Mandibulectomy is a surgical procedure to remove part or all of the lower jawbone (mandible). It is usually done to treat mouth or jaw cancer, especially if the tumor has spread to the bone. It may also be done for severe infections or trauma.
After the surgery, the jaw may be reconstructed using bone from another part of the body (like the leg or shoulder) to help restore appearance and function (like chewing or speaking).
Numbers And Statistcs About Mandibulectomy
🎯 Overall Survival Rates
In a large cohort of 403 patients undergoing segmental mandibulectomy with neck dissection, 5‑year overall survival was:
~33% overall
42% with postoperative radiotherapy
16% with preoperative radiotherapy
17% if surgery was performed as salvage after prior treatment
In a 106‑patient study comparing marginal vs. segmental mandibulectomy, the 5‑year survival rate was higher about 60%.
📊 Short-Term Survival & Quality of Life
In a recent Iranian study (2015–2019) involving 82 patients who underwent segmental mandibulectomy, the 3‑year survival rate was 69.5% (mean follow-up ~1.35 years).
🦷 Marginal Mandibulectomy Outcomes
In a cohort of 142 patients treated for SCC of the lower gingiva:
5‑year disease-specific survival (DSS) was 88%
5‑year locoregional control (LRC) was 85%
Other studies of marginal mandibulectomy reported:
2‑year disease-free survival: ~69%
5‑year disease-free survival: ~60%
Local recurrence-free survival at 2 and 5 years: 79% and 70% respectively
🗣 Functional & Speech Outcomes
After segmental mandibulectomy with fibular free‑flap reconstruction:
37% decline in Speech Handicap Index at 3 months
35% decline in swallowing function (per MD Anderson Dysphagia Inventory)
Swallowing function improved by 12 months, though speech remained impaired
Speech & Swallowing Function (post‑reconstruction)
~35–37% decline at 3 mos
What Is the Purpose of a Mandibulectomy?
✅ 1. Treating Oral Cancer
Main Purpose: The most common reason.
Cancers Involved: Usually squamous cell carcinoma of the oral cavity (tongue, floor of mouth, gums or cheek).
If the cancer invades the jawbone, part (marginal mandibulectomy) or all (segmental mandibulectomy) of the bone must be removed to ensure complete tumor clearance.
The goal is to remove all cancerous tissue with clear margins to prevent recurrence.
✅ 2. Preventing Cancer Spread
If oral cancer is close to the mandible or has already started eroding it, mandibulectomy helps prevent the spread of cancer to surrounding tissues, lymph nodes or the skull base.
✅ 3. Treating Severe Infections or Osteoradionecrosis
Osteoradionecrosis (ORN): A serious condition where the jawbone dies due to radiation therapy.
Untreatable jaw infections: Infections that destroy bone and don’t respond to antibiotics or other treatments may require partial jaw removal to stop further damage.
✅ 4. Managing Trauma or Bone Necrosis
Rarely, trauma (e.g., severe fracture or blast injury) or bone necrosis because of poor blood supply might lead to irreversible damage, making mandibulectomy necessary to restore function or prevent complications.
✅ 5. Reconstructing the Jaw
In some cases, the procedure also involves reconstructive surgery (e.g., fibula free flap or titanium plate) to restore appearance, chewing and speaking abilities after part of the jaw is removed.
What are The Different Types of Mandibulectomy?
🔹 1. Marginal Mandibulectomy (or Rim Mandibulectomy)
What it is: Only a portion of the upper edge (rim) of the mandible is removed, preserving the continuity of the jawbone.
When it’s used: For early-stage cancers that are near the jawbone but haven’t invaded deeply.
Benefit: Maintains jaw shape and function; better for speech and chewing.
🔹 2. Segmental Mandibulectomy
What it is: A full-thickness section of the mandible is removed, creating a gap.
When it’s used: When cancer has invaded the bone, especially in advanced or aggressive tumors.
Requires reconstruction: Usually with a fibula bone graft, metal plate or 3D-printed prosthesis.
Impact: Greater functional and cosmetic changes than marginal resection.
🔹 3. Hemimandibulectomy
What it is: Removal of one entire half of the mandible (left or right side).
When it’s used: For extensive tumors affecting a large portion of the jaw.
Usually involves reconstruction with bone from the leg, shoulder blade or hip.
🔹 4. Total Mandibulectomy
What it is: Rare; involves removal of the entire mandible.
When it’s used: Extremely advanced disease or massive osteoradionecrosis.
Always requires complex reconstruction and results in significant speech and chewing difficulty.
🔹 5. Composite Mandibulectomy
What it is: Removal of a portion of the mandible along with surrounding soft tissues (e.g., floor of the mouth, tongue, lymph nodes).
When it’s used: For larger or invasive cancers that affect both the jawbone and surrounding tissues.
Often combined with neck dissection and reconstructive surgery.
📌 Summary Table:
Type
Jawbone Removed?
Jaw Continuity Preserved?
Typical Use Case
Marginal Mandibulectomy
Upper edge only
✅ Yes
Early-stage or superficial cancer
Segmental Mandibulectomy
Full-thickness section
❌ No
Cancer invading the bone
Hemimandibulectomy
One side of the jaw
❌ No
Large or aggressive tumors
Total Mandibulectomy
Entire mandible
❌ No
Rare, very advanced cases
Composite Mandibulectomy
Jaw + soft tissue
Depends on extent
Extensive cancer + soft tissue spread
What is The Survival Rate For a Mandibulectomy?
✅ 1. Overall 5-Year Survival Rates
Marginal Mandibulectomy (early-stage cancer):
5-year survival:60%–88%
Best outcomes are seen in patients with no bone invasion and clear surgical margins.
Segmental Mandibulectomy (more advanced cancer):
5-year survival:33%–42%
Drops to ~16–17% if surgery is done after failed radiation (salvage surgery) or if bone invasion is extensive.
✅ 2. Disease-Specific & Disease-Free Survival
5-year Disease-Specific Survival (DSS):
~88% in early-stage oral squamous cell carcinoma with marginal resection
Drops significantly if there’s bone invasion or positive lymph nodes
5-year Disease-Free Survival (DFS):
Around 60–70% depending on cancer stage and whether clean margins were achieved.
✅ 3. Factors That Affect Survival
Tumor stage: Early-stage (T1–T2) tumors have far better survival than advanced (T3–T4)
Bone invasion: Presence of bone invasion lowers survival
