BACKGROUND AND OBJECTIVES: The majority of patients with persistent idiopathic facial pain (PIFP) do not respond to conservative treatment and thus require alternative therapeutic modalities. This study compared the effects of transnasal and ultrasound (US)-guided suprazygomatic approaches for sphenopalatine ganglion (SPG) block on pain management in refractory PIFP. METHODS: This study included 38 patients with PIFP who underwent transnasal (Group T, n = 18) and US-guided suprazygomatic (Group U, n = 20) SPG block. Numeric Rating Scale (NRS) and Head Impact Test-6 (HIT-6) were used to assess therapeutic efficacy. Clinical evaluations were performed according to the scores recorded at baseline, 1 h, 1 week, and 4 weeks. RESULTS: Transnasal and US-guided suprazygomatic SPG blocks in patients with PIFP provided effective and successful treatment results between groups at 1 h, 1 week, and 4 weeks compared to baseline (P <
0.001). However, when NRS scores were compared at 1 h and 4 weeks, the US-guided suprazygomatic block provided significantly better pain relief (P = 0.041 and P = 0.030, respectively). No adverse effects were observed, except transient facial paresthesia described in two patients in Group U. CONCLUSIONS: This retrospective study concluded that US-guided suprazygomatic SPG block can provide effective pain relief in PIFP patients at 4-week follow-up. This method can be regarded as an alternative treatment option, given that it is both safe and simple to apply.