Unit 2: Bones of the Head and Face

Female Bones

- Bones are thinner - Eminences are less prominent - Vertex is lower and more rounded - Smoother facial bones - Jaw and teeth are smaller

Skull variations

- In an adult the facial portion of the skull is approximately 1/2, an infant is 1/8. - From birth to age 7 the skull grows rapidly and almost reaches full size. - From age 7 to puberty growth slows considerably. - At puberty all parts, especially the frontal and facial area (sinuses). - At age 22 ossification begins.

Alveolar Process

A bony ridge found on the inferior surface of the Maxillae and the superior surface of the Mandible which contains the sockets for the teeth.

Ethmoid Bone

A horizontal plate that forms the roof of the nasal cavity and closes the anterior part of the base of the cranium.

Maxilla

A paired bone with several processes that form the skeletal base of most of the superior face, roof of the mouth, sides of the nasal cavity, and floor of the orbit (upper jaw bone).

Condyle

A rounded eminence at the articulating end of a bone; the posterior process of the ramus of the mandible.

Vomer

A single bone along the midline of nasal cavity. Forms part of the septum.

Glabella

A single bony prominence of the frontal bone located between the superciliary arches in the inferior part of the frontal bone above the root of the nose-not apparent on all foreheads.

Mental Eminence

A triangular projection on the inferior portion of the anterior mandible.

Length

A vertical dimension.

Frontal Bone

Anterior 1/3 of the cranium forming the forehead and parts of the eye socket and most of the anterior of the cranial floor.

Temporal Bones

Inferior portion of the sides and base of the cranium, lies below (inferior to) the parietal bones and in front of (anterior to) the occipital bone.

Nasal

Lies directly inferior to the glabella and form the bridge of the nose and dome over superior portion of nasal cavity.

Sphenoid Bone

Located at the anterior part of the base of the skull and binds cranial bones together.

Palatine

Located in back part of the nasal cavity behind the maxillae. Help form back part of roof of mouth.

Coronoid Process

Shaped like a crow's beak; the anterior process of the ramus of the mandible to which the temporalis muscle attaches.

Lateral Margins of the Eye-socket

The anterior edge as it dips concavely between the forehead and cheekbone corresponds with the position of the lateral corner of the closed eyelids. The edge of the lateral margin is posterior to the median margin because of the bilateral curvature of the skull.

Frontal Process of the Maxilla

The ascending part of the upper jaw which gradually protrudes as it rises beside the nasal bone to meet the frontal bone; the ascending process of the upper jaw.

Orbital Cavities

The bony sockets which contain and protect the eyeball--it's quadrilateral in outline.

Temporal Cavity

The concave surface of the head overlying the temporal bone.

Incisive Fossa

The depression between the mental eminence and the inferior incisor teeth

Zygomatic

The diamond-shaped bones that form the cheekbones.

Width

The dimension of an object measured across from side to side.

Cranium

The part of the human skull which encloses the brain.

Zygomatic Arch

The processes on the temporal and zygomatic bones; they determine the widest part of the face (cheekbones).

Mastoid Process

The rounded projection on the inferior portion of the temporal bones just posterior to the lobe of the ear.

Foramen Magnum

An opening in the occipital bone through which passes the spinal cord from the brain (use for repair of a decapitation).

Loss of Teeth

As you age there is a reduction in the size of the jaws due to loss of teeth. Also a reduction in the vertical length of the face.

Skull

Bony structures of head which consists of the cranium and face.

Lacrimal

Located in the medial wall of each orbit between the ethmoid and maxillary bones (shape of fingernail).

Frontal Eminences

Paired, rounded, unmargined prominences of the frontal bone found approximately one inch beneath the normal hairline (upper 2/3 of forehead).

Thumb and Index Finger

The distance from the tip of the thumb to the tip of the index finger is equal to: - The length of the ear - The length of the nose - The normal hairline to the root of the nose - The base of the nose to the bottom of the chin

External Auditory Meatus

The external opening of the ear passage.

Eyes

The face is five eyes wide from zygomatic arch to zygomatic arch. - The distance between the eyes is equal to the width of one eye. - The mouth is two eyes wide.

Nose

The face is three noses long. The length of the nose is equal to the length of the ear. - The width of the nose at the base of the wings is equal to the width of an eye.

After Puberty

The female skull is lighter and smaller than that of the male. The cranial capacity of the female is about 10% less in area than a male.

Body of the Mandible

The horizontal portion of the lower jaw

Mandible

The horseshoe-shaped bone forming the inferior jaws (lower jaw bone & chin).

Superciliary Arches

The inferior part of the forehead just superior to the median ends of the eyebrows.

Line of the Temples

The irregularly formed continuous border of the forehead and eye-sockets. It merges with the border of the temple to define changes in plane of the area of the head.

Lower Division

The lower third of the face (from the base of the nose to the base of the chin) also has three horizontal divisions. - Draw lines through: - Base of the nose - Line of lip closure - Top of chin - Bottom of chin

Occipital Bone

The lowest part of the back and base of the cranium, forming a cradle for the brain.

Parietal Eminence

The rounded peak of the external convexity of the parietal bones; determines the widest part of the cranium (located just above the top of the ears).

Geometric Form of Skull

The shape of a plane figure determined by its outline such as rounded or oval; - Front - Side - Crown

Nasal Spine of the Maxilla

The sharp, bony projection located medially at the inferior margin of the nasal cavity.

Mandibular Fossa

The small oval depression on the zygomatic process of the temporal bone into which the condyle of the mandible articulates; just anterior to the external auditory meatus.

Ear

The superior border of the ear is on the same horizontal plane as the eyebrows. The inferior border of the ear is on the same horizontal plane as the base of the nose.The face is three ears long.

Supraorbital Margins

The superior rim of the eye sockets.

Ramus

The vertical portion of the mandible.

Squama

The vertical surface of the temporal bone; scale-like, thin, and translucent. Any impact causes swollen and discolored eyes.

Angle of the Mandible

The widest part of the jaw - a bony angle formed by the junction of the posterior edge of the ramus of the mandible and the inferior surface of the body of the mandible. It influences the form of the head as it may be turned inward or outward adjusting width, etc. The measurement is similar to the distance between the zygomatic bones.

Proportional Relationships

There are other methods which can be implemented to determine facial proportions by using different facial features as units of measurements for the face.

Divisions of the Face

There are three equal horizontal divisions of the face Draw lines through: - Hairline - Eyebrows - Base of nose - Base of chin

Horizontal Lines of the Head

There are two equal halves: - A line from the vertex (top) of the cranium to the line of closure of the eyes. -A line from the closure of the eyes to the base of the chin.

Parietal Bone

Two bones that form the roof and part of the sides of the skull.

Vertical Lines

Vertical lines are used to determine the width of the face by using the eye as a standard of measurement. - The face is considered to be five eyes wide. - Lines drawn from the inner canthus (corner) of the eye will extend to the corner of the wings of the nose. - Lines drawn from the center of the eyes will extend to the corners of the mouth.