Academy of Dental Knowledge

MALOCCLUSION Proposed by Edward H. Angle in 1890, the Angle Classifications are based on the relationship of the buccal groove of the mandibular first permanent molar and the mesiobuccal cusp of the maxillary first permanent molar. This classification is considered to be one of the most commonly used as its easy to use.

  Bleeding disorders: dental considerations Acquired or congenital bleeding disorders of dental treatment concern include haemophilia, von Willebrand disease, other factor deficiencies and thrombocytopenia. Some systemic conditions also interfere with haemostasis, such as kidney, liver and bone marrow disorders. Patients with bleeding disorders should be managed in a specialist setting, with appropriate consultation with the patient’s specialist or multidisciplinary team. Bleeding Disorders haemophilia von Willebrand disease Other factor deficiencies  thrombocytopenia Causes Bleeding disorder may be due to defect in platelet activation, function and contact activation.  It may also be due to defect in clotting proteins or antithrombin function.  The commonest caused of bleeding disorder are  warfarin von Willebrand disease aspirin Warfarin is the commonest anticoagulant that interferes by preventing the production of clotting factors by blocking vitamin K. von W...

Congestive Heart Failure Congestive heart failure or  h eart failure  occurs when the heart muscle weakens and doesn't pump enough blood as it should. When this happens, blood often backs up and fluid can build up in the lungs, causing shortness of breath. Certain heart conditions, for example,  coronary artery disease or  high blood pressure, gradually leave the heart too weak or stiff to fill and pump blood properly.  Signs and symptoms of congestive heart failure   Shortness of breath with activity or when lying down Fatigue and weakness Swelling in the legs, ankles and feet Rapid or irregular heartbeat Reduced ability to exercise Persistent cough or wheezing with white or pink blood-tinged mucus Swelling of the belly area (abdomen) Very rapid weight gain from fluid build-up Nausea and lack of appetite Difficulty concentrating or decreased alertness Chest pain if heart failure is caused by a heart attack

Antibiotic prophylaxis is recommended for invasive dental procedures that involve the manipulation of gingival tissue or periapical region or perforation of the mucosa when performed on high-risk individuals. Australian guidelines have provided a list of dental procedures that are likely to cause a high incidence of bacteraemia that always require prophylaxis. These are as follows: Tooth extraction. Periodontal surgery, subgingival scaling and root planning. Replantation of avulsed teeth. Other surgical procedures such as implant placement or apicoectomy. Procedures that cause a moderate incidence of bacteraemia might be considered for prophylaxis if multiple procedures are being conducted, in cases where the procedure is prolonged, or in the setting of periodontal disease. Antibiotic prophylaxis is not recommended for procedures with a low possibility of bacteraemia such as: Local anaesthetic injections. Dental X-rays. Treatment of superficial caries. Orthodontic appliance placement a...

The laboratory findings in haemophilia will be as follows. APTT (activated partial prothrombin time) -prolonged PT (prothrombin time)-normal BT (bleeding time)-normal [1] or increased [2] Factor VIII-C- low Factor VIIIR:Ag [von Willebrand factor] and factor VIIIR:RCo [Ristocetin cofactor]-normal Ref: Crispian Scully, Roderick A. Cawson Medical problems in dentistry page 142 5th Ed.  https://www.cdc.gov/ncbddd/hemophilia/diagnosis.html

Oral Erythroplakia Erythroplakia is a clinical term for a potentially malignant fiery red lesion that cannot be attributed to any particular condition. Signs and Symptoms Lesions are usually asymptomatic and isolated, and commonly appear on the floor of the mouth, tongue, soft palate and buccal mucosa. Lesions may appear as smooth, velvety, granular or nodular plaques, often with clear margins.

Antimicrobials used in dentistry Chemotherapy is the use of chemicals to destroy or inhibit the growth of cells. Two broad classes of chemotherapeutic agents are used in pharmacology:  antimicrobials and  anticancer drugs.  The basis of antimicrobial chemotherapy is a differential sensitivity of the patient and microbe cells to the action of the drug. The drug may affect a structural component of the target cell which is not found in the patient, for example, the bacterial cell wall. Alternatively, a chemotherapeutic agent may inhibit a metabolic pathway peculiar to the microbe cells, for example, synthesis of folate.

