Anatomy of the Parotid Gland

Salivary Glands

• Parotid gland produces approximately 30% of total saliva and has a well-developed connective tissue capsule with numerous septa that subdivide the gland into lobes and lobules.
• The parotid gland lies anterior to the ear between the masseter and skin.
• The parotid duct opens into the vestibule next to the second upper molar.

Sublingual Gland

• It is the smallest of the three major salivary glands, weighing only 2-3 grams and producing about 5% of total salivary output.
• It lies anterior to the submandibular gland under the tongue and opens via 10-12 ducts into the floor of the mouth.
• The gland is composed of mucous tubular secretory units, many of which are capped by a small cluster of serous cells, known as serous demilunes (Giannuzi Demilunes).

Submandibular Gland

• It weighs around 12-15 grams and produces approximately 60% of total salivary output.
• About 90% of the acini produce serous saliva, whereas the remainder manufacture a mucous saliva.
• It lies along the medial aspect of the mandibular body, and its ducts open to the base of the lingual frenulum.

Periodontal Ligament

• It is located in the PDL space, defined as the region between the cementum of the root and the bony alveolus.
• It is dense irregular collagenous connective tissue with principal fiber groups, composed of type I collagen fibers, that are arranged in specific, predetermined patterns to absorb and counteract masticatory forces.
• The ends of the principal fiber groups are embedded in the alveolus and cementum as Sharpey's fibers, which permit the periodontal ligament to suspend the tooth in its socket.

Alveolus

• It is the bony socket in which the tooth is suspended by fibers of the periodontal ligament.
• The alveolar process, a bony continuation of the mandible and maxilla, is divided into compartments, each known as an alveolus, that house the root.

Gingiva (Gums)

• It is attached to the enamel surface by a thin, wedge-shaped, stratified squamous nonkeratinized epithelium, known as the junctional epithelium.
• As the epithelium of the gingiva approaches the tooth, it forms a hairpin turn, proceeds apically (toward the root tip) for 1 to 2 mm, and then attaches to the enamel surface by the formation of hemidesmosomes.

Tongue

• On the dorsal surface, there are two unequal regions: a larger anterior two-thirds and a smaller posterior one-third.
• The two regions are separated from one another by a shallow, V-shaped groove, the sulcus terminalis, whose apex points posteriorly and contains a deep concavity, foramen cecum, which is a reminder of the thyroglossal canal.
• The mucosa consists of squamous keratinized epithelium on the dorsal surface and squamous nonkeratinized epithelium on the ventral surface with underlying thin lamina propria.

Lingual Papillae

• They cover the dorsal surface of the tongue anterior to the sulcus terminalis.
• There are four types of papillae: filiform, fungiform, circumvallate, and foliate papillae.
• Filiform papillae are the smallest and most numerous in humans, don't contain taste buds, and serve only a mechanical role.