Clinical Scenario

A 73‐year‐old man presents to the dental clinic with an ulcer on the right side of the tongue which is particularly painful when speaking and eating. He feels that it may be related to an adjacent rough area on the lower jaw which he first became aware of approximately 2 months ago.

Oral Examination

• Poor oral hygiene with multiple soft and hard deposits all quadrants
• Chronic periodontal disease in relation to all the remaining teeth
• An area > 1 cm of bony exposure in the region of the right mandibular alveolar crest, painful on probing; no purulent discharge (Figure 16.2.1)
• An ulcer > 1 cm in the right lateral border of the tongue adjacent to the exposed area of bone
• Extensive caries in #44
• Partially edentate with missing posterior teeth: #14–17, #24–26, #35–37 and #45–47
• Overlying trauma from a poorly fitting lower partial denture

Structured Learning

1. What is your provisional diagnosis for the exposed area of bone?
   • Whilst it is important to exclude bone metastasis secondary to prostate cancer, the appearance of bone coupled with the patient’s history of taking an antiangiogenic drug suggests that the area of exposed bone is due to medication‐related osteonecrosis of the jaw (MRONJ)
   • This patient has associated pain on probing, suggestive of infection; hence this would be described as Stage 2 MRONJ
2. What MRONJ risk factors does this patient have?
   • Related to the antiresorptive drug: denosumab (high‐potency drug)
   • Related to other drugs: chemotherapy and corticosteroids
   • Patient‐related: older age
   • Local factors: poorly fitting lower partial denture causing trauma to the mandibular crestal ridge, poor oral health/existing periodontal disease
3. What are the treatment options for managing this lesion?
   • Antimicrobial treatment with a 0.12–0.2% chlorhexidine mouthwash (twice per day)
   • Antibiotics, e.g. doxycycline (200 mg/day) from 7 days prior to the surgery until 3 weeks after the procedure (or an alternative antibiotic regime)
   • Removal of sequestrum
   • Reduce trauma to the tongue (gently smooth the exposed bone)
   • Pain relief for the tongue ulcer (anaesthetic gel/anti‐inflammatory mouthwash)
   • Reduce trauma from the denture (avoid wearing it, adapt by adjusting it so that there is no contact, and/or replace with once the area has stabilised)
4. What factors are considered important in assessing the risk of managing this patient?
   • Social
     • Reduced mobility
     • Requires escort/support for attending appointments
   • Medical
     • Poor prognosis (metastasised prostate cancer)
     • Risk of acute adrenal insufficiency/crisis due to systemic steroids (see Chapter 12.1)
     • Local and distant infection risk, delayed wound healing and bleeding tendency due to adverse effects of the antineoplastic agent (see Chapter 12.2)
     • Risk of a hypertensive crisis (see Chapter 8.1)
     • Risk of complications due to hypertension‐related target organ involvement (see Chapter 8.1)
   • Dental
     • Poor oral hygiene
     • Periodontal disease
     • Lack of posterior occlusal support and hence increased risk of continued denture‐associated trauma may trigger further MRONJ
     • Extensive caries in #44: dental extraction can trigger further MRONJ; preferable to undertake endodontic treatment and seal the root surface; this also maintains support for the denture as an overdenture abutment
5. Would you advise the patient to discontinue denosumab in view of the MRONJ?
   • There is insufficient evidence to support or refute the discontinuation of bone‐modifying agents such as denosumab
   • Administration of denosumab may be deferred at the discretion of the treating physician, in conjunction with the patient and with input from the dentist regarding the oral findings
   • However, careful consideration should be given to the risks of discontinuation as the systemic complications in relation to the bony metastases in this patient are significant
   • As denosumab has a shorter half‐life than bisphosphonates, it has been suggested that if an oral surgical procedure is planned, this should be conducted no sooner than 1 month after the last injection and when there are at least 6 weeks until the next injection to allow for adequate healing (although there is some controversy on this matter)
6. What circumstances would justify referring the patient to a hospital‐based maxillofacial surgery department?
   • Medical comorbidities and frailty related to cancer diagnosis and the arterial hypertension (close liaison with the physician/oncologist required)
   • Significant haematological abnormalities due to the antineoplastic chemotherapy
   • If the sequestrum is large (greater than 3 cm) and/or if primary closure appears impossible
7. What antibiotics are indicated during the perioperative period?
   • Maxillofacial/oral surgeons mostly prefer penicillin‐based antibiotics plus beta‐lactamase inhibitor or metronidazole for MRONJ surgery
   • Based on empirical experience, doxycycline has also shown satisfactory results

General Dental Considerations

Dental Management

• For patients who are administered antiresorptive or antiangiogenic agents, the recommendation is to implement a protocol that includes preventive and procedural measures, mainly applicable when performing surgical procedures in the dentoalveolar area (Table 16.2.1)
• A risk assessment is required to ensure a specific informed consent is undertaken before any invasive dental procedure (Table 16.2.2)

Collect information on the drug product, dosage, envisaged treatment duration and concomitant administration of other drugs Provide verbal and written information to the patient about the risk of medication‐related osteonecrosis of the jaw (informed consent) Extract the non‐restorable teeth Perform restorative and prosthodontic treatment for the teeth with good prognoses Diagnose and treat periodontal disease Assess the risk of caries and periodontal disease Teach the patient oral hygiene techniques and implement an individual maintenance protocol For patients with cancer, close liaison with the oncologist is required to ensure adequate healing in relation to the timing of cancer therapy