Glossary

Biphosphonates are a class of drugs that are used to prevent the loss of bone density in cases of osteoporosis, or in cases of other bone problems where the density of bone is abnormal. Sometimes they are prescribed after an injury where there are abnormal bone fractures in the wrist, arm, spine, or hips. They are also given to patients who are at a higher risk of issues like osteoporosis or at a risk for bone loss due to taking certain medications like steroids. The most common bisphosphonates are alendronate, ibandronate, risedronate and zoledronic acid. Although these medicines can be helpful in patients with certain conditions, they do come with side effects. For example, the side effects of bisphosphonates include but are not limited to joint and muscle pain, heartburn, nausea, difficulty swallowing, irritation of the esophagus, and gastric ulcers. The medicine can also cause a serious side effect of osteonecrosis of the jaw bone.

Osteonecrosis of the jaw is a rare condition with many different causes. About 95% of cases of osteonecrosis could be attributed to high-dose, IV administered bisphosphonate therapy in cancer patients, while the remaining 5% were attributed to low-dose bisphosphonate therapy used for patients with osteoporosis. Osteonecrosis of the jaw is defined as an area of bone that is exposed to air, causing damage, and does not heal on its own within 8 weeks. It is not well understood how bisphosphonate therapy contributes to osteonecrosis of the jaw, because osteonecrosis can also occur in people who are not taking bisphosphonates. However, bisphosphonate-associated osteonecrosis (BON) can be clinically diagnosed in patients who have had an exposed area of bone in the maxillofacial area that has not healed within 8 weeks and who are currently taking bisphosphonates and are not receiving radiation. Also, other causes must be excluded, like periodontal disease and trauma.

Studies have shown that the use of bisphosphonate in patients with cancer is associated with osteonecrosis of the jaw. While osteonecrosis can be caused by a number of other factors, this particular form of the condition is called bisphosphonate-induced osteonecrosis of the jaw (BIONJ). Patients who have been on long term, high-dose bisphosphonates to manage different types of cancer (typically breast cancer, prostate cancer, and myeloma)are at risk for BIONJ if they get a tooth extracted. The bone becomes exposed to air and becomes necrotic after not healing on its own for several weeks. About 5% of patients with cancer who are also being treated with bisphosphonates will get bisphosphonate-induced osteonecrosis of the jaw, and the risk is lower in patients who do not have cancer. Physicians should recommend that their patients see a dentist prior to beginning bisphosphonate treatment as well as during treatment.

Bisphosphonate-related osteonecrosis of the jaw, or BRONJ, is a complication that may be experienced by a patient who has not received radiation treatments to the head or neck and who is under current or previous bisphosphonate treatment. The condition is characterized by exposed necrotic bone in the maxillofacial region that does not heal within eight weeks after diagnosis and proper care. Bisphosphonates are a class of drug that are prescribed to individuals at risk for bone resorption as experienced in osteoporosis, hypercalcemia of malignancy, and metastatic cancers which have spread to the bone. There is an established association between the use of these drugs and BRONJ though not all patients taking bisphosphonates will experiences this condition. Risk factors for developing BRONJ include route of administration (intravenous versus oral), duration of therapy, and type of bisphosphonate (nitrogen containing or not). The majority of individuals who develop BRONJ as a result of bisphosphonate received the drug intravenously.

Osteoporosis is a serious condition, and the most common metabolic bone disease in the world. The standard treatment for osteoporosis is oral bisphosphonates, which unfortunately can cause a host of unpleasant side effects. Common side effects include acid reflux, esophageal irritation, and stomach ulcers. One of the most serious side effects of this type of therapy is bisphosphonate-related osteonecrosis of the jaw (BRONJ). It’s not well understood how bisphosphonate therapy causes or contributes to BRONJ, but risk factors have been identified, such as steroid usage and dentoalveolar surgery. To isolate this condition from others, the American Society for Bone and Mineral research states that a BRONJ diagnosis can be made if a patient is currently being treated or has been treated with a bisphosphonate medication, has exposed bone in the maxillofacial region that has not healed in 8 weeks or more, and has no history of jaw radiation therapy.

