Histories & Contraindications
Patient Assessment and Clinical Justification
🎯 Learning Objectives
- Identify the clinical significance of medical history in radiography.
- Define “Contraindication” and “Indication” for dental X-rays.
- Understand the impact of Bisphosphonates and Radiation Therapy on bone health.
- Apply ALARA principles to pregnant and medically compromised patients.
1. Medical History “Red Flags”
Before pressing the exposure button, the dental assistant must review the medical history for conditions that affect bone density or healing. The DANB exam focuses on these specific areas:
Previous Radiation Therapy
Patients who have had radiation for head/neck cancer have a higher risk of Osteoradionecrosis (bone death). We must minimize extra radiation to these areas.
Pregnancy
While the ADA states dental X-rays are safe during pregnancy with a lead apron, elective X-rays (like an FMX) are often postponed until after delivery.
2. Medications & Radiography
Certain medications alter how we interpret radiographs or plan for surgery. One category is a “Must Know” for the exam:
Bisphosphonates (e.g., Fosamax, Boniva)
Used to treat osteoporosis or bone cancer. These drugs slow down bone turnover. On radiographs, the bone may appear extremely dense (radiopaque), and these patients are at risk for MRONJ (Medication-Related Osteonecrosis of the Jaw) if they undergo extractions or implants.
3. Clinical Justification
Radiographs should never be taken “because it’s been 6 months.” Clinical Indications must justify them:
- Indication: A reason to take an X-ray (e.g., toothache, deep decay, history of perio).
- Contraindication: A reason not to take an X-ray (e.g., a patient just had an FMX at another office yesterday).
🚨 DANB EXAM ALERT: Transfer of Records
The most effective way to reduce radiation exposure (ALARA) is to request previous radiographs from the patient’s prior dentist. Taking a new FMX because “it’s easier than calling the other office” violates radiation safety standards.