Table 1. Summary of the visual scores (mean±standard deviation), by observer and round of observation, and registration technique.

	Observer 1		Observer 2		Observer 3		Observer 4
Registration technique	Round 1	Round 2	Round 1	Round 2	Round 1	Round 2	Round 1	Round 2	Average of all observers and rounds
Manual	3.3±1.1	3.2±1.2	3.4±0.8	4.3±0.9	2.8±1.2	3.6±1.6	3.1±1.3	3.6±1.2	3.4±1.3
Rigid	3.2±1.2	3.2±1.3	3.3±0.8	4.2±0.7	2.6±0.9	3.5±1.6	2.9±1.1	3.3±0.9	3.3±1.2
Non-rigid	2.5±0.6	2.5±0.5	2.8±0.7	3.7±0.6	2.0±0.1	2.3±0.6	1.9±0.7	2.5±0.7	2.5±0.8