• Poorly differentiated tumors: Highest malignancy
• Argon – beam coagulation: Controls bleeding <3 mm vessels
• Cryosurgery: Liquid nitrogen ( – 196°C), CO₂/N₂O ( – 200 to – 900°C)
• PET imaging: Uses Fluorodeoxyglucose (FDG) → detects ↑ glucose uptake in malignancy
• Organ of Chievitz: Juxtaoral organ near internal pterygoid; may mimic perineural invasion

Osteomyelitis of the Jaw (OML)

Osteomyelitis of the jaw (OML) is a serious infection of the bone that can lead to significant morbidity if not properly diagnosed and treated. Understanding the etiology and microbiological profile of OML is crucial for effective management. Here’s a detailed overview based on the information provided.

Historical Perspective on Etiology

• Traditional View: In the past, the etiology of OML was primarily associated with skin surface bacteria, particularly Staphylococcus aureus. Other bacteria, such as Staphylococcus epidermidis and hemolytic streptococci, were also implicated.
• Reevaluation: Recent findings indicate that S. aureus is not the primary pathogen in cases of OML affecting tooth-bearing bone. This shift in understanding highlights the complexity of the microbial landscape in jaw infections.

Microbiological Profile

1. Common Pathogens:

   • Aerobic Streptococci:
     • α-Hemolytic Streptococci: Particularly Streptococcus viridans, which are part of the normal oral flora and can become pathogenic under certain conditions.
   • Anaerobic Streptococci: These bacteria thrive in low-oxygen environments and are significant contributors to OML.
   • Other Anaerobes:
     • Peptostreptococcus: A genus of anaerobic bacteria commonly found in the oral cavity.
     • Fusobacterium: Another group of anaerobic bacteria that can be involved in polymicrobial infections.
     • Bacteroides: These bacteria are also part of the normal flora but can cause infections when the balance is disrupted.

2. Additional Organisms:

   • Gram-Negative Organisms:
     • Klebsiella, Pseudomonas, and Proteus species may also be isolated in some cases, particularly in chronic or complicated infections.
   • Specific Pathogens:
     • Mycobacterium tuberculosis: Can cause osteomyelitis in the jaw, particularly in immunocompromised individuals.
     • Treponema pallidum: The causative agent of syphilis, which can lead to specific forms of osteomyelitis.
     • Actinomyces species: Known for causing actinomycosis, these bacteria can also be involved in jaw infections.

Polymicrobial Nature of OML

• Polymicrobial Disease: Established acute OML is typically a polymicrobial infection, meaning it involves multiple types of bacteria. The common bacterial constituents include:
  • Streptococci (both aerobic and anaerobic)
  • Bacteroides
  • Peptostreptococci
  • Fusobacteria
  • Other opportunistic bacteria that may contribute to the infection.

Clinical Implications

• Sinus Tract Cultures: Cultures obtained from sinus tracts in the jaw may often be misleading. They can be contaminated with skin flora, such as Staphylococcus species, which do not accurately represent the pathogens responsible for the underlying osteomyelitis.
• Diagnosis and Treatment: Understanding the polymicrobial nature of OML is essential for effective diagnosis and treatment. Empirical antibiotic therapy should consider the range of potential pathogens, and cultures should be interpreted with caution.

Surgical Considerations for the Submandibular and Parotid Glands

When performing surgery on the submandibular and parotid glands, it is crucial to be aware of the anatomical structures and nerves at risk to minimize complications. Below is an overview of the key nerves and anatomical landmarks relevant to these surgical procedures.

Major Nerves at Risk During Submandibular Gland Surgery

1. Hypoglossal Nerve (CN XII):

   • This nerve is responsible for motor innervation to the muscles of the tongue. It lies deep to the submandibular gland and is at risk during surgical manipulation in this area.

2. Marginal Mandibular Nerve:

   • A branch of the facial nerve (CN VII), the marginal mandibular nerve innervates the muscles of the lower lip and chin. It runs just deep to the superficial layer of the deep cervical fascia, below the platysma muscle, making it vulnerable during submandibular gland surgery.

3. Lingual Nerve:

   • The lingual nerve provides sensory innervation to the anterior two-thirds of the tongue and carries parasympathetic fibers to the submandibular gland via the submandibular ganglion. It is located in close proximity to the submandibular gland and is at risk during dissection.

Anatomical Considerations for Parotid Gland Surgery

• Parotid Fascia:

  • The parotid gland is encased in a capsule of parotid fascia, which provides a protective layer during surgical procedures.

• Facial Nerve (CN VII):

  • The facial nerve is a critical structure to identify during parotid gland surgery to prevent injury. Key landmarks for locating the facial nerve include:
    • Tympanomastoid Suture Line: This is a reliable landmark for identifying the main trunk of the facial nerve, which lies just deep and medial to this suture.
    • Tragal Pointer: The nerve is located about 1 cm deep and inferior to the tragal pointer, although this landmark is less reliable.
    • Posterior Belly of the Digastric Muscle: This muscle provides a reference for the approximate depth of the facial nerve.
    • Peripheral Buccal Branches: While following these branches can help identify the nerve, this should not be the standard approach due to the risk of injury.

