Incisor retraction may result in lip retraction, interlabial gap closure and increase of the nasolabial angle but a clear consensus on the effect of incisor retraction on facial aesthetics has not yet been achieved. Despite current evidence being weak, it seems to indicate that in a well-managed orthodontic case, with or without extractions, the soft-tissue and facial aesthetic changes are generally favourable or clinically insignificant.
AckermanJLProffitWRSarverDM (1999) The emerging soft tissue paradigm in orthodontic diagnosis and treatment planning. Clinical Orthodontics and Research2: 49–52.
2.
ArmijoBSBrownMGuyuronB (2012) Defining the ideal nasolabial angle. Plastic and Reconstructive Surgery129: 759–764.
3.
ArnettGWBergmanRT (1993) Facial keys to orthodontic diagnosis and treatment planning. Part II. American Journal of Orthodontics and Dentofacial Orthopedics103: 395–411.
4.
BisharaSEJakobsenJR (1997) Profile changes in patients treated with and without extractions: assessments by lay people. American Journal of Orthodontics and Dentofacial Orthopedics112: 639–644.
5.
BisharaSEJakobsenJRHessionTJet al. (1998) Soft tissue profile changes from 5 to 45 years of age. American Journal of Orthodontics and Dentofacial Orthopedics114: 698–706.
6.
BokasJCollettT (2006) Effect of upper premolar extractions on the position of the upper lip. Australian Orthodontic Journal22: 31–37.
7.
BowmanSJJohnstonLEJr (2000) The esthetic impact of extraction and nonextraction treatments on Caucasian patients. Angle Orthodontist70: 3–10.
8.
BrockRAIITaylorRWBuschangPHet al. (2005) Ethnic differences in upper lip response to incisor retraction. American Journal of Orthodontics and Dentofacial Orthopedics127: 683–691.
9.
DrobockyOBSmithRJ (1989) Changes in facial profile during orthodontic treatment with extraction of four first premolars. American Journal of Orthodontics and Dentofacial Orthopedics95: 220–230.
10.
GeronSShpackNKandosSet al. (2003) Anchorage loss: a multifactorial response. The Angle Orthodontist73: 730–737.
11.
HayashidaHIoiHNakataSet al. (2011) Effects of retraction of anterior teeth and initial soft tissue variables on lip changes in Japanese adults. European Journal of Orthodontics33: 419–426.
12.
HodgesARossouwPECampbellPMet al. (2009) Prediction of lip response to four first premolar extractions in white female adolescents and adults. Angle Orthodontist79: 413–421.
13.
HoldawayRA (1983) A soft-tissue cephalometric analysis and its use in orthodontic treatment planning. Part I. American Journal of Orthodontics84: 1–28.
14.
JacobsJD (1978) Vertical lip changes from maxillary incisor retraction. American Journal of Orthodontics74 (4): 396–404.
15.
KasaiK (1998) Soft tissue adaptability to hard tissues in facial profiles. American Journal of Orthodontics and Dentofacial Orthopedics113: 674–684.
16.
KonstantonisDVasileiouDPapageorgiouSNet al. (2018) Soft tissue changes following extraction vs. nonextraction orthodontic fixed appliance treatment: a systematic review and meta-analysis. European Journal of Oral Sciences126: 167–179.
17.
KuhnMMarkicGDoulisIet al. (2016) Effect of different incisor movements on the soft tissue profile measured in reference to a rough-surfaced palatal implant. American Journal of Orthodontics and Dentofacial Orthopedics149: 349–357.
18.
LoFDHunterWS (1982) Changes in nasolabial angle related to maxillary incisor retraction. American Journal of Orthodontics82: 384–391.
19.
MirabellaDBacconiSGraccoAet al. (2008) Upper lip changes correlated with maxillary incisor movement in 65 orthodontically treated adult patients. World Journal of Orthodontics9: 337–348.
20.
MirabellaDQuartaroneLLombardoLet al. (2012) Assessment of lower lip changes following incisor displacement in 92 orthodontically-treated adults. International Orthodontics10: 289–310.
21.
MoselingKPWoodsMG (2004) Lip curve changes in females with premolar extraction or nonextraction treatment. Angle Orthodontist74: 51–62.
22.
OliverBM (1982) The influence of lip thickness and strain on upper lip response to incisor retraction. American Journal of Orthodontics82: 141–149.
23.
