You Do Need power plug adapter while traveling from Oman to Myanmar (Burma).

Here is Why You Need An Adapter

The outlet and plug type used in Myanmar (Burma) are A, C, D, G and I and in Oman is G. This is how they look like.

Oman

In Oman, outlets of type G are in use.

Type G

Myanmar (Burma)

In Myanmar (Burma), outlets of type A, C, D, G and I are in use.

Type A

Type C

Type D

Type G

Type I