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BONES. 129
of the skull. It is made up of parts of five bones—the temporal, the
sphenoid, and the malar below, the parietal and the frontal above—and
is crossed by seven sutures uniting these bones. It is also traversed by
grooves for the accommodation of the deep temporal arteries, and
marked by fim-like grooves for the origin of the deep fibres of the
temporal muscle.
The temporal fossa is bounded in front by the posterior surface of the
frontal process of the malar, the external angular process of the frontal,
and part of the great wing of the sphenoid bones. It is bounded above
and behind by the supratemporal ridge. This is formed by two slightly-
elevated borders that originate near the fronto-malar articulation from a
single point, from which it diverges into two nearly semicircular lines
that curve upward, backward, and downward across the fronto-parietal
suture at a distange of about a half inch or more from each other.
The Inferior Line extends backward and curves downward to join the
posterior root of the zygomatic process of the temporal bone. This
line is the uppermost limit of the deep attachment of the temporal
muscle.
The Superior Line, which is separated from the inferior, gradually
increasing the distance as it proceeds backward and downward, termi-
nates near the parieto-occipito-mastoid articulation. This upper line
and space between it and the lower afford attachment to the temporal
fascia. The inferior boundary of the temporal fossa internally is foi-med
by the infratemporal ridge. This ridge extends from the parieto-occip-
ito-mastoid articulation forward along the posterior root of the zygo-
matic process of the temporal bone, across the pterygoid ridge, Aviiich
separates the lateral from the inferior surface of the great wing of the
sphenoid bone, to the roughened prominence on the posterior border of
the malar bone. The external boundary of the temporal fossa is formed
by the zygomatic arch, and in the recent state by the temporal fascia.
This fossa accommodates the tendon and muscular fibres of the temporal
muscle.
The Zygomatic Fossa is below the zygomatic arch. It is an irregularly-
shaped cavity, bounded anteriorly by the posterior or zygomatic sur-
face of the superior maxilla ; internally, by the external pterygoid
plate ; superiorly, by the inferior surface of the great wing of the
sphenoid bone and a part of the squamous portion of the temporal
bone, the infratemporal ridge dividing the zygomatic from the tem-
poral fossa in this region ; and laterally by the ramus of the inferior
maxilla.
The following openings will be found within the fossa : The orifices
of the Posterior Dental Canals, situated in the superior maxillary bone
for the transmission of the posterior dental vessels and nerves ; the
Spheno-maxillary Fissure, between the sjihenoid and the superior max-
illary bones, leading into the orbit ; the Pteri/f/o-maxiUary Fissure,
between the pterygoid process of the sphenoid bone and the superior
maxilla, leading into the spheno-maxillary space or fossa ; the Foramen
Ovale and Foramen Spinosum, situated in the great wing of the sphe-
noid bone in close proximity to each other. The foramen ovale trans-
mits the third division of the fifth nerve and a small meningeal artery,
Vol. I.—
BONES. 129
of the skull. It is made up of parts of five bones—the temporal, the
sphenoid, and the malar below, the parietal and the frontal above—and
is crossed by seven sutures uniting these bones. It is also traversed by
grooves for the accommodation of the deep temporal arteries, and
marked by fim-like grooves for the origin of the deep fibres of the
temporal muscle.
The temporal fossa is bounded in front by the posterior surface of the
frontal process of the malar, the external angular process of the frontal,
and part of the great wing of the sphenoid bones. It is bounded above
and behind by the supratemporal ridge. This is formed by two slightly-
elevated borders that originate near the fronto-malar articulation from a
single point, from which it diverges into two nearly semicircular lines
that curve upward, backward, and downward across the fronto-parietal
suture at a distange of about a half inch or more from each other.
The Inferior Line extends backward and curves downward to join the
posterior root of the zygomatic process of the temporal bone. This
line is the uppermost limit of the deep attachment of the temporal
muscle.
The Superior Line, which is separated from the inferior, gradually
increasing the distance as it proceeds backward and downward, termi-
nates near the parieto-occipito-mastoid articulation. This upper line
and space between it and the lower afford attachment to the temporal
fascia. The inferior boundary of the temporal fossa internally is foi-med
by the infratemporal ridge. This ridge extends from the parieto-occip-
ito-mastoid articulation forward along the posterior root of the zygo-
matic process of the temporal bone, across the pterygoid ridge, Aviiich
separates the lateral from the inferior surface of the great wing of the
sphenoid bone, to the roughened prominence on the posterior border of
the malar bone. The external boundary of the temporal fossa is formed
by the zygomatic arch, and in the recent state by the temporal fascia.
This fossa accommodates the tendon and muscular fibres of the temporal
muscle.
The Zygomatic Fossa is below the zygomatic arch. It is an irregularly-
shaped cavity, bounded anteriorly by the posterior or zygomatic sur-
face of the superior maxilla ; internally, by the external pterygoid
plate ; superiorly, by the inferior surface of the great wing of the
sphenoid bone and a part of the squamous portion of the temporal
bone, the infratemporal ridge dividing the zygomatic from the tem-
poral fossa in this region ; and laterally by the ramus of the inferior
maxilla.
The following openings will be found within the fossa : The orifices
of the Posterior Dental Canals, situated in the superior maxillary bone
for the transmission of the posterior dental vessels and nerves ; the
Spheno-maxillary Fissure, between the sjihenoid and the superior max-
illary bones, leading into the orbit ; the Pteri/f/o-maxiUary Fissure,
between the pterygoid process of the sphenoid bone and the superior
maxilla, leading into the spheno-maxillary space or fossa ; the Foramen
Ovale and Foramen Spinosum, situated in the great wing of the sphe-
noid bone in close proximity to each other. The foramen ovale trans-
mits the third division of the fifth nerve and a small meningeal artery,
Vol. I.—
