Gingiva

At a glance

English

Gingiva

Latin (TA2)

Gingiva

System

Digestive

Region

Whole body

Side

Single, on the midline

About the gingiva

The gingiva is the part of the oral lining that covers the alveolar processes of the maxilla and mandible and wraps the necks of the teeth. It is continuous with the looser, redder alveolar mucosa at a scalloped boundary, the mucogingival junction, on the outer surfaces of both jaws and on the inner surface of the lower jaw. On the palate there is no such boundary, because the gum blends directly with the tough palatal mucosa.

Two zones are usually described. The attached gingiva is bound tightly to the bone and to the root surface by dense connective tissue, so it does not move when the lips and cheeks move, and in health it often has a stippled, orange-peel surface. The free or marginal gingiva forms a narrow collar round each tooth, separated from the attached part by a shallow groove. Between the free gum and the tooth is a shallow trench, the gingival sulcus, normally only a few millimetres deep. Where teeth touch, the gum rises into a pointed interdental papilla that fills the space between them.

The gum is covered by stratified squamous epithelium, keratinised on the outer surface. At the bottom of the sulcus a special junctional epithelium sticks directly to the enamel or root surface, forming a seal between the mouth and the tissues that hold the tooth. Healthy gingiva is pale pink, firm and does not bleed when brushed, although pigment can make it darker in some people.

When dental plaque builds up along the gum line, the margin becomes red, swollen and prone to bleeding: gingivitis. This is reversible with good cleaning. If it persists, inflammation can spread to the ligament and bone holding the tooth, a condition called periodontitis; the sulcus deepens into a pocket, the gum recedes and teeth may loosen. Gum disease has been linked with general conditions such as diabetes.

Function and supply

Function

Seals the necks of the teeth against the mouth, protects the alveolar bone, and resists friction from chewing.

Nerve supply

Sensory branches of the trigeminal nerve: from the maxillary nerve (superior alveolar, greater palatine and nasopalatine) above, and from the mandibular nerve (inferior alveolar, buccal and lingual) below.

Blood supply

Branches of the maxillary artery, including the superior and inferior alveolar arteries, with palatine, buccal and lingual twigs.