Anatomy of periodontium

anatomy of periodontium

1. Anatomy of Periodontium Submitted by: Dr. Arunima PG Resident Submitted to: Dept. of Periodontics

2. The Periodontium Periodontium is a complex anatomical formation of CT origin, located in a gap between tooth socket (compact plate of a tooth socket) and cementum of a root. Periodontium is a CT that surrounds tooth root.

3. Parts of Periodontium Cementum ( Celullar and Acellular/ Primary and Secondary) Periodontal Ligament Alveolar Bone. Gingiva.

4. Gingiva Gingiva is part of oral mucosa and it covers ALVEOLAR processes of jaws and surrounds the NECKS of the teeth Parts of Gingiva 1.Marginal 2. Attached 3. Interdental

5. Healthy gingiva Pink in color Firm and resilient (resist deformity) in consistency and not bleeding on probing. Knife-edged and scalloped to conform to the contour of the teeth. The surface of the gingiva exhibits an orange peel-like appearance referred to as stippling

6. All the soft tissue in the mouth are known as the oral mucosa, it is divided into three different types Masticatory mucosa: Is a tissue that is firmly attached to the underlying bone and covered with parakeratinized or keratinized epithelium. The gingiva and the tissue covering the hard palate are examples. Lining mucosa: Loosely attached to their underlying structures and covered with non-keratinized epithelium. Lips, cheeks, floor of the mouth. Specialized mucosa: Covers the dorsal surface of the tongue.

7. Marginal Gingiva Other name for it is Unattached Gingiva. Free gingival groove- Shallow linear depression that demarcates marginal gingiva. The most apical point of the marginal gingiva is called Gingival Zenith. The marginal gingiva forms a cuff 1-2 mm wide around the neck of the tooth and it is external wall of the gingival crevice. The marginal gingiva can be separated from the tooth by a blunt probe. The surface of marginal gingiva is smooth in contrast to the attached gingiva which is stippled. The marginal gingiva is demarcated from the attached gingiva by a shallow, v-shaped or an indentation called the free gingival groove.

8. Epithelial layers of marginal gingiva It has four cell layers: Stratum Basale( Basal Layer) Stratum Spinosum (Prickle cell layer) Stratum granulosum (granular layer) Stratum corneum (cornified layer)

9. Attached gingiva Firm, resilient and bounded to underlying periosteum of the alveolar bone. Mucogingival junction is made of it. Stippling- orange peel appearance. Width vary from zero to 9mm. (greatest in incisor region=3.5-1.5 in maxilla, 3.3-3.9 in mandible) (least in canine and premolar area (1.9mm in maxilla, 1.8mm in mandible) It extends from the free gingival groove to the mucogingival junction where it meets the alveolar mucosa. The attached gingiva is tightly bound to the underlying alveolar bone.

10. Attached gingiva Function of attached gingiva: 1- It provides gingival tissue that can withstand the mechanical forces of mastication, brushing and tension applied on mucosa. 2- Prevent free gingiva from being pulled away from the tooth when tension is applied to the alveolar mucosa.

11. Interdental gingiva Occupies the space in the interdental embrasure apical to the contact point. There are 3 parts: Facial papilla Lingual papilla Col region

12. Interdental gingiva In anterior teeth, the interdental papilla is pyramidal form while in the molar region, the papillae are flattened in buccolingual direction (tent shape). The shape of the interdental papilla is determined by: the contact relationships between the teeth the width of the proximal tooth surfaces coarse of the CEJ.

13. Gingival sulcus Shallow crevice/space around the tooth that is bounded by the surface of tooth on one side/ the epithelium lining the free margin of the gingiva on the other side. It is V shaped. Stratum corneum is absent. Under normal or ideal conditions it is about 2 to 3 mm. The gingival sulcus is probing depth of a clinically-normal gingival. It provides good resistance to mechanical forces.

14. Gingival crevicular fluid It is an inflammatory exudate that carries polymorphonuclear leukocytes and other antimicrobial substances into the gingival crevice (sulcus). If filter paper strip is inserted into the gingival crevice it will absorb gingival fluid already in the crevice and also stimulate the outward flow of the gingival fluid. The increase in gingival fluid flow is also associated with inflammation.

15. Gingival crevicular fluid The gingival fluid forms part of the defense mechanism of the dentogingival junction. In summary, it performs the following functions: It washes the crevice, carrying out shed epithelial cells, leukocytes and bacteria. It contains antimicrobial components e.g. lysosome, antibodies and complement. It carries PMNLs and macrophages which are capable of phagocytosing bacteria.

16. Interdental papilla(gingival papilla) If the contours of interproximal contact are flat, the gingiva will be narrow and short. If the proximal contours are more convex with a small coronally positioned contact area, the interdental gingiva will be broad and high.

17. Col region In teeth with contact surface rather than contact point, the interdental papilla has a col region. The "col" is depression which joins the facial and lingual papilla. The col region is covered by a non-keratinized epithelium which is not a powerful barrier against bacterial insult.

18. Microscopic features of gingiva It consists of: 1. Gingival epitheium Oral(outer) epithelium Sulcular epithelium Junctional epithelium 2. Gingival connective tissue

19. Gingival epithelium Three zones of gingival epithelium: Oral (outer) epithelium which is keratinized(from the mucogingival junction to the gingival margin). Sulcular epithelium which are non keratinized (lines the gingival crevice). Junctional epithelium which are nonkeratinized (lies at the base of the gingival crevice).

20. Gingival connective tissue Composed of Ground substance Gingival fibers Cells Blood vessels Nerves Lymphatic vessels

21. Alveolar mucosa The alveolar mucosa is separated from the periosteum by a loose, highly vascular connective tissue. Thus the alveolar mucosa is relatively loose and mobile tissue, deep red, in marked contrast to the pale pink attached gingiva.

22. Cementum Acellular cementum- Cover the root adjacent to dentin whereas cellular Cementum is found in the apical area. Cellular: Apical area and overlying acellular cementum. (Present in interradicular areas) Cementum is more cellular as the thickness increases in order to maintain Viability.

23. Alveolar bone Is the bone of jaw which forms the alveolus around teeth. Osteoblasts- create bone and osteoclasts destroy it, especially when force is applied. Alveolar process has 2 parts 1: Proper alveolar bone 2: Supporting alveolar bone

24. Periodontal ligament Connective tissue that surrounds the ROOT and connects it with the BONE. It is continuous with the CT of Gingiva and communicates with the MARROW spaces through vascular channels. The average width is 0.2mm.

25. Functions of PDL Support Shock absorbing Formative Sensory Nutritive

26. Conclusion All of the anatomical parts of the periodontium are of great importance in order to carry out the proper diagnosis and better understanding of the treatment plan.