Submasseteric Space Infection

Submasseteric space infection refers to an infection that occurs in the submasseteric space, which is located beneath the masseter muscle. This space is clinically significant in the context of dental infections, particularly those arising from the lower third molars (wisdom teeth) or other odontogenic sources. Understanding the anatomy and potential spread of infections in this area is crucial for effective diagnosis and management.

Anatomy of the Submasseteric Space

1. Location:

   • The submasseteric space is situated beneath the masseter muscle, which is a major muscle involved in mastication (chewing).
   • This space is bordered superiorly by the masseter muscle and inferiorly by the lower border of the ramus of the mandible.

2. Boundaries:

   • Inferior Boundary: The extension of an abscess or infection inferiorly is limited by the firm attachment of the masseter muscle to the lower border of the ramus of the mandible. This attachment creates a barrier that can restrict the spread of infection downward.
   • Anterior Boundary: The forward spread of infection beyond the anterior border of the ramus is restricted by the anterior tail of the tendon of the temporalis muscle, which inserts into the anterior border of the ramus. This anatomical feature helps to contain infections within the submasseteric space.

3. Posterior Boundary: The posterior limit of the submasseteric space is generally defined by the posterior border of the ramus of the mandible.

Clinical Implications

1. Sources of Infection:

   • Infections in the submasseteric space often arise from odontogenic sources, such as:
     • Pericoronitis associated with impacted lower third molars.
     • Dental abscesses from other teeth in the mandible.
     • Periodontal infections.

2. Symptoms:

   • Patients with submasseteric space infections may present with:
     • Swelling and tenderness in the area of the masseter muscle.
     • Limited mouth opening (trismus) due to muscle spasm or swelling.
     • Pain that may radiate to the ear or temporomandibular joint (TMJ).
     • Fever and systemic signs of infection in more severe cases.

3. Diagnosis:

   • Diagnosis is typically made through clinical examination and imaging studies, such as panoramic radiographs or CT scans, to assess the extent of the infection and its relationship to surrounding structures.

4. Management:

   • Treatment of submasseteric space infections usually involves:
     • Antibiotic Therapy: Broad-spectrum antibiotics are often initiated to control the infection.
     • Surgical Intervention: Drainage of the abscess may be necessary, especially if there is significant swelling or if the patient is not responding to conservative management. Incision and drainage can be performed intraorally or extraorally, depending on the extent of the infection.
     • Management of the Source: Addressing the underlying dental issue, such as extraction of an impacted tooth or treatment of a dental abscess, is essential to prevent recurrence.

• Normal clotting time: 8 – 15 minutes.
• Platelet – rich plasma (1 unit): Raises platelet count by 7,000 – 10,000/μL.
• Fresh frozen plasma (150 mL): Contains 200 μ factors VIII & IX, 400 mg fibrinogen.
• Cryoprecipitate: Contains factors VIII, XIII, vWF, fibrinogen.
• DIC marker: Elevated D – dimers.
• Hemophilia factor levels: Majority have < 5%.
• Surgery in hemophilia: Raise factor levels to 50 – 75%.

Endotracheal Route (L.E.A.N.)

Mnemonic for drugs that can be administered via endotracheal tube:

L - Lidocaine

• Dose: 1-1.5 mg/kg
• Indication: Ventricular arrhythmias, laryngospasm
• Mechanism: Sodium channel blockade
• Dilution: 5-10ml normal saline

E - Epinephrine

• Dose: 0.01-0.1 mg/kg (0.1-1 ml/kg of 1:10,000)
• Indication: Cardiac arrest, severe anaphylaxis
• Mechanism: α and β adrenergic stimulation
• Dilution: 5-10ml normal saline

A - Atropine

• Dose: 0.02-0.04 mg/kg (minimum 0.1mg)
• Indication: Bradycardia, organophosphate poisoning
• Mechanism: Muscarinic receptor antagonism
• Dilution: 5-10ml normal saline

N - Narcan (Naloxone)

• Dose: 0.01-0.1 mg/kg
• Indication: Opioid overdose reversal
• Mechanism: Opioid receptor antagonism
• Dilution: 5-10ml normal saline

Administration Technique

• Volume: Dilute in 5-10ml normal saline
• Method: Inject via suction catheter or directly into tube
• Follow-up: Bag ventilation to distribute drug
• Absorption: Lower bioavailability than IV route
• Monitoring: May need higher doses or repeat administration

