The gingiva is the keratinized mucosa that surrounds the teeth. It forms a collar
around each tooth, that ranges in width from1 to 9 mm. The narrowest zone of the gingiva is usually found on the buccal surface of the mandibular canine to first premolar region. The widest zone is often located on the lingual aspect of the last mandibular molar. The gingiva is attached
in part to the cementum of the tooth and in part to the alveolar process (Fig. 2). The gingiva is
composed of masticatory mucosa.
A. Clinical features
Fig. 3 In light-skinned individuals the gingiva (G) can be readily distinguished
from the adjacent dark red alveolar mucosa
(AM) by its lighter pink color. Its apical
border, that separates it from the adjacent alveolar mucosa, is the mucogingival junction (MGJ). A
similar tissue relationship can be seen on the lingual aspect of the mandible (Fig. 5).
Fig. 4 In dark-skinned persons the gingiva may contain melanin pigment to a greater extent than the adjacent
alveolar mucosa. The melanin pigment is synthesized in specialized cells, the melanocytes, located in the basal layer of the
epithelium (see below). The melanin is produced as granules, the melanosomes, that are stored within the cytoplasm of
the melanocytes, as well as the cytoplasm of adjacent keratinocytes. Melanocytes are
embryologically derived from neural crest cells that eventually migrate into the
epithelium. If pigmented gingiva is surgically resected, it will often heal with
little or no pigmentation. Therefore, surgical procedures should be designed so as
to preserve the pigmented tissues.
Fig. 5: Lingual aspect of the mandible showing the tightly adhering gingiva (G) and the
adjacent non-keratinized alveolar mucosa (AM) that lines part of the alveolar process and
floor of the mouth (F). MGJ, mucogingival junction.
Fig. 6 is a similar view. Note the small mucosal tags on the lingual aspect of each
lower canine (P). These structures are called retrocuspid papillae. This is a normal
anatomic variation of the gingiva in this location. It does not require any
corrective treatment.
The most coronal portion of the gingiva is the gingival margin. The term marginal gingiva refers to that portion of the gingiva that is located close to the gingival margin (see Fig. 1).
The gingival sulcus is the shallow groove between the marginal gingiva and the tooth (see Fig. 1).
The gingival groove is an indentation that parallels the oral or vestibular surface of the gingival margin (see Fig. 1). It is located at about the same level as the apical border of the junctional epithelium. Note: its level does not correspond to that of the bottom of the gingival sulcus. It is only present occasionally. Its presence or absence is not related to gingival health. Inflammation may cause the tissues to swell and mask its presence.
Clinicians sometime use the terms "free"
and "attached" gingiva.
Although these terms may have some clinical relevance, they are anatomically
incorrect. The determination as to whether the gingiva is "free" or
"attached" is made by probing the gingival sulcus with a periodontal probe.
This instrument will frequently penetrate the junctional epithelium beyond the
sulcus bottom, particularly in the presence of inflammation. This results in the
clinical impression that the marginal gingiva is detached from the tooth to a much greater
degree than is the case.anatomically. "Attached" gingiva refers to the
portion of the gingiva apical to the "free" gingiva which is firmly bound to the
underlying tooth and alveolar process.
Fig.7:
This view of the hard palate shows the absence of a mucogingival junction on the palatal
aspect. Instead, the masticatory mucosa of the gingiva (G) blends imperceptibly with
the masticatory mucosa of the hard palate (PM). Note the palatal rugae (RR), the ridges behind the anterior
teeth, on either side of the incisive papilla
(IP).
Fig. 8: The gingiva that occupies the
interdental spaces coronal to the alveolar crest
is the interdental gingiva.
It is composed of a pyramidal interdental
papilla in the incisor region (Fig. 8 A). In the posterior region (Fig. 8
B) it is composed of an oral and a vestibular papilla (P) joined by an interdental "col" (C). The interdental
gingiva is attached to the tooth by junctional
epithelium (JE) coronally and by connective tissue fibers apically (not shown). The
most coronal portion of the interdental gingiva is lined with sulcular epithelium (SE)
