Maxillectomy

Maxillectomy is a surgical procedure involving the resection of the maxilla (upper jaw) and is typically performed to remove tumors, treat severe infections, or address other pathological conditions affecting the maxillary region. The procedure requires careful planning and execution to ensure adequate access, removal of the affected tissue, and preservation of surrounding structures for optimal functional and aesthetic outcomes.

Surgical Access and Incision

1. Weber-Fergusson Incision:

   • The classic approach to access the maxilla is through the Weber-Fergusson incision. This incision provides good visibility and access to the maxillary region.
   • Temporary Tarsorrhaphy: The eyelids are temporarily closed using tarsorrhaphy sutures to protect the eye during the procedure.

2. Tattooing for Aesthetic Alignment:

   • To achieve better cosmetic results, it is recommended to tattoo the vermilion border and other key points on both sides of the incision with methylene blue. These points serve as guides for alignment during closure.

3. Incision Design:

   • The incision typically splits the midline of the upper lip but can be modified for better cosmetic outcomes by incising along the philtral ridges and offsetting the incision at the vermilion border.
   • The incision is turned 2 mm from the medial canthus of the eye. Intraorally, the incision continues through the gingival margin and connects with a horizontal incision at the depth of the labiobuccal vestibule, extending back to the maxillary tuberosity.

4. Continuation of the Incision:

   • From the maxillary tuberosity, the incision turns medially across the posterior edge of the hard palate and then turns 90 degrees anteriorly, several millimeters to the proximal side of the midline, crossing the gingival margin again if possible.

5. Incision to Bone:

   • The incision is carried down to the bone, except beneath the lower eyelid, where the orbicularis oculi muscle is preserved. The cheek flap is then reflected back to the tuberosity.

Surgical Procedure

1. Extraction and Elevation:

   • The central incisor on the involved side is extracted, and the gingival and palatal mucosa are elevated back to the midline.

2. Deepening the Incision:

   • The incision extending around the nose is deepened into the nasal cavity. The palatal bone is divided near the midline using a saw blade or bur.

3. Separation of Bone:

   • The basal bone is separated from the frontal process of the maxilla using an osteotome. The orbicularis oculi muscle is retracted superiorly, and the bone cut is extended across the maxilla, just below the infraorbital rim, into the zygoma.

4. Maxillary Sinus:

   • If the posterior wall of the maxillary sinus has not been invaded by the tumor, it is separated from the pterygoid plates using a pterygoid chisel.

5. Specimen Removal:

   • The entire specimen is removed by severing the remaining attachments with large curved scissors placed behind the maxilla.

Postoperative Considerations

• Wound Care: Proper care of the surgical site is essential to prevent infection and promote healing.
• Rehabilitation: Patients may require rehabilitation to address functional issues related to speech, swallowing, and facial aesthetics.
• Follow-Up: Regular follow-up appointments are necessary to monitor healing and assess for any complications or recurrence of disease.

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.

Sagittal Split Osteotomy (SSO)

Sagittal split osteotomy (SSO) is a surgical procedure used to correct various mandibular deformities, including mandibular prognathism (protrusion of the mandible) and retrognathism (retraction of the mandible). It is considered one of the most versatile osteotomies for addressing discrepancies in the position of the mandible relative to the maxilla.

Overview of the Procedure

1. Indications:

   • Mandibular Prognathism: In cases where the mandible is positioned too far forward, SSO can be used to setback the mandible, improving occlusion and facial aesthetics.
   • Mandibular Retrognathism: For patients with a retruded mandible, the procedure allows for advancement of the mandible to achieve a more balanced facial profile and functional occlusion.

2. Surgical Technique:

   • The procedure involves making a sagittal split in the ramus and posterior body of the mandible. This is typically performed through an intraoral approach, which minimizes external scarring.
   • The osteotomy creates two segments of the mandible: the proximal segment (attached to the maxilla) and the distal segment (which can be repositioned).
   • Depending on the desired outcome, the distal segment can be either advanced or set back to achieve the desired occlusal relationship and aesthetic result.

3. Cosmetic Considerations:

   • The intraoral approach used in SSO helps to avoid visible scarring on the face, making it a highly cosmetic procedure.
   • The broader bony contact between the osteotomized segments promotes better healing and stability, which is crucial for achieving long-term results.

4. Healing and Recovery:

   • The procedure typically results in good healing due to the increased surface area of contact between the bone segments.
   • Postoperative care includes monitoring for complications, managing pain, and ensuring proper oral hygiene to prevent infection.

Advantages of Sagittal Split Osteotomy

• Versatility: SSO can be used to correct a wide range of mandibular discrepancies, making it suitable for various clinical scenarios.
• Cosmetic Outcome: The intraoral approach minimizes external scarring, enhancing the aesthetic outcome for patients.
• Stability: The broad bony contact between the segments ensures good stability and promotes effective healing.
• Functional Improvement: By correcting occlusal discrepancies, SSO can improve chewing function and overall oral health.

Considerations and Potential Complications

• Nerve Injury: There is a risk of injury to the inferior alveolar nerve, which can lead to temporary or permanent numbness in the lower lip and chin.
• Malocclusion: If not properly planned, there is a risk of postoperative malocclusion, which may require further intervention.
• Infection: As with any surgical procedure, there is a risk of infection at the surgical site.

Seddon’s Classification of Nerve Injuries

1. Neuropraxia:

   • Definition: This is the mildest form of nerve injury, often caused by compression or mild trauma.
   • Sunderland Classification: Type I (10).
   • Nerve Sheath: Intact; the surrounding connective tissue remains undamaged.
   • Axons: Intact; the nerve fibers are not severed.
   • Wallerian Degeneration: None; there is no degeneration of the distal nerve segment.
   • Conduction Failure: Transitory; there may be temporary loss of function, but it is reversible.
   • Spontaneous Recovery: Complete recovery is expected.
   • Time of Recovery: Typically within 4 weeks.

2. Axonotmesis:

   • Definition: This injury involves damage to the axons while the nerve sheath remains intact. It is often caused by more severe trauma, such as crush injuries.
   • Sunderland Classification: Type II (20), Type III (30), Type IV (40).
   • Nerve Sheath: Intact; the connective tissue framework is preserved.
   • Axons: Interrupted; the nerve fibers are damaged but the sheath allows for potential regeneration.
   • Wallerian Degeneration: Yes, partial; degeneration occurs in the distal segment of the nerve.
   • Conduction Failure: Prolonged; there is a longer-lasting loss of function.
   • Spontaneous Recovery: Partial recovery is possible, depending on the extent of the injury.
   • Time of Recovery: Recovery may take months.

3. Neurotmesis:

   • Definition: This is the most severe type of nerve injury, where both the axons and the nerve sheath are disrupted. It often results from lacerations or severe trauma.
   • Sunderland Classification: Type V (50).
   • Nerve Sheath: Interrupted; the connective tissue is damaged, complicating regeneration.
   • Axons: Interrupted; the nerve fibers are completely severed.
   • Wallerian Degeneration: Yes, complete; degeneration occurs in both the proximal and distal segments of the nerve.
   • Conduction Failure: Permanent; there is a lasting loss of function.
   • Spontaneous Recovery: Poor to none; recovery is unlikely without surgical intervention.
   • Time of Recovery: Recovery may begin by 3 months, if at all.