Analysis of Lingual Arch Form in Dental Students of Nepal with Normal Occlusion

Figures & data

Figure 1 (A) Marking of reference points. (B) Measurement of x and y co-ordinates.

Figure 2 Measurement of lingual arch dimensions. (A) Canine depth. (B) First molar depth. (C) Second molar depth.

Table 1 Comparison Between Lingual Measurements of Males and Females

Lingual Measurements	Male (Mean± S.D)	Female (Mean± S.D)	p-value
Inter-canine width	22.47± 1.44	22.34± 1.28	0.78(NS)
Inter-molar width	34.35± 2.81	33.71± 1.92	0.82(NS)
Inter-2nd molar width	40.88± 3.05	40.33± 2.22	0.91(NS)
Canine depth	4.35± 1.13	4.61± 0.96	0.47(NS)
First molar depth	24.87± 1.42	25.76± 1.32	0.07(NS)
Second molar depth	34.13± 1.73	35.23± 1.69	0.07(NS)
Canine width/depth	5.59± 1.89	5.03± 1.02	0.37(NS)
First molar width/depth	1.35± 0.17	1.31± 0.1	0.37(NS)
Second molar width/depth	1.2± 0.08	1.15± 0.07	0.06(NS)

Note: P≤ 0.05.

Abbreviation: NS, not significant.

Table 2 Evaluation of Reliability of Measurement with Paired t-Test and Dahlberg’s Formula

Tooth	Measurement 1 (Mean ± S.D.)	Measurement 2 (Mean ± S.D)	p-value	Casual Error
21x	4.13±0.35	3.93±0.45	0.18(NS)	0.31
23x	13.93±0.7	13.7±1.1	0.33(NS)	0.36
25x	16.8±1.2	16.5±1.2	0.33(NS)	0.36
27x	21.2±2.0	21.4±2.2	0.30(NS)	0.36
31x	−2.73±0.45	−2.87±0.58	0.43(NS)	0.25
33x	−11.13±1.0	−10.93±0.96	0.18(NS)	0.31
35x	−14.73±1.5	−14.47±1.12	0.49(NS)	0.36
37x	−20.13±1.9	−20.53±2.8	0.58(NS)	0.44
21y	56.0±2.6	55.0±2.2	0.61(NS)	0.31
23y	49.27±2.5	49.0±2.44	0.48(NS)	0.36
25y	36.67±2.8	36.33±2.5	0.38(NS)	0.40
27y	19.2±3.0	19.2±2.4	1.00(NS)	0.00
31y	55.4±2.6	55.27±2.7	0.82(NS)	0.25
33y	51.0±2.9	50.6±2.8	0.53(NS)	0.44
35y	39.0±3.4	38.6±2.9	0.67(NS)	0.40
37y	21.07±3.1	20.47±3.4	0.50(NS)	0.31

Note: P≤0.05.

Abbreviation: NS, not significant.

Table 3 Cluster Distribution

Cluster	Number of Subjects	% of Total
1	20	60.6
2	13	39.4

Table 4 Cluster Properties

	Cluster
	1 (Mean ± SD)	2 (Mean ± SD)	Combined (Mean ± SD)	p-value (Cluster 1 and 2)
Inter-canine width (mm)	21.76 ±1.17	23.38 ±0.88	22.39±1.32	0.00*
Inter-molar width (mm)	32.44 ±1.25	36.34 ±1.36	33.98 ±2.32	0.00*
Inter-2nd molar width (mm)	38.94 ±1.71	43.05 ±1.38	40.56 ±2.57	0.00*
Canine depth (mm)	4.46 ±1.06	4.61 ±.87	4.5±.98	0.74
First molar depth (mm)	25.26 ± 1.65	25.56 ±.98	25.38 ±1.41	0.74
Second molar depth (mm)	34.37±1.93	35.36 ±1.32	34.76 ±1.76	0.2
Canine width/depth	5.16 ±1.34	5.24 ±1.00	5.19 ±1.20	0.76
First molar width/depth	1.28 ±.096	1.42 ±.093	1.34 ±.11	0.00*
Second molar width/depth	1.13 ±.063	1.21 ±.072	1.16 ±.077	0.01*

Notes: P≤0.05, *statistically significant.

Figure 3 Template of maxillary lingual arch form. (A) Cluster 1. (B) Cluster 2.

Figure 4 Template of mandibular lingual arch form. (A) Cluster 1. (B) Cluster 2.