Classification of Periodontal Diseases
- Internationally agreed classification formulated in 1989
- Divided periodontal diseases into 5 groups: adult periodontitis, early-onset periodontitis, periodontitis associated with systemic disease, necrotizing ulcerative periodontitis, and refractory periodontitis
- 1993 classification simplified and dropped categories of systemic disease and refractory periodontitis
- New classification developed in 1999, reclassifying adult periodontitis to chronic periodontitis and early-onset periodontitis to aggressive periodontitis
- Latest classification in 2017 addressed limitations of previous classifications, including defining the threshold between periodontal health and gingivitis, introducing staging and grading system, and introducing a new classification for peri-implant diseases

Gingival Diseases
- Gingival diseases share common features such as inflammation, restricted to gingiva, and potential for return to health
- Plaque-induced gingivitis is the most common form, caused by bacterial biofilm and characterised by red, swollen gums that bleed easily
- Factors influencing plaque-induced gingivitis include hormonal fluctuations, drugs, systemic diseases, and malnutrition
- Non-plaque-induced gingival diseases are less common and caused by bacterial, viral, fungal, genetic, or allergic sources
- Specific bacterial species, such as Neisseria gonorrhoeae and Treponema pallidum, can cause gingival lesions, as well as herpes simplex virus and varicella-zoster virus

Non-plaque-induced Gingival Diseases
- Non-plaque-induced gingival diseases are less common than plaque-induced lesions
- Inflammation can be caused by allergic reactions, trauma, foreign bodies, toxic reactions, or genetics
- Hereditary gingival fibromatosis is a genetic disease causing fibrous enlargement of the gums
- Certain bacterial, viral, and fungal infections can cause gingival lesions
- Systemic conditions like lichen planus and pemphigus vulgaris may manifest as gingival inflammation

Traumatic and Foreign Body Reactions
- Trauma to the gingiva can be chemical, physical, or thermal
- Traumatic lesions can be self-inflicted, iatrogenic, or accidental
- Foreign body reactions can cause longstanding lesions or trigger chronic inflammatory responses
- Dental materials can become impregnated in the gingival tissues and cause chronic inflammation
- Granulomatous or lichenoid lesions may occur as a result of foreign body reactions

Periodontitis
- Periodontitis is a type of periodontal disease characterised by extensive bone loss and soft tissue inflammation
- It is a common condition affecting a significant portion of the population
- Periodontitis can lead to tooth loss if left untreated
- Risk factors for periodontitis include poor oral hygiene, smoking, diabetes, and genetic predisposition
- Treatment for periodontitis involves professional cleaning, scaling, and root planing, as well as maintenance of good oral hygiene practices.

Subtopic: Aggressive periodontitis
- Distinguished from chronic periodontitis by faster rate of progression
- Loss of attachment may occur despite good oral hygiene
- Can occur in younger individuals
- Genetic aspect, may run in families
- Risk factors may not include smoking

Subtopic: Manifestation of systemic diseases
- Systemic diseases can be associated with development of periodontitis
- Host immune response to plaque may be altered by systemic condition
- Hematological disorders associated with periodontitis include acquired neutropenia and leukemias
- Genetic disorders potentially associated include Down syndrome and Ehlers-Danlos syndrome
- Other systemic diseases such as histiocytosis syndromes and glycogen storage disease may also be linked

Subtopic: Necrotizing periodontal diseases
- Acute necrotizing ulcerative gingivitis is characterised by painful, bleeding gums and loss of interdental papillae
- Necrotizing periodontal diseases are non-contagious infections
- Predisposing factors include stress, poor oral hygiene, smoking, and immunosuppression
- Necrotizing ulcerative periodontitis can lead to attachment loss
- Necrotizing stomatitis (cancrum oris) involves tissue beyond the mucogingival junction

Subtopic: Abscesses
- Abscesses are localised collections of pus
- Periodontal abscesses do not arise from pulp necrosis
- Gingival abscess involves the marginal gingiva or interdental papilla
- Periodontal abscess involves a greater dimension of gum tissue, extending apically
- Pericoronal abscess occurs around partially erupted and impacted mandibular third molars

Subtopic: Associated with endodontic lesions
- Combined pulpal and periodontal pathology can occur in a tooth and surrounding periodontium
- Developmental or acquired conditions can influence the outcome of periodontitis
- Combined periodontic-endodontic lesions can occur when periapical lesion becomes continuous with a periodontal lesion
- Vice versa, a periodontal lesion can become continuous with a periapical lesion
- Certain conditions can affect the prognosis and treatment of periodontitis

Subtopic: Early Lesion
- Infiltration and plasma cells at the edges of the area
- Up to 15% of connective tissue occupied by the lesion
- Altered fibroblasts with swollen mitochondria and rupture of cell membranes
- Acute exudative inflammation with crevicular lymphocytes
- Junctional epithelium may resemble a microabscess

Subtopic: Established Lesion
- Overwhelming presence of plasma cells
- Plasma cells clustered around blood vessels and between collagen fibers
- Production of IgG and some IgA by plasma cells
- Presence of complement and antigen-antibody complexes
- Proliferation and apical migration of junctional epithelium

Subtopic: Advanced Lesion
- Periodontal pocket formation
- Gingival ulcer

List of periodontal diseases (Wikipedia)

Periodontal pathology, also termed gum diseases or periodontal diseases, are diseases involving the periodontium (the tooth supporting structures, i.e. the gums). The periodontium is composed of alveolar bone, periodontal ligament, cementum and gingiva.

Periodontal pathology
Other names	Gum diseases, periodontal diseases
Gingival enlargement can be a feature in some periodontal diseases.
Specialty	Dentistry