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Oral and Maxillofacial Surgery

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.

 Differences between Cellulitis and Abscess

1. Duration

  • Cellulitis: Typically presents in the acute phase, meaning it develops quickly, often within hours to days. It can arise from a break in the skin, such as a cut or insect bite, leading to a rapid inflammatory response.
  • Abscess: Often represents a chronic phase of infection. An abscess may develop over time as the body attempts to contain an infection, leading to the formation of a localized pocket of pus.

2. Pain

  • Cellulitis: The pain is usually severe and generalized, affecting a larger area of the skin and subcutaneous tissue. Patients may describe a feeling of tightness or swelling in the affected area.
  • Abscess: Pain is localized to the site of the abscess and is often more intense. The pain may be throbbing and can worsen with movement or pressure on the area.

3. Localization

  • Cellulitis: The infection has diffuse borders, meaning it spreads through the tissue without a clear boundary. This can make it difficult to determine the exact extent of the infection.
  • Abscess: The infection is well-circumscribed, meaning it has a defined boundary. The body forms a capsule around the abscess, which helps to contain the infection.

4. Palpation

  • Cellulitis: On examination, the affected area may feel doughy or indurated (hardened) due to swelling and inflammation. There is no distinct fluctuation, as there is no localized collection of pus.
  • Abscess: When palpated, an abscess feels fluctuant, indicating the presence of pus. This fluctuation is a key clinical sign that helps differentiate an abscess from cellulitis.

5. Bacteria

  • Cellulitis: Primarily caused by aerobic bacteria, such as Streptococcus and Staphylococcus species. These bacteria thrive in the presence of oxygen and are commonly found on the skin.
  • Abscess: Often caused by anaerobic bacteria or a mixed flora, which can include both aerobic and anaerobic organisms. Anaerobic bacteria thrive in low-oxygen environments, which is typical in the center of an abscess.

6. Size

  • Cellulitis: Generally larger in area, as it involves a broader region of tissue. The swelling can extend beyond the initial site of infection.
  • Abscess: Typically smaller and localized to the area of the abscess. The size can vary, but it is usually confined to a specific area.

7. Presence of Pus

  • Cellulitis: No pus is present; the infection is diffuse and does not form a localized collection of pus. The inflammatory response leads to swelling and redness but not to pus formation.
  • Abscess: Yes, pus is present; the abscess is characterized by a collection of pus within a cavity. The pus is a result of the body’s immune response to the infection.

8. Degree of Seriousness

  • Cellulitis: Generally considered more serious due to the potential for systemic spread and complications if untreated. It can lead to sepsis, especially in immunocompromised individuals.
  • Abscess: While abscesses can also be serious, they are often more contained. They can usually be treated effectively with drainage, and the localized nature of the infection can make management more straightforward.

Clinical Significance

  • Diagnosis: Differentiating between cellulitis and abscess is crucial for appropriate treatment. Cellulitis may require systemic antibiotics, while an abscess often requires drainage.
  • Management:
    • Cellulitis: Treatment typically involves antibiotics and monitoring for systemic symptoms. In severe cases, hospitalization may be necessary.
    • Abscess: Treatment usually involves incision and drainage (I&D) to remove the pus, along with antibiotics if there is a risk of systemic infection.

Vestibuloplasty

Vestibuloplasty is a surgical procedure aimed at deepening the vestibule of the oral cavity, which is the space between the gums and the inner lining of the lips and cheeks. This procedure is particularly important in prosthodontics and oral surgery, as it can enhance the retention and stability of dentures by increasing the available denture-bearing area.

Types of Vestibuloplasty

  1. Vestibuloplasty (Sulcoplasty or Sulcus Deepening Procedure):

    • This procedure involves deepening the vestibule without the addition of bone. It is primarily focused on modifying the soft tissue to create a more favorable environment for denture placement.
    • Indications:
      • Patients with shallow vestibules that may compromise denture retention.
      • Patients requiring improved aesthetics and function of their prostheses.
    • Technique:
      • The procedure typically involves the excision of the mucosa and submucosal tissue to create a deeper vestibule.
      • The soft tissue is then repositioned to allow for a deeper sulcus, enhancing the area available for denture support.
  2. Labial Vestibular Procedure (Transpositional Flap Vestibuloplasty or Lip Switch Procedure):

    • This specific type of vestibuloplasty involves the transposition of soft tissue from the inner aspect of the lip to a more favorable position on the alveolar bone.
    • Indications:
      • Patients with inadequate vestibular depth who require additional soft tissue coverage for denture support.
      • Cases where the labial vestibule is shallow, affecting the retention of dentures.
    • Technique:
      • A flap is created from the inner lip, which is then mobilized and repositioned to cover the alveolar ridge.
      • This procedure increases the denture-bearing area by utilizing the soft tissue from the lip, thereby enhancing the retention and stability of the denture.
      • The flap is sutured into place, and the healing process allows for the integration of the new tissue position.

