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

Transoral Lithotomy: Procedure for Submandibular Duct Stone Removal

Transoral lithotomy is a surgical technique used to remove stones (calculi) from the submandibular duct (Wharton's duct). This procedure is typically performed under local anesthesia and is effective for addressing sialolithiasis (the presence of stones in the salivary glands).

Procedure

  1. Preoperative Preparation:

    • Radiographic Assessment: The exact location of the stone is determined using imaging studies, such as X-rays or ultrasound, to guide the surgical approach.
    • Local Anesthesia: The procedure is performed under local anesthesia to minimize discomfort for the patient.
  2. Surgical Technique:

    • Suture Placement: A suture is placed behind the stone to prevent it from moving backward during the procedure, facilitating easier access.
    • Incision: An incision is made in the mucosa of the floor of the mouth, parallel to the duct. Care is taken to avoid injury to surrounding structures, including:
      • Lingual Nerve: Responsible for sensory innervation to the tongue.
      • Submandibular Gland: The gland itself should be preserved to maintain salivary function.
  3. Blunt Dissection:

    • After making the incision, blunt dissection is performed to carefully displace the surrounding tissue and expose the duct.
  4. Identifying the Duct:

    • The submandibular duct is located, and the segment of the duct that contains the stone is identified.
  5. Stone Removal:

    • A longitudinal incision is made over the stone within the duct. The stone is then extracted using small forceps. Care is taken to ensure complete removal to prevent recurrence.
  6. Postoperative Considerations:

    • After the stone is removed, the incision may be closed with sutures, and the area is monitored for any signs of complications.

Complications

  • Bacterial Sialadenitis: If there is a secondary infection following the procedure, it can lead to bacterial sialadenitis, which is an inflammation of the salivary gland due to infection. Symptoms may include pain, swelling, and purulent discharge from the duct.

Hockey Stick or London Hospital Elevator

The Hockey Stick Elevator, also known as the London Hospital Elevator, is a dental instrument used primarily in oral surgery and tooth extraction procedures. It is designed to facilitate the removal of tooth roots and other dental structures.

Design and Features

  • Blade Shape: The Hockey Stick Elevator features a straight blade that is angled relative to the shank, similar to the Cryer’s elevator. However, unlike the Cryer’s elevator, which has a triangular blade, the Hockey Stick Elevator has a straight blade with a convex surface on one side and a flat surface on the other.

  • Working Surface:

    • The flat surface of the blade is the working surface and is equipped with transverse serrations. These serrations enhance the instrument's grip and contact with the root stump, allowing for more effective leverage during extraction.
  • Appearance: The instrument resembles a hockey stick, which is how it derives its name. The distinctive shape aids in its identification and use in clinical settings.

Principles of Operation

  • Lever and Wedge Principle:
    • The Hockey Stick Elevator operates on the same principles as the Cryer’s elevator, utilizing the lever and wedge principle. This means that the instrument can be used to apply force to the tooth or root, effectively loosening it from the surrounding bone and periodontal ligament.
  • Functionality:
    • The primary function of the Hockey Stick Elevator is to elevate and luxate teeth or root fragments during extraction procedures. It can be particularly useful in cases where the tooth is impacted or has a curved root.

Basic Airway Management

Head Positioning

  • Head tilt-chin lift: Standard maneuver
  • Jaw thrust: When cervical spine injury suspected
  • Sniffing position: Optimal for intubation

Bag-Mask Ventilation

  • Two-person technique: Often more effective
  • Seal: C-E grip for mask seal
  • Ventilation: Gentle, avoid gastric insufflation
  • Adjuncts: Oropharyngeal/nasopharyngeal airways

Advanced Airway Management

Laryngeal Mask Airway (LMA)

  • Indications: Bridge device, difficult intubation
  • Insertion: Blind technique, high success rate
  • Advantages: Easier than intubation, seals airway
  • Limitations: Doesn't protect against aspiration

