Table 2.

Characteristic of included studies related to intraoral ultrasonography.

References	Nationality	Period	Study type	Pts (n)	Mean age	Gender (% of males)	Tumor site/subsite	T	N	US probe	Setting	Pearson (r)
Iida et al. (28)	Japan	2008–2015	Retrospective	56	59	61%	Tongue	1–4	0	16 MHz	Preoperative	0.86
Yesuratnam et al. (19)	Australia	2007–2012	Prospective	88	63	58%	Tongue	1–4	0	15–5 MHz	Preoperative	0.8
Chammas et al. (29)	Brazil	2006–2009	Prospective	19	60	58%	Tongue	1–4	1–3	5–10 MHz	Preoperative	0.83
Lodder et al. (30)	Netherlands	2004–2010	Retrospective	65	65	52%	Tongue/Fom	1–2	0–2	7–15 MHz	Intraoperative	0.93
Kodama et al. (31)	Japan	2005–2007	Prospective	13	61,6	62%	Tongue	1–2	0	7.5 MHz	Intraoperative	0.981
Mark Taylor et al. (32)	Canada	-	Prospective	21	65	57%	Tongue/Fom	1–4	0–2	10–12 MHz	Preoperative	0.981
Kaneoya et al. (33)	Japan	-	Prospective	48	57	56%	Tongue	1–2	0	12 MHz	Intraoperative	0.824
Baek et al. (34)	South Korea	2006–2007	Prospective	20	57	50%	Tongue	1–2	0	8–10 MHz	Intraoperative	0.744
Yamane et al. (35)	Japan	1998–2002	Prospective	109	57	70%	Tongue	1–2	0	10 MHz	Preoperative	0.985
Songra et al. (36)	United Kingdom	1997–2002	Prospective	14	-	-	Oral cavity	1–4	0–3	5–10 MHz	Preoperative	0.948
Kurokawa et al. (37)	Japan	2000–2003	Prospective	28	59,4	64%	Tongue	1–4	1–2	7.5 MHz	Preoperative	0.976
Shintani et al. (38)	Japan	-	Prospective	39	58	64%	Oral cavity	1–4	0–2	7.5 MHz	Preoperative	0.99

US, ultrasonography. Fom, floor of mouth.