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📖 Oral and Maxillofacial Surgery

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Basic Principles of Treatment of a Fracture
Oral and Maxillofacial Surgery

Basic Principles of Treatment of a Fracture

The treatment of fractures involves a systematic approach to restore the normal anatomy and function of the affected bone. The basic principles of fracture treatment can be summarized in three key steps: reduction, fixation, and immobilization.

1. Reduction

Definition: Reduction is the process of restoring the fractured bone fragments to their original anatomical position.

  • Methods of Reduction:

    • Closed Reduction: This technique involves realigning the bone fragments without direct visualization of the fracture line. It can be achieved through:
      • Reduction by Manipulation: The physician uses manual techniques to manipulate the bone fragments into alignment.
      • Reduction by Traction: Gentle pulling forces are applied to align the fragments, often used in conjunction with other methods.

  • Open Reduction: In some cases, if closed reduction is not successful or if the fracture is complex, an open reduction may be necessary. This involves surgical exposure of the fracture site to directly visualize and align the fragments.

2. Fixation

Definition: After reduction, fixation is the process of stabilizing the fractured fragments in their normal anatomical relationship to prevent displacement and ensure proper healing.

  • Types of Fixation:

    • Internal Fixation: This involves the use of devices such as plates, screws, or intramedullary nails that are placed inside the body to stabilize the fracture.
    • External Fixation: This method uses external devices, such as pins or frames, that are attached to the bone through the skin. External fixation is often used in cases of open fractures or when internal fixation is not feasible.

  • Goals of Fixation: The primary goals are to maintain the alignment of the bone fragments, prevent movement at the fracture site, and facilitate healing.

3. Immobilization

Definition: Immobilization is the phase during which the fixation device is retained to stabilize the reduced fragments until clinical bony union occurs.

  • Duration of Immobilization: The length of the immobilization period varies depending on the type of fracture and the bone involved:

    • Maxillary Fractures: Typically require 3 to 4 weeks of immobilization.
    • Mandibular Fractures: Generally require 4 to 6 weeks of immobilization.
    • Condylar Fractures: Recommended immobilization period is 2 to 3 weeks to prevent temporomandibular joint (TMJ) ankylosis.

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Lines in Third Molar Assessment
Oral and Maxillofacial Surgery

Lines in Third Molar Assessment

In the context of third molar (wisdom tooth) assessment and extraction, several lines are used to evaluate the position and inclination of the tooth, as well as the amount of bone that may need to be removed during extraction. These lines provide valuable information for planning the surgical approach and predicting the difficulty of the extraction.

1. White Line

  • Description: The white line is a visual marker that runs over the occlusal surfaces of the first, second, and third molars.
  • Purpose: This line serves as an indicator of the axial inclination of the third molar. By assessing the position of the white line, clinicians can determine the orientation of the third molar in relation to the adjacent teeth and the overall dental arch.
  • Clinical Relevance: The inclination of the third molar can influence the complexity of the extraction procedure, as well as the potential for complications.

2. Amber Line

  • Description: The amber line is drawn from the bone distal to the third molar towards the interceptal bone between the first and second molars.
  • Purpose: This line helps to delineate which parts of the third molar are covered by bone and which parts are not. Specifically:
    • Above the Amber Line: Any part of the tooth above this line is not covered by bone.
    • Below the Amber Line: Any part of the tooth below this line is covered by bone.
  • Clinical Relevance: The amber line is particularly useful in the Pell and Gregory classification, which categorizes the position of the third molar based on its relationship to the surrounding structures and the amount of bone covering it.

3. Red Line (George Winter's Third Line)

  • Description: The red line is a perpendicular line drawn from the amber line to an imaginary line of application of an elevator. This imaginary line is positioned at the cement-enamel junction (CEJ) on the mesial aspect of the tooth, except in cases of disto-angular impaction, where it is at the distal CEJ.
  • Purpose: The red line indicates the amount of bone that must be removed before the elevation of the tooth can occur. It effectively represents the depth of the tooth in the bone.
  • Clinical Relevance: The length of the red line correlates with the difficulty of the extraction:
    • Longer Red Line: Indicates that more bone needs to be removed, suggesting a more difficult extraction.
    • Shorter Red Line: Suggests that less bone removal is necessary, indicating an easier extraction.
Management of Skin Loss in the Face
Oral and Maxillofacial Surgery

Management of Skin Loss in the Face

Skin loss in the face can be a challenging condition to manage, particularly when it involves critical areas such as the lips and eyelids. The initial assessment of skin loss may be misleading, as retraction of skin due to underlying muscle tension can create the appearance of tissue loss. However, when significant skin loss is present, it is essential to address the issue promptly and effectively to prevent complications and promote optimal healing.

