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Oral and Maxillofacial Surgery

Cryosurgery

Cryosurgery is a medical technique that utilizes extreme rapid cooling to freeze and destroy tissues. This method is particularly effective for treating various conditions, including malignancies, vascular tumors, and aggressive tumors such as ameloblastoma. The process involves applying very low temperatures to induce localized tissue destruction while minimizing damage to surrounding healthy tissues.

Mechanism of Action

The effects of rapid freezing on tissues include:

  1. Reduction of Intracellular Water:

    • Rapid cooling causes water within the cells to freeze, leading to a decrease in intracellular water content.
  2. Cellular and Cell Membrane Shrinkage:

    • The freezing process results in the shrinkage of cells and their membranes, contributing to cellular damage.
  3. Increased Concentrations of Intracellular Solutes:

    • As water is removed from the cells, the concentration of solutes (such as proteins and electrolytes) increases, which can disrupt cellular function.
  4. Formation of Ice Crystals:

    • Both intracellular and extracellular ice crystals form during the freezing process. The formation of these crystals can puncture cell membranes and disrupt cellular integrity, leading to cell death.

Cryosurgery Apparatus

The equipment used in cryosurgery typically includes:

  1. Storage Bottles for Pressurized Liquid Gases:

    • Liquid Nitrogen: Provides extremely low temperatures of approximately -196°C, making it highly effective for cryosurgery.
    • Liquid Carbon Dioxide or Nitrous Oxide: These gases provide temperatures ranging from -20°C to -90°C, which can also be used for various applications.
  2. Pressure and Temperature Gauge:

    • This gauge is essential for monitoring the pressure and temperature of the cryogenic gases to ensure safe and effective application.
  3. Probe with Tubing:

    • A specialized probe is used to direct the pressurized gas to the targeted tissues, allowing for precise application of the freezing effect.

Treatment Parameters

  • Time and Temperature: The specific time and temperature used during cryosurgery depend on the depth and extent of the tumor being treated. The clinician must carefully assess these factors to achieve optimal results while minimizing damage to surrounding healthy tissues.

Applications

Cryosurgery is applied in the treatment of various conditions, including:

  • Malignancies: Used to destroy cancerous tissues in various organs.
  • Vascular Tumors: Effective in treating tumors that have a significant blood supply.
  • Aggressive Tumors: Such as ameloblastoma, where rapid and effective tissue destruction is necessary.

Dry Socket (Alveolar Osteitis)

Dry socket, also known as alveolar osteitis, is a common complication that can occur after tooth extraction, particularly after the removal of mandibular molars. It is characterized by delayed postoperative pain due to the loss of the blood clot that normally forms in the extraction socket.

Key Features

  1. Pathophysiology:

    • After a tooth extraction, a blood clot forms in the socket, which is essential for healing. In dry socket, this clot is either dislodged or dissolves prematurely, exposing the underlying bone and nerve endings.
    • The initial appearance of the clot may be dirty gray, and as it disintegrates, the socket may appear gray or grayish-yellow, indicating the presence of bare bone without granulation tissue.
  2. Symptoms:

    • Symptoms of dry socket typically begin 3 to 5 days after the extraction. Patients may experience:
      • Severe pain in the extraction site that can radiate to the ear, eye, or neck.
      • A foul taste or odor in the mouth due to necrotic tissue.
      • Visible empty socket with exposed bone.
  3. Local Therapy:

    • Management of dry socket involves local treatment to alleviate pain and promote healing:
      • Irrigation: The socket is irrigated with a warm sterile isotonic saline solution or a dilute solution of hydrogen peroxide to remove necrotic material and debris.
      • Application of Medications: After irrigation, an obtundent (pain-relieving) agent or a topical anesthetic may be applied to the socket to provide symptomatic relief.
  4. Prevention:

    • To reduce the risk of developing dry socket, patients are often advised to:
      • Avoid smoking and using straws for a few days post-extraction, as these can dislodge the clot.
      • Follow postoperative care instructions provided by the dentist or oral surgeon.

Champy Technique of Fracture Stabilization

The Champy technique, developed by Champy et al. in the mid-1970s, is a method of fracture stabilization that utilizes non-compression monocortical miniplates applied as tension bands. This technique is particularly relevant in the context of mandibular fractures and is based on biomechanical principles that optimize the stability and healing of the bone.

