Efficacy of invisible advancement correction for mandibular retraction in adolescents based on Pancherz analysis

Table 1 Skeletal measurement items and notes on lateral radiographs

Measurement	Definition
ss/OLP (mm)	Maxillary position, vertical distance from ss point to OLP
Pg/OLP (mm)	Mandibular position, vertical distance from Pg point to OLP
Co/OLP (mm)	Condyle position, vertical distance from Co point to OLP
Pg/OLP + Co/OLP (mm)	Mandibular length
Co-Go (mm)	Length of mandibular ascending ramus
Go-Pg (mm)	Length of mandibular body
Co-Pg (mm)	The total length of the mandible
SNA (°)	Sagittal relationship of anterior maxilla to basal bone
SNB	Sagittal relationship of anterior mandibular to basal bone
ANB	Sagittal position relationship between upper and lower basal bone
Wits	The distance between upper and lower alveolar points and occlusal plane
SN-MP	The plane angle of the mandible, the plane tangent to the lower edge of the mandible through the point Me
S-Go/N-Me	Posterior height/anterior height
ANS-Me/N-Me	Anterior inferior height/anterior height
is/OLP	Position of upper central incisor
ii/OLP	Position of lower central incisor
ms/OLP	Position of maxillary first molar
mi/OLP	Position of the lower first molar
U1-NA	Inclination of maxillary central incisor
U1-SN	Upper central incisor angle
L1-NB	Inclination of lower central incisor
L1-MP	Lower central incisor angle
is/OLP-ii/OLP	The distance from is point to OLP minus the distance from ii point to OLP is used to represent overjet
ms/OLP-mi/OLP	The distance from ms point to OLP minus the distance from mi point to OLP is used to describe molars
is/OLP-ss/OLP	Changes in the position of the upper central incisor relative to the maxilla
ii/OLP-pg/OLP	Changes in the position of the lower central incisor relative to the mandible
ms/OLP-ss/OLP	The position change of maxillary first permanent molars relative to maxilla
mi/OLP-pg/OLP	Change in the position of the first permanent molars relative to the mandible

NA: The line that connects point N to point A; SN: SN plane, the line that connects point gonion to point gnathion; NB: The line that connects point N to point B; SNA: The angle between SN and NA; SNB: The angle between SN and NB; ANB: The angle between NA and NB; SN-MP: The angle between SN and MP.

Table 2 Cephalometric analysis and comparison of changes and calculated measurement items after mandibular advancement treatment

Measurement	Pre-treatment T0	Post treatment T1	Difference T1-T0	T value	P value
ss/OLP (mm)	71.42 ± 3.76	72.02 ± 4.05	0.60 ± 0.82	-0.532	0.258
Pg/OLP (mm)	72.55 ± 3.25	75.68 ± 4.53	3.13 ± 0.89	-1.561	0.029a
Co-OLP (mm)	-8.57 ± 0.65	-9.60 ± 0.45	-1.03 ± 0.79	-1.349	0.000c
Pg/OLP + Co/OLP (mm)	82.01 ± 1.57	86.25 ± 2.05	4.14 ± 2.18	-1.687	0.000c
Co-Go (mm)	50.03 ± 4.15	54.12 ± 3.65	4.09 ± 1.58	-3.037	0.018a
Go-Pg (mm)	76.18 ± 5.43	80.43 ± 3.90	4.25 ± 2.87	-4.581	0.001b
Co-Pg (mm)	108.58 ± 7.08	113.60 ± 6.58	5.02 ± 1.83	-3.803	0.038a
SNA (°)	80.95 ± 1.90	80.67 ± 1.54	-0.28 ± 0.04	1.915	0.166
SNB (°)	74.89 ± 1.78	76.85 ± 1.65	1.96 ± 2.56	3.218	0.000c
ANB (°)	6.11 ± 1.06	4.08 ± 1.34	-2.03 ± 1.32	18.370	0.000c
Wits (mm)	6.41 ± 2.45	3.51 ± 1.18	-2.90 ± 1.72	7.138	0.000c
SN-MP (°)	31.20 ± 3.62	32.85 ± 3.51	1.65 ± 1.37	-1.478	0.043a
S-Go/N-Me	64.12 ± 2.68	62.08 ± 3.09	-2.04 ± 1.68	1.386	0.035a
ANS-Me/N-Me	54.40 ± 1.89	55.85 ± 2.18	1.45 ± 1.37	-2.087	0.045a
is/OLP	77.98 ± 6.07	76.65 ± 5.71	-1.33 ± 3.08	1.657	0.353
ii/OLP	71.11 ± 5.04	74.09 ± 4.76	2.98 ± 1.08	-1.709	0.071
ms/OLP	46.86 ± 5.34	45.67 ± 4.87	-1.19 ± 0.39	1.687	0.205
mi/OLP	45.30 ± 3.28	47.80 ± 5.18	2.50 ± 1.04	-1.560	0.082
U1-NA	28.89 ± 7.51	25.45 ± 5.40	-3.44 ± 6.89	-7.760	0.010a
U1-SN	108.04 ± 3.01	103.98 ± 4.78	-4.06 ± 4.88	4.673	0.000c
L1-MP	95.20 ± 2.93	96.43 ± 2.86	1.23 ± 0.40	-0.318	0.000c
L1-NB	22.78 ± 4.08	25.40 ± 3.32	2.62 ± 1.63	-3.341	0.030a
is/OLP-ii/OLP	6.87 ± 1.51	2.56 ± 0.76	-4.31 ± 1.43	16.30	0.000c
ms/OLP-mi/OLP	2.13 ± 1.20	-1.74 ± 1.31	-3.87 ± 0.78	10.61	0.000c
is/OLP-ss/OLP	7.04 ± 1.07	6.48 ± 2.09	-0.61 ± 1.71	4.25	0.089
ii/OLP-pg/OLP	-1.12 ± 1.65	0.05 ± 1.70	1.17 ± 0.83	1.75	0.005b
ms/OLP-ss/OLP	-23.18 ± 2.69	-24.34 ± 1.98	-1.16 ± 1.78	-15.68	0.000c
mi/OLP-pg/OLP	-26.98 ± 2.45	-26.80 ± 2.78	0.18 ± 1.57	3.05	0.185

^aP < 0.05.

^bP < 0.01.

^cP < 0.001.

Co: Condylion; OLP: Occlusal line perpendicular; Pg: Pogonion; Go: Gonion; ss: Subspinale; MP: MP plane, the line connecting the gonion point and gnathion point; SNA: The angle between SN and NA; SNB: The angle between SN and NB; ANB: The angle between NA and NB; SN-MP: The angle between SN and MP.