A three-dimensional finite element analysis of molar distalization with a palatal plate, pendulum, and headgear according to molar eruption stage.
OBJECTIVE
This study aimed to (1) evaluate the effects of maxillary second and third molar eruption status on the distalization of first molars with a modified palatal anchorage plate (MPAP), and (2) compare the results to the outcomes of the use of a pendulum and that of a headgear using three-dimensional finite element analysis.


METHODS
Three eruption stages were established: an erupting second molar at the cervical one-third of the first molar root (Stage 1), a fully erupted second molar (Stage 2), and an erupting third molar at the cervical one-third of the second molar root (Stage 3). Retraction forces were applied via three anchorage appliance models: an MPAP with bracket and archwire, a bone-anchored pendulum appliance, and cervical-pull headgear.


RESULTS
An MPAP showed greater root movement of the first molar than crown movement, and this was more noticeable in Stages 2 and 3. With the other devices, the first molar showed distal tipping. Transversely, the first molar had mesial-out rotation with headgear and mesial-in rotation with the other devices. Vertically, the first molar was intruded with an MPAP, and extruded with the other appliances.


CONCLUSIONS
The second molar eruption stage had an effect on molar distalization, but the third molar follicle had no effect. The application of an MPAP may be an effective treatment option for maxillary molar distalization.
Department of Dentistry, Graduate School, The Catholic University of Korea, Seoul, Korea.
Ju-Man
JM
Kang
Postgraduate Orthodontic Program, Arizona School of Dentistry & Oral Health, A.T. Still University, Mesa, AZ, USA.; Graduate School of Dentistry, Kyung Hee University, Seoul, Korea.
Jae Hyun
JH
Park
Department of Dentistry, Graduate School, The Catholic University of Korea, Seoul, Korea.; Department of Postgraduate Studies, the Universidad Autonóma del Paraguay, Asunción, Paraguay.
Mohamed
M
Bayome
Department of Orthodontics, St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea.
Moonbee
M
Oh
Private Practice, Seoul, Korea.; Department of Orthodontics, School of Dentistry, Seoul National University, Seoul, Korea.
Chong Ook
CO
Park
Department of Orthodontics, St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea.
Yoon-Ah
YA
Kook
Department of Orthodontics, Graduate School of Clinical Dental Science, The Catholic University of Korea, Seoul, Korea.
Sung-Seo
SS
Mo
Class II; Distalizing; Headgear; Palatal plate
Am J Orthod Dentofacial Orthop. 1989 Mar;95(3):200-7
2923100
Angle Orthod. 2006 Nov;76(6):923-9
17090171
Angle Orthod. 2013 Jul;83(4):735-42
23167519
Am J Orthod Dentofacial Orthop. 2009 Oct;136(4):578-86
19815162
Angle Orthod. 2003 Apr;73(2):187-93
12725376
Am J Orthod Dentofacial Orthop. 2008 Nov;134(5):604.e1-16; discussion 604-5
18984391
Dental Press J Orthod. 2013 Nov-Dec;18(6):58-64
24351151
Am J Orthod Dentofacial Orthop. 2014 Oct;146(4):467-76
25263150
Korean J Orthod. 2015 Jul;45(4):171-9
26258063
J Clin Orthod. 2015 Sep;49(9):587-95
26457619
Am J Orthod Dentofacial Orthop. 2011 Apr;139(4):495-503
21457860
Am J Orthod Dentofacial Orthop. 2014 Jan;145(1):85-94
24373658
Eur J Orthod. 2008 Aug;30(4):425-30
18678761
Am J Orthod. 1986 Feb;89(2):113-21
3456205
Eur J Orthod. 2008 Oct;30(5):477-82
18725383
Am J Orthod Dentofacial Orthop. 2014 Jul;146(1):47-54
24974998
Angle Orthod. 1997;67(4):261-70
9267574
Am J Orthod Dentofacial Orthop. 2015 Oct;148(4):674-84
26432323
Am J Orthod Dentofacial Orthop. 1990 Apr;97(4):336-48
2321602
Korean J Orthod. 2015 Jan;45(1):20-8
25667914
Am J Orthod Dentofacial Orthop. 2008 Sep;134(3):383-8
18774084
Angle Orthod. 2004 Dec;74(6):838-50
15673149
Angle Orthod. 1997;67(4):249-60
9267573
Am J Orthod Dentofacial Orthop. 1998 Jul;114(1):66-72
9674683
Angle Orthod. 2015 Jul;85(4):657-64
25191840
Am J Orthod Dentofacial Orthop. 2004 Jan;125(1):8-23
14718874
Korean J Orthod. 2014 Mar;44(2):88-95
24696825
Am J Orthod Dentofacial Orthop. 1996 Dec;110(6):639-46
8972811
Med Eng Phys. 2009 Jun;31(5):539-46
19054703
Int J Adult Orthodon Orthognath Surg. 2000 Summer;15(2):129-37
11307423
Eur J Orthod. 2013 Aug;35(4):507-14
22968670
Angle Orthod. 2006 Jul;76(4):650-9
16808573
Am J Orthod Dentofacial Orthop. 2015 Aug;148(2):310-20
26232840
Am J Orthod Dentofacial Orthop. 2009 Jun;135(6):698.e1-10; discussion 698-9
19524823
Am J Orthod Dentofacial Orthop. 2011 Jun;139(6):722-9
21640877
Eur J Orthod. 2014 Aug;36(4):394-402
22051536
Angle Orthod. 1973 Jul;43(3):221-32
4515770
Am J Orthod. 1984 Apr;85(4):294-307
6585147
Eur J Orthod. 2008 Dec;30(6):572-9
19054813
Am J Orthod Dentofacial Orthop. 2008 Mar;133(3):339.e9-339.e17
18331928
Am J Orthod Dentofacial Orthop. 2000 Mar;117(3):333-43
10715093
PLoS One. 2013;8(3):e58803
23554928
Eur J Orthod. 2007 Apr;29(2):118-25
17218719