Table 4 Regression analyses of risk factors for permanent facial weakness after parotidectomy

Gender

M vs. F (ref)

1.558

0.819

2.966

0.177

Age

Continuous

1.029

1.006

1.053

0.013

1.031

1.007

1.055

0.011

Pathology

Malignancy vs. benign (ref)

4.381

2.302

8.336

<0.0001

4.019

2.006

8.092

<0.0001

Tumor size

Continuous

1.316

1.074

1.613

0.008

1.159

0.932

1.441

0.186

Number of tumors

Multiple vs. single (ref)

2.518

0.844

7.507

0.098

Tumor subsite

Superficial (ref)

1

1

vs. deep

1.494

0.506

4.412

0.467

0.972

0.309

3.056

0.961

vs. both

5.895

2.741

12.680

<0.0001

2.769

1.130

6.788

0.026

Extent of surgery

ECD (ref)

1

vs. partial

2.154

0.276

16.804

0.464

vs. superficial

4.350

0.547

34.578

0.165

vs. total parotidectomy

19.800

2.576

152.201

0.004

Type of surgery (recurrent tumors)

Revision vs. primary surgery (ref)

5.289

2.266

12.345

0.0001

4.270

1.483

12.290

0.007