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Oral and Maxillofacial Surgery - NEETMDS- courses
Oral and Maxillofacial Surgery

Microvascular Trigeminal Decompression (The Jannetta Procedure)

Microvascular decompression (MVD), commonly known as the Jannetta procedure, is a surgical intervention designed to relieve the symptoms of classic trigeminal neuralgia by addressing the underlying vascular compression of the trigeminal nerve. This procedure is particularly effective for patients who have not responded to medical management or who experience significant side effects from medications.

Overview of the Procedure

  1. Indication:

    • MVD is indicated for patients with classic trigeminal neuralgia, characterized by recurrent episodes of severe facial pain, often triggered by light touch or specific activities.
  2. Anesthesia:

    • The procedure is performed under general anesthesia to ensure the patient is completely unconscious and pain-free during the surgery.
  3. Surgical Approach:

    • The surgery is conducted using an intraoperative microscope for enhanced visualization of the delicate structures involved.
    • The arachnoid membrane surrounding the trigeminal nerve is carefully opened to access the nerve.
  4. Exploration:

    • The trigeminal nerve is explored from its entry point at the brainstem to the entrance of Meckel’s cave, where the trigeminal ganglion (Gasserian ganglion) is located.
  5. Microdissection:

    • Under microscopic and endoscopic visualization, the surgeon performs microdissection to identify and mobilize any arteries or veins that are compressing the trigeminal nerve.
    • The most common offending vessel is a branch of the superior cerebellar artery, but venous compression or a combination of arterial and venous compression may also be present.
  6. Decompression:

    • Once the offending vessels are identified, they are decompressed. This may involve:
      • Cauterization and division of veins that are compressing the nerve.
      • Placement of Teflon sponges between the dissected blood vessels and the trigeminal nerve to prevent further vascular compression.

Outcomes and Efficacy

  • Immediate Pain Relief:

    • Most patients experience immediate relief from facial pain following the decompression of the offending vessels.
    • Reports indicate rates of immediate pain relief as high as 90% to 98% after the procedure.
  • Long-Term Relief:

    • Many patients enjoy long-term relief from trigeminal neuralgia symptoms, although some may experience recurrence of pain over time.
  • Complications:

    • As with any surgical procedure, there are potential risks and complications, including infection, cerebrospinal fluid leaks, and neurological deficits. However, MVD is generally considered safe and effective.

Marsupialization

Marsupialization, also known as decompression, is a surgical procedure used primarily to treat cystic lesions, particularly odontogenic cysts, by creating a surgical window in the wall of the cyst. This technique aims to reduce intracystic pressure, promote the shrinkage of the cyst, and encourage bone fill in the surrounding area.

Key Features of Marsupialization

  1. Indication:

    • Marsupialization is indicated for large cystic lesions that are not amenable to complete excision due to their size, location, or proximity to vital structures. It is commonly used for:
      • Odontogenic keratocysts
      • Dentigerous cysts
      • Radicular cysts
      • Other large cystic lesions in the jaw
  2. Surgical Technique:

    • Creation of a Surgical Window:
      • The procedure begins with the creation of a window in the wall of the cyst. This is typically done through an intraoral approach, where an incision is made in the mucosa overlying the cyst.
    • Evacuation of Cystic Content:
      • The cystic contents are evacuated, which helps to decrease the intracystic pressure. This reduction in pressure is crucial for promoting the shrinkage of the cyst and facilitating bone fill.
    • Suturing the Cystic Lining:
      • The remaining cystic lining is sutured to the edge of the oral mucosa. This can be done using continuous sutures or interrupted sutures, depending on the surgeon's preference and the specific clinical situation.
  3. Benefits:

    • Pressure Reduction: By decreasing the intracystic pressure, marsupialization can lead to the gradual reduction in the size of the cyst.
    • Bone Regeneration: The procedure promotes bone fill in the area previously occupied by the cyst, which can help restore normal anatomy and function.
    • Minimally Invasive: Compared to complete cyst excision, marsupialization is less invasive and can be performed with less morbidity.
  4. Postoperative Care:

    • Patients may experience some discomfort and swelling following the procedure, which can be managed with analgesics.
    • Regular follow-up appointments are necessary to monitor the healing process and assess the reduction in cyst size.
    • Oral hygiene is crucial to prevent infection at the surgical site.
  5. Outcomes:

    • Marsupialization can be an effective treatment for large cystic lesions, leading to significant reduction in size and promoting bone regeneration. In some cases, if the cyst does not resolve completely, further treatment options, including complete excision, may be considered.