Bruxism is a common condition where a patient clenches or grinds their teeth together. They often do this without their own knowledge, particularly during sleep. High amounts of stress and anxiety can contribute to bruxism, and bruxism tends to go hand-in-hand with TMJ, or temporomandibular joint disorder. Bruxism that is untreated can cause mild to severe pain in the jaw and teeth, and can even cause headaches. Bruxism can cause wear and tear up to 80 times the normal amount of wear and tear on the teeth, and it’s important to protect the teeth from damage along with reducing the unpleasant symptoms of bruxism. A bite splint is a simple device that is available from your dentist and is typically worn at night. Some dentists may recommend that it be worn during the day if bruxism is severe. A bite split reduces the pressure and grinding of teeth, relieving symptoms and protecting teeth from damage.

Bone loss often shows up as a black space on a dental x-ray. The amount of bone loss determines how much space is shown. On a normal x-ray, the bone and gums will be level with the bottom of the teeth, between the crown and the root. A very small amount of black space may be present, but this typically does not indicate bone loss. When there is a large amount of black space and the bone and gum line is below the bottom of the tooth and in line with the root of the tooth, this indicates significant bone loss. In some cases of very severe bone loss, the black space on a dental x-ray will extend beyond the roots of the tooth and potentially even below them. For patients with bone loss indicated by black space on an x-ray, bone grafting may be recommended, especially in cases where a dental implant is being considered.

A black triangle in between the teeth can indicate a number of issues. While it may start out small at first, it can widen into a larger triangle shaped gap if not treated. This black triangle most likely indicates that the gums are starting to recede, which is often due to periodontal disease. A deep cleaning, or a scale and root planing, may be necessary to remove plaque and debris far up underneath the gum line. A black triangle in between the teeth can also be an indicator that bone loss is beginning to occur, which may go hand in hand with periodontal disease. Advanced periodontal disease can cause bone loss, which in turn weakens the entire structure of the jaw and teeth. Patients that notice black triangles in between their teeth should see a dentist promptly, particularly if it appears that the black triangles started out small and are beginning to get larger in size.

A blade implant is a laminar endosseous dental implant that is designed to be placed within the bone. Blade implants were developed for use in the alveolar crest but are especially suited to being placed in thin alveolar bone. This type of implant could allow some patients to avoid alveolar bone grafting procedures by utilizing tricortical anchorage. While titanium blade implants do show a high rate of osseointegration and can help patients avoid receiving bone grafts, they are also subject to higher rates of failure when placed by a surgeon who does not have sufficient experience with blade implant procedures. The success of the blade implant depends upon several factors which must be carefully evaluated prior to its placement. These factors include use in atrophic crestal bone, failure to consider the patient’s tongue movements, and failure to accurately evaluate the patient’s alveolar crest anatomy. For a blade implant to be successful, the practitioner must have experience in selecting the proper patient.

Bone density indirectly indicates an individual’s risk of fracture. Bone density is determined by performing an investigative test to measure the degree of mineralization of trabecular bone that is present in a certain volume of bone. The degree of mineralization can be determined using dual-energy X-ray absorptiometry (densitometry). Dental Implant Surgeons use the quantitative measurement of minerals in bone to indicate the structural strength of a patient’s jawbone.

Historically, the volume of a patient’s exiting bone was the main factor used when creating a dental implant treatment plan. When less bone was available, fewer and/or shorter implants were used. Patients with large bone volumes would receive more and/or longer implants. However, treatment plans today take the final prosthesis options into consideration first. The patient’s desires are noted. Bone density in the areas where implant abutments will be placed must be evaluated.

Today, it is the density of the bone that determines treatment planning, including:

• Surgical approach
• Implant design
• Healing time
• Initial progressive bone loading during prosthetic reconstruction