Α. Osteoradionecrosis

Osteoradionecrosis is a potentially serious late complication of head and neck radiotherapy.

Its incidence varies among the different cancer centers, between 2% - 22%.
The mandible is the most common location for the development of necrosis.

Increased risk of osteoradionecrosis has been observed in patients after a dental extraction, during or after radiotherapy.

Clinically, osteoradionecrosis is characterized by a non-healing ulceration of the mucosa, with the exposure of necrotic bone.
The patient complains of dysgeusia, bad taste, paraesthesia, and local pain. The exposure of the bone may lead to pathologic fracture.

Risk factors for the development of osteoradionecrosis:

• The total and daily dose of radiation
• Preceded surgery
• The oral and dental health of the patient
• Trauma, local infection, periodontal disease, periapical lesions
• The location of the tumor with infiltration of the jaw
• The intralesional radiation, in case of tumor location in the floor of the mouth

Treatment of osteoradionecrosis

Treatment varies according to severity of the clinical picture.
Conservative treatment with good oral hygiene, local antiseptics and antibiotics may show be beneficial.
In addition, the necrotic bone may be removed surgically. The treatment with hyberbaric oxygen may also help.

Selected references

1. Νικολάτου-Γαλίτη Ο. Οι βλάβες του στόματος στον ογκολογικό ασθενή. Εκδόσεις Μπονισσέλ. Αθήνα 2001.
2. Cooper JS et al. Late effects of radiation therapy in the head and neck region. Int J Radiation Oncology Biol Phys 1995;31:1141-1164.
3. Curri MM et al. Osteoradionecrosis of the jaws: a retrospective study of the background factors an dtreatment in 104 cases. J Oral Maxillofac Surg 1997;55:540-544.

Β. Jaw bone necrosis in oncology patients receiving bisphosphonates

Bisphosphonates prevent the function of osteoclasts.
They have also antiangiogenic effect and act against the neoplastic cell increase, while they promote their apoptosis.
They contribute to patients' quality of life.

Bisphosphonates are administered mainly to patients with multiple myeloma, breast and prostate cancer, when they develop bone disease.

Since 2003, the administration of bisphopshonates has been related to the appearance of jaw bone necrosis.
The incidence of the necrosis varies between 8% - 10%.

Promoting factors for the necrosis:

• Necrosis develops under several promoting factors in about 75% - 80%
  of the cases
• The most common factor is tooth extraction
• Less common is periodontal surgical treatment, apicoectomy, dental implants, the presence of advanced periodontitis, trauma from ill fitting dentures, the orthodontic treatment.
• Necrosis is "automatic" in about 20% - 25% of the cases.

Predisposing factors:

• Genetic predisposition
• Concurrent administration of antineoplastic chemotherapy or radiotherapy
• States that predispose to necrosis, such as vascular disease, kidney disfunction, alcohol and smoke, poor nutrition, and female gender

Clinical picture:

• Pain, paraisthesia
• Inflammatory-like picture which mimics dental or periodontal inflammatory disease
• Inability of an ulcer to heal
• Ulceration of the oral mucosa
• Dead bone, exposed in the oral cavity
• Edema of the surrounding soft tissues
• Fistulas with pus
• Chronic sinusitis, and oroantral fistula
• The mandible is most commonly affected (65%)
• The necrosis develops usually after 9 - 40 months
• Biopsy and histologic examination is recommended for the differential diagnosis of the necrosis from metastatic disease

Treatment:

It aims at: the prevention of superinfetions of soft tissues, the pain control, the prevention of osteomyelitis and extention of the lesion

Treatment is mainly conservative and includes:

• Mouthwashes with antiseptics
• Antibiotics, continueusly or intermittent
• Antifungals and antivirals, when needed
• The interruption of bisphosphonates is not recommended

Prevention of osteonecrosis:

α) before the initiation of bisphosphonates

• Immediate and thorough evaluation of the oral mucosa, teeth and periodontium
• Tooth extractions , if needed or any other oral surgical procedure should be performed at least one month before the initiation of bisphosphonates
• The patient is well educated on the importance of the good oral health and the referral of symptoms to his doctor. Written consent is obtained.

β) after the initiation of bisphosphonate therapy

• Oral, dental and periodontal evaluation every 3 - 4 months
• Preservation of optimum oral care
• Topical fluoride applications
• Regular check up of the dentures
• Avoid tooth extractions, prefer endodontic treatments
• Avoid any oral surgical procedure
• Inform the patient and get a signed consent about the benefit versus risk for the administration of bisphosphonates
• Dentists should also get the consent of the patient for any surgical dental procedure during bisphopshonate therapy

Selected references

1. Χanthinaki Α, Nicolatou-Galitis O, et al. Jaw bone necrosis in bisphosphonates. Report of 10 cases and review of the literature. Sent for publication to Greek Forum of Clinical Oncology.
2. Bamias A, Kastritis E, Bamia C, et al. Osteonecrosis of the jaw in cancer after treatment with bisphosphonates: incidence and risk factors. J Clin Oncol 2005;23:8580.
3. Expert panel recommendation for the prevention, diagnosis and treatment of osteonecrosis of the jaw: March 2005. Professional education material; Novartis March 2005.
4. Marx RE, Sawatari Y, Fortin M, et al. Bisphosphonate-induced exposed bone (osteonecrosis/osteopetrosis) of the jaws : risk factors, recognition, prevention, and treatment. J Oral Maxillofac Surg 2005;63:1567
5. Μigliorati CA, Schubert MM, Peterson DE, et al. Bisphosphonate-associated osteonecrosis of mandibular and maxillary bone. An emerging oral complication of supportive cancer therapy. Cancer 2005;104:83.
6. Migliorati CA et al. Bisphosphonate-associated osteonecrosis: a long-term complication of bisphopshonate treatment. Lancet Oncol 2006;7:447-449.