Long-Term Outcomes of Dental Implants Placed in Fibula-free Flaps Used for Reconstruction of Maxillo-Mandibular Defects

Authors: Malik Michael, MD, DDS; Brandon Baker, MD, DDS; Rui Fernandes, MD, DMD, FACS, FRCS(Ed)

Source: Oral Maxillofacial Surg Clin N Am 37 (2025) 109–120

DOI: 10.1016/j.coms.2024.08.002

Affiliation: Department of Oral and Maxillofacial Surgery, Division of Head and Neck Surgery, University of Florida, Jacksonville, FL

Overview

Narrative review of dental implant rehabilitation in patients whose jaws are reconstructed with a free fibula flap (FFF) — the recognized standard of care after segmental mandibular resection due to trauma, infection, large jaw cysts, or ablative oral cancer surgery.

Reconstruction of the maxilla or mandible with an FFF is standard when resection involves segmental resection. An increasingly popular strategy for head and neck cancer patients is the use of dental endosseous implants and overdentures as part of oral/dental rehabilitation. The fibula free flap is considered ideal because of:

Ease of harvest
Availability of a long span of bone
Segmental periosteal blood supply
Length of vascular pedicle
Pliability of skin paddle
Reliable vascular anatomy
Ability to use a 2-team approach

The first reports of dental prosthetic rehabilitation of the mandible using free tissue transfer and endosseous implants date to 1989.

Key Findings

Success Rates

Implants placed in non-irradiated fibulas have success rates similar to implants in native bone.
Average overall survival in FFF at 1–5 years: 93.5% (range 83.3–97%).
Average 10-year survival: ~80% (range 78–83%).
Reported 20-year survival: 69%.
Kolokythas et al. meta-analysis: 242 patients, 848 implants placed secondarily in free fibula flaps → estimated success proportion 0.94 (94%), 95% CI 0.91–0.96; annual implant failure rate 0.02 (95% CI 0.01–0.03).
Liu et al. meta-analysis (primary vs. secondary implantation, 7 studies, 186 patients):
- Primary implantation survival: 93.3%
- Secondary implantation survival: 93.4%
- No significant difference: OR = 0.813 (95% CI 0.383–1.725, P = .589)
Ching et al.: slightly higher (not statistically significant) implant loss in fibulas (8.6%) vs. native mandibles (2.6%) and maxillas (2.2%). No statistically significant variation in implant loss between patients who received adjuvant radiation therapy and those who did not.
Sandoval et al.: specifically studied adjuvant radiation in patients with fibula + primary implant placement vs. fibulas without implants → no significant difference in adverse outcomes.
Implants in FFF show higher overall implant loss and peri-implant bone loss than native bone, especially when placed in the maxilla.
Maxillofacial subunit reconstruction with implant-supported prosthesis + FFF has high implant survival, minimal crestal bone loss (<1 mm), and minimal complication rates — durable over the long run.

Virtual Surgical Planning

Major factor in both primary and secondary implant placement.
Involves computer-aided surgical planning and creation of surgical guides using CAD/CAM technology.
Enables accurate evaluation of anatomy, creation of a patient-specific plan for FFF and implant placement, and implementation via custom-fabricated cutting and implant placement guides.
Allows endosseous implant placement planned while avoiding the reconstruction plate and screws.
Enables precise cutting of fibula segments, patient-specific reconstruction plates, and planning of osteotomies at the defect site via prefabricated fibula cutting and implant placement guides.
Permits optimal positioning, predefined angulation, and position of implants in both fibulas and native jaws.
Prevents interference between implants and transosseous screws securing the FFF.
Benefits: reduced operating times, fewer procedures, increased implant utilization, shorter prosthesis delivery times, higher rates of tertiary prosthetic rehabilitation, enhanced patient satisfaction and QOL — offsetting the higher cost of VSP.

