The present invention provides a mixed reality surgical navigation system (10) to be worn by a user (106) during a surgical procedure comprising: a display device (104), to be worn by a user (106) during a surgical procedure, comprising a processor unit (102), a display generator (204), a sensor suite (210) having at least one camera (206) or depth sensor wherein the processing unit (102) creates a reference surface map (5804) of an exposed surface (5806) of an anatomical object (4204) with data received from the sensor suite (210); the processing unit (102) establishes a reference frame (5810) relative to the sensor suite (210) for the reference surface map (5804); orientation of the reference frame (5810) is established by creating additional surface maps (5834) of other anatomical features (5824) of the anatomical object (4204); the processing unit (102) tracks a pose of the anatomical object (4204) relative to the system (10) by creating a displaced surface map (5814) of the exposed surface (5806) and rotating and translating the displaced surface map (5814) and reference frame (5810) to achieve a best fit to the reference surface map (5804).