NEET MDS Lessons
Oral and Maxillofacial Surgery
Overview of Infective Endocarditis (IE):
- Infective endocarditis is an inflammation of the inner lining of the heart, often caused by bacterial infection.
- Certain cardiac conditions increase the risk of developing IE, particularly during dental procedures that may introduce bacteria into the bloodstream.
High-Risk Cardiac Conditions: Antibiotic prophylaxis is recommended for patients with the following high-risk cardiac conditions:
- Prosthetic cardiac valves
- History of infective endocarditis
- Cyanotic congenital heart disease
- Surgically constructed systemic-pulmonary shunts
- Other congenital heart defects
- Acquired valvular dysfunction
- Hypertrophic cardiomyopathy
- Mitral valve prolapse with regurgitation
Moderate-Risk Cardiac Conditions:
- Mitral valve prolapse without regurgitation
- Previous rheumatic fever with valvular dysfunction
Negligible Risk Conditions:
- Coronary bypass grafts
- Physiological or functional heart murmurs
Prophylaxis Recommendations
When to Administer Prophylaxis:
- Prophylaxis is indicated for dental procedures that involve:
- Manipulation of gingival tissue
- Perforation of the oral mucosa
- Procedures that may cause bleeding
Antibiotic Regimens:
- The standard prophylactic regimen is a single dose administered 30-60
minutes before the procedure:
- Amoxicillin:
- Adult dose: 2 g orally
- Pediatric dose: 50 mg/kg orally (maximum 2 g)
- Ampicillin:
- Adult dose: 2 g IV/IM
- Pediatric dose: 50 mg/kg IV/IM (maximum 2 g)
- Clindamycin (for penicillin-allergic patients):
- Adult dose: 600 mg orally
- Pediatric dose: 20 mg/kg orally (maximum 600 mg)
- Cephalexin (for penicillin-allergic patients):
- Adult dose: 2 g orally
- Pediatric dose: 50 mg/kg orally (maximum 2 g)
- Amoxicillin:
Based on Absorption
Absorbable Sutures
- Natural: Catgut (plain and chromic)
- Synthetic: Vicryl, PDS-II, Monocryl, Biosyn
Non-Absorbable Sutures
- Natural: Silk, linen
- Synthetic: Nylon, polypropylene, polyester
Based on Structure
Monofilament
- Examples: PDS-II, Monocryl, nylon, polypropylene
- Advantages: Smooth passage, less tissue drag, reduced bacterial adherence
- Disadvantages: Difficult handling, knot security issues
Multifilament/Braided
- Examples: Vicryl, silk, polyester
- Advantages: Better handling, superior knot security
- Disadvantages: Increased tissue drag, potential for bacterial harboring
Marginal Resection
Marginal resection, also known as en bloc resection or peripheral osteotomy, is a surgical procedure used to treat locally aggressive benign lesions of the jaw. This technique involves the removal of the lesion along with a margin of surrounding bone, while preserving the continuity of the jaw.
Key Features of Marginal Resection
-
Indications:
- Marginal resection is indicated for benign lesions with a known
propensity for recurrence, such as:
- Ameloblastoma
- Calcifying epithelial odontogenic tumor
- Myxoma
- Ameloblastic odontoma
- Squamous odontogenic tumor
- Benign chondroblastoma
- Hemangioma
- It is also indicated for recurrent lesions that have been previously treated with enucleation alone.
- Marginal resection is indicated for benign lesions with a known
propensity for recurrence, such as:
-
Rationale:
- Enucleation of locally aggressive lesions is not a safe procedure, as it can lead to recurrence. Marginal resection is a more effective approach, as it allows for the complete removal of the tumor along with a margin of surrounding bone.
-
Benefits:
- Complete Removal of the Tumor: Marginal resection ensures the complete removal of the tumor, reducing the risk of recurrence.
- Preservation of Jaw Continuity: This procedure allows for the preservation of jaw continuity, avoiding deformity, disfigurement, and the need for secondary cosmetic surgery and prosthetic rehabilitation.
-
Surgical Technique:
- The procedure involves the removal of the lesion along with a margin of surrounding bone. The extent of the resection is determined by the size and location of the lesion, as well as the patient's overall health and medical history.
-
Postoperative Care:
- Patients may experience some discomfort and swelling following the procedure, which can be managed with analgesics and anti-inflammatory medications.
- Regular follow-up appointments are necessary to monitor the healing process and assess for any potential complications.
-
Outcomes:
- Marginal resection is a highly effective procedure for treating locally aggressive benign lesions of the jaw. It allows for the complete removal of the tumor, while preserving jaw continuity and minimizing the risk of recurrence.