An Introduction to Psychologic Factors in Orthodontic Treatment: Theoretical and Methodological Issues Roger B. FiUingim and Pramod K. Sinha

The influence of psychologic factors on both the process and the outcome of orthodontic treatment is a topic of substantial clinical and scientific impor- tance. Research in this area, as reviewed in this issue of Seminars in Orth- odontics, has focused primarily on 3 themes (1) compliance with orthodontic treatment, (2) psychosocial factors influencing decisions about treatment, and (3) psychologic outcomes following orthodontic or orthognathic treat- ment. This article discusses several methodological and theoretical issues relevant to these lines of research. In addition, recommendations for apply- ing psychologic principles to clinical practice are also provided. (Semin Orthod 2000;6:209-213.) Copyright © 2000 by W.B. Saunders Company

T he articles in this issue of Seminars in Orth-

odontics discuss the impor tance of psycho- logic factors in or thodont ic t rea tment and or- thognathic surgery. There are 3 impor tan t lines of research reviewed in this issue: (1) investigat- ing the factors that impact patients ' compliance with t rea tment and examining the effectiveness of interventions designed to improve compli- ance; (2) unders tanding the variables influenc- ing patients ' decisions regarding treatment; and (3) de termining the psychologic outcomes of or thodont ic and or thognathic surgical treat- ments. The authors thoroughly review the vari- ous literatures, and based on this information, it can be concluded that psychologic variables and o r thodon t i c /o r thogna th ic t reatments interact bidirectionally. That is, psychologic factors are impor tan t in de termining t rea tment outcomes, and t rea tment can have significant influence on certain psychologic dimensions. In this introduc-

From the Departments oJ Psychology and Orthodontics, Univer- sity of Alabama at Birmingt~am, Bi~vningham, AL, and the C¢nter ./'or Advanced Dental Education, St Louis U, ive~ity and Private Practice, Spokane, WA.

Address correspondence to Roger B. Fillingim, PhD, University of Florida College of Dentistry, Public Health Services and Research, 1600 SW Archer Rd, Rm D8-44A, PO BOX 100404, GainesviUe, I~L 32610.

Copyright © 2000 by W.B. Saunde~ Compa* U 1073-8746/00/0604-0002510. 00/0 doi: 10.1053/sodo. 2000.19072

tory article, the authors highlight 2 sets of im- por tan t issues related to psychologic research in orthodontics. First, impor tan t methodological factors to consider in both the interpretat ion and the conduct of such studies are discussed. Second, the authors review impor tan t theoreti- cal foundat ions f rom psychology that may in- form future investigation in orthodontics. The article concludes by discussing the practical im- plications of this research for clinical or thodon- tics.

Methodological Issues

One impor tan t issue relates to the measu remen t methodology used to assess variables of interest, including compliance, psychologic factors, and or thodont ic outcomes. Basic principles of psy- chometr ics indicate that in order to yield mean- ingful results, assessment instruments must be both reliable and valid. Reliability refers to the consistency with which an assessment instru- m e n t measures a construct. 1 Two types of reli- ability are important: test-retest reliability, whether a measures provides consistent results over time, and inter-rater reliability, whether similar results are obta ined by different examin- ers. I f test-retest reliability is poor, then changes in that variable over t ime are not interpretable, because they could be due to measuremen t er-

Seminars in Orthodontics, Vol 6, No 4 (December), 2000: pp 209-213 209

210 Filling~m and Sinha

ror rather than the effects of treatment. In ad- dition, the instability of the measure may ob- scure treatment effects that are actually present. An instrument or method with poor inter-rater reliability will likewise introduce measurement error, but in this case the error will be due to which examiner obtained the measure. Low in- ter-rater reliability also suggests limited practical usage, because the results are not comparable across examiners. Reliability is a necessary but not sufficient property of an instrument, it is also important to document the validity of a measure.

Validity refers to whether the instrument ac- curately assesses the construct it purports to measure, ~ which is most often documented by relating the self-report instrument to some well established "gold standard." Unfortunately, there is no gold standard for compliance with many aspects of orthodontic treatment, and the validity of many measures of compliance is ques- tionable. However, in this issue, Lyons and Ram- sey provide examples of technology that may become the gold standard for estimating the monitor ing headgear use. Another form of va- lidity, predictive validity, examines whether a measure can predict future outcomes. For in- stance, one would expect that a measure of com- pliance would be associated with orthodontic outcome; however, it is certainly the case that apparently compliant patients sometimes get poor orthodontic treatment results, whereas some patients with low compliance have positive outcomes. This poor predictive validity may be due to measurement error or it may indicate that factors other than compliance can have im- portant influences on treatment outcome.