Alternative Routes

• Intravenous: Preferred when available
• Intraosseous: Good alternative to IV
• Intramuscular: Limited utility in emergencies
• Sublingual: Some medications (nitroglycerin)

Catgut Sutures

• Composition: Processed animal intestine (usually sheep)
• Degradation mechanism: Enzymatic degradation by tissue enzymes
• Types:
  • Plain catgut: Resorbs in 7-10 days
  • Chromic catgut: Cross-linked with chromium, resorbs in 2-3 weeks
• Advantages: Natural, good handling
• Disadvantages: Variable absorption, inflammatory response, potential allergic reactions

Vicryl (Polyglactin 910)

• Composition: Synthetic copolymer of glycolic and lactic acid
• Degradation mechanism: Hydrolysis (broken down by water)
• Absorption time: 2-3 weeks (loses tensile strength in 2-3 weeks, completely absorbed in 60-90 days)
• Variants:
  • Vicryl: Standard braided suture
  • Vicryl Rapide: Faster absorption (7-10 days)
  • Vicryl Plus: Contains triclosan for antibacterial properties
• Advantages: Predictable absorption, minimal tissue reaction, good knot security
• Clinical uses: Soft tissue closure, periodontal surgery, buried sutures

Polydiaxone (PDS-II)

• Composition: Synthetic polymer (polydioxanone)
• Structure: Monofilament
• Degradation mechanism: Hydrolysis
• Absorption time: ~6 months with minimal tissue reaction
• Tensile strength: Retains 70% at 2 weeks, 50% at 4 weeks
• Advantages:
  • Longest absorption time among synthetic absorbables
  • Excellent biocompatibility
  • Minimal inflammatory response
  • Good for wounds requiring extended support
• Clinical uses: Deep tissue layers, slow-healing wounds, pediatric surgery

Other Synthetic Absorbable Sutures

Monocryl (Poliglecaprone 25)

• Absorption: 3-4 months
• Advantages: Low tissue reaction, good cosmetic results
• Uses: Subcuticular closure, soft tissue approximation

Biosyn (Glycomer 631)

• Absorption: 3-4 months
• Advantages: Braided with monofilament properties
• Uses: General soft tissue approximation

Temporomandibular Joint (TMJ) Ankylosis

Definition: TMJ ankylosis is a condition characterized by the abnormal fusion of the bones that form the temporomandibular joint, leading to restricted movement of the jaw. This fusion can be either fibrous (non-bony) or bony, resulting in varying degrees of functional impairment.

Etiology

TMJ ankylosis can result from various factors, including:

1. Trauma: Fractures or injuries to the jaw can lead to the development of ankylosis, particularly if there is associated soft tissue damage.
2. Infection: Conditions such as osteomyelitis or septic arthritis can lead to inflammation and subsequent ankylosis of the joint.
3. Congenital Conditions: Some individuals may be born with anatomical abnormalities that predispose them to ankylosis.
4. Systemic Diseases: Conditions like rheumatoid arthritis or ankylosing spondylitis can affect the TMJ and lead to ankylosis.
5. Previous Surgery: Surgical interventions in the area, such as those for cleft lip and palate, can sometimes result in scar tissue formation and ankylosis.

Pathophysiology

• Fibrous Ankylosis: In this type, fibrous tissue forms between the articulating surfaces of the joint, leading to limited movement. The joint surfaces remain intact but are functionally immobilized.
• Bony Ankylosis: This more severe form involves the formation of bone between the joint surfaces, resulting in complete loss of joint mobility. This can occur due to chronic inflammation or trauma.

Clinical Features

1. Restricted Jaw Movement: Patients typically present with limited mouth opening (trismus), which can severely affect eating, speaking, and oral hygiene.
2. Facial Asymmetry: Over time, the affected side of the face may appear smaller or less developed due to lack of movement and muscle atrophy.
3. Pain and Discomfort: Patients may experience pain in the jaw, face, or neck, particularly during attempts to open the mouth.
4. Difficulty with Oral Functions: Eating, swallowing, and speaking can become challenging due to limited jaw mobility.
5. Clicking or Popping Sounds: In some cases, patients may report sounds during jaw movement, although this is less common in complete ankylosis.

Diagnosis

Diagnosis of TMJ ankylosis typically involves:

1. Clinical Examination: Assessment of jaw movement, facial symmetry, and pain levels.
2. Imaging Studies:
   • X-rays: Can show joint space narrowing or bony fusion.
   • CT Scans: Provide detailed images of the bone structure and can help assess the extent of ankylosis.
   • MRI: Useful for evaluating soft tissue involvement and the condition of the articular disc.

