I do not know the correct English term for the position, so I will just refer it to as "chest-side down". The following CNN page seem to call it the "stomach position", and they say it is the worst position to sleep.
They have listed the shortcomings of that position, but there is no detailed explanation. I do not feel any pain when I sleep chest-side down other than pain on my neck, but this is only because I have to turn my face to one side, and this can be fixed if I buy a special pillow (something used at a massage shop).
Is it really true that it causes back pain? We are mammals and almost all mammals live and sleep chest-side down. Dogs, for example, seem to love to rest their chest and head laid down on the floor. Do we have some special spines that need to be rested chest-side up, unlike other mammals?
And secondly, how does it cause more wrinkles than sleeping chest-side up?
Bad for: Avoiding neck and back pain, minimizing wrinkles
The scoop: "Stomach-sleeping makes it difficult to maintain a neutral position with your spine," Shannon explains. What's more, the pose puts pressure on joints and muscles, which can irritate nerves and lead to pain, numbness, and tingling.