. 2020 Jun 12;20(4):642–648. doi: 10.1007/s12663-020-01391-2

Table 2.

Comparison of postoperative swelling and edema between two study groups in different time intervals

	Group	Number	Mean ± SD	Range (min–max)	P value
Postoperative edema on 2nd day	Piezotome	20	3.00 ± 0.65	2–4	z = 0.45 P = 0.655
Postoperative edema on 2nd day	Conventional diamond round bur	20	3.07 ± 0.70	2–4	z = 0.45 P = 0.655
Postoperative edema on 7th day	Piezotome	20	1.67 ± 0.82	1–4	z = 0.63 P = 0.527
Postoperative edema on 7th day	Conventional diamond round bur	20	1.53 ± 0.64	1–3	z = 0.63 P = 0.527

Z Mann–Whitney test