Principles of Management

  1. Assessment Under Anesthesia: A thorough examination under anesthesia is necessary to accurately assess the extent of skin loss and plan the most suitable repair strategy.

  2. No Healing by Granulation: Unlike other areas of the body, wounds on the face should not be allowed to heal by granulation. This approach can lead to unacceptable scarring, contracture, and functional impairment.

  3. Repair Options: The following options are available for repairing skin loss in the face:

    • Skin Grafting: This involves transferring a piece of skin from a donor site to the affected area. Skin grafting can be used for small to moderate-sized defects.
    • Local Flaps: Local flaps involve transferring tissue from an adjacent area to the defect site. This approach is useful for larger defects and can provide better color and texture match.
    • Apposition of Skin to Mucosa: In some cases, it may be possible to appose skin to mucosa, particularly in areas where the skin and mucosa are closely approximated.

Types of skin grafts:

Split-thickness skin graft (STSG):The most common type, where only the epidermis and a thin layer of dermis are harvested.

Full-thickness skin graft (FTSG):Includes the entire thickness of the skin, typically used for smaller areas where cosmetic appearance is crucial.

Epidermal skin graft (ESG):Only the outermost layer of the epidermis is harvested, often used for smaller wounds.

Considerations for Repair

  1. Aesthetic Considerations: The face is a highly visible area, and any repair should aim to restore optimal aesthetic appearance. This may involve careful planning and execution of the repair to minimize scarring and ensure a natural-looking outcome.

  2. Functional Considerations: In addition to aesthetic concerns, functional considerations are also crucial. The repair should aim to restore normal function to the affected area, particularly in critical areas such as the lips and eyelids.

  3. Timing of Repair: The timing of repair is also important. In general, early repair is preferred to minimize the risk of complications and promote optimal healing.

Primary Bone Healing and Rigid Fixation
Oral and Maxillofacial Surgery

Primary Bone Healing and Rigid Fixation

Primary bone healing is a process that occurs when bony fragments are compressed against each other, allowing for direct healing without the formation of a callus. This type of healing is characterized by the migration of osteocytes across the fracture line and is facilitated by rigid fixation techniques. Below is a detailed overview of the concept of primary bone healing, the mechanisms involved, and examples of rigid fixation methods.

Concept of Compression

  • Compression of Bony Fragments: In primary bone healing, the bony fragments are tightly compressed against each other. This compression is crucial as it allows for the direct contact of the bone surfaces, which is necessary for the healing process.

  • Osteocyte Migration: Under conditions of compression, osteocytes (the bone cells responsible for maintaining bone tissue) can migrate across the fracture line. This migration is essential for the healing process, as it facilitates the integration of the bone fragments.

Characteristics of Primary Bone Healing

  • Absence of Callus Formation: Unlike secondary bone healing, which involves the formation of a callus (a soft tissue bridge that eventually hardens into bone), primary bone healing occurs without callus formation. This is due to the rigid fixation that prevents movement between the fragments.

  • Haversian Remodeling: The healing process in primary bone healing involves Haversian remodeling, where the bone is remodeled along the lines of stress. This process allows for the restoration of the bone's structural integrity and strength.

  • Requirements for Primary Healing:

    • Absolute Immobilization: Rigid fixation must provide sufficient stability to prevent any movement (interfragmentary mobility) between the osseous fragments during the healing period.
    • Minimal Gap: There should be minimal distance (gap) between the fragments to facilitate direct contact and healing.

Examples of Rigid Fixation in the Mandible

  1. Lag Screws: The use of two lag screws across a fracture provides strong compression and stability, allowing for primary bone healing.

  2. Bone Plates:

    • Reconstruction Bone Plates: These plates are applied with at least three screws on each side of the fracture to ensure adequate fixation and stability.
    • Compression Plates: A large compression plate can be used across the fracture to maintain rigid fixation and prevent movement.

  3. Proper Application: When these fixation methods are properly applied, they create a stable environment that is conducive to primary bone healing. The rigidity of the fixation prevents interfragmentary mobility, which is essential for the peculiar type of bone healing that occurs without callus formation.