Accuracy of Gonial Angle Measurements Using Panoramic Imaging versus Lateral Cephalograms in Adults with Different Mandibular Divergence Patterns

Figures & data

Table 1 Anatomical Landmarks, Lines, and Angles Used in the Study

Landmarks and lines
Sella-Nasion (SN)	Line extended from sella point to the nasion point
Nasion-A point (NA)	Line extended from nasion point to A point
Nasion-B point (SN)	Line extended rom nasion point to B point
Frankfort Horizontal (FH)	Line extended from orbitale point to porion point
Mandibular plane	Line extended form gonion point (Go) to menton point (Me)
Angles
ANB	The difference between SNA and SNB. Indicates the relation of the jaws to each other and is used to classify patients as Class I (within normal range), Class II (above normal range) or Class III (below normal range)
SN-GoMe	The angle between the cranial base and the mandibular plane. Indicates a hyper- or hypo-divergent mandible
FMA	The angle between the FH and mandibular plane. Indicates a hyper- or hypo-divergent mandible
Gonial angle	The angle between the posterior border of the ramus and the mandible plane.

Figure 1 Lateral cephalogram showing the landmarks locations and measurements made using WebCeph.

Figure 2 Gonial angle measured on a panoramic radiograph.

Table 2 Descriptive Statistics and Comparison of the Gonial Angle Measurements on Lateral Cephalograms and Panoramic Radiographs Between Both Genders (Significant at P≤0.05)

Radiograph Type	Gender	Gonial Angle (°)	P-value
Lateral cephalograms	Male	126.052 ± 6.943	0.379
	Female	128.159 ± 6.701
Panoramic radiographs	Male	129.480 ± 6.864	0.116
	Female	130.670 ± 6.803

Table 3 Comparison of the Gonial Angle Measurements on Lateral Cephalograms and Panoramic Radiographs

Radiograph Type	Gonial Angle (°)	P-value
Lateral cephalograms	127.185 ± 6.887	0.022*
Panoramic radiographs (avg)	130.120 ± 6.849

Note: *Significant at p≤0.05.

Table 4 Comparison of Gonial Angle Measurements Between the Lateral Cephalograms and Panoramic Radiographs Among Different Mandibular Divergence Groups (FMA)

Radiograph Type	Mandibular Divergence	Gender		P-value
		No. of Male	No. of Female
Lateral cephalograms	Normal	91 (44%)	79 (33%)	0.317
	Hypo – divergent	32 (15%)	31 (13%)
	Hyper – divergent	84 (41%)	131 (54%)
Panoramic radiographs (avg)	Normal	91 (44%)	79 (33%)	0.004*
	Hypo – divergent	32 (15%)	31 (13%)
	Hyper – divergent	84 (41%)	131 (54%)

Note: *Significant at p≤0.05.

Table 5 Comparison of Gonial Angle Measurements Between the Lateral Cephalograms and Panoramic Radiographs Among Different Mandibular Divergence Groups (Sn-GoMe)

Radiograph Type	Mandibular Divergence	Gender		P-value
		No. of Male	No. of Female
Lateral cephalograms	Normal	82 (40%)	79 (33%)	0.291
	Hypo - divergent	41 (19%)	46 (19%)
	Hyper - divergent	84 (41%)	116 (48%)
Panoramic radiographs (avg)	Normal	82 (40%)	79 (33%)	0.002*
	Hypo - divergent	41 (19%)	46 (19%)
	Hyper - divergent	84 (41%)	116 (48%)

Note: *Significant at p≤0.05.

Table 6 Comparison of Gonial Angle Measurements Between the Lateral Cephalograms and Panoramic Radiographs Among Different Malocclusions. Significant at P≤0.05

Radiograph Type	Malocclusion	Gender		P-value
		No. of Male	No. of Female
Lateral cephalograms	Class I	38 (18%)	37 (15%)	0.421
	Class II	111 (54%)	171 (71%)
	Class III	58 (28%)	33 (14%)
Panoramic radiographs (avg)	Class I	38 (18%)	37 (15%)	0.390
	Class II	111 (54%)	171 (71%)
	Class III	58 (28%)	33 (14%)