Mandibular Tori

Mandibular tori are bony growths that occur on the mandible, typically on the lingual aspect of the alveolar ridge. While they are often asymptomatic, there are specific indications for their removal, particularly when they interfere with oral function or prosthetic rehabilitation.

Indications for Removal

  1. Interference with Denture Construction:

    • Mandibular tori may obstruct the proper fitting of full or partial dentures, necessitating their removal to ensure adequate retention and comfort.
  2. Ulceration and Slow Healing:

    • If the mucosal covering over the torus ulcerates and the wound exhibits extremely slow healing, surgical intervention may be required to promote healing and prevent further complications.
  3. Interference with Speech and Deglutition:

    • Large tori that impede normal speech or swallowing may warrant removal to improve the patient's quality of life and functional abilities.

Surgical Technique

  1. Incision Placement:

    • The incision should be made on the crest of the ridge if the patient is edentulous (without teeth). This approach allows for better access to the torus while minimizing trauma to surrounding tissues.
    • If there are teeth present in the area, the incision should be made along the gingival margin. This helps to preserve the integrity of the gingival tissue and maintain aesthetics.
  2. Avoiding Direct Incision Over the Torus:

    • It is crucial not to make the incision directly over the torus. Incising over the torus can lead to:
      • Status Line: Leaving a visible line on the traumatized bone, which can affect aesthetics and function.
      • Thin Mucosa: The mucosa over the torus is generally very thin, and an incision through it can result in dehiscence (wound separation) and exposure of the underlying bone, complicating healing.
  3. Surgical Procedure:

    • After making the appropriate incision, the mucosal flap is elevated to expose the underlying bone.
    • The torus is then carefully removed using appropriate surgical instruments, ensuring minimal trauma to surrounding tissues.
    • Hemostasis is achieved, and the mucosal flap is repositioned and sutured back into place.
  4. Postoperative Care:

    • Patients may experience discomfort and swelling following the procedure, which can be managed with analgesics.
    • Instructions for oral hygiene and dietary modifications may be provided to promote healing and prevent complications.
  5. Follow-Up:

    • Regular follow-up appointments are necessary to monitor healing and assess for any potential complications, such as infection or delayed healing.

Maxillectomy

Maxillectomy is a surgical procedure involving the resection of the maxilla (upper jaw) and is typically performed to remove tumors, treat severe infections, or address other pathological conditions affecting the maxillary region. The procedure requires careful planning and execution to ensure adequate access, removal of the affected tissue, and preservation of surrounding structures for optimal functional and aesthetic outcomes.

Surgical Access and Incision

  1. Weber-Fergusson Incision:

    • The classic approach to access the maxilla is through the Weber-Fergusson incision. This incision provides good visibility and access to the maxillary region.
    • Temporary Tarsorrhaphy: The eyelids are temporarily closed using tarsorrhaphy sutures to protect the eye during the procedure.
  2. Tattooing for Aesthetic Alignment:

    • To achieve better cosmetic results, it is recommended to tattoo the vermilion border and other key points on both sides of the incision with methylene blue. These points serve as guides for alignment during closure.
  3. Incision Design:

    • The incision typically splits the midline of the upper lip but can be modified for better cosmetic outcomes by incising along the philtral ridges and offsetting the incision at the vermilion border.
    • The incision is turned 2 mm from the medial canthus of the eye. Intraorally, the incision continues through the gingival margin and connects with a horizontal incision at the depth of the labiobuccal vestibule, extending back to the maxillary tuberosity.
  4. Continuation of the Incision:

    • From the maxillary tuberosity, the incision turns medially across the posterior edge of the hard palate and then turns 90 degrees anteriorly, several millimeters to the proximal side of the midline, crossing the gingival margin again if possible.
  5. Incision to Bone:

    • The incision is carried down to the bone, except beneath the lower eyelid, where the orbicularis oculi muscle is preserved. The cheek flap is then reflected back to the tuberosity.

