Sharp VDH score	I	II	I vs II	III	I vs III	IV	I vs IV
			(p)		(p)		(p)
Erosion	26.95 (32.02)	54.59 (55.63)	0.044	44.61 (50.85)	0.197	28.54 (36.81)	0.873
Narrowing space	55.47 (40.74)	78.03 (43.72)	0.051	67.83 (41.59)	0.339	61.00 (35.31)	0.597
Total	82.42 (67.72)	132.62 (96.51)	0.039	112.43 (89.17)	0.235	89.54 (68.87)	0.712