Key Principles of the Champy Technique

  1. Biomechanical Considerations:

    • Tensile and Compressive Stresses: Biomechanical studies have shown that tensile stresses occur in the upper border of the mandible, while compressive stresses are found in the lower border. This understanding is crucial for the placement of plates.
    • Bending and Torsional Forces: The forces acting on the mandible primarily produce bending movements. In the symphysis and parasymphysis regions, torsional forces are more significant than bending moments.
  2. Ideal Osteosynthesis Line:

    • Champy et al. established the "ideal osteosynthesis line" at the base of the alveolar process. This line is critical for the effective placement of plates to ensure stability during the healing process.
    • Plate Placement:
      • Anterior Region: In the area between the mental foramina, a subapical plate is placed, and an additional plate is positioned near the lower border of the mandible to counteract torsional forces.
      • Posterior Region: Behind the mental foramen, the plate is applied just below the dental roots and above the inferior alveolar nerve.
      • Angle of Mandible: The plate is placed on the broad surface of the external oblique ridge.
  3. Tension Band Principle:

    • The use of miniplates as tension bands allows for the distribution of forces across the fracture site, enhancing stability and promoting healing.

Treatment Steps

  1. Reduction:

    • The first step in fracture treatment is the accurate reduction of the fracture fragments to restore normal anatomy.
  2. Stabilization:

    • Following reduction, stabilization is achieved using the Champy technique, which involves the application of miniplates in accordance with the biomechanical principles outlined above.
  3. Maxillomandibular Fixation (MMF):

    • MMF is often used as a standard method for both reduction and stabilization, particularly in cases where additional support is needed.
  4. External Fixation:

    • In cases of atrophic edentulous mandibular fractures, extensive soft tissue injuries, severe communication, or infected fractures, external fixation may be considered.

Classification of Internal Fixation Techniques

  • Absolute Stability:

    • Rigid internal fixation methods, such as compression plates, lag screws, and the tension band principle, fall under this category. These techniques provide strong stabilization but may compromise blood supply to the bone.
  • Relative Stability:

    • Techniques such as bridging, biologic (flexible) fixation, and the Champy technique are classified as relative stability methods. These techniques allow for some movement at the fracture site, which can promote healing by maintaining blood supply to the cortical bone.

Biologic Fixation

  • New Paradigm:
    • Biologic fixation represents a shift in fracture treatment philosophy, emphasizing that absolute stability is not always beneficial. Allowing for some movement at the fracture site can enhance blood supply and promote healing.
  • Improved Blood Supply:
    • Not pressing the plate against the bone helps maintain blood supply to the cortical bone and prevents the formation of early temporary porosity, which can be detrimental to healing.

Ludwig's Angina

Ludwig's angina is a serious, potentially life-threatening cellulitis or connective tissue infection of the submandibular space. It is characterized by bilateral swelling of the submandibular and sublingual areas, which can lead to airway obstruction. The condition is named after the German physician Wilhelm Friedrich Ludwig, who provided a classic description of the disease in the early 19th century.

Historical Background

  • Coining of the Term: The term "Ludwig's angina" was first coined by Camerer in 1837, who presented cases that included a classic description of the condition. The name honors W.F. Ludwig, who had described the features of the disease in the previous year.

  • Etymology:

    • The word "angina" is derived from the Latin word "angere," which means "to suffocate" or "to choke." This reflects the potential for airway compromise associated with the condition.
    • The name "Ludwig" recognizes the contributions of Wilhelm Friedrich Ludwig to the understanding of this medical entity.
  • Ludwig's Personal Connection: Interestingly, Ludwig himself died of throat inflammation in 1865, which underscores the severity of infections in the head and neck region.

Clinical Features

Ludwig's angina typically presents with the following features:

  1. Bilateral Swelling: The most characteristic sign is bilateral swelling of the submandibular area, which can extend to the sublingual space. This swelling may cause the floor of the mouth to elevate.

  2. Pain and Tenderness: Patients often experience pain and tenderness in the affected area, which may worsen with movement or swallowing.

  3. Dysphagia and Dysarthria: Difficulty swallowing (dysphagia) and changes in speech (dysarthria) may occur due to swelling and discomfort.

  4. Airway Compromise: As the swelling progresses, there is a risk of airway obstruction, which can be life-threatening. Patients may exhibit signs of respiratory distress.

  5. Systemic Symptoms: Fever, malaise, and other systemic signs of infection may be present.

Etiology

Ludwig's angina is most commonly caused by infections that originate from the teeth, particularly the second or third molars. The infection can spread from dental abscesses or periodontal disease into the submandibular space. The most common pathogens include:

  • Streptococcus species
  • Staphylococcus aureus
  • Anaerobic bacteria

Diagnosis and Management

  • Diagnosis: Diagnosis is primarily clinical, based on the characteristic signs and symptoms. Imaging studies, such as CT scans, may be used to assess the extent of the infection and to rule out other conditions.

  • Management:

    • Airway Management: Ensuring a patent airway is the top priority, especially if there are signs of respiratory distress.
    • Antibiotic Therapy: Broad-spectrum intravenous antibiotics are initiated to target the likely pathogens.
    • Surgical Intervention: In cases of significant swelling or abscess formation, surgical drainage may be necessary to relieve pressure and remove infected material.

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

  1. 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.
  2. 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.
  3. 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.
  4. 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.
  5. 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.
  6. 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.

 

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