Timing Options: Immediate, Secondary, and Jaw in a Day

Number of factors make the post-ablative patient unsuitable for conventional (non-implant-supported) dentures:

Low bone density
Poor soft tissue quantity and quality
Radiation therapy complications (soft tissue loss, xerostomia → ulceration from acrylic rubbing against mucosa)
Poor denture retention
Poor suction

Primary / One-Stage

Can be safely carried out without vascular compromise to the flap.
Adds extra time to the total surgical period; overall FFF warm ischemia time is less than 4 hours.
Improves functional outcome and is cost-effective (decreases overall reconstruction time by reducing OR visits).
Benefits: easier access to the fibula bone, fewer surgical procedures, reduced cost, early oral rehabilitation, quicker return to oral nutrition and prosthesis use, time for implants to osseointegrate before radiation therapy, and possibly lower risk of implant loss.
Drawbacks: implant placement errors, radiation therapy interference, changes to local anatomy, potential for tumor recurrence at the implant placement site hindering surveillance.
Not advised after excision of a malignant tumor due to the possibility of recurrence.

Secondary / Two-Stage

Done in 2 steps:
1. Bone defect reconstructed with a reconstruction plate and FFF; left to heal 4 to 6 months.
2. Optimal implant location and angulation determined by the surgeon with VSP assistance. Implant placement postponed 1 year following completion of therapy in malignant tumor defects treated with FFF + adjuvant radiation therapy.
In second-stage surgery, reconstructive hardware is removed if it interferes with implant placement.
Vestibuloplasty, flap skin paddle debulking, and surrounding implant grafting can be done concurrently with implant placement or during implant uncovering.
Benefits: identifying motivated patients, shorter initial surgical procedure, optimal implant placement guide and prosthodontic plan, time to rule out local tumor recurrence.
Drawbacks: higher costs, more OR visits, longer time for oral rehabilitation.

Jaw in a Day

With modern virtual technology, the FFF, guided implants, and dental prostheses can all be placed in a single surgical procedure.
Limited experience in malignant disease, but preliminary reports indicate it can be used successfully for patients requiring adjuvant radiation therapy after surgery.
Rationale: radiation therapy’s detrimental effects on bone take several weeks to manifest. Since radiation usually starts 6 weeks after surgery, much of osseointegration has already occurred before higher radiation doses accumulate.
The strategy of placing implants in non-radiated bone is supported by prior research: implant placement before radiation therapy appears to have no effect on successful integration and may even slightly increase survival.
CAD-CAM introduction and high success rates have spurred a trend toward rapid prosthesis fabrication and implantation.
Chiapasco and Gatti were first to demonstrate immediate prosthetic loading of implants (2 patients with severely atrophied, edentulous maxilla; fibula free flap reconstruction, implants/prosthesis 3 months later — all implants survived).
Okay et al. (28 patients): 3 months after free flap reconstruction, patients with immediate loading of a provisional prosthesis had an implant success rate of 89.3% — opening the door to single-stage total maxillomandibular reconstruction with immediate functional loading.

Techniques (Detailed)

1. Fibula Positioning and Geometry

Bone shape varies along its length:

Location	Shape
Head	Triangular
Middle	Quadrilateral
Malleolus (distal)	Oval / irregular

In most cases of reconstructed defects, the distal fibula bone — which is typically quadrilateral in shape — is used to enable a longer vascular pedicle length.

Minimum segment size: Ideally, segments of the osteotomized fibula should not be smaller than 2 cm.

Vertical height problem: Adult dentate mandible height is approximately half that of the fibula bone (13–15 mm). A fibula placed at the inferior border gives aesthetically pleasing results but lacks vertical "alveolar" height — requiring a significantly taller prosthesis, which increases loading forces on implants.

Compensation strategies:

Place the fibula segment 5–10 mm above the mandibular inferior border.
- Results in a minor cosmetic defect at the inferior border.
- Can be corrected by placing a deepithelialized vascularized fibula skin paddle over the reconstruction plate to compensate for soft tissue loss and the higher fibula position.
Rebuild the alveolus with nonvascularized corticocancellous autograft.
Double-barreling and vertical distraction osteogenesis are additional strategies.
- Caveat: placing immediate, well-positioned implants in a double-barreled fibula can be difficult.
- Caveat: vertical distraction is unpredictable and can result in lingual tipping of the superior segment.

Access/clearance requirements:

≥15 mm of mouth opening at the incisal edge of the anterior teeth — needed to place implants, take dental impressions, allow mastication, and deliver a prosthesis.
10–15 mm of space between the superior edge of the fibula and the occlusal plane of the opposing dentition — to enable development of the implant-supported framework of the prosthesis.
The ideal fibula position avoids the reconstruction plate screws and permits correct implant angulation.
Mandible osteotomies should be built on optimal fibula positioning and clinically sound margins. Sometimes resection margins must be extended to avoid short fibula segments with a less robust blood supply.

