Table 1.

Basic characteristics of included studies and results of literature quality

Study	Location	Study design	Follow time	Sample (PSP/SP)	Age	Male (%)	Tumor size	Outcome	NOS
Lu, 2017	China	Retrospective study	6 months–5 years	92/76	20–74	44.05	0.8–4.0 cm	Surgery time, Tumor recurrence, Temporary facial nerve paralysis, Salivary fistula, Frey's syndrome	8
Ogreden, 2016	Turkey	Retrospective study	5 years	32/18	44.5	50		Frey's syndrome, Tumor recurrence	7
Al-Aroomi, 2021	China	Prospective study	12 months	20/35	18–77	56.4	2.8 cm	Surgery time, Temporary facial nerve, Permanent facial nerve, Frey's syndrome, Sialocele, Hematoma	7
Ruohoalho, 2017	Finland	Prospective study	12 months	53/32	20–86	44.7	0.3–5.5 cm	Temporary facial nerve, Permanent facial nerve, Frey's syndrome, Salivary fistula	8
Zhang,2013	China	Retrospective study	18 months	163/105	51	56	<  = 2 cm	Tumor recurrence, Temporary facial nerve, Permanent facial nerve, Salivary flow	6
Koch, 2010	German	Retrospective study	76.7 months	34/134	50.7	54.5		Tumor recurrence, Temporary facial nerve, Permanent facial nerve, Salivary fistula	7
Li,2014	China	Retrospective study	62 months	58/71	40.8	44	< 2 cm, 2–4 cm, > 4 cm	Tumor recurrence, Temporary facial nerve, Permanent facial nerve, Salivary fistula, Frey's syndrome, Operative time	7
Ciuman, 2012	German	Retrospective study	>  = 1 year	95/52		52		Temporary facial nerve, Permanent facial nerve, Frey's syndrome	6
Stathopoulos, 2018	Ireland	Prospective study	5 years	135/43	55.9	45	3.38 cm	Tumor recurrence, Temporary facial nerve, Permanent facial nerve, Frey's syndrome, Sialocele, Hematoma	6
Roh, 2007	Korea	Prospective study	48 months	52/49	11–82	47		Tumor recurrence, Temporary facial nerve, Permanent facial nerve, Frey's syndrome, Sialocele, Surgery time	7
Mlees, 2020	Egypt	Retrospective study	7 years	44/40	19–76	36	2.6/2.4	Tumor recurrence, Temporary facial nerve, Permanent facial nerve, Frey's syndrome, Sialocele, Hematoma, Surgery time	8
Huang, 2015	China	Retrospective study		79/241	19–83	41		Tumor recurrence, Temporary facial nerve, Permanent facial nerve, Frey's syndrome	8
Kilavuz, 2018	Turkey	Retrospective study	79 months	131/190	18–87	57		Tumor recurrence, Temporary facial nerve, Permanent facial nerve, Frey's syndrome, Salivary fistula, Hematoma, Surgery time	8
Emodi, 2010	Israel	Retrospective study	57 months	30/18	43	39.6		Tumor recurrence, Temporary facial nerve, Permanent facial nerve, Frey's syndrome, Surgery time	7
Papadogeorgakis, 2004	Greece	Retrospective study	55 months	42/17	30–77	61		Tumor recurrence, Temporary facial nerve, Permanent facial nerve, Frey's syndrome, Sialocele	7
Witt, 2009	USA	Retrospective study	1 month	100/20	57.3	45	2.1 cm	Sialocele	5
Plaza, 2015	Spain	Retrospective study	4 years	25/25	42	60	1.2–3.3 cm	Tumor recurrence, Temporary facial nerve, Permanent facial nerve, Frey's syndrome, Surgery time	6
Witt, 2002	USA	Retrospective study	8 years	20/20	42.2/45.7	43	1.94/2.0 cm	Tumor recurrence, Temporary facial nerve, Permanent facial nerve, Frey's syndrome	6
Schapher, 2021	German	Retrospective study	13.1 years	6/30	47.6	36	2.4 cm	Frey's syndrome	8
Zheng, 2019	China	Retrospective study	3 years	91/92	49/48	56	2.6/2.7 cm	Tumor recurrence, Temporary facial nerve, Permanent facial nerve, Sialocele, Frey's syndrome, Surgery time	7
Wong, 2018	New Zealand	Prospective study	31.58 weeks	56/40	18–86	46.5		Temporary facial nerve, Permanent facial nerve, Salivary fistula, Sialocele, Frey's Syndrome, Hematoma	8
Gao, 2017	China	Retrospective study	29.8 months	50/49	18–85	57.6	2.96/2.78	Temporary facial nerve, Permanent facial nerve, Frey's syndrome, Salivary fistula, Surgery time	7
Eski, 2018	Turkey	Retrospective study	41.79 months	22/17	51/57	51.3	2.5 cm	Tumor recurrence, Temporary facial nerve	8

Age is expressed as the mean or range (minimum–maximum)