Group

Number of operation

（n）

First operation stone clearance rate

First-stage Sinus Tract Stone clearance rate

Second-stage Sinus Tract Stone Clearance Rate

Total stone clearance rate

Stone clearance rate at 1 year

Observation

1.24±0.32

35（46.7）

24/40(60.0)

12/16(75.0)

71(94.7)

5/71(7.1)

Control

1.97±0.47

33（44.0）

12/42(28.6)

13/30(43.3)

58(77.3)

12/58(20.7)

Statistical value

t=6.124

χ²=1.862

χ²=12.537

χ²=14.763

χ²=7532

χ²=8.694

P value

P=0.035

P=0.283

P<0.001

P<0.001

P=0.021

P=0.016