Bone Grafting

An Overview

When a tooth is removed, the jawbone associated with that tooth collapses. This often leaves poor quality and quantity of bone needed for placement of dental implants.

Today, we can regrow that lost bone. This not only gives us the opportunity to place implants of proper length and width, it also gives us a chance to restore functionality and esthetics.

Bone grafting can repair potential implant sites with inadequate bone structure due to previous extractions, gum disease or injuries. The bone is typically obtained from a tissue bank, or in some cases from inside the mouth. In addition, special barrier membranes may be utilized that protect the bone graft and encourage bone regeneration. This is called guided bone regeneration (GBR). Sinus bone grafts are also frequently performed to replace bone in the posterior upper jaw.

The Importance of Teeth for Jawbone Health

When teeth are extracted jawbone is lost. This loss of can develop into additional problems, both with your appearance and your overall health.

In that same way that muscles are maintained through exercise, bone tissue is maintained by use. Natural teeth are embedded in the jawbone, and stimulate the jawbone through activities such as chewing and biting. When teeth are missing, the portion of the jawbone that anchors the teeth in the mouth, no longer receives the necessary stimulation, and breaks down. The body no longer uses or “needs” the jawbone, so it deteriorates and goes away.

Potential Consequences of Tooth and Jawbone Loss

Inability to chew
Unattractive smile
Problems with remaining teeth, including, misalignment, drifting, loosening and loss
Collapsed facial profile
Limited lip support
Skin wrinkling around the mouth
Distortion of other facial features
Tempromandibular joint (TMJ) pain, facial pain, and headaches
Difficulty speaking and communicating
Inadequate nutrition as a result of the inability to chew properly and painlessly
Sinus expansion

Jawbone Loss and Deterioration

The following are the most common causes for jawbone deterioration and loss that may require a bone grafting procedure:

Tooth Extractions

When an adult tooth is removed and not replaced with an implant or bone grafted, jawbone deterioration may occur.

Periodontal Disease

Periodontal diseases are ongoing infections of the gums that gradually destroy the support of your natural teeth. Periodontal disease destroys bone that holds in teeth.

Dentures/Bridgework

Unanchored dentures are placed on top of the gum and do not provide any direct stimulation to the underlying bone. Over time, the lack of stimulation causes the bone to resorb. Because this type of denture relies on the bone to hold them in place, people often experience loosening of their dentures and problems eating and speaking. Eventually, bone loss may become so severe that dentures cannot be held in place even with strong adhesives, and a new set may be required. Proper denture care, repair, and refitting are essential to maintaining oral health. Some dentures are supported by anchors, which do help adequately stimulate, and therefore preserve bone. This problem can be solved by placement of dental implants.

Trauma

Teeth can be knocked out from injury or accident, jaw fractures, or teeth with a history of trauma that experience nerve death and lead to bone loss years after the initial trauma.

Misalignment of Teeth

Misalignment issues can create a situation in the mouth where some teeth no longer have an opposing tooth structure. The unopposed tooth can erupt, causing deterioration of the underlying bone.

Issues such as TMJ problems, normal wear-and-tear, and lack of treatment can also create abnormal physical forces that interfere with the teeth’s ability to grind and chew properly. Over time, bone deterioration can occur where bone is losing stimulation.

Pathology

Some conditions, syndromes, or birth defects are characterized by missing portions of the teeth, facial bones, jaw or skull. Additionally, removal of some benign growths in the gums and/or jaws may result in removal of a large portion of bone.

Sinus Deficiencies

When molars are removed from the upper jaw, resorption of the bone that formerly held the teeth in place occurs. As a result, the sinuses become enlarged. This condition usually develops anywhere from three months to several years following tooth removal in some of these cases the bone must be rebuilt (a sinus elevation) before dental implants can be placed.

What is Bone Grafting?

Bone grafts are used to replace bone destroyed by periodontal diseases, tooth extractions, or improperly fitted dentures.

Types of Bone Grafts

➤ Autogenous Bone Grafts

Autogenous bone grafts, also known as autografts, are your own bone, taken from somewhere else in the mouth. Autogenous bone grafts are advantageous in that the graft material is live bone, meaning it contains living cellular elements that enhance bone growth.

However, one downside to the autograft is that it requires a larger surgical area.

➤ Allogenic Bone

Allogenic bone, or allograft, is bone harvested from a human cadaver, then processed using a freeze-drying method to extract the water, cellular components, and proteins. Unlike autogenous bone, allogenic bone cannot produce new bone on its own. Rather, it serves as a framework or scaffold over which bone from the surrounding bony walls can grow to fill the defect or void. Disease transmission associated with properly harvested allogenic bone has not been reported.

➤ Xenogenic Bone

Xenogenic bone is derived from another species, usually a cow. The bone is processed at very high temperatures to avoid the potential for immune rejection and contamination. Like allogenic grafts, xenogenic grafts serve as a framework for bone from the surrounding area to grow and fill the void.