Endotracheal Intubation

  • Gold standard: Definitive airway protection
  • Technique: Direct laryngoscopy or video laryngoscopy
  • Confirmation: Capnography, bilateral breath sounds
  • Complications: Esophageal intubation, aspiration

Difficult Airway Algorithm

Prediction

  • Mallampati score: Visibility of oral structures
  • Neck mobility: Range of motion assessment
  • Jaw opening: Interincisal distance
  • History: Previous difficult intubation

Management Steps

  1. Preparation: Equipment check, team briefing
  2. Positioning: Optimize head/neck position
  3. Pre-oxygenation: 100% oxygen for 3-5 minutes
  4. Attempt: Limit to 3 attempts maximum
  5. Fallback: LMA or emergency surgical airway

Hemostatic Agents

Hemostatic agents are critical in surgical procedures to control bleeding and promote wound healing. Various materials are used, each with unique properties and mechanisms of action. Below is a detailed overview of some commonly used hemostatic agents, including Gelfoam, Oxycel, Surgical (Oxycellulose), and Fibrin Glue.

1. Gelfoam

  • Composition: Gelfoam is made from gelatin and has a sponge-like structure.

  • Mechanism of Action:

    • Gelfoam does not have intrinsic hemostatic properties; its hemostatic effect is primarily due to its large surface area, which comes into contact with blood.
    • When Gelfoam absorbs blood, it swells and exerts pressure on the bleeding site, providing a scaffold for the formation of a fibrin network.
  • Application:

    • Gelfoam should be moistened in saline or thrombin solution before application to ensure optimal performance. It is essential to remove all air from the interstices to maximize its effectiveness.
  • Absorption: Gelfoam is absorbed by the body through phagocytosis, typically within a few weeks.

2. Oxycel

  • Composition: Oxycel is made from oxidized cellulose.

  • Mechanism of Action:

    • Upon application, Oxycel releases cellulosic acid, which has a strong affinity for hemoglobin, leading to the formation of an artificial clot.
    • The acid produced during the wetting process can inactivate thrombin and other hemostatic agents, which is why Oxycel should be applied dry.
  • Limitations:

    • The acid produced can inhibit epithelialization, making Oxycel unsuitable for use over epithelial surfaces.

3. Surgical (Oxycellulose)

  • Composition: Surgical is a glucose polymer-based sterile knitted fabric created through the controlled oxidation of regenerated cellulose.

  • Mechanism of Action:

    • The local hemostatic mechanism relies on the binding of hemoglobin to oxycellulose, allowing the dressing to expand into a gelatinous mass. This mass acts as a scaffold for clot formation and stabilization.
  • Application:

    • Surgical can be applied dry or soaked in thrombin solution, providing flexibility in its use.
  • Absorption: It is removed by liquefaction and phagocytosis over a period of one week to one month. Unlike Oxycel, Surgical does not inhibit epithelialization and can be used over epithelial surfaces.

4. Fibrin Glue

  • Composition: Fibrin glue is a biological adhesive that contains thrombin, fibrinogen, factor XIII, and aprotinin.

  • Mechanism of Action:

    • Thrombin converts fibrinogen into an unstable fibrin clot, while factor XIII stabilizes the clot. Aprotinin prevents the degradation of the clot.
    • During wound healing, fibroblasts migrate through the fibrin meshwork, forming a more permanent framework composed of collagen fibers.
  • Applications:

    • Fibrin glue is used in various surgical procedures to promote hemostasis and facilitate tissue adhesion. It is particularly useful in areas where traditional sutures may be challenging to apply.

Ridge Augmentation Procedures

Ridge augmentation procedures are surgical techniques used to increase the volume and density of the alveolar ridge in the maxilla and mandible. These procedures are often necessary to prepare the site for dental implants, especially in cases where there has been significant bone loss due to factors such as tooth extraction, periodontal disease, or trauma. Ridge augmentation can also be performed in conjunction with orthognathic surgery to enhance the overall facial structure and support dental rehabilitation.

