Effects of crown-root angle on stress distribution in the maxillary central incisors’ PDL during application of intrusive and retraction forces: a three-dimensional finite element analysis

Progress in Orthodontics

Table 1 Stress in two points from the models of maxillary central incisors during retraction force loading

Node	CRA 166.7°	Stress in C₁	CRA 173.4°	Stress in C₂	C₁-C₂difference
7,208	B1	0.0118219	B1	0.0152682	-0.0034462
7,533	B2	0.0011850	B2	0.0021201	-0.0009350
7,807	B3	0.0101753	B3	0.0134645	-0.0032891
7,195	P1	0.0096988	P1	0.0135697	-0.0038709
7,502	P2	0.0033937	P2	0.0037428	-0.0003491
7,763	P3	0.0112585	P3	0.0143661	-0.0031076
7,185	A	0.0049120	A	0.0065409	-0.0016289

A, apex; B₁, a node in the labial surface, near the apex; B₂, a node in the labial surface, near the middle of the root; B₃, a node in the labial surface, near the cervix; CRA, crown-root angle; P₁, a node in the palatal surface, near the apex; P₂, a node in the palatal surface, near the middle of the root; P₃, a node in the palatal surface, near the cervix. Stress in the two points from the models of maxillary central incisors with crown-root angles of 166.7° and 173.4° during retraction force loading and the differences between these corresponding points.