Osteonecrosis Of The Jaw: Symptoms, Types, Causes and Treatment

Osteonecrosis of the jaw (ONJ) is a rare but serious condition where the bone tissue in the jaw fails to heal and begins to die, often after dental procedures or as a side effect of certain medications. Awareness and understanding of this disease are essential for patients, dentists, and healthcare providers, especially as ONJ is most commonly associated with drugs used to treat cancer and osteoporosis. In this article, we’ll explore ONJ in depth—reviewing its symptoms, types, causes, and treatment strategies—so you can better understand this challenging condition and how it is managed today.

Symptoms of Osteonecrosis Of The Jaw

Osteonecrosis of the jaw can be subtle in its early stages, but as it progresses, the symptoms become increasingly noticeable and problematic. Recognizing these symptoms early is crucial for prompt intervention and better outcomes. Let’s take a closer look at the symptoms you should be aware of.

Symptom	Description	Stage/Severity	Source(s)
Exposed Bone	Persistent area of bone in the jaw visible through the gum	Hallmark sign, present for more than 8 weeks	1 3 7
Pain	Ache or discomfort in the jaw or mouth	Common, may be severe	1 6 7
Swelling	Swelling of the gums or jaw area	May accompany infection	1 3 7
Loose Teeth	Teeth may become unstable or fall out	Often with advanced disease	1 7
Infection	Gum or soft tissue infection near jawbone	Can cause pus, bad breath	1 2 7
Ulceration	Non-healing sores or ulcers in the mouth	May expose bone	1 3
Numbness	Paresthesia in the chin, lip, or jaw	Indicates nerve involvement	1 7

Table 1: Key Symptoms

Understanding the Symptoms

ONJ often starts quietly. The most distinctive symptom is an area of exposed, necrotic bone in the jaw that does not heal for more than eight weeks, especially in patients with a relevant medication history and no history of radiation therapy to the head and neck (1 3 7). However, not all cases begin with visible bone—early symptoms can include jaw pain or discomfort, which may prompt a dental visit.

Progression of Symptoms

• Mild/Early Stage: Discomfort or pain in the jaw; sometimes tingling or numbness.
• Moderate Stage: Swelling, gum infection, and development of non-healing ulcers.
• Advanced Stage: Persistent exposed bone, loose teeth, significant pain, soft tissue infection, and possibly numbness due to nerve involvement (1 6).

Staging

Clinicians often classify ONJ into four stages (0 to 3), ranging from no clinical evidence of necrotic bone but nonspecific symptoms (stage 0) to extensive exposed bone with infection and possible jaw fracture (stage 3) (1 7).

Types of Osteonecrosis Of The Jaw

Osteonecrosis of the jaw is not a single disease but a group of related conditions with different underlying causes and clinical presentations. Understanding these types helps tailor prevention and treatment strategies.

Type	Main Cause/Trigger	Clinical Features	Source(s)
MRONJ	Medications (bisphosphonates, denosumab, antiangiogenics)	Exposed necrotic jawbone, linked to medication use	2 3 5 7
ORN	Radiation therapy for head/neck cancer	Non-healing bone post-radiation	4 10
Other	Steroids, immunomodulators, recreational drugs	Jawbone necrosis, rare and variable	4 11

Table 2: Types of Osteonecrosis of the Jaw

Medication-Related ONJ (MRONJ)

MRONJ is the most common and widely discussed form, resulting from the use of antiresorptive drugs (like bisphosphonates and denosumab) or antiangiogenic agents. It typically presents after dental extractions or trauma in patients being treated for cancer or osteoporosis (2 3 5 7 11).

Osteoradionecrosis (ORN)

ORN occurs after radiation therapy to the head and neck, damaging blood supply and bone healing capacity. The clinical picture is similar but the cause is distinct—no relevant medication, but a history of significant radiation exposure (4 10).

Other, Less Common Types

Other causes include long-term steroid therapy, immunomodulatory drugs, or even recreational drug use, each leading to jawbone necrosis through different mechanisms (4 11). These are less common but can present similarly.

Staging Across Types

While MRONJ and ORN have their own staging systems, both recognize increasing severity from mild, nonspecific symptoms to extensive bone loss and secondary complications (7 10).

Causes of Osteonecrosis Of The Jaw

Understanding what causes ONJ is essential for prevention and risk reduction. The underlying mechanisms are complex and often multifactorial, involving medication effects, local trauma, and individual patient factors.

Cause/Trigger	Mechanism/Pathway	Risk Factors	Source(s)
Antiresorptive Drugs	Inhibit osteoclasts, suppress bone remodeling	High-dose, IV use, cancer therapy	2 3 5 7 8
Antiangiogenic Drugs	Inhibit new blood vessel formation	Cancer therapy	3 5 11
Radiation Therapy	Damages blood supply, impairs healing	High-dose, head/neck sites	4 10
Dental Procedures	Extractions/trauma create entry for infection	Poor dental health, invasive surgery	1 7 9
Local Infection	Promotes inflammation, bone exposure	Poor oral hygiene, periodontitis	1 2 7
Systemic Factors	Diabetes, immunosuppression, steroids	Chronic illness, elderly	7 11

Table 3: Common Causes and Risk Factors

Medications: Bisphosphonates, Denosumab, and Others

• Bisphosphonates: These drugs suppress bone resorption by inhibiting osteoclasts, leading to improved bone density but also decreased bone turnover and healing capacity. High-dose intravenous bisphosphonates, commonly used in cancer patients, pose the greatest risk (2 3 5 7 8).
• Denosumab: A monoclonal antibody that blocks osteoclast formation, function, and survival, denosumab has a similar risk profile for ONJ as bisphosphonates, especially at high doses (2 3 8).
• Antiangiogenic Agents: Used in oncology to inhibit new blood vessel formation, these drugs can impair bone healing and contribute to jaw necrosis (3 5 11).