Submandibular Gland Anatomy

• Location:

  • The submandibular gland is situated in the submandibular triangle of the neck, which is bordered by the mandible and the digastric muscles.

• Mylohyoid Muscle:

  • The gland wraps around the mylohyoid muscle, which is typically retracted anteriorly during surgery to provide better exposure of the gland.

• CN XII:

  • The hypoglossal nerve lies deep to the submandibular gland, making it important to identify and protect during surgical procedures.

Coagulation Tests: PT and PTT

Prothrombin Time (PT) and Partial Thromboplastin Time (PTT) are laboratory tests used to evaluate the coagulation pathways involved in blood clotting. Understanding these tests is crucial for diagnosing bleeding disorders and managing patients with specific factor deficiencies.

Prothrombin Time (PT)

• Purpose: PT is primarily used to assess the extrinsic pathway of coagulation.
• Factors Tested: It evaluates the function of factors I (fibrinogen), II (prothrombin), V, VII, and X.
• Clinical Use: PT is commonly used to monitor patients on anticoagulant therapy (e.g., warfarin) and to assess bleeding risk before surgical procedures.

Partial Thromboplastin Time (PTT)

• Purpose: PTT is used to assess the intrinsic pathway of coagulation.
• Factors Tested: It evaluates the function of factors I (fibrinogen), II (prothrombin), V, VIII, IX, X, XI, and XII.
• Clinical Use: PTT is often used to monitor patients on heparin therapy and to evaluate bleeding disorders.

Specific Factor Deficiencies

In certain bleeding disorders, specific factor deficiencies can lead to increased bleeding risk. Preoperative management may involve the administration of the respective clotting factors or antifibrinolytic agents to minimize bleeding during surgical procedures.

1. Hemophilia A:

   • Deficiency: Factor VIII deficiency.
   • Management: Administration of factor VIII concentrate before surgery.

2. Hemophilia B:

   • Deficiency: Factor IX deficiency.
   • Management: Administration of factor IX concentrate before surgery.

3. Hemophilia C:

   • Deficiency: Factor XI deficiency.
   • Management: Administration of factor XI concentrate or fresh frozen plasma (FFP) may be considered.

4. Von Willebrand’s Disease:

   • Deficiency: Deficiency or dysfunction of von Willebrand factor (vWF), which is important for platelet adhesion.
   • Management: Desmopressin (DDAVP) may be administered to increase vWF levels, or factor replacement therapy may be used.

5. Antifibrinolytic Agent:

   • Aminocaproic Acid: This antifibrinolytic agent can be used to help stabilize clots and reduce bleeding during surgical procedures, particularly in patients with bleeding disorders.

• Latency period:
  • Adults: 5 – 7 days
  • Infants (8 months): 0 – 2 days
• Consolidation phase: Time between traction cessation & device removal
• Transport DO:
  • Trailing edge: Bone formation
  • Leading edge: Cartilage formation
• Midface distraction age: ≥3.5 years
• SARPE indication: Transverse expansion > 5 mm

Gow-Gates Technique for Mandibular Anesthesia

The Gow-Gates technique is a well-established method for achieving effective anesthesia of the mandibular teeth and associated soft tissues. Developed by George Albert Edwards Gow-Gates, this technique is known for its high success rate in providing sensory anesthesia to the entire distribution of the mandibular nerve (V3).

Overview

• Challenges in Mandibular Anesthesia: Achieving successful anesthesia in the mandible is often more difficult than in the maxilla due to:
  • Greater anatomical variation in the mandible.
  • The need for deeper penetration of soft tissues.
• Success Rate: Gow-Gates reported an astonishing success rate of approximately 99% in his experienced hands, making it a reliable choice for dental practitioners.

Anesthesia Coverage

The Gow-Gates technique provides sensory anesthesia to the following nerves:

• Inferior Alveolar Nerve
• Lingual Nerve
• Mylohyoid Nerve
• Mental Nerve
• Incisive Nerve
• Auriculotemporal Nerve
• Buccal Nerve

This comprehensive coverage makes it particularly useful for procedures involving multiple mandibular teeth.

Technique

Equipment

• Needle: A 25- or 27-gauge long needle is recommended for this technique.

Injection Site and Target Area

1. Area of Insertion:

   • The injection is performed on the mucous membrane on the mesial aspect of the mandibular ramus.
   • The insertion point is located on a line drawn from the intertragic notch to the corner of the mouth, just distal to the maxillary second molar.

2. Target Area:

   • The target for the injection is the lateral side of the condylar neck, just below the insertion of the lateral pterygoid muscle.

Landmarks

Extraoral Landmarks:

• Lower Border of the Tragus: This serves as a reference point. The center of the external auditory meatus is the ideal landmark, but since it is concealed by the tragus, the lower border is used as a visual aid.
• Corner of the Mouth: This helps in aligning the injection site.

Intraoral Landmarks:

• Height of Injection: The needle tip should be placed just below the mesiopalatal cusp of the maxillary second molar to establish the correct height for the injection.
• Penetration Point: The needle should penetrate the soft tissues just distal to the maxillary second molar at the height established in the previous step.