Treatment

The management of TMJ ankylosis often requires surgical intervention, especially in cases of significant functional impairment. Treatment options include:

1. Surgical Options:

   • Arthroplasty: This procedure involves the removal of the ankylosed tissue and reconstruction of the joint. It can be performed as gap arthroplasty (creating a gap between the bones) or interpositional arthroplasty (placing a material between the joint surfaces).
   • Osteotomy: In cases of severe deformity, osteotomy may be performed to realign the jaw.
   • TMJ Replacement: In severe cases, a total joint replacement may be necessary.

2. Postoperative Care:

   • Physical Therapy: Post-surgical rehabilitation is crucial to restore function and improve range of motion. Exercises may include gentle stretching and strengthening of the jaw muscles.
   • Pain Management: Analgesics and anti-inflammatory medications may be prescribed to manage postoperative pain.

3. Long-term Management:

   • Regular Follow-up: Patients require ongoing monitoring to assess joint function and detect any recurrence of ankylosis.
   • Oral Hygiene: Maintaining good oral hygiene is essential, especially if mouth opening is limited.

Prognosis

The prognosis for patients with TMJ ankylosis varies depending on the severity of the condition, the type of surgical intervention performed, and the patient's adherence to postoperative rehabilitation. Many patients experience significant improvement in jaw function and quality of life following appropriate treatment.

Management of Mandibular Fractures: Plate Fixation Techniques

The management of mandibular fractures involves various techniques for fixation, depending on the type and location of the fracture. .

1. Plate Placement in the Body of the Mandible

• Single Plate Fixation:

  • A single plate is recommended to be placed just below the apices of the teeth but above the inferior alveolar nerve canal. This positioning helps to avoid damage to the nerve while providing adequate support to the fracture site.
  • Miniplate Fixation: Effective for non-displaced or minimally displaced fractures, provided the fracture is not severely comminuted. The miniplate should be placed at the superior border of the mandible, acting as a tension band that prevents distraction at the superior border while maintaining compression at the inferior border during function.

• Additional Plates:

  • While a solitary plate can provide adequate rigidity, the placement of an additional plate or the use of multi-armed plates (Y or H plates) can enhance stability, especially in more complex fractures.

2. Plate Placement in the Parasymphyseal and Symphyseal Regions

• Two Plates for Stability:

  • In the parasymphyseal and symphyseal regions, two plates are recommended due to the torsional forces generated during function.
    • First Plate: Placed at the inferior aspect of the mandible.
    • Second Plate: Placed parallel and at least 5 mm superior to the first plate (subapical).

• Plate Placement Behind the Mental Foramen:

  • A plate can be fixed in the subapical area and another near the lower border. Additionally, plates can be placed on the external oblique ridge or parallel to the lower border of the mandible.

3. Management of Comminuted or Grossly Displaced Fractures

• Reconstruction Plates:
  • Comminuted or grossly displaced fractures of the mandibular body require fixation with a locking reconstruction plate or a standard reconstruction plate. These plates provide the necessary stability for complex fractures.

4. Management of Mandibular Angle Fractures

• Miniplate Fixation:
  • When treating mandibular angle fractures, the plate should be placed at the superolateral aspect of the mandible, extending onto the broad surface of the external oblique ridge. This placement helps to counteract the forces acting on the angle of the mandible.

5. Stress Patterns and Plate Design

• Stress Patterns:

  • The zone of compression is located at the superior border of the mandible, while the neutral axis is approximately at the level of the inferior alveolar canal. Understanding these stress patterns is crucial for optimal plate placement.

• Miniplate Characteristics:

  • Developed by Michelet et al. and popularized by Champy et al., miniplates utilize monocortical screws and require a minimum of two screws in each osseous segment. They are smaller than standard plates, allowing for smaller incisions and less soft tissue dissection, which reduces the risk of complications.

6. Other Fixation Techniques

• Compression Osteosynthesis:

  • Indicated for non-oblique fractures that demonstrate good body opposition after reduction. Compression plates, such as dynamic compression plates (DCP), are used to achieve this. The inclined plate within the hole allows for translation of the bone toward the fracture site as the screw is tightened.

• Fixation Osteosynthesis:

  • For severely oblique fractures, comminuted fractures, and fractures with bone loss, compression plates are contraindicated. In these cases, non-compression osteosynthesis using locking plates or reconstruction plates is preferred. This method is also suitable for patients with questionable postoperative compliance or a non-stable mandible.