INTRODUCTION:- ۞ GINGIVA is a masticatory mucosa and covers the alveolar process of the jaw and surrounds the neck of the teeth. ۞ The gingival extends from the dentogingival junction to the alveolar mucosa. It is subject to friction and pressure of mastication.۞ The stratified squamous epithelium may be keratinized or non-keratinized but most often it is parakeratinized.۞ The gingival appears slightly depressed between adjacent teeth, corresponding to the depression
on the alveolar process between eminence of the sockets.۞ The gingiva is limited on the outer surface of both the jaws by the mucogival junction, which separates it from the alveolar mucosa.۞ The alveolar mucosa is red & contains numerous small vessels coursing close to the surface.۞ The gingival is normally pink but sometimes have grayish tint.۞ Gingiva is attached immovably and firmly to the periosteum of the alveolar bone.۞ On the inner surface of the lower jaw a line of demarcation is found between the gingival and the mucosa on the floor of the mouth.
TYPES OF GINGIVA:-The gingival is divided into three types: A) Free or unattached or marginal gingival B) Gingival sulcus. C) Attached gingiva.
A) FREE OR UNATTACHED OR MARGINAL GINGIVA:-۞ The free gingival is the terminal edge of the gingival which is usually about 1mm wide and surrounds the teeth.۞ The free gingival forms one of the walls of the gingival sulcus and is separated from the attached gingival by a groove called free gingival groove. B) ATTACHED GINGIVA:-۞ It is the continuation of the free gingival and extends up to the alveolar mucosa.۞ The attached gingival is separated from the alveolar mucosa by a mucogingival sulcus.۞ The width :- →3.5-4.5 mm in the maxillary anterior region →3.3-3.9mm in the mandibular anterior region. →Posteriorly the width of the attached gingival is less.
→It is the least at the first premolar area being →1.9mm-maxilla and 1.8mm-mandible.C) INTERDENTAL PAPILLA:-۞ It is the part of gingival that fills the space between two adjacent teeth.۞ It is a shallow V shaped space surrounding the tooth.۞ It is bounded on one side by the tooth and on the other side by the free gingiva.۞ From oral or vestibular aspect, the surface of the interdental papilla is triangular.۞ The depressed part of interdental papilla is called COL.۞ Col is covered by thin non-keratinized epithelium.۞ Elastic fibers known as OXYTALAN fibers are present.
MICROSCOPIC FEATURES OFGINGIVA:-۞ Broadly speaking gingival is made up of epithelium and connective tissue.۞ The gingival epithelium can be studied under three headings:- 1) Outer or oral epithelium 2) Sulcular epithelium 3) Junctional epithelium. GINGIVAL EPITHELIUM OUTER OR ORAL SULCULAR JUNCTIONAL EPITHELIUM EPITHELIUM EPITHELIUM STRATUM BASALE STRATUM CORNEUM STRATUM SPINOSUM
1) OUTER OR ORAL EPITHELIUM:- ۞ The epithelium consists of the following layers: a) Stratum basale:- cuboidal cells. b) Stratum spinosum:- large polyhedral cells →Desmosomes c) Stratum corneum:- superficial most layer Large, wide, flat and lacking nucleus.
2) SULCULAR EPITHELIUM:- ۞ Extends from the coronal area of the junctional epithelium to the free margin of the gingival. ۞ Epithelium is nonkeratinized. ۞ Epithelium lacks heavy ridges and papillae. ۞ It is not keratinized due to constant irritation of plaque.3) JUNCTIONAL EPITHELIUM:- ۞ Cells become cuboidal after ameloblasts have finished formation of enamel. ۞ It forms a collar around the fully erupted tooth. ۞ It consist of stratified squamous nonkeratinizing epithelium of 3-4 cell thickness having length of 0.25-1.35 mm.TYPES OF GINGIVALLIGAMENT:-
۞ The gingival contains dense fibers of collagen, sometimes referred to as gingival ligament, which is divided into:- 1) DENTOGINGIVAL:- Extends from cervical cementum into the lamina propria of the gingival. 2) ALVEOLOGINGIVAL:- The fibers arise from the alveolar crest & extend into the lamina propria.
3) CIRCULAR:- A small groups of fibers that circle the tooth & interlace with the other fibers. 4) DENTOPERIOSTEAL:- These fibers can be followed from the cementum into the periosteum of the alveolar crest and of the vestibular and oral surfaces of the alveolar bone.۞ There are also accessory fibers that extend interproximally between adjacent teeth & are also referred to as transseptal fibers.۞ These fibers make the interdental ligament.
DIFFERENT TYPES OFEPITHELIAL LAYERS:- 1) KERATINIZATION (75%) :- # In which the superficial cells form scales of keratin & lose their nuclei. # A stratum granulosum is present. 2) PARAKERATINIZATION (15%) :- # In which the superficial cells retain pyknotic nuclei & show some signs of being keratinized. # However, the stratum granulosum is generally absent. 3) NON-KERATINIZATION (10%) :- # In which the surface cells are nucleated & show no signs of keratinization.
BlOOD SUPPLY:- Blood supply of gingiva is by ALVEOLAR ARTERYNERVE SUPPLY:- NERVE SUPPLY MAXILLARY MANDIBULAR NASOPALATINE NERVE Inferior alveolar nerve (Supplies facial aspect of anterior teeth) POSTERIOR SUPERIOR ALVEOLAR NERVE (Supplies facial aspect of posterior teeth) GREATER PALATINE NERVE (Supplies lingual aspect of posterior teeth) ANTERIOR PALATINE NERVE (Supplies lingual aspect of anterior teeth)
CONTENTS:- 1) INTRODUCTION 2) TYPES OF GINGIVA 3) MICROSCOPIC FEATURES OF GINGIVA 4) TYPES OF GINGIVAL LIGAMENT 5) DIFFERENT TYPES OF EPITHELIAL LAYERS 6) ARTERIAL SUPPLY 7) NERVE SUPPLY 8) REFERENCES
REFERNECES:-۞ Oral histology and embryology - ORBANS S.N.Bhaskar۞ Oral histology and embryology - A.R. Ten Cate۞ Clinical periodontology - Caranza Glick Man۞ Oral pathology - Shaffers۞ Local Anaesthesia - Mallamaid