The Gums.

the Gums.

The gums or gingiva, consist of the mucosal tissue that lies over the mandible and maxilla inside the mouth.

When you think about dental health, the focus is likely to be on preventing cavities in your teeth. But it's important to pay attention to your gums, too. Gums play a major role not only in your dental health, but in your overall well-being.

The gums are connective tissue covered with mucous membrane, attached to and surrounding the necks of the teeth and adjacent alveolar bone. Before the erupting teeth enter the mouth cavity, gum pads develop; these are slight elevations of the overlying oral mucous membrane. When tooth eruption is complete, the gum embraces the neck region of each tooth. As well as being attached to adjacent alveolar bone, gum is connected to the cement of each tooth and to the tooth enamel.

The gingiva are composed of dense fibrous tissue, closely connected to the periosteum of the alveolar processes, and surrounding the necks of the teeth. They are covered by smooth and vascular mucous membrane, which is remarkable for its limited sensibility. Around the necks of the teeth this membrane presents numerous fine papillæ, and is reflected into the alveoli, where it is continuous with the periosteal membrane lining these cavities.

Structure of the Gingiva :

The normal gingiva may range in color from light coral pink to heavily pigmented. It is normally stippled in appearance (resembling an orange peel). The makeup of the gingival tissue varies according to its location and function. There are two types of gingiva and several important anatomic regions.

-Alveolar mucosa – The area of tissue beyond the mucogingival junction. It seems less firmly attached and redder than the attached gingiva. It is non-keratinized and provides a softer and more flexible area for the movement of the cheeks and lips.
-Attached gingiva – The attached gingiva is the gingival tissue which lies between the mobile gingiva and the alveolar gingiva. It is four to five millimeters in width and is irremovable from the underlying structures without causing damage. This tissue is adjacent to the free gingiva and is keratinized and firmly attached to the bone structure. It can range from 3-12 mm in height.
-Free gingiva – This tissue is not attached and forms a collar around the tooth. The trough around the tooth is called the sulcus and its depth is normally 1-3 mm. It is lined with sulcular epithelium and attached to the tooth at its base by the epithelial attachment.
-Gingival margin – The border region of the gingiva that touches the tooth. The marginal gingiva is a 1.5 mm strip of gingival tissue which surrounds the neck of the tooth and is known as such due to the fact that the inner wall forms the gingival wall of the sulcus. This means that when a probe is placed at the gingival margin in a healthy mouth, it can be inserted up to three millimeters into the sulcus formed between the tooth and the mucosa, due to the fact that the soft tissue is moveable.
-Interdental papillae – The region of gingival tissue that fills the space between adjacent teeth. In a healthy mouth this is usually knife-edged and fills the interdental space.
-Muco-gingival junction – The scalloped line that divides the attached gingiva from the alveolar mucosa.

Histology :

The gingival epithelium encompasses the external surface of the gingiva including the mobile and fixed areas as well as the gingival sulcus and the junctional epithelium. It is divided up into three major sections known as the:
-oral epithelium
-the sulcular epithelium
-the junctional epithelium
The oral epithelium is comprised of stratified squamous keratinizing epithelium and covers the oral and vestibular gingival surfaces. It is limited by the mucogingival junction and the gingival margin and also merges with the palatal epithelium at the borders of the palate.
The sulcular epithelium is continuous with the oral epithelium and lines the gingival sulcus. At the bottom of the gingival sulcus in its apex, the junctional epithelium lines the dentoepithelial junction.

Attachment Mechanism :

The attachment of the tooth to the surrounding and supporting structures (bone) is accomplished through the cementum of the tooth, periodontal ligaments and the alveolar bone. The root of the tooth (cementum) is attached to the underlying bone by a series of periodontal fibers that make up the periodontal ligament and allow for minor movement of the tooth in the socket without damage to the tooth or the underlying structures. These fibers are classified apical, oblique, horizontal, alveolar crest and interradicular fibers.

Bone :

The alveolar bone supports the teeth and is covered by gingival tissue. It contains several different types of bone. The inner and outer surfaces of the bone are made up of dense cortical plates. The portion between the cortical plates is called trabecular or cancellous bone. It resembles a sponge in appearance and has many irregular spaces within. The wall of the tooth socket is made of lamina dura, which is a thin, dense bone where the periodontal ligament is attached.

Characteristics of healthy gums :

Color :

Healthy gums usually have a color that has been described as "coral pink." Other colours like red, white, and blue can signify inflammation (gingivitis) or pathology. Smoking or drug use can cause discoloring as well (such as “meth mouth”). Although described as the colour coral pink, variation in colour is possible. This can be the result of factors such as: thickness and degree of keratinization of the epithelium, blood flow to the gums, natural pigmentation of the skin, disease, and medications.

Since the colour of the gums can vary, uniformity of colour is more important than the underlying color itself. Excess deposits of melanin can cause dark spots or patches on the gums (melanin gingival hyperpigmentation), especially at the base of the interdental papillae. Gum depigmentation (aka gum bleaching) is a procedure used in cosmetic dentistry to remove these discolorations.

Contour :

Healthy gums have a smooth curved or scalloped appearance around each tooth. Healthy gums fill and fit each space between the teeth, unlike the swollen gum papilla seen in gingivitis or the empty interdental embrasure seen in periodontal disease. Healthy gums hold tight to each tooth in that the gum surface narrows to "knife-edge" thin at the free gingival margin. On the other hand, inflamed gums have a "puffy" or "rolled" margin.

Texture :

Healthy gums have a firm texture that is resistant to movement, and the surface texture often exhibits surface stippling. Unhealthy gums, on the other hand, is often swollen and less firm. Healthy gums have an orange-peel like texture to it due to the stippling.

Reaction to disturbance :

Healthy gums usually have no reaction to normal disturbance such as brushing or periodontal probing. Unhealthy gums, conversely, will show bleeding on probing (BOP) and/or purulent exudate.

Read more: Human tooth, maxilla.