Influence of overjet and overbite on soft tissue profile in mature adults: A cross-sectional population study Georgios Kanavakis, a Laura Krooks, b Raija L€ ahdesm€ aki, c and Pertti Pirttiniemi c Basel, Switzerland, Boston, Mass, and Oulu, Finland Introduction: The aim of this study was to explore the association of soft tissue profile and severity of overbite and overjet in a large adult population. Methods: The study population consisted of 1630 adults (age, 46 years; 712 men, 919 women), all part of the Northern Finland Birth Cohort 1966. A clinical examination was performed on all subjects, including recording of overjet and overbite, and digital facial (frontal and profile) photographs were obtained. A multivariate regression model was developed to study the correlation of soft tissue measure- ments with overjet and overbite, considering the effect of sex. Results: The regression model explained approx- imately 30% of the variability in overjet in our sample and approximately 22% of the variability in overbite. Overjet was related more significantly to upper and lower anteroposterior lip position, and upper and lower facial height (P \0.05). Overbite showed a stronger association with anteroposterior position of the lower lip, pogonion, and soft tissue B-point (P \0.05). Conclusions: Soft tissue profile was weakly to moderately correlated with severity of overjet and overbite in the entire sample. However, in subjects with negative overjet (mandibular progna- thism), this association was highly significant. (Am J Orthod Dentofacial Orthop 2019;155:57-63) I n orthodontics, great emphasis is placed on the po- tential for creating facial change by correcting malocclusion. This agrees with patients' primary motivation to undergo orthodontic treatment: ie, facial esthetics. 1-4 Historically, the criteria for achieving optimal facial esthetics have been changing to adapt to societal perceptions, 5 and orthodontists have always played an important role by applying these criteria to their treatment planning. Technological advances in im- aging, 6 photography, 7 and intraoral scanning 8 provide great opportunities for studying patients' characteristics more accurately, and even allow clinicians to make soft tissue predictions with varying degrees of accuracy. 9 Inarguably, dental malocclusion has a significant impact on facial soft tissue characteristics, 10-12 which in turn have an impact on facial and smile appearance. Particularly, overjet and anterior open bite have been shown to strongly influence the position of the upper lip and the dimension of the lower face, respectively. 11,12 In addition to cephalometric methods 13-15 and to overcome their inherent limitations, 16 alternative methods to study facial soft tissues from frontal and profile photographs have also been proposed. 10,11,17 Despite their restrictions related to patient position and standardization of obtaining the images, photographs are a noninvasive alternative tool that can be potentially useful in day-to-day clinical diagnosis and treatment planning. 18 Most orthodontic patients are adolescents; hence, the impact of orthodontic treatment on facial soft tis- sues will be additive to any natural changes. After the a Department of Orthodontics and Pediatric Dentistry, Universit€ares Zentrum f€ ur Zahnmedizin Basel University School of Dental Medicine, University of Basel, Basel, Switzerland; Research Unit of Oral Health Sciences, Medical Faculty, Uni- versity of Oulu, Oulu, Finland; Department of Orthodontics and Dentofacial Or- thopedics, School of Dental Medicine, Tufts University, Boston, Mass. b Research Unit of Oral Health Sciences, Medical Faculty, University of Oulu, Oulu, Finland. c Research Unit of Oral Health Sciences, Medical Faculty, University of Oulu, Oulu, Finland; Medical Research Center, Oulu University Hospital, Oulu, Finland. All authors have completed and submitted the ICMJE Form for Disclosure of Po- tential Conflicts of Interest, and none were reported. Georgios Kanavakis and Laura Krooks are joint first authors and contributed equally to this work. The Northern Finland Birth Cohort 1966 received financial support from the Uni- versity of Oulu (grant number 24000692), the Oulu University Hospital (grant number 24301140), and the European Regional Development Fund (grant num- ber 539/2010 A31592). Laura Krooks received research funding from the Finnish Dental Society Apollonia and the Finnish Women Dentist Association. Address correspondence to: Georgios Kanavakis, Department of Orthodontics and Pediatric Dentistry, UZB-University School of Dental Medicine, University of Basel, 3 Hebelstrasse, 4056 Basel, Switzerland; e-mail, georgios.kanavakis@ unibas.ch. Submitted, September 2017; revised and accepted, February 2018. 0889-5406/$36.00 Ó 2018 by the American Association of Orthodontists. All rights reserved. https://doi.org/10.1016/j.ajodo.2018.02.015 57 ORIGINAL ARTICLE