The Occlusal Plane Inclination Analysis for Determining Skeletal Class III Malocclusion Diagnosis

Figures & data

Figure 1 Anatomical lines and angles used in this study to determine vertical dysplasia and growth of the nasomaxillary and mandibular complexes in the vertical direction.

Figure 2 Anatomical lines and angles used in this study to determine sagittal dysplasia and growth of the nasomaxillary and mandibular complexes in the horizontal direction.

Figure 3 Anatomical lines and angles used in this study to determine the inclination of the occlusal plane.

Table 1 Descriptive Data of Measurement Class III Malocclusions Variable

	Minimum	Maximum	Mean	Std. Dev	Normal Value
Saddle Angle	113.75	134.17	123.33	4.73	119.20–128.60
Facial Axis	76.43	100.03	89.15	4.87	82.74–90
Y-Axis	52.64	73.24	62.41	5.21	53–64.6
FMA	17.51	45.26	31.18	7.37	16–35
SN-GoGn	20.51	48.74	34.11	7.06	24.82–35.76
Gonial Angle	111.23	150.13	130.15	8.86	110.32–123.0
Upper Gonial Angle	42.41	64.02	51.12	5.00	40.30–47.70
Lower Gonial Angle	66.28	89.38	79.04	6.54	68.5–77.58
Byork Sum	380.79	408.74	394.79	7.18	336.20–395.6
SNA	71.64	86.32	80.77	3.52	79.2–85.6
SNB	75.11	92.45	85.23	4.30	77.3–83.5
ANB	−11.01	−0.42	−4.47	2.74	0.30–3.70
OP-SN	5.81	43.63	18.26	6.75	11.31–19.17
OP-FH	2.53	26.03	14.25	6.48	5.50–12.1
OP-GoGn	5.68	28.38	16.93	5.23	12–20
OP-AB	99.09	123.04	108.92	6.17	88.6–95.8
Facial Height Ratio	55.92	77.72	65.20	5.62	65.56–74.92
Lower Facial Height	30.22	58.02	44.77	6.23	42.77–49.79

Table 2 The Differences in Occlusal Plane Inclination Between Class I and Class III Malocclusions

Parameter	OP-SN	OP-FH	OP-GoGn	OP-AB
Means Class I	40.60	31.70	37.38	21.15
Means Class III	40.40	49.30	43.63	59.85
Significance	0.968	0.000*	0.215	0.000*

Note: *Significant at p<0.05.

Table 3 Results of the First Canonical Correlation Set

Canonical Loadings
Variables	1	2	3	4
Saddle angle	0.061	−0.425	−0.471	−0.133
Facial axis	−0.599	0.583	−0.277	0.047
Y axis	−0.662	0.644	0.104	−0.148
FMA	−0.371	0.860	−0.092	0.106
SN-GoGn	−0.425	0.576	−0.586	0.234
Gonial angle	0.049	0.741	0.023	0.394
Uppergonial	0.286	0.355	0.277	0.285
Lowergonial	−0.174	0.836	−0.208	0.359
Byork sum	−0.313	0.601	−0.559	0.170
SNA	0.078	−0.294	0.470	0.429
SNB	0.746	0.331	0.426	0.122
ANB	−0.767	−0.569	−0.132	0.165
Lower Facial Height	0.228	−0.408	0.167	−0.309
Facial Height Ratio	0.207	−0.563	0.654	−0.085

Table 4 Results of the Second Canonical Correlation Set

Canonical Loadings
Variables	1	2	3	4
OP-SN	−0.289	0.394	−0.628	−0.605
OP-FH	−0.262	0.794	0.111	−0.537
OP-GoGn	−0.268	0.499	−0.212	0.797
OP-AB	0.656	0.708	0.077	−0.250