The importance of reliability and validity has practical implications, and these psychometric principles apply to all types of measures ranging from patient self-report to automated devices (eg, headgear use monitors). First, whenever possible, investigators should use well-estab- lished, psychometrically sound measures rather than developing their own. This not only en- sures good reliability and validity but allows com- parison of results across studies. Second, when the instruments or methods used have question- able reliability and validity, multiple measures of the same construct should be used to increase the utility of the results. For example, combining patient reports of headgear use with parental reports increases the information available to

the clinician. Third, when new measures must be developed, data concerning their psychomet- ric properties should be provided, ideally de- rived from an independent sample before con- ducting the clinical outcome study.

Another important set of methodological is- sues involves the characteristics of the patient population. Obviously, age is important due to both psychologic and biological developmental factors. Moreover, other demographic variables, such as sex, ethnicity, family composition, socio- economic status and educational level can mod- erate treatment effects. The complex influence of these variables on treatment demand, need, and compliance is thoroughly reviewed by both Kiyak and Sergl in this issue of Seminars in Orth- odontics. In addition to their effects on compli- ance, demographic factors have been shown to affect access to treatment, -~ demand for treat- ment, 4 and uptake of treatment. 5 Due to these effects, investigators must describe the demo- graphics of their study populations, and clini- cians should be aware of the potential influence of these characteristics on the process and out- come of treatment.

It is also important to acknowledge that out- comes may be impacted by nonspecific treat- ment effects, that is, factors not due to the actual orthodontic aspect of treatment. One important source of such effects is time, especially for ad- olescents who are undergoing substantial biolog- ical and psychologic maturation concurrent with treatment (discussed by Rivera et al in this is- sue). Other sources of nonspecific effects in- clude attention from treatment providers and psychologic changes associated with treatment participation. For example, an adolescent may experience increased self-esteem due to the at- tention she receives from the orthodontic team or simply because she is engaged in treatment designed to improve her appearance. Although such nonspecific effects would not be expected to alter occlusion or objective dentofacial indi- ces, their effects on patients' appraisal of their own appearance as well as satisfaction with treat- ment can be substantial. This relates to another important issue, the choice of outcome mea- sures. Although occlusal traits represent the key orthodontic outcomes, patients are primarily concerned about improvements in their appear- ance as perceived by themselves and their peers. The 9 are often related, however, it is certainly

P~ychologic Factors in Orthodontic T, tatment 211

possible for patients to show substantial occlusal improvemen t and yet be dissatisfied with the esthetic result. Likewise, some patients may re- por t high satisfaction with their appearance, de- spite suboptimal occlusal outcomes. Thus, dif- ferent ou tcome measures may yield discrepant information regarding the success of t reatment , which indicates the impor tance of obtaining multiple ou tcome indicators.

Theoretical Issues

The impor tance of health-related behaviors has been increasingly emphasized recently in many areas of biomedicine, including the impor tance of exercise, balanced nutri t ion and smoking ces- sation. This has p r o m p t e d the deve lopment and application of sophisticated theoretical models of health behavior, and many of these models are highly relevant to compliance with orth- odontic t reatment. The application of one the- oretical model to compliance in or thodont ics is presented in the article by Lyons and Ramsey in this issue. The value of these theories of health behavior lie in their potential to (1) identify factors associated with improvements in health behavior; (2) predict the circumstances in which health behavior will be optimal; and (3) provide a rational basis for interventions designed to enhance health behaviors. The authors discuss 4 impor tan t models of health behavior and their implications for or thodont ic t reatment: (1) the health belief model; (2) the theory of reasoned action; (3) self-regulation theory; and (4) the stages of change model .

Heal th Belief Model

This model proposes that an individual 's beliefs are impor tan t determinants of h i s / he r health- related behaviors. 6 Four sets of beliefs are thought to predict health-related behaviors (1) perceived susceptibility to disease or problems, (2) perceived severity of the problem, (3) per- ceived benefits of health behaviors, and (4) per- ceived barriers to heal th-enhancing behaviors. For example, a pat ient is instructed to wear an appliance or a negative ou tcome will ensue (eg, diminished esthetic results). If the pat ient be- lieves their susceptibility to that ou tcome is low, the pat ient is less likely to wear the appliance. Likewise, if the pat ient acknowledges that the

outcome may occur, but judges this ou tcome to be low in severity, again engaging in the recom- m e n d e d behavior is improbable . On the o ther hand, if the pat ient believes that wearing the appliance will confer significant benefits, then the behavior is more likely. Finally, barriers to appliance use, such as concerns about appear- ance or the complexity of the regimen, will de- crease the f requency of the behavior. Thus, ef- forts to improve compliance should address these pat ient beliefs through education, and barriers to compliance should be minimized while maximizing the perceived benefits of the behavior.