Indications for Ridge Augmentation

  • Insufficient Bone Volume: To provide adequate support for dental implants.
  • Bone Resorption: Following tooth extraction or due to periodontal disease.
  • Facial Aesthetics: To improve the contour of the jaw and facial profile.
  • Orthognathic Surgery: To enhance the results of jaw repositioning procedures.

Types of Graft Materials Used

Ridge augmentation can be performed using various graft materials, which can be classified into the following categories:

  1. Autografts:

    • Bone harvested from the patient’s own body, typically from intraoral sites (e.g., chin, ramus) or extraoral sites (e.g., iliac crest).
    • Advantages: High biocompatibility, osteogenic potential, and lower risk of rejection or infection.
    • Disadvantages: Additional surgical site, potential for increased morbidity, and limited availability.
  2. Allografts:

    • Bone grafts obtained from a human donor (cadaveric bone) that have been processed and sterilized.
    • Advantages: No additional surgical site required, readily available, and can provide a scaffold for new bone growth.
    • Disadvantages: Risk of disease transmission and potential for immune response.
  3. Xenografts:

    •  Bone grafts derived from a different species, commonly bovine (cow) bone.
    • Advantages: Biocompatible and provides a scaffold for bone regeneration.
    • Disadvantages: Potential for immune response and slower resorption compared to autografts.
  4. Alloplasts:

    •  Synthetic materials used for bone augmentation, such as hydroxyapatite, calcium phosphate, or bioactive glass.
    • Advantages: No risk of disease transmission, customizable, and can be designed to promote bone growth.
    • Disadvantages: May not integrate as well as natural bone and can have variable resorption rates.

Surgical Techniques

  1. Bone Grafting:

    • The selected graft material is placed in the deficient area of the ridge to promote new bone formation. This can be done using various techniques, including:
      • Onlay Grafting: Graft material is placed on top of the existing ridge.
      • Inlay Grafting: Graft material is placed within the ridge.
  2. Guided Bone Regeneration (GBR):

    • A barrier membrane is placed over the graft material to prevent soft tissue infiltration and promote bone healing. This technique is often used in conjunction with grafting.
  3. Sinus Lift:

    • In the maxilla, a sinus lift procedure may be performed to augment the bone in the posterior maxilla by elevating the sinus membrane and placing graft material.
  4. Combination with Orthognathic Surgery:

    • Ridge augmentation can be performed simultaneously with orthognathic surgery to correct skeletal discrepancies and enhance the overall facial structure.

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.

Sunderland Classification (5 Grades)

More detailed anatomical classification based on specific nerve structure damage:

Grade I (Neurapraxia)

  • Damage: Myelin sheath only
  • Structures intact: Axon, endoneurium, perineurium, epineurium
  • Recovery: Complete, 2-12 weeks
  • Treatment: Observation

Grade II (Axonotmesis - Mild)

  • Damage: Axon disrupted
  • Structures intact: Endoneurium, perineurium, epineurium
  • Recovery: Complete regeneration along intact tubes
  • Timeline: 2-12 months
  • Treatment: Observation, supportive care

Grade III (Axonotmesis - Moderate)

  • Damage: Axon + endoneurium disrupted
  • Structures intact: Perineurium, epineurium
  • Recovery: Incomplete, misdirected regeneration possible
  • Timeline: 6-18 months
  • Treatment: May require surgical exploration

Grade IV (Axonotmesis - Severe)

  • Damage: Axon + endoneurium + perineurium disrupted
  • Structures intact: Epineurium only
  • Recovery: Poor, significant misdirection
  • Timeline: Limited recovery over 1-2 years
  • Treatment: Usually requires surgical repair

Grade V (Neurotmesis)

  • Damage: Complete transection of all structures
  • Recovery: None without surgical intervention
  • Treatment: Mandatory surgical repair/reconstruction

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