      Normally there is one opening of the parotid gland which is located in buccal vestibule opposite the upper 2nd molar tooth.      Parotid fistula is a patent tract connecting a parotid gland or duct to the exterior apart from the parotid duct opening. Photo 1. Pre-operative picture of parotid fistula with leakage of serous fluid from the fistulous tract and scarring of surrounding area (red circle) [1]       Parotid fistula may be of two types     1. Glandular: It arises directly from gland. It shows minimal discharge during rest or eating. 2. Ductal: It arises from duct. It shows profuse discharge during eating. Parotid fistula may be extra oral or intraoral. Extraoral fistulas are seen in the preauricular region or near the angle of mandible (see photo 1 and 2). Photo 2. showing discharge of serous fluid from the right cheek in the angle of mandible region [2] Causes 1. After superficial parotidectomy. 2.   After drai...

Darsogluteal Intramuscular Injections

  Kaposi sarcoma (in AIDS): Important points to remember about Kaposi Sarcoma Kaposi's sarcoma is a type of cancer that forms in the lining of blood and lymph vessels. Kaposi's sarcoma or oral cavity Kaposi's sarcoma of the skin Clinical Features It is the most common malignancy in AIDS. It is associated with the infection with a virus called the Kaposi sarcoma associated herpesvirus (KSHV), also known as human herpesvirus 8 (HHV8). The commonly affected sites are palate, gingiva, tongue, and oropharynx or the skin of the face and feet. It is seen early in the course of the disease. It can sometimes be confused with Bacillary angiomatosis. There is a specific histologic stain for Kaposi sarcoma known as Warthin-Starry stain. With the use of HAART, incidence of KS is decreasing and soon NHL may become the most common malignancy associated with AIDS.  

Cemento-osseous dysplasia (COD) is a benign fibro-osseous lesion of bone characterized by the replacement of normal bone by fibrous tissue and subsequently followed by its calcification with osseous and cementum-like material. It arises from the fibroblasts of the periodontal ligaments. It is mostly asymptomatic in nature and requires no treatment. When secondarily infected, it becomes symptomatic and intervention is required. Orthopantamogram showing a well-defined radiopaque mass in the right mandible region extending from the distal root of 45 to the mesial root of 47 [1] As per WHO, there are three clinical presentation of cemento-osseous dysplasia. Periapical Focal Florid Periapical cemento-osseous dysplasia These occur in the anterior mandible and involve only a few adjacent teeth. Focal cemento-osseous dysplasia. involve few teeth in posterior mandible Florid cemento-osseous dysplasia or Familial gigantiform cementoma It is a more extensive form. it occurs bilaterally in m...

The cells of periapical granuloma which are predominantly lymphocytes increase by division at the periphery.  There are hyperaemia and oedema of the PDL; localised increase in the vascularity leads to local bone  resorption mediated by osteoclast mediated delayed hypersensitivity. In the specimen slide, cholesterol crystals having needle-like appearance, and eosinic hyaline bodies known as Rushton bodies are seen. Macrophages and multinucleated giant cells are also seen. Epithelium is present. The cells in the centre are separated from their source of nutrition; hence degenerate and liquefy. This results in an epithelium lined cavity filled with fluid known as periapical cyst. Treatment involves RCT with apicoectomy or extraction with curettage. Ref: Radiographic Interpretation between Periapical Cysts and Periapical Granuloma- A Diagnostic Tool Periapical cyst/radicular cyst

Periapical infection with Streptococci & Staphylococci Majority of streptococci produce hyaluronidase, an enzyme that dissolves hyaluronic acid which is a universal intercellular cementing substance. It helps in the spread of infection. Usually staphylococci are good producers of hyaluronidase, so there is no spread of infection and the infection becomes localised in the form of abscess in case of staph infection.

Oral cancer is associated with significant morbidity and mortality. Early presentations of oral cancer are usually asymptomatic, whereas late presentations include pain, discomfort, reduced mobility of the tongue, increased mobility of the teeth or an inability to wear dentures. Oral cancer varies in appearance and can mimic many other oral mucosal diseases. Squamous cell carcinoma of the left anterior ventral surface of the tongue Squamous cell carcinoma of the left mandibular alveolus Oral cancer can mimic many other oral mucosal diseases, so early specialist referral is required for investigation and biopsy of any suspicious lesion.   Any suspicious lesion needs early specialist referral for investigation and biopsy. Squamous cell carcinoma is the most common oral malignancy, which arises from the epithelium of the oral cavity. Oral squamous cell carcinoma can affect any part of the oral mucosa; however, it most commonly occurs on the lateral surfaces of...