2. Implant Placement into the Fibula

Bone minimums: Fibula must be at least 10 mm in height and 5 mm wide for endosseous implant placement.

Bicortical placement is crucial — because fibula has no cancellous bone, bicortical engagement is required for stability and higher removal torque values.

Spacing / sizing rules:

Parameter	Value
Max implants per 2-cm fibula segment	2
Minimum spacing between 2 implants	3 mm (same as native mandible)
Minimum distance from osteotomy site	3 mm
Minimum distance from lingual or buccal cortical plate	0.5 mm

Fixation of segments:

Stabilize with a reconstruction plate and 1 or 2 screws to preserve maximal bone vascularity.
For longer segments, use a minimum of 2 monocortical screws — to prevent micromovement at the osteotomy site, minimize rotational forces on segments, and avoid devascularization from excessive subperiosteal dissection.

Angulation and torque:

Implants should be parallel to each other with proper angulation.
Angled abutments permit up to 15° of divergence during prosthesis fabrication.
Insertion torque: minimum 20 Ncm, maximum 45 Ncm.
If insertion torque ≥35 Ncm → screw-retained prosthesis can be delivered immediately.
If insertion torque <35 Ncm → use a 2-stage protocol.

Drilling caution: Fibula has high bone density. The implant osteotomy site should be tapped to avoid bone fracture after implant drilling.

Surgical guides: A guide using bone, mucosa, or tooth support can direct endosseous implant placement. With implant placement guides, implants can be positioned, angled, and spaced within a 1 mm margin of error.

Native jaw bone: Implant placement follows the same guidelines as fibula bone, with the exception of the high-density fibula requiring tapping.

3. Planning Workflow (VSP-Specific)

Three key steps:

CT scan of the fibulas and jaws with 1 mm cuts.
Intraoral optical scan → creates a digital file used as a template for a temporary dental prosthesis and a reference for implant positioning.
- Stereolithography (STL) is the most widely used digital format.
- If preoperative dentition is intact, teeth can be optically scanned and 3D-printed into a temporary prosthesis.
Upload the intraoral scan to the VSP planner to merge with the CT data.

The 4 components planned using VSP:

Dental implant placement
Fibula orientation
Mandible resection location
Plate/screw design

Optimal fibula positioning should be the foundation for mandible osteotomies, in addition to clinically sound margins.

4. Type of Implants and Prosthesis

Implant selection:

Implant brand does not influence survival — most commercially available systems are equally suitable for FFF dental restoration.
Surface-treated (rough-surface) implants have comparatively fewer failures than machined implants — likely because rough surfaces have a larger surface area and accelerate osseointegration.
In irradiated fields, short implants have higher failure rates than standard-size implants (≥10 mm).
Recommendation for FFF reconstruction: surface-treated implant, minimum width 3 mm, minimum length 10 mm.

Prosthesis design:

Bar connectors are preferable to ball-and-socket connectors — they minimize implant micromovement and resolve issues with misaligned or incorrectly positioned implants.
Removable implant-supported prostheses with ball-and-socket connectors have a higher failure rate.
Minimum of 4 implants per arch for edentulous patients receiving implant-supported overdentures.
Kumar et al. (2016): no QOL difference between 2- vs. 4-implant overdentures, though the 2-implant group had higher marginal bone loss.
Ideal: 4 implants with bar attachments supporting a removable implant-supported overdenture.
Prosthesis survival rate for rehabilitated patients: >98%.
Patients with FFF + implant-supported overdentures fare better than those without.
Patients reconstructed with FFF and implant-supported overdentures showed statistically significant QOL improvements vs. no prosthesis or non-implant-supported prosthesis in post-ablative defects.
Restorative options: hybrid prosthesis, overdentures, implant-supported cement- or screw-retained bridges.
Maxillectomy patients can use implant-supported obturators to seal oronasal communications.
Best option: fixed hybrid screw-retained prosthesis that does not rely on mucosa — minimizes pressure necrosis and soft tissue ulceration risk.
Avoid cement-retained prostheses and acrylic restorations — they cause granulation tissue formation at the implant and bone interface.

