In an OEM build, the factory produces an existing, proven platform with your branding: housing color, logo, packaging and language files. You are buying a known quantity — the engineering risk is already retired.
In an ODM build, the factory engineers around your specification: custom housing tooling, modified handpieces, your UI. You get differentiation, and you inherit the engineering timeline that comes with it — tooling samples, pilot runs and a longer aging schedule before mass production.
The honest question to ask a supplier is not “can you do ODM” but “show me a previous ODM build and its pilot-run records”. The answer separates factories from showrooms.