Surgical Procedure

  1. Extraction and Elevation:

    • The central incisor on the involved side is extracted, and the gingival and palatal mucosa are elevated back to the midline.
  2. Deepening the Incision:

    • The incision extending around the nose is deepened into the nasal cavity. The palatal bone is divided near the midline using a saw blade or bur.
  3. Separation of Bone:

    • The basal bone is separated from the frontal process of the maxilla using an osteotome. The orbicularis oculi muscle is retracted superiorly, and the bone cut is extended across the maxilla, just below the infraorbital rim, into the zygoma.
  4. Maxillary Sinus:

    • If the posterior wall of the maxillary sinus has not been invaded by the tumor, it is separated from the pterygoid plates using a pterygoid chisel.
  5. Specimen Removal:

    • The entire specimen is removed by severing the remaining attachments with large curved scissors placed behind the maxilla.

Postoperative Considerations

  • Wound Care: Proper care of the surgical site is essential to prevent infection and promote healing.
  • Rehabilitation: Patients may require rehabilitation to address functional issues related to speech, swallowing, and facial aesthetics.
  • Follow-Up: Regular follow-up appointments are necessary to monitor healing and assess for any complications or recurrence of disease.

Dental/Oral/Upper Respiratory Tract Procedures: Antibiotic Prophylaxis Guidelines

Antibiotic prophylaxis is crucial for patients at risk of infective endocarditis or other infections during dental, oral, or upper respiratory tract procedures. The following guidelines outline the standard and alternate regimens for antibiotic prophylaxis based on the patient's allergy status and ability to take oral medications.

I. Standard Regimen in Patients at Risk

  1. For Patients Allergic to Penicillin/Ampicillin/Amoxicillin:

    • Erythromycin:
      • Dosage: Erythromycin ethyl-succinate 800 mg or erythromycin stearate 1.0 gm orally.
      • Timing: Administer 2 hours before the procedure.
      • Follow-up Dose: One-half of the original dose (400 mg or 500 mg) 6 hours after the initial administration.
    • Clindamycin:
      • Dosage: Clindamycin 300 mg orally.
      • Timing: Administer 1 hour before the procedure.
      • Follow-up Dose: 150 mg 6 hours after the initial dose.
  2. For Non-Allergic Patients:

    • Amoxicillin:
      • Dosage: Amoxicillin 3.0 gm orally.
      • Timing: Administer 1 hour before the procedure.
      • Follow-up Dose: 1.5 gm 6 hours after the initial dose.

II. Alternate Prophylactic Regimens in Patients at Risk

  1. For Patients Who Cannot Take Oral Medications:

    • For Penicillin/Amoxicillin Allergic Patients:
      • Clindamycin:
        • Dosage: Clindamycin 300 mg IV.
        • Timing: Administer 30 minutes before the procedure.
        • Follow-up Dose: 150 mg IV (or orally) 6 hours after the initial dose.
    • For Non-Allergic Patients:
      • Ampicillin:
        • Dosage: Ampicillin 2.0 gm IV or IM.
        • Timing: Administer 30 minutes before the procedure.
        • Follow-up Dose: Ampicillin 1.0 gm IV (or IM) or amoxicillin 1.5 gm orally 6 hours after the initial dose.
  2. For High-Risk Patients Who Are Not Candidates for the Standard Regimen:

    • For Penicillin/Amoxicillin Allergic Patients:
      • Vancomycin:
        • Dosage: Vancomycin 1.0 gm IV.
        • Timing: Administer over 1 hour, starting 1 hour before the procedure.
        • Follow-up Dose: No repeat dose is necessary.
    • For Non-Allergic Patients:
      • Ampicillin and Gentamicin:
        • Dosage: Ampicillin 2.0 gm IV (or IM) plus gentamicin 1.5 mg/kg IV (or IM) (not to exceed 80 mg).
        • Timing: Administer 30 minutes before the procedure.
        • Follow-up Dose: Amoxicillin 1.5 gm orally 6 hours after the initial dose. Alternatively, the parenteral regimen may be repeated 8 hours after the initial dose.

Nasogastric Tube (Ryles Tube)

nasogastric tube (NG tube), commonly referred to as a Ryles tube, is a medical device used for various purposes, primarily involving the stomach. It is a long, hollow tube made of polyvinyl chloride (PVC) with one blunt end and multiple openings along its length. The tube is designed to be inserted through the nostril, down the esophagus, and into the stomach.

