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Oral and Maxillofacial Surgery
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Osteomyelitis is an infection of the bone that can occur in the jaw, particularly in the mandible, and is characterized by a range of clinical features. Understanding these features is essential for effective diagnosis and management, especially in the context of preparing for the Integrated National Board Dental Examination (INBDE). Here’s a detailed overview of the clinical features, occurrence, and implications of osteomyelitis, particularly in adults and children.
Occurrence
- Location: In adults, osteomyelitis is more common in
the mandible than in the maxilla. The areas most frequently affected
include:
- Alveolar process
- Angle of the mandible
- Posterior part of the ramus
- Coronoid process
- Rarity: Osteomyelitis of the condyle is reportedly rare (Linsey, 1953).
Clinical Features
Early Symptoms
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Generalized Constitutional Symptoms:
- Fever: High intermittent fever is common.
- Malaise: Patients often feel generally unwell.
- Gastrointestinal Symptoms: Nausea, vomiting, and anorexia may occur.
-
Pain:
- Nature: Patients experience deep-seated, boring, continuous, and intense pain in the affected area.
- Location: The pain is typically localized to the mandible.
-
Neurological Symptoms:
- Paresthesia or Anesthesia: Intermittent paresthesia or anesthesia of the lower lip can occur, which helps differentiate osteomyelitis from an alveolar abscess.
-
Facial Swelling:
- Cellulitis: Patients may present with facial cellulitis or indurated swelling, which is more confined to the periosteal envelope and its contents.
- Mechanisms:
- Thrombosis of the inferior alveolar vasa nervorum.
- Increased pressure from edema in the inferior alveolar canal.
- Dental Symptoms: Affected teeth may be tender to percussion and may appear loose.
-
Trismus:
- Limited mouth opening due to muscle spasm or inflammation in the area.
Pediatric Considerations
- In children, osteomyelitis can present more severely and may be
characterized by:
- Fulminating Course: Rapid onset and progression of symptoms.
- Severe Involvement: Both maxilla and mandible can be affected.
- Complications: The presence of unerupted developing teeth buds can complicate the condition, as they may become necrotic and act as foreign bodies, prolonging the disease process.
- TMJ Involvement: Long-term involvement of the temporomandibular joint (TMJ) can lead to ankylosis, affecting the growth and development of facial structures.
Radiographic Changes
- Timing of Changes: Radiographic changes typically occur only after the initiation of the osteomyelitis process.
- Bone Loss: Significant radiographic changes are noted only after 30% to 60% of mineralized bone has been destroyed.
- Delay in Detection: This degree of bone alteration requires a minimum of 4 to 8 days after the onset of acute osteomyelitis for changes to be visible on radiographs.
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.
Champy Technique of Fracture Stabilization
The Champy technique, developed by Champy et al. in the mid-1970s, is a method of fracture stabilization that utilizes non-compression monocortical miniplates applied as tension bands. This technique is particularly relevant in the context of mandibular fractures and is based on biomechanical principles that optimize the stability and healing of the bone.
Key Principles of the Champy Technique
-
Biomechanical Considerations:
- Tensile and Compressive Stresses: Biomechanical studies have shown that tensile stresses occur in the upper border of the mandible, while compressive stresses are found in the lower border. This understanding is crucial for the placement of plates.
- Bending and Torsional Forces: The forces acting on the mandible primarily produce bending movements. In the symphysis and parasymphysis regions, torsional forces are more significant than bending moments.
-
Ideal Osteosynthesis Line:
- Champy et al. established the "ideal osteosynthesis line" at the base of the alveolar process. This line is critical for the effective placement of plates to ensure stability during the healing process.
- Plate Placement:
- Anterior Region: In the area between the mental foramina, a subapical plate is placed, and an additional plate is positioned near the lower border of the mandible to counteract torsional forces.
- Posterior Region: Behind the mental foramen, the plate is applied just below the dental roots and above the inferior alveolar nerve.
- Angle of Mandible: The plate is placed on the broad surface of the external oblique ridge.
-
Tension Band Principle:
- The use of miniplates as tension bands allows for the distribution of forces across the fracture site, enhancing stability and promoting healing.