Theory of Planned Behavior

This theory proposes that people are reasonable and make decisions about health-related behav- ior by using available informat ion to achieve a desired goal. 7 In this theory, a person 's intention to engage in a behavior directly determines whether they pe r to rm that behavior. In tent ion is inf luenced by 3 factors (1) the person ' s attitude toward the behavior (eg, "I don ' t like wearing cumbersome devices that make me look differ- ent"), (2) social influences on the behavior ("People will make fun of me"), and (3) the person 's perceived behavioral control, which re- flects a person ' s perceived ability to overcome obstacles and is inf luenced by their past behav- ior. As in the health belief model, both internal events such as attitudes and environmental fac- tors including social pressures and perceived ob- stacles influence the behavior, but in this model they do so by de termining whether the person intends to pe r fo rm the behavior. One clear im- plication of this model is that assessing a pa- t ient 's intentions to adhere to the t rea tment reg imen can be an impor tan t first step in iden- tifying potential noncompliance . I f intentions to change behavior are low, then interventions to alter attitudes or increase behavioral control may be indicated.

Self-Regulation Theory

As discussed by Lyons and Ramsey later in this issue, this theory suggests that individuals regu- late their own behavior using the following 3 processes, s First, individuals moni to r both the determinants and outcomes of their behavior. For example, a pat ient evaluates why he or she is

212 FiUingim and Sinha

wearing h i s /he r appliance (eg, "Because the doctor told me to."), and monitors the outcome of that behavior (eg, "I feel like I 'm taking good care of my teeth."). Second, patients evaluate their behavior based on personal standards ("I'm doing pretty well for me.") and environ- mental conditions ("Under the circumstances, I can' t be expected to do much better."). Third, patients adjust their behavior depending on how it compares with these personal standards ("I really am not doing as well as I can."). Thus, this theory proposes reciprocal interactions among behavior, the environment and personal factors, such as internal standards and cognitive pro- cesses. One of the central concepts in self-regu- lation theory is self-efficacy, which refers to the belief that one can produce a desired outcome through one 's own efforts. Several research stud- ies have shown that high self-efficacy for specific health-related behavior changes (eg, exercise, smoking cessation) is associated with improved adherence with those behavior changes. 9,1° Self- efficacy has also been associated with increased frequency of brushing and flossing. 11 These findings suggest that increasing a patient's belief that he or she can successfully perform the be- haviors requested (eg, p roper brushing and flossing, appliance use) can improve their ad- herence.

Stages of Change Model

This model proposes that people progress through 5 stages when making a behavior change, ~9 and Broder and Phillips (in this issue) apply this model to understanding decisions re- garding treatment. The first stage is precontem- plation, in which people typically fail to acknowl- edge the need for behavior change and have no intention of changing their behavior. In the sec- ond stage, contemplation, individuals recognize a need for change and are considering a change in behavior, but have not yet taken any steps in that direction. The third stage is preparation, and this stage involves making specific plans for behavior change. The fourth stage, action, in- volves implementing those plans, and this is the first stage in which overt behavior change oc- curs. The final stage is maintenance, in which people are at tempting to sustain the behavior changes that they have made. An important im- plication of this model is that patients at differ-

ent stages will require different interventions to assist them with behavior change. It is also im- portant to recognize that people frequently seek consultation during the contemplat ion stage, but they will not be ready to commence treat- ment until they proceed through the prepara- tion stage and enter the action stage. This can take widely variable amounts of time.

An important implication of each of these models is that patients' attitudes, thoughts, feel- ings, and perceptions are important determi- nants of their health-related behavior. There- fore, clinicians must take these patient factors into account in order to provide optimal treat- ment. This is most effectively implemented through a patient-centered approach. Tradition- ally, or thodont ic t reatment has been prescribed by the practit ioner based on defined profes- sional standards without considering the priori- ties and capabilities of the patient. Patients who fail to follow prescribed instruction are labeled as "noncompliant." This is often done without considering the fact that the treatment pre- scribed may not have taken into account the capabilities, motivations, and expectations of each individual patient. Hence, patients have had to burden the outcome of noncompliance rather than considering the inability of the prac- titioner to understand individual patient needs and make appropriate t reatment plans. A pa- t ient-centered approach would place some of the responsibility of successful patient compli- ance on the practitioner. In this model, the prac- titioner would prescribe t reatment plans based on individual patient expectations, priorities and capabilities. The application of this ap- proach has to consider legal and professional ramifications. In situations of conflict, options including nont rea tment should be provided to the patients and parents.

