Table 3.

Comparison of the number of lymph nodes identified by pathology and central neck lymph node metastasis in the CNs and control groups

	CN group (n = 334)	Control group (n = 52)	χ2(t/Z) value	P value
Number of identified lymph nodes ($\overline{x}\pm s$)
Unilateral CND	5.88 ± 4.12	6.02 ± 4.44	t = − 0.215	0.830
Bilateral CND	9.81 ± 5.68	11.06 ± 7.84	Z = − 0.178	0.859
Central neck lymph node metastasis (n/N, %)
LN (+)	176/334 (52.7%)	24/52 (46.2%)	χ2 = 0.771	0.380
LN (−)	158/334 (47.3%)	28/52 (53.8%)

CNs carbon nanoparticles, CND central neck dissection, LN lymph node