Radiation-Induced

Radiation therapy for head and neck cancers can cause osteoradionecrosis by damaging the jawbone’s blood supply, making it less able to repair itself after minor injuries or dental procedures (4 10).

Dental Procedures and Local Factors

Tooth extractions and other invasive dental procedures are major local risk factors, especially in patients on antiresorptive or antiangiogenic therapy. Poor oral hygiene and pre-existing dental disease further increase the risk (1 7 9).

Infection and Systemic Factors

Oral infection, chronic inflammation, diabetes, and immunosuppression weaken the body’s ability to heal, increasing susceptibility to ONJ (1 2 7 11). Glucocorticoid (steroid) use and advanced age also contribute.

Multifactorial Pathogenesis

The current understanding is that ONJ results from a combination of:

• Suppressed bone turnover (due to medication)
• Impaired blood supply (due to medication or radiation)
• Local trauma (from dental procedures or ill-fitting dentures)
• Infection and inflammation (2 3 8 11)

Treatment of Osteonecrosis Of The Jaw

Treating ONJ can be challenging and must be tailored to the individual patient. The main goals are to control infection, limit the progression of bone necrosis, alleviate pain, and preserve quality of life. There is no universal “gold standard,” and management often depends on the stage of the disease.

Treatment	Approach/Method	Indication/Stage	Source(s)
Conservative	Oral rinses, antibiotics, pain relief	Early/less severe cases	1 9 11 13
Surgical	Debridement, sequestrectomy, resection	Advanced/non-responsive cases	7 13 14
Drug Holiday	Temporary cessation of at-risk medications	Before/during surgery (case-by-case)	13
Preventive	Dental checkups, oral hygiene, pre-treatment screening	High-risk patients	2 3 7 9 11 12
Experimental	Stem cell therapy, growth factors, laser therapy	Under investigation	6 7 12

Table 4: Treatment Strategies

Conservative Management

• When Used: Preferred in early stages or when surgery is contraindicated due to comorbidities.
• What It Involves: Includes antimicrobial mouth rinses (e.g., chlorhexidine), systemic antibiotics for infection, and pain control. Conservative therapy aims to stabilize the disease and prevent progression (1 9 11 13).
• Effectiveness: Often effective in early-stage MRONJ, but less so in advanced stages (13 14).

Surgical Management

• When Used: Reserved for advanced, non-responsive, or severe cases with extensive necrosis or persistent symptoms.
• What It Involves: Surgical removal of necrotic bone (debridement or sequestrectomy), sometimes followed by reconstruction. Surgery aims to remove dead bone and enable healing (7 13 14).
• Outcomes: Surgery can achieve complete healing in many cases, especially if conservative management fails (14).

Drug Holiday

• What It Is: Temporarily stopping antiresorptive or antiangiogenic medication before invasive dental procedures.
• Evidence: May improve healing after surgery, but should be considered on an individual basis, balancing the risks and benefits (13).

Preventive Strategies

• Dental Screening: Assess and treat dental disease before starting at-risk medications (2 3 7 9 11 12).
• Oral Hygiene: Ongoing professional cleanings and patient education reduce risk.
• Antibiotics: Prophylactic antibiotics around dental surgery can lower risk (2 12).

Experimental Therapies

• Emerging Treatments: Include application of growth factors (e.g., VEGF), stem cell therapy, low-level laser therapy, and hyperbaric oxygen. These are still under investigation and not standard care (6 7 12).

Multidisciplinary Care

A team approach, involving dentists, oncologists, and maxillofacial surgeons, is essential for optimal outcomes. Treatment should be tailored to the individual, considering disease stage, comorbidities, and patient preferences (1 9 11).

Conclusion

Osteonecrosis of the jaw is a complex, multifactorial disease that requires vigilance and collaboration for prevention, early detection, and effective management. Here’s what we’ve covered:

• Symptoms: Persistent exposed jawbone, pain, swelling, infection, loose teeth, and numbness are key signs to watch for in at-risk individuals.
• Types: ONJ includes medication-related (MRONJ), radiation-induced (ORN), and rarer forms linked to steroids or immunomodulators.
• Causes: Most commonly linked to antiresorptive and antiangiogenic drugs, especially in cancer and osteoporosis patients, but also associated with radiation and local trauma.
• Treatment: Ranges from conservative (antibiotics, rinses) to surgical (debridement, resection), with prevention and dental screening being crucial. Experimental therapies are on the horizon.

Key Points:

• Early recognition and prevention are pivotal.
• Staging guides treatment choices.
• Conservative management is first-line for early cases; surgery for advanced or refractory disease.
• Multidisciplinary care is essential for best outcomes.
• Ongoing research promises new strategies for prevention and healing.

Staying informed and working closely with your healthcare team can help minimize the risks and complications of osteonecrosis of the jaw.