Treatment Steps
-
Reduction:
- The first step in fracture treatment is the accurate reduction of the fracture fragments to restore normal anatomy.
-
Stabilization:
- Following reduction, stabilization is achieved using the Champy technique, which involves the application of miniplates in accordance with the biomechanical principles outlined above.
-
Maxillomandibular Fixation (MMF):
- MMF is often used as a standard method for both reduction and stabilization, particularly in cases where additional support is needed.
-
External Fixation:
- In cases of atrophic edentulous mandibular fractures, extensive soft tissue injuries, severe communication, or infected fractures, external fixation may be considered.
Classification of Internal Fixation Techniques
-
Absolute Stability:
- Rigid internal fixation methods, such as compression plates, lag screws, and the tension band principle, fall under this category. These techniques provide strong stabilization but may compromise blood supply to the bone.
-
Relative Stability:
- Techniques such as bridging, biologic (flexible) fixation, and the Champy technique are classified as relative stability methods. These techniques allow for some movement at the fracture site, which can promote healing by maintaining blood supply to the cortical bone.
Biologic Fixation
- New Paradigm:
- Biologic fixation represents a shift in fracture treatment philosophy, emphasizing that absolute stability is not always beneficial. Allowing for some movement at the fracture site can enhance blood supply and promote healing.
- Improved Blood Supply:
- Not pressing the plate against the bone helps maintain blood supply to the cortical bone and prevents the formation of early temporary porosity, which can be detrimental to healing.
Distoangular Impaction
Distoangular impaction refers to the position of a tooth, typically a third molar (wisdom tooth), that is angled towards the back of the mouth and the distal aspect of the mandible. This type of impaction is often considered one of the most challenging to manage surgically due to its orientation and the anatomical considerations involved in its removal.
Characteristics of Distoangular Impaction
-
Pathway of Delivery:
- The distoangular position of the tooth means that it is situated in a way that complicates its removal. The pathway for extraction often requires significant manipulation and access through the ascending ramus of the mandible.
-
Bone Removal:
- A substantial amount of distal bone removal is necessary to access the tooth adequately. This may involve the use of surgical instruments to contour the bone and create sufficient space for extraction.
-
Crown Sectioning:
- Once adequate bone removal has been achieved, the crown of the tooth is typically sectioned from the roots just above the cervical line. This step is crucial for improving visibility and access to the roots, which can be difficult to see and manipulate in their impacted position.
-
Removal of the Crown:
- The entire crown is removed to facilitate better access to the roots. This step is essential for ensuring that the roots can be addressed without obstruction from the crown.
-
Root Management:
- Divergent Roots: If the roots of the tooth are divergent (spreading apart), they may need to be further sectioned into two pieces. This allows for easier removal of each root individually, reducing the risk of fracture or complications during extraction.
- Convergent Roots: If the roots are convergent (closer together), a straight elevator can often be used to remove the roots without the need for additional sectioning. The elevator is inserted between the roots to gently lift and dislodge them from the surrounding bone.
Surgical Technique Overview
-
Anesthesia: Local anesthesia is administered to ensure patient comfort during the procedure.
-
Incision and Flap Reflection: An incision is made in the mucosa, and a flap is reflected to expose the underlying bone and the impacted tooth.
-
Bone Removal: Using a surgical bur or chisel, the distal bone is carefully removed to create access to the tooth.
-
Crown Sectioning: The crown is sectioned from the roots using a surgical handpiece or bur, allowing for improved visibility.
-
Root Extraction:
- For divergent roots, each root is sectioned and removed individually.
- For convergent roots, a straight elevator is used to extract the roots.
-
Closure: After the tooth is removed, the surgical site is irrigated, and the flap is repositioned and sutured to promote healing.
Considerations and Complications
- Complications: Distoangular impactions can lead to complications such as nerve injury (especially to the inferior alveolar nerve), infection, and prolonged recovery time.
- Postoperative Care: Patients should be advised on postoperative care, including pain management, oral hygiene, and signs of complications such as swelling or infection.