my dental scanner mesure things in microns , and when i use meshmixer , meshmixer changes the dimensions of my object

[walaababeer]

sometimes when I import stuff to meshmixer to hollow, meshmixer changes the dimensions of the object what are the solutions for this problem.? dental scanners measure everything in microns and the smallest dimension in meshmixer is mm how can I balance between these 2 units?

[hfcandrew]

Go Analysis>Unit/Dimensions and see what it says the size is in millimeters.

If it is scaled wrong then you may need to divide by 1000 (bc 1000 microns are in 1 millimeter) and retype that number in.

[MagWeb]

If the result of the division owns more than 3 decimal places and you put it into one of the fields in Units/Dimensions MM will crops the displayed number in the field to 3 decimal places while MM actually handles more than 3 decimal places (not sure about how many). E.g. look at the numbers shown in the 3DViewer which are the rounded (4 decimal places) result of the input number.

Also some input fields in different tools are limited to 4 decimal places (e.g. the needed input field OffsetDistance in Hollow) if you actually need such accuracy. 

This information could help in such a case:

In case of OBJ and STL a mesh file contains no information about the used unit. There are just pure numbers to describe the position of the vertices.

So if you know that your scanner writes the numbers using microns you might think of the values appearing in MM as microns (no matter which unit is actually displayed). So simply put in the desired OffsetDistance as microns as well and ignore the displayed unit.

Also keep an eye on the units used in your output device (e.g. 3DPrinter, CNCMill or some further third party application used in your workflow). Most standard machines interpret  the numbers as mm.  In this case you would need to convert microns to mm after you did all stuff inside MM(as explained by Andrew above) to get a proper real world output size. But that might be different on a device specialised on tiny objects...?

The default unit used in some third party software might be a different one (m, cm, mm or imperial units...). Some give the option to set the correct unit in their import options....