Benefits of Vestibuloplasty

  • Increased Denture Retention: By deepening the vestibule and increasing the denture-bearing area, patients often experience improved retention and stability of their dentures.
  • Enhanced Aesthetics: The procedure can improve the overall appearance of the oral cavity, contributing to better facial aesthetics.
  • Improved Function: Patients may find it easier to eat and speak with well-retained dentures, leading to improved quality of life.

Considerations and Postoperative Care

  • Healing Time: Patients should be informed about the expected healing time and the importance of following postoperative care instructions to ensure proper healing.
  • Follow-Up: Regular follow-up appointments may be necessary to monitor healing and assess the need for any adjustments to the dentures.
  • Potential Complications: As with any surgical procedure, there are risks involved, including infection, bleeding, and inadequate healing. Proper surgical technique and postoperative care can help mitigate these risks.

Classes of Hemorrhagic Shock (ATLS Classification)

Hemorrhagic shock is a critical condition resulting from significant blood loss, leading to inadequate tissue perfusion and oxygenation. The Advanced Trauma Life Support (ATLS) course classifies hemorrhagic shock into four classes based on various physiological parameters. Understanding these classes helps guide the management and treatment of patients experiencing hemorrhagic shock.

Class Descriptions

  1. Class I Hemorrhagic Shock:

    • Blood Loss: 0-15% (up to 750 mL)
    • CNS Status: Slightly anxious; the patient may be alert and oriented.
    • Pulse: Heart rate <100 beats/min.
    • Blood Pressure: Normal.
    • Pulse Pressure: Normal.
    • Respiratory Rate: 14-20 breaths/min.
    • Urine Output: >30 mL/hr, indicating adequate renal perfusion.
    • Fluid Resuscitation: Crystalloid fluids are typically sufficient.
  2. Class II Hemorrhagic Shock:

    • Blood Loss: 15-30% (750-1500 mL)
    • CNS Status: Mildly anxious; the patient may show signs of distress.
    • Pulse: Heart rate >100 beats/min.
    • Blood Pressure: Still normal, but compensatory mechanisms are activated.
    • Pulse Pressure: Decreased due to increased heart rate and peripheral vasoconstriction.
    • Respiratory Rate: 20-30 breaths/min.
    • Urine Output: 20-30 mL/hr, indicating reduced renal perfusion.
    • Fluid Resuscitation: Crystalloid fluids are still appropriate.
  3. Class III Hemorrhagic Shock:

    • Blood Loss: 30-40% (1500-2000 mL)
    • CNS Status: Anxious or confused; the patient may have altered mental status.
    • Pulse: Heart rate >120 beats/min.
    • Blood Pressure: Decreased; signs of hypotension may be present.
    • Pulse Pressure: Decreased.
    • Respiratory Rate: 30-40 breaths/min.
    • Urine Output: 5-15 mL/hr, indicating significant renal impairment.
    • Fluid Resuscitation: Crystalloid fluids plus blood products may be necessary.
  4. Class IV Hemorrhagic Shock:

    • Blood Loss: >40% (>2000 mL)
    • CNS Status: Confused or lethargic; the patient may be unresponsive.
    • Pulse: Heart rate >140 beats/min.
    • Blood Pressure: Decreased; severe hypotension is likely.
    • Pulse Pressure: Decreased.
    • Respiratory Rate: >35 breaths/min.
    • Urine Output: Negligible, indicating severe renal failure.
    • Fluid Resuscitation: Immediate crystalloid and blood products are critical.

Odontogenic Keratocyst (OKC)

The odontogenic keratocyst (OKC) is a unique and aggressive cystic lesion of the jaw with distinct histological features and a high recurrence rate. Below is a comprehensive overview of its characteristics, treatment options, and prognosis.

