1. Acute suppurative osteomyelitis
   1. Polymicrobial infection- Staphylococcus aureus, Staphylococcus albus, 7 streptococci Anaerobes- Bacteroides, Porphyromonas or prevotella
   2. Clinical features
      1. Maxilla- well localized Mandible- diffuse & wide spread Adult- severe pain, trismus & paresthesia of the lips in case of mandibular involvement with lymphadenopathy & fever Tooth mobile- difficult to eat Pus exuded from the gingival margin No swelling or redness until periostitis develops
   3. Radiographic features
      1. No evidence for 1-2 weeks later individual trabeculae become fuzzy, indistinct and radiolucent area begin to appear
   4. Histological features
      1. Medullary space filled with inflammatory exudate Chiefly PMNLs occasionally lymphocytes and plasma cells Osteoblasts bordering trabeculae are destroyed bone become necrosed and resorbed at later stage
   5. Treatment
      1. Debridement, drainage and antimicrobial therapy
2. chronic Osteomyelitis
   1. Chronic suppurative osteomyelitis
      1. Arises from a previous acute osteomyelitis, dental infection or rarely as a complication of irradiation
      2. Clinical features
         1. Male> female Mandible> maxilla Pain , swelling, purulent discharge, sinus formation, mobile teeth
      3. Radiographic features
         1. Ill defined mot eaten RL Central RO sequestration
      4. Histological features
         1. Chronically/ subacutely inflamed CT filling the inter trabecular area of the bone Scattered sequestra and pocket of abscess formation
      5. Treatment
         1. Difficult to manage medically ( pockets of necrosed bone and bacteria are protected from antibiotics by the surrounding wall of fibrous CT) Surgical intervention id mandatory
   2. Chronic focal sclerosing osteomyelitis
      1. Condensing osteitis mild bacterial infection entering the bone through a carious tooth in person who have a high degree of tissue resistance
      2. Clinical features
         1. Mostly in children and young adults Most commonly involved teeth- Mandibular 1st molars mild pain
      3. Radiographic features
         1. Well circumscribed RO mass of sclerosing bone Intact lamina dure widening of PDL space Border of the lesion may be smooth and distinct or appears to blend into the surrounding bone. D/D- cemento-osseous dysplasia, Benign cementoblastoma
      4. Histologic features
         1. Dense mass of bony trabeculae with little with little interstitial marrow tissue( if present fibrotic and infiltered by lymphocyte) Trabeculae exhibit multiple reversal and resting lines giving pagetoid appearance Osteocytic lacunae empty D/D- Idiopathic osteosclerosis
      5. Treatment
         1. Associated teeth- RCT/ extraction Surgical removal of lesion not indicated unless symptomatic
   3. Chronic diffuse sclerosing osteomyelitis
      1. Proliferative reaction of the bone to low grade infection In many of the cases portal of entry- not dental caries
      2. Clinical features
         1. Any age but most common in older persons Edentulous mandibular jaws Acute exacerbation of chronic infection- Vague pain, unpleasant taste & mild suppuration, spontaneous fistula formation
      3. Radiographic features
         1. Diffuse, patchy, sclerosis of bone often- cotton wool appearance Border between normal bone and sclerosis is indistinct D/D- Paget's disease, cemento-osseous dysplasia
      4. Histological features
         1. Dense irregular trabeculae of bone, bordered by active layer of osteoblast Mosaic pattern Connective tissue- proliferative fibroblast, capillaries, lymphocytes and plasma cells
      5. Treatment
         1. Conservative Acute- Antibiotic therapy
   4. Garre's chronic nonsuppurative sclerosing osteitis
      1. Chronic osteomyelitis with proliferative periostitis/ Periostitis ossificans
      2. Clinical features
         1. Subtopic 1
      3. Radiographic features
         1. Reveal a carious tooth opposite the hard bony mass focal overgrowth of bone on the outer surface of the cortex, described as duplication of the cortical layer of bone with smooth and rather well calcified and show a thin but definite cortical layer
      4. Histological features
         1. Supracortical subperiosteal mass composed of much reactive new bone and osteoid tissue, with osteo- blasts bordering many of the trabeculae. Trabeculae oriented perpendicular to the cortex, and arranged parallel to each other or in a retiform pattern. The connective tissue fibrous and shows a diffuse or patchy sprinkling of lymphocytes and plasma cells
      5. D/D- Hypervitaminosis, ewing's sarcoma, metastatic neuroblastoma, syphilis, leukaemia
      6. Treatment
         1. Endodontic treatment/ extraction of associated teeth No surgical intervention
3. Periapical abscess
   1. Dentoalveolar abscess/ Alveolar abscess
      1. Acute or chronic suppurative process of the dental periapical region
   2. Acute periapical abscess
      1. Clinical features extreme tenderness of tooth Relieved by application of pressure Regional lymphadenitis and fever may be present Rapid extension to adjacent bone marrow- Osteomyelitis
      2. Radiographic features Widening of PDL space may be seen usually no evidence of its presence
   3. Chronic periapical abscess
      1. Clinical features No symptoms Mild, well circumscribed area of suppuration that little tendency to spread from local area
      2. Ill defined radiolucency at the periapical region
   4. Histologic features
      1. Central area of disintegrating PMNL surrounded by viable leukocyte Dilatation of blood vessel in PD and adjacent marrow space Marrow space also shows inflammatory cell infiltrate Serous exudate on the tissue around the suppuration
   5. Treatment & prognosis
      1. Drainage by either opening the pulp chamber or extracting the tooth RCT If untreated leads to osteomyelitis, cellulitis, bacteraemia and fistulous tract opening on the skin or oral mucosa
4. apical periodontitis
   1. Acute apical periodontitis
      1. Clinical features
         1. Constant throbbing pain Tooth is slightly elevated in the socket Tenderness on percussion +ve Vitality test -ve / shows delayed +ve response
      2. Radiographic features
         1. Normal except for slight widening of PDL space
      3. Histological features
         1. Inflammatory sign in PDL Vascular dilatation Infiltration with PMNL (initially changes confined to root apex as this area is richly vascular) If it is associated with bacterial infection- leads to periapical/ alveolar abscess
      4. Treatment & prognosis
         1. Tretment option
            1. Cause
         2. selectiveOcclusal grinding
            1. Occlusal trauma
         3. Extraction/ endodontic treatment
            1. Spread of pulpal infection
   2. Chronic apical periodontitis (Periapical granuloma)
      1. Periapical granuloma is a localized mass of granulation tissue formed in response to the infection. But there is no true granulomatous inflammation microscopically
      2. Clinical features
         1. Involved tooth is Non vital Usually asymptomatic Symptoms- mild pain on biting Tooth feels slightly elongated in the socket Signs- may be slightly tender on percussion with a dull sound
      3. Radiographic features
         1. Earliest sign PDL space widening Proliferation of granuloma-> resorption of bone-> Radiolucency at the periapical region (<2mm) well defined/ ill defined Loss of apical lamina dura Root resorption is common D/D- periapical cyst (size <2mm
      4. Histological features
         1. Inflamed granulation tissue surrounded by fibrous CT wall Granulomatous tissue predominantly contains Macrophages, lymphocyte and plasma cells, and less frequently with mast cell and eosinophils. Russel bodies and pyronins bodies may be seen Epithelial rest of malassez may be identified Cholesterol crystals RBC extravasation with hemosiderin pigmentation Small foci of acute inflammation with focal abcess formation
      5. Treatment & prognosis
         1. Extraction/ endodontic treatment