It is useful to take a systematic look at the theme of maxillofacial surgical reconstruction for an impression of the philosophy, the working and the limitations of this technically highly developed approach to restore form and function. Maxillofacial reconstructive surgery relies heavily on the exploitation of human anatomy and nature’s ingenious ways of incorporating resilience into living systems.

There are two aspects of classification: a systematic view of defects, and a systematic view of reconstructive techniques.

Classification of defects

In addition to the size, location and anatomical complexity, defects can be divided into types of tissue that needs to be reconstructed:

In practice, bone defects usually have some soft tissue component involved as well. It is often easier to think of the dominant tissue that is missing in the defect.

Reconstructive techniques

Many different reconstructive techniques are available:

Open wound healing can be the best option in certain circumstances, leaving a superficial open wound to heal. This includes laser wounds (see Figure 1), as well as some defects in young children.

There is clearly a limit to this option because deep or extensive wounds usually heal slowly with scarring and resulting deformity.

Figure 1: The result after granulation following laser excision of a small squamous cell carcinoma of the lateral (side) tongue.

Healing by primary closure is the most common reconstructive method used when the defect is small and the surrounding tissue is slack enough to allow advancement for closure of the wound. It provides the best outcome because the adjacent area provides similar quality tissue without the need for a separate donor site wound. The wound should also heal faster and, apart from suture removal, requires relatively simple aftercare.

Healing by primary closure is not a viable option when there is inadequate adjacent tissue because closure under tension will simply break down.

A graft is the transfer of tissue by complete separation from the donor site to the recipient site. This potentially dead piece of tissue then gains a new blood supply by ingrowth of new vessels from the recipient bed. This process works on the principle that the tissue’s nutritional needs are initially met by fibrin attachment with oxygen diffusion from the plasma of the tissue bed (coined ‘plasmatic imbibition’). Capillary ingrowth with establishment of new vascular supply follows shortly.

A graft can be from the same individual (autograft), from another individual of the same species (allograft) or from a different species (xenograft). Autografts are better for several reasons, including compatibility with the person’s immune system, lower rates of infection and ultimately better outcomes.

A graft can consist of

A flap is transferred tissue that has its own blood supply. Reconstruction using grafts (see above) is limited by the need for a well-vascularised recipient site for a graft to ‘take’. A flap is much less dependent on the recipient site for ‘take’ because it brings its own, new, blood supply. The use of flaps with their own blood supply allows more tissue bulk and predictable healing and viability. The greater tissue bulk in flaps can provide better form, structure and character in comparison with grafts. The better the blood supply, the larger and more complex the amount of tissue will be transferable.

A flap can be

Figure 2: Left: an example of arterial and venous micro-anastomosis; right: controversy exists on whether more (as shown here) or fewer venous anastomoses are advantageous.

There are two main patterns of blood supply for flaps – random or axial. A random pattern relies on general subcutaneous blood flow.  An axial flap supply is based on a specific vascular pedicle. Some flaps feature a combination of the two types of blood supply.

Free flaps can consist of soft or hard (bone) tissue, or a combination of both. Free flaps can be harvested from many different distant body locations.

The following two sections discuss in detail the different types of grafts and flaps and the reconstructive options for different types and locations of defects.

Table 1 gives an overview of reconstructive options for mouth, jaws and face.

Table 1 Options for reconstruction of the mouth, jaws and face

Options Advantages Disadvantages Indications
Leave to heal (open wound) Simple
No donor site
Contracture, scarring
Wound dressings needed
Superficial wounds
Some laser wounds
Primary closure Simple
No donor site Linear scar
Heal fastest
Dehiscence (splitting) risk
Adjacent tissue distortion
Small defects with lax adjacent tissue
Should be used whenever possible
Graft Relatively simple
Skills possessed by most surgeons
Reliance on healthy bed to take
Limited character and bulk (cosmesis)
Superficial wounds where primary closure is not feasible
Local flap Matching tissue characteristics
Ease of harvest
Can further distort local function if sizeable defect A popular option for small to medium defects
Distant pedicled flap Large tissue transfer from healthy region Poorer tissue match Donor site morbidity
Additional larger procedure
Medium to large defects
Distant free transfers Can tailor best tissue available to suit defect
Healthy tissue with good vascular supply allowing better healing
Complex procedure requiring specialised expertise
All or none phenomenon – failure will result in defect remaining
Anastomoses (and flap) at risk if patient is unstable medically
Reconstruction of choice for most significant defects in most patients fit for major surgery
Prefabricated flaps Better flap quality with modification or prefabrication Extra surgical procedure with prefabrication
Can risk flap outcome with previous surgery
Ideal for traumatic or congenital defects (less suitable for cancer patients with disease progression)
Prosthesis No surgical reconstruction needed
Allows inspection of defect for recurrence of malignancy
Needs expertise of prosthetist
Limited by patient’s compliance and dexterity
Low-level maxillary defects

Next section: Reconstruction