Characteristics of Odontogenic Keratocyst

  1. Definition and Origin:

    • The term "odontogenic keratocyst" was first introduced by Philipsen in 1956. It is believed to originate from remnants of the dental lamina or basal cells of the oral epithelium.
  2. Biological Behavior:

    • OKCs exhibit aggressive behavior and have a recurrence rate of 13% to 60%. They are considered to have a neoplastic nature rather than a purely developmental origin.
  3. Histological Features:

    • The cyst lining is typically 6 to 10 cells thick, with a palisaded basal cell layer and a surface of corrugated parakeratin.
    • The epithelium may produce orthokeratin (10%), parakeratin (83%), or both (7%).
    • No rete ridges are present, and mitotic activity is frequent, contributing to the cyst's growth pattern.
  4. Types:

    • Orthokeratinized OKC: Less aggressive, lower recurrence rate, often associated with dentigerous cysts.
    • Parakeratinized OKC: More aggressive with a higher recurrence rate.
  5. Clinical Features:

    • Age: Peak incidence occurs in individuals aged 20 to 30 years.
    • Gender: Predilection for males (approximately 1:5 male to female ratio).
    • Location: More commonly found in the mandible, particularly in the ramus and third molar area. In the maxilla, the third molar area is also a common site.
    • Symptoms: Patients may be asymptomatic, but symptoms can include pain, soft-tissue swelling, drainage, and paresthesia of the lip or teeth.
  6. Radiographic Features:

    • Typically appears as a unilocular lesion with a well-defined peripheral rim, although multilocular varieties (20%) can occur.
    • Scalloping of the borders is often present, and it may be associated with the crown of a retained tooth (40%).

Treatment Options for Odontogenic Keratocyst

  1. Surgical Excision:

    • Enucleation: Complete removal of the cyst along with the surrounding tissue.
    • Curettage: Scraping of the cyst lining after enucleation to remove any residual cystic tissue.
  2. Chemical Cauterization:

    • Carnoy’s Solution: Application of Carnoy’s solution (6 ml absolute alcohol, 3 ml chloroform, and 1 ml acetic acid) after enucleation and curettage can help reduce recurrence rates. It penetrates the bone and can assist in freeing the cyst from the bone wall.
  3. Marsupialization:

    • This technique involves creating a window in the cyst to allow for drainage and reduction in size, which can be beneficial in larger cysts or in cases where complete excision is not feasible.
  4. Primary Closure:

    • After enucleation and curettage, the site may be closed primarily or packed open to allow for healing.
  5. Follow-Up:

    • Regular follow-up is essential due to the high recurrence rate. Patients should be monitored for signs of recurrence, especially in the first few years post-treatment.

Prognosis

  • The prognosis for OKC is variable, with a significant recurrence rate attributed to the aggressive nature of the lesion and the potential for residual cystic tissue.
  • Recurrence is not necessarily related to the size of the cyst or the presence of satellite cysts but is influenced by the nature of the lesion itself and the presence of dental lamina remnants.
  • Multilocular lesions tend to have a higher recurrence rate compared to unilocular ones.
  • Surgical technique does not significantly influence the likelihood of relapse.

Associated Conditions

  • Multiple OKCs can be seen in syndromes such as:
    • Nevoid Basal Cell Carcinoma Syndrome (Gorlin-Goltz Syndrome)
    • Marfan Syndrome
    • Ehlers-Danlos Syndrome
    • Noonan Syndrome

Management of Septic Shock

Septic shock is a life-threatening condition characterized by severe infection leading to systemic inflammation, vasodilation, and impaired tissue perfusion. Effective management is crucial to improve outcomes and reduce mortality. The management of septic shock should be based on several key principles:

Key Principles of Management

  1. Early and Effective Volume Replacement:

    • Fluid Resuscitation: Initiate aggressive fluid resuscitation with crystalloids (e.g., normal saline or lactated Ringer's solution) to restore intravascular volume and improve circulation.
    • Goal: Aim for a rapid infusion of 30 mL/kg of crystalloid fluids within the first 3 hours of recognition of septic shock.
  2. Restoration of Tissue Perfusion:

    • Monitoring: Continuous monitoring of vital signs, urine output, and laboratory parameters to assess the effectiveness of resuscitation.
    • Target Blood Pressure: In most patients, a systolic blood pressure of 90 to 100 mm Hg or a mean arterial pressure (MAP) of 70 to 75 mm Hg is considered acceptable.
  3. Adequate Oxygen Supply to Cells:

