mastication; it transfers food from one area of the
mouth to another; it mixes food with saliva, which
assists in the digestive process; assists in swallowing;
and cleans the mouth of residue.
MYLOHYOID AND GENIOHYOID
The mylohyoid muscles anatomically and
functionally form the floor of the mouth (fig. 3-20).
They elevate the tongue and depress the mandible.
Their origin is the mandible and insertion is the upper
border of the hyoid bone. The geniohyoid muscles are
found next to each other, on each side of the midline,
directly on top of the mylohyoid muscle. They have
the same origin and function as the mylohyoid muscle.
The palate (fig. 3-21) forms the roof of the mouth
and is divided into two sections:
Hard palateThis section is formed by the
palatine process of the maxillary bones and is located in
the anterior portion of the roof of the mouth. It has
irregular ridges or folds behind the central incisors
Soft palateThis section forms a soft muscular
arch in the posterior part of the palate. The uvula is
located on the back portion of the soft palate. When you
swallow, the uvula is drawn upward and backward by
the muscles of the soft palate. This process blocks the
opening between the nasal cavity and pharynx, not
allowing food to enter the nasal cavity. The soft palate
must function properly to allow good speech quality.
Located in the posterior part of the mouth, on both
sides of the tongue, are two masses of lymphatic tissue
called the palatine tonsils. They assist the body to
protect against infections.
The teeth are located in the alveolar process of the
maxillae and the mandible. They serve important
functions of tearing and masticating food, assisting in
swallowing, speaking, and in appearance. The health
of the teeth affects the health of the entire body.
The functions of the three major salivary glands
are to keep the lining of our mouths moist, and to bond
with food particles creating a lubricant effect that
assists in the swallowing process of food. It acts as a
cleaning agent to wash away food particles that
accumulate in the mouth and on the teeth. Figure 3-22
illustrates the salivary glands.
The salivary glands produce two to three pints of
saliva daily, which greatly aids in the digestion
Enzymes are present in saliva, they act on food,
and start the breakdown process. In dentistry, knowing
exactly where the saliva glands and ducts (openings)
are located is important in keeping the mouth dry
Figure 3-20.Mylohyoid and geniohyoid muscles.