Description and Insertion

  • Structure: The NG tube has a blunt end that is inserted into the nostril, and it features multiple openings to allow for the passage of fluids and air. The open end of the tube is used for feeding or drainage.

  • Insertion Technique:

    1. The tube is gently passed through one of the nostrils and advanced through the nasopharynx and into the esophagus.
    2. Care is taken to ensure that the tube follows the natural curvature of the nasal passages and esophagus.
    3. Once the tube is in place, its position must be confirmed before any feeds or medications are administered.
  • Position Confirmation:

    • To check the position of the tube, air is pushed into the tube using a syringe.
    • The presence of air in the stomach is confirmed by auscultation with a stethoscope, listening for the characteristic "whoosh" sound of air entering the stomach.
    • Only after confirming that the tube is correctly positioned in the stomach should feeding or medication administration begin.
  • Securing the Tube: The tube is fixed to the nose using sticking plaster or adhesive tape to prevent displacement.

Uses of Nasogastric Tube

  1. Nutritional Support:

    • Enteral Feeding: The primary use of a nasogastric tube is to provide nutritional support to patients who are unable to take oral feeds due to various reasons, such as:
      • Neurological conditions (e.g., stroke, coma)
      • Surgical procedures affecting the gastrointestinal tract
      • Severe dysphagia (difficulty swallowing)
  2. Gastric Lavage:

    • Postoperative Care: NG tubes can be used for gastric lavage to flush out blood, fluids, or other contents from the stomach after surgery. This is particularly important in cases where there is a risk of aspiration or when the stomach needs to be emptied.
    • Poisoning: In cases of poisoning or overdose, gastric lavage may be performed using an NG tube to remove toxic substances from the stomach. This procedure should be done promptly and under medical supervision.
  3. Decompression:

    • Relieving Distension: The NG tube can also be used to decompress the stomach in cases of bowel obstruction or ileus, allowing for the removal of excess gas and fluid.
  4. Medication Administration:

    • The tube can be used to administer medications directly into the stomach for patients who cannot take oral medications.

Considerations and Complications

  • Patient Comfort: Insertion of the NG tube can be uncomfortable for patients, and proper technique should be used to minimize discomfort.

  • Complications: Potential complications include:

    • Nasal and esophageal irritation or injury
    • Misplacement of the tube into the lungs, leading to aspiration
    • Sinusitis or nasal ulceration with prolonged use
    • Gastrointestinal complications, such as gastric erosion or ulceration

Management of Greenstick/Crack Fractures of the Mandible

Greenstick fractures (or crack fractures) are incomplete fractures that typically occur in children due to the flexibility of their bones. Fracture in mandible,  can often be managed conservatively, especially when there is no malocclusion (misalignment of the teeth).

Conservative Management

  • No Fixation Required:
    • For greenstick fractures without malocclusion, surgical fixation is generally not necessary.
    • Closed Reduction: The fracture can be managed through closed reduction, which involves realigning the fractured bone without surgical exposure.
  • Dietary Recommendations:
    • Patients are advised to consume soft foods and maintain adequate hydration with lots of fluids to facilitate healing and minimize discomfort during eating.

Surgical Management Options

In cases where surgical intervention is required, or for more complex fractures, the following methods can be employed:

  1. Kirschner Wire (K-wire) Fixation:

    • Indications: K-wires can be used for both dentulous (having teeth) and edentulous (without teeth) mandibles.
    • Technique: K-wires are inserted through the bone fragments to stabilize the fracture. This method provides internal fixation and helps maintain alignment during the healing process.
  2. Circumferential Wiring:

    • Indications: This technique is also applicable for both dentulous and edentulous mandibles.
    • Technique: Circumferential wiring involves wrapping wire around the mandible to stabilize the fracture. This method can provide additional support and is often used in conjunction with other fixation techniques.
  3. External Pin Fixation:

    • Indications: Primarily used for edentulous mandibles.
    • Technique: External pin fixation involves placing pins into the bone that are connected to an external frame. This method allows for stabilization of the mandible while avoiding intraoral fixation, which can be beneficial in certain clinical scenarios.

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