    • Oxygen Delivery: Ensure adequate oxygen delivery to tissues by maintaining hemoglobin saturation (SaO2) above 95% and arterial oxygen tension (PaO2) above 60 mm Hg.
    • Hematocrit: Maintain hematocrit levels above 30% to ensure sufficient oxygen-carrying capacity.
  4. Control of Infection:

    • Antibiotic Therapy: Administer broad-spectrum antibiotics as soon as possible, ideally within the first hour of recognizing septic shock. Adjust based on culture results and sensitivity.
    • Source Control: Identify and control the source of infection (e.g., drainage of abscesses, removal of infected devices).

Pharmacological Management

  1. Vasopressor Therapy:

    • Indication: If hypotension persists despite adequate fluid resuscitation, vasopressors are required to increase arterial pressure.
    • First-Line Agents:
      • Dopamine: Often the first choice due to its ability to maintain organ blood flow, particularly to the kidneys and mesenteric circulation. Typical dosing is 20 to 25 micrograms/kg/min.
      • Noradrenaline (Norepinephrine): Should be added if hypotension persists despite dopamine administration. It is the preferred vasopressor for septic shock due to its potent vasoconstrictive properties.
  2. Cardiac Output and Myocardial Function:

    • Dobutamine: If myocardial depression is suspected (e.g., low cardiac output despite adequate blood pressure), dobutamine can be added to improve cardiac output without significantly increasing arterial pressure. This helps restore oxygen delivery to tissues.
    • Monitoring: Continuous monitoring of cardiac output and systemic vascular resistance is essential to assess the effectiveness of treatment.

Additional Considerations

  • Supportive Care: Provide supportive care, including mechanical ventilation if necessary, and monitor for complications such as acute respiratory distress syndrome (ARDS) or acute kidney injury (AKI).
  • Nutritional Support: Early enteral nutrition should be initiated as soon as feasible to support metabolic needs and improve outcomes.
  • Reassessment: Regularly reassess the patient's hemodynamic status and adjust fluid and medication therapy accordingly.

Rigid Fixation

Rigid fixation is a surgical technique used to stabilize fractured bones.

Types of Rigid Fixation

Rigid fixation can be achieved using various types of plates and devices, including:

  1. Simple Non-Compression Bone Plates:

    • These plates provide stability without applying compressive forces across the fracture site.
  2. Mini Bone Plates:

    • Smaller plates designed for use in areas where space is limited, providing adequate stabilization for smaller fractures.
  3. Compression Plates:

    • These plates apply compressive forces across the fracture site, promoting bone healing by encouraging contact between the fracture fragments.
  4. Reconstruction Plates:

    • Used for complex fractures or reconstructions, these plates can be contoured to fit the specific anatomy of the fractured bone.

Transosseous Wiring (Intraosseous Wiring)

Transosseous wiring is a traditional and effective method for the fixation of jaw bone fractures. It involves the following steps:

  1. Technique:

    • Holes are drilled in the bony fragments on either side of the fracture line.
    • A length of 26-gauge stainless steel wire is passed through the holes and across the fracture.
  2. Reduction:

    • The fracture must be reduced independently, ensuring that the teeth are in occlusion before securing the wire.
  3. Twisting the Wire:

    • After achieving proper alignment, the free ends of the wire are twisted to secure the fracture.
    • The twisted ends are cut short and tucked into the nearest drill hole to prevent irritation to surrounding tissues.
  4. Variations:

    • The single strand wire fixation in a horizontal manner is the simplest form of intraosseous wiring, but it can be modified in various ways depending on the specific needs of the fracture and the patient.

Other fixation techniques

Open reduction and internal fixation (ORIF):
Surgical exposure of the fracture site, followed by reduction and fixation with plates, screws, or nails

Closed reduction and immobilization (CRII):
Manipulation of the bone fragments into alignment without surgical exposure, followed by cast or splint immobilization

Intramedullary nailing:
Insertion of a metal rod (nail) into the medullary canal of the bone to stabilize long bone fractures

External fixation:
A device with pins inserted through the bone fragments and connected to an external frame to provide stability
 
Tension band wiring:
A technique using wires to apply tension across a fracture site, particularly useful for avulsion fractures

 

 

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