Causes of prosthetic rehabilitation failure:

Poor intermaxillary relationships
Tumor recurrence
Implant loss
Microstomia
Lack of patient cooperation

Poor implant vectors, misaligned arches, long abutments, and increased distances between the fibula and opposing occlusal surface cause a poor emergence profile, increased loading forces, and stress on implants — potentially compromising long-term implant survival.

5. Soft-Tissue Management

FFF harvest is frequently combined with a skin paddle.
The skin paddle separates the oral cavity from the neck, sinuses, and nasal cavity — providing required bulk and integrity for reconstruction.
If radiation therapy is needed after ablation and reconstruction, implant placement typically occurs 6 months after completion of radiation therapy.
Techniques to create attached tissue surrounding implants upon exposure:
- Debulking the flap skin paddle
- Placement of split-thickness or full-thickness skin grafts
- Palatal mucosa grafts

Goals of proper soft-tissue management (to prevent peri-implantitis):

Thin out bulky or redundant tissue from the skin paddle
Create vestibules for the lips, labial, and buccal regions
Allow unrestricted tongue mobility
Enhance cosmesis

Evidence on grafting:

Debulking the skin paddle + split-thickness skin grafts to provide keratinized tissue around implants → encouraging outcomes, no notable complications with hyperplastic granulation tissue forming at the implant–skin interface.
Palatal mucosa graft is the best option — provides keratinized attached mucosa that seals around implants, permits proper hygiene, and inhibits granulation tissue formation and bone loss around implants.

Healing-phase adjunct:

Skin and mucosal grafts + a custom-fabricated compressive splint lined with tissue conditioner can inhibit granulation tissue formation around abutments.
These splints can be used for vestibuloplasty concurrently.
They should be left in place 6 to 8 weeks to allow the graft to firmly adapt to underlying tissue and form a vestibule.

Complications

Peri-implantitis — the most frequent issue related to implant placement in this population, and the most frequent cause of implant loss in FFF.
Osteomyelitis
Fibula devascularization
Fibula fracture
Osteoradionecrosis (ORN)
Tumor recurrence at the implant placement site

All instances of tumor recurrence at implant locations occurred in implants that were mostly placed primarily. Recurrence at primary implant sites may result from:

Peri-implantitis
Long-term alcohol and tobacco use
Interference with radiation dosage from metallic implants
General increased susceptibility to chronically irritated oral mucosa

Chronic peri-implantitis should be closely monitored, treated, and biopsied to rule out oral squamous cell carcinoma.

Drawbacks of fibula flap + dental rehabilitation:

Insufficient bone height
Interference of the skin paddle
Poor skin graft take at the donor site
Immobilization of the leg
Possible vascular compromise of the foot
Inconsistent split-thickness skin graft outcome at the FFF donor site

Main drawback: absence of vertical height (fibula 13–15 mm vs. ~half that for adult dentate mandible). Mitigation: position reconstruction plate + fibula 5–10 mm higher; cosmetic defect at the inferior border can be corrected by placing a deepithelialized vascularized fibula skin paddle over the plate.

Effects of Radiation

Timing of radiation therapy before or after implant placement does not have an impact on implant survival per recent data.
Intensity-modulated radiation therapy (IMRT) has demonstrated statistically higher implant survival than conventional radiation therapy — may explain this finding.
While exact timing does not affect overall implant survival, most studies advise delaying implant placement at least 6 to 12 months after radiation therapy.
Metallic objects in the radiation field alter radiation doses to nearby tissues:
- Primary implant placement before radiation therapy may result in dose escalation in the bone in front of the implant, shielding behind the implant, and backscattering.
- Greater implant sizes → more localized x-ray/gamma-ray backscatter → higher local radiation doses → increased ORN risk.
- Dose increases by 15% at the implant–bone interface due to backscatter, but drops to almost nothing within 1–2 mm of the interface.
- Multi-vectored radiation therapy mitigates backscatter effects.
- Therefore: place the smallest clinically feasible implants to prevent higher radiation doses and increased backscatter at the bone–implant interface.
Survival in irradiated fields:
- Average overall implant survival 91.33% over 1–5 years.
- Long-term survival 78% to 85% at 15 years.
- Implants in the irradiated maxilla have lower survival than those in the irradiated mandible.
- Irradiated FFF implants have lower survival than native maxilla or mandible implants.
- Noticeably increased risk of implant loss in previously irradiated FFF that has already developed ORN.
Filho et al. (2016) systematic review: no significant correlation between time of implant placement after radiation therapy and radiation dose in terms of implant loss.
Hyperbaric oxygen therapy is controversial during the peri-implant placement period:
- Available data shows its use does not appear to be associated with a higher risk of implant failure and does not appear to improve implant survival.
- It also does not appear to prevent ORN after implant placement.
In both irradiated and non-irradiated fibulas, the majority of implant failures occur within the first 6 to 12 months following implantation.