OmarZShortLBantingDWet al. (2018) Profile changes following extraction orthodontic treatment: A comparison of first versus second premolar extraction. International Orthodontics16: 91–104.
24.
OngHBWoodsMG (2001) An occlusal and cephalometric analysis of maxillary first and second premolar extraction effects. Angle Orthodontist71: 90–102.
25.
PaquetteDEBeattieJRJohnstonLEJr. (1992) A long-term comparison of nonextraction and premolar extraction edgewise therapy in ‘borderline’ Class II patients. American Journal of Orthodontics and Dentofacial Orthopedics102: 1–14.
26.
ParkYCBurstoneCJ (1986) Soft-tissue profile: fallacies of hard-tissue standards in treatment planning. American Journal of Orthodontics and Dentofacial Orthopedics90: 52–62.
27.
RainsMDNandaR (1982) Soft-tissue changes associated with maxillary incisor retraction. American Journal of Orthodontics81: 481–488.
28.
RamosALSakimaMTPinto AdosSet al. (2005) Upper lip changes correlated to maxillary incisor retraction: a metallic implant study. Angle Orthodontist75: 499–505.
29.
RickettsRM (1960) Cephalometric synthesis: an exercise in stating objectives and planning treatment with tracings of the head roentgenogram. American Journal of Orthodontics46: 647–673.
30.
SarverDMAckermanJL (2000) Orthodontics about face: the re-emergence of the esthetic paradigm. American Journal of Orthodontics and Dentofacial Orthopedics117: 575–576.
31.
SarverDMAckermanMB (2003) Dynamic smile visualization and quantification: Part 2. Smile analysis and treatment strategies. American Journal of Orthodontics and Dentofacial Orthopedics124: 116–127.
32.
ShearnBNWoodsMG (2000) An occlusal and cephalometric analysis of lower first and second premolar extraction effects. American Journal of Orthodontics and Dentofacial Orthopedics117: 351–361.
33.
SinnoHHMarkarianMKIbrahimAMet al. (2014) The ideal nasolabial angle in rhinoplasty: a preference analysis of the general population. Plastic and Reconstructive Surgery134: 201–210.
34.
SolemRCMarascoRGuiterrez-PulidoLet al. (2013) Three-dimensional soft-tissue and hard-tissue changes in the treatment of bimaxillary protrusion. American Journal of Orthodontics and Dentofacial Orthopedics144: 218–228.
35.
SpyropoulosMNHalazonetisDJ (2001) Significance of the soft tissue profile on facial esthetics. American Journal of Orthodontics and Dentofacial Orthopedics119: 464–471.
36.
StaggersJA (1990) A comparison of results of second molar and first premolar extraction treatment. American Journal of Orthodontics and Dentofacial Orthopedics98: 430–436.
37.
StephensCKBoleyJCBehrentsRGet al. (2005) Long-term profile changes in extraction and nonextraction patients. American Journal of Orthodontics and Dentofacial Orthopedics128: 450–457.
38.
SteynCLdu PreezRJHarrisAM (1997) Differential premolar extractions. American Journal of Orthodontics and Dentofacial Orthopedics112: 480–486.
39.
TadicNWoodsMG (2007) Incisal and soft tissue effects of maxillary premolar extraction in Class II treatment. The Angle Orthodontist77: 808–816.
40.
TalassMFTalassLBakerRC (1987) Soft-tissue profile changes resulting from retraction of maxillary incisors. American Journal of Orthodontics and Dentofacial Orthopedics91: 385–394.
41.
TweedCH (1936) The application of the principles of the edgewise arch in the treatment of class II, division 1, malocclusion. Angle Orthodontist6: 198–208.
42.
WaldmanBH (1982) Change in lip contour with maxillary incisor retraction. The Angle Orthodontist52: 129–134.
43.
WholleyCJWoodsMG (2003) The effects of commonly prescribed premolar extraction sequences on the curvature of the upper and lower lips. Angle Orthodontist73: 386–395.
44.
WholleyCJWoodsMG (2004) Tooth and lip responses to three commonly prescribed premolar extraction sequences: a review of recent research findings. Australian Orthodontic Journal20: 115–121.
45.
WilliamsRHosilaFJ (1976) The effect of different extraction sites upon incisor retraction. American Journal of Orthodontics69: 388–410.
46.
WisthJ (1974) Soft tissue response to upper incisor retraction in boys. British Journal of Orthodontics1: 199–204.
