Double faced models problem

[Ectevy]

Hello everyone,
I'm currently ripping Digimon world 1 models and for some of them I've encountered a small problem.
When a model needs to have two faces (like for wings, teeth, hair or a transparent body), it shows as "gltiched" in any 3d software.
For example:

Spoiler

Here the model is must be completely white, like the area around the mouth.

Spoiler

and here The wings must like the one at the top right.

I don't really know why some area appears normally and the other not but if any of you know to correct this problem and what is the cause I'll be glad to hear about it.

[HavocHardee]

Hello everyone,
I'm currently ripping Digimon world 1 models and for some of them I've encountered a small problem.
When a model needs to have two faces (like for wings, teeth, hair or a transparent body), it shows as "gltiched" in any 3d software.
For example:

Spoiler

Here the model is must be completely white, like the area around the mouth.

Spoiler

and here The wings must like the one at the top right.

I don't really know why some area appears normally and the other not but if any of you know to correct this problem and what is the cause I'll be glad to hear about it.

Could you upload the file your working on so I can see exactly what your talking about?

[Ectevy]

Here you go !
Just in case I used Blender for the screenshots.