Summary

The use of FFF and implant-supported prostheses for maxillary and mandibular reconstruction is a reliable and long-lasting method to give patients integrity, function, and form while enhancing quality of life.

Caution should be exercised when performing secondary implant reconstruction in patients who have previously undergone radiation therapy following FFF placement.
Soft-tissue management should be carried out as needed to maintain implant integrity.
A fixed hybrid metal ceramic screw-retained prosthesis is the ideal tool for prosthodontic rehabilitation.
Preservation and success of the reconstruction depend on a determined patient, strict hygiene, and ongoing follow-up.

Clinics Care Points

The efficacy and prognosis of dental implants placed in free bone flaps have been extensively studied, with the fibula free flap being an ideal option for mandibular reconstruction with dental rehabilitation.
Patients reconstructed with FFF and implant-supported overdentures showed statistically significant improvements in QOL when compared with no prosthesis or non-implant-supported prosthesis in post-ablative defects.
Dental implants can be placed in free fibula flaps using immediate, secondary, or jaw in a day technique. These techniques should be individualized based on the patient’s diagnosis, history, prognosis, motivation, needs, and wishes.
Success rates of dental implants placed in non-irradiated fibulas are comparable with those placed in native bone.
Implants inserted into the irradiated maxilla have a lower survival rate than implants inserted into the irradiated mandible, and irradiated FFF implants have a lower survival rate than native maxilla or mandible implants.

Quick-Reference Tables

Technique Parameters

Parameter	Value
Min osteotomized fibula segment (general guideline)	not smaller than 2 cm
Fibula height for implants	≥10 mm
Fibula width for implants	≥5 mm
Fibula vertical height (adult)	13–15 mm
Fibula position above inferior border	5–10 mm
Min alveolar clearance to opposing occlusion	10–15 mm
Min mouth opening	15 mm
Max implants	2 per 2-cm segment
Inter-implant spacing	≥3 mm
Implant to osteotomy site	≥3 mm
Implant to cortical plate	≥0.5 mm
Insertion torque	20–45 Ncm
Immediate load threshold	≥35 Ncm
Abutment divergence	≤15°
Guide accuracy	1 mm
Min implants per arch (overdenture)	4
Splint duration post-graft	6–8 weeks
Secondary implant healing interval	4–6 months
Delay after radiation (typical)	6–12 months

Survival Rates

Scenario	Survival
FFF implants, 1–5 years	93.5% (range 83.3–97%)
FFF implants, 10 years	~80% (range 78–83%)
FFF implants, 20 years	69%
Primary implantation (meta-analysis)	93.3%
Secondary implantation (meta-analysis)	93.4%
Implant loss, fibula (Ching)	8.6%
Implant loss, native mandible (Ching)	2.6%
Implant loss, native maxilla (Ching)	2.2%
Immediate loading, provisional prosthesis (Okay)	89.3%
Irradiated field, 1–5 years	91.33%
Irradiated field, 15 years	78–85%
Prosthesis survival (rehabilitated patients)	>98%

Recommended Implant/Prosthesis Characteristics

Feature	Recommendation
Implant brand	No influence on survival
Implant surface	Surface-treated (rough) preferred
Implant width	≥3 mm
Implant length	≥10 mm
Connector type	Bar > ball-and-socket
Definitive prosthesis	Fixed hybrid metal ceramic screw-retained
Prostheses to avoid	Cement-retained, acrylic (granulation tissue)
Implants per arch (overdenture)	4