Wensing, C.J.G. (2002). Textbook of Veterinary
Anatomy (3rd Ed). Elsevier, USA,
Evans, H.E. (1993). The skeleton in: Millers Anatomy of the Dog. Ed:
Evans H.E., W.B. Saunders Comp. Philadelphia. Pp.130-133
Fox, W.M. (1964). Anatomy of the Canine Skull in Low-grade
Otocephaly. Canadian Journal of Comparave Medicine Veterinary
Science, 28,105-107.
Judkins, R.F, Li, H. (1997). Surgical anatomy of the rat middle ear.
Ocial Journal of American Academy of Otolaryngology-Head
and Neck Surgery, 117, 438-47. hps://doi.org/10.1016/s0194-
5998(97)70011-1
Kemaloğlu, Y.K., Göksu. N., Öcal, K., Karademir, N., Hazıroğlu, R., İnal,
E. (1996). The eustachian tube caliber and craniofacial skeleton in
guinea pigs. Internaonal journal of Pediatric Otorhinolaryngology,
38, 53-63. hps://doi.org/10.1016/S0165-5876(96)01419-X
König, H.E. (2007). The vesbulocochlear organ in: Veterinary Anatomy
of Domesc Mammals Ed: Liebich H-G, Schaauer GmbH, Stugard
\ Newyork.
Louis, G., (2004). Small Animal Ear Diseases (2nd ed.). Chapter 4 digital
imaging of the ear, pp24.
Mann, W., Jonas, I., Münker G. (1979). Growth inuence on tubal
funcon. Acta Oto-Laryngologica, 87, 451-457. hps://doi.
org/10.3109/00016487909126450
Mawson SR. Middle ear eusions: therapy and clinical results. Annals
of Otology, Rhinology & Laryngology. 1974 Mar-Apr;83: Suppl
11:71-2. PMID: 4819101.
Mihelic, D., Pavic, M., Hincak, Z. A. (2013). Craniometrical Analysis of
the Early Bronze Age Dogs from Vucedol Site (East Slavonia, Croaa).
Collegium Antropologicum, 37(1), 239–244. PMID: 23697279
Njaa, B.L., Cole, L.K., Tabacca, N. (2012). Praccal oc anatomy and
physiology of the dog and cat. The Veterinary Clinics of North
America Small Animal Pracce, 42, 1109-1126. hps://doi.
org/10.1016/j.cvsm.2012.08.011
Onar, V., (1999). Morphometric analysis of the foramen magnum in
German Shepherd dogs (Alsaans). Annals of Anatomy, 179, 563-
568, hps://doi.org/10.1016/S0940-602(97)80022-
Onar, V., Güneş H., (2003). On the variability of skull shape in German
Shepherd (Alsaan) puppies. The Anatomical Record Part A, 272A,
460-466. hps://doi.org/10.1002/ar.a.10052
Özdamar, K., (2004). Paket programları ile istasksel veri analizi -1.
MINITAB, NCSS, SPSS. Kaan kitabevi, Eskişehir,
Sadler-Kimes, D., Siegel, M.I., Todhunter, J.S. (1989). Age-
related morphologic dierences in the components of the
eustachian tube\middle ear system. The Annals of Otology,
Rhinology and, Laryngology, 98(11), 854-858. hps://doi.
org/10.1177%2F000348948909801104
Sahni, D., Jit, I., Neelam, Sanjeev. (2005). Time of closure of cranial
sutures in northwest Indian adults. Forensic Science Internaonal,
148(2-3), 199-205. hps://doi.org/10.1016/j.forsciint.2004.06.002
Samsar, E., Akın, F., (2006). Özel cerrahi, Medipress, Malatya
Schmidt, M.J., Neumann A.C., Amort, K.H., Failing, K., Kramer M.
(2011). Cephalometric measurements and determinaon of
general skull type of cavalier king charles spaniels. Veterinary
Radiology & Ultrasound, 52(4), 436–440. hps://doi.org/10.1111/
j.1740-8261.2011.01825.x
Schmidt, M.J., Volk, H., Klingler, M., Failing K., Kramer K., Ondreka N.
(2013). Comparison of closure mes for cranial base Synchondroses
ın mesacephalıc, brachycephalıc, and cavalier kingcharles spaniel
dogs. Veterinary Radiology & Ultrasound, 54 (5), 497-503. hps://
doi.org/10.1111/vru.12072
Sırıkçı, A., Bayazıt, Y.A., Bayram, M., Kanlıkama, M. (2001). Signicance
of the auditory tube and mastoid size in chronic ear disease. Surgical
and Radiologic Anatomy, 23, 91-95. hps://doi.org/10.1007/
s00276-001-0091-1
Takeuchi, Y., Savara, B.S., Shadel, R.J. (1980). Biennial size norms of
eight measures of the temporal bone from four to twenty years
of age. The Angle Orthodonst, 50(2), 107-113. hps://doi.
org/10.1043/0003-3219(1980)050%3C0107:bsnoem%3E2.0.co;2.
Thrall, D.E., Robertson, I.D. (2008). Atlas of Normal Radiographic
Anatomy and Anatomic Variants in the Dog and Cat. St. Louis,
Missourio: Elsevier/Saunders; 2011. p. 10
Todd, N.W., Marn, W.S., (1988). Relaonship of eustachian tube
bony landmarks and temporal bone pneumazaon. The Annals of
Otology, Rhinology and, Laryngology, 97(3 Pt 1), 277-80. hps://
doi.org/10.1177%2F000348948809700313
Vijay, K.A.G., Agarwal, S.S., Basa, B.K., Shivaramu M.G., (2013). Sexual
Variaon in Cranial Suture Closure-A Cross Seconal Post Mortem
Study Done on Terary Care Hospital. Open Access Scienc
Reports, 2, 611. hps://doi:10.4172/sciencreports.611