Practical Implications

Several authors in this issue have emphasized the difficulty of identifying specific personal characteristics that reliably predict adherence to or thodont ic treatment, and even when such vari- ables have been repor ted (eg, gender, socioeco- nomic status), they are of limited clinical utility, because they cannot be altered. However, it has also been noted that patients' personal beliefs, locus of control, and their social developmental

Psychologic Factors in Orthodontic Treatment 213

status can have impor tan t effects on compliance and t rea tment results. This highlights the sub- stantial influence that psychologic variables can have on the process and outcome of or thodont ic treatment. Psychosocial variables can also impact decisions regarding whether to seek orthodontic or orthognathic surgical t reatment (Broder and Phillips), and these treatments can also produce psychologic benefits for patients (Rivera et al). This informat ion clearly indicates that psycho- logic processes are a central c o m p o n e n t of orth- odontic t reatment, and optimal clinical practice requires an appreciat ion of these factors.

Based on these theoretical models, the follow- ing recommenda t ions for clinical practice are suggested.

1. Assess patients ' intentions to adhere to treat- men t regimens (eg, "How often do you plan to brush and floss?"). One can be relatively sure that if intentions to change behavior are low, then the likelihood of behavior change is also very low. In these instances, educational or behavioral intmwentions to increase inten- tions and p romote adherence will be needed.

2. Assess patients ' self-efficacy for successfully complet ing the prescribed t rea tment (eg, "How capable do you feel you are of using this appliance as prescribed?"). If patients doubt their ability, then additional instruc- tion and in office practice in the required behaviors are indicated.

3. Be aware that patients seek t rea tment at very different points along the stages of change, and parents and children may also differ in their readiness for change. T rea tmen t should be initiated only when the pat ient reports being ready to assume the responsibility and make the behavioral c o m m i t m e n t required to successflflly complete treatment.

4. Try to identify barriers to compliance with t rea tment recommendat ions . These may in- clude personal characteristics of the patients (eg, age, educational level, socioeconomic status) or environmental factors, such as high levels of psychosocial stress or a lack of un- derstanding regarding the impor tance of headgear use. When barriers are identified, steps should be taken to reduce the barriers or to tailor t rea tment a round the barriers.

5. T rea tmen t plans should incorporate the pri- orities and capabilities of the patient. This

approach allows patients to participate in the decision-making process and furthers the pa- tient 's commitment . In cases in which a pa- t ient 's decision conflicts with professional standards, limitations of the selected treat- men t plan should be presented. Options in- cluding non t r ea tmen t should be presented to the pat ient and parent .

The ability to implement such changes de- pends on an effective relationship between the clinician and the patient, which requires open communica t ion in both directions. While at- tending to psychosocial and behavioral aspects of t rea tment requires considerable effort and resources, the benefits in terms of improved t rea tment ou tcome as well as increased satisfac- tion for both the pat ient and the provider pro- vide a high re turn on investment.

References 1. Anastasi A. Psychological Testing, New York, NY, Mac-

millan, 1982. 2. Ghiselli E, Campbell J, Zedech S. Measurement theory

for the behavioral sciences, San Francisco, CA, WH Free- man and Company, 1981.

3. Turbill EA, Richmond S, Wright JL. A closer look at general dental service orthodontics in England and Wales. I: Factors influencing effectiveness. Br Dent J 1999;187:211-216.

4. Wheeler TT, McGorray SP, Yurkiewicz L, et al. Orth- odontic treatment demand and need in third and fourth grade schoolchildren. Am l Orthod Dentofac Orthoped 1994; 106:22-33.

5. O'Brien K, McComb JL, Fox N, WrightJ. Factors influ- encing the uptake of orthodontic treatment. Br.l Orthod 1996;23:331-334.

6. Becker M, Rosenstock I. Compliance with medical ad- vice, in Steptoe A, Matthews A (eds): Health care and human behavior. London, England, Academic Press, 1984.

7. Ajzen I. Attitudes, personality, and behavior. Chicago, IL, Dorsey Press, 1988.

8. Bandura A. Hmnan agency in social cognitive theory. Am Psychol 1989;44:1175-1184.

9. Borrelli B, Mermelstein R. Goal setting and behavior change in a smoking cessation program. Cognitive Ther- apy and Research 1994;18:69-82.

10. Winkelby MA, Flora JA, Kraemer HC. A community- based heart disease intervention: Predictors of change. Am J Public Health 1994;84:767-772.

11. Tedesco LA, Keffer MA, Davis EL, Christersson LA. Selt~ efficacy and reasoned action: Predicting oral health sta- tus and behavior at one, three, and six month intelaeals. Psychology and Health 1993;8:105-121.

12. ProchaskaJO, DiClemente CC. Stages of change in the modification of problem behaviors. Prog Behav Modif 1992;28:183-218.