Is small FOV CBCT indicated before retreatment of #16 with suspected missed MB2?

**Is small FOV CBCT indicated before retreatment of #16 with suspected missed MB2?**

30s M. Tooth #16 — failed RCT, now acute flare-up (fever 38.1°C, pain, right-sided nasal congestion, blood-tinged postnasal drip).

Retreatment started at dental faculty: old GP removed, **3 canals instrumented** (MB 15mm, DB 19mm, P 21mm), Ca(OH)₂ placed. No CBCT, no microscope. Amoxicillin + metronidazole ×5 days. Fever now resolved (36.3°C).

**Concern:** MB2 likely missed. Only 3 canals found without magnification or CBCT. Next appointment is with a private endodontist on April 20 — Ca(OH)₂ can wait.

**Questions:**

1. Is small FOV CBCT clearly indicated here per AAE/AAOMR guidelines (Recommendations 7 & 8)?

2. One imaging center refused without a written referral, citing radiation — is that justified for a 20-100 μSv scan with clear clinical indication?

3. Is the blood-tinged postnasal drip likely just mucosal irritation, or concerning for sinus perforation?

NAD