Why a New Approach?

Psychological theories are used to explain why some individuals engage in behaviors conducive to health, whereas others, despite knowing they have poor health fail to adopt healthier behaviors recommended by health care providers. Self Determination Theory (SDT) represents a broad contemporary theory of personality development and self-motivated behavior change.¹² The two main assumptions are based on an individual’s need to grow and gain fulfillment through internal sources of motivation. SDT also focuses on how social and cultural factors facilitate or undermine people’s sense of volition and initiative, in addition to their well-being and the quality of their performance. Conditions supporting the individual’s experience of autonomy, competence, and relatedness are argued to foster the most volitional and high quality forms of motivation and engagement for activities, including enhanced performance, persistence, and creativity.¹³ If the clinician does not clearly demonstrate relatedness, recognize the patient as an autonomous individual, they will fail to effectively engage the patient.¹³

MI and SDT both posit individuals have an innate tendency for personal growth towards psychological integration. Both MI and SDT are closely aligned on the human propensity for personal growth. MI in fact is described by Miller as a movement toward integration and cohesion when the client’s beliefs, attitudes, and behaviors become consistent with the values core to their personal identity.¹⁴ This is accomplished in MI when the client recognizes inconsistencies between a behavior and their core values and sense of self. SDT and MI also both convey support for clients, encourage exploration of the client’s own reasons for change, and refrain from pressuring patients to change. SDT suggestions for specific behavioral strategies are also similar to MI including: eliciting and acknowledging client perspectives, supporting client choices, providing a rationale for advice given, providing a menu of effective options of change, minimizing control and judgement and exploring aspirations.¹⁵

Clinicians can play a pivotal role by helping patients uncover and verbalize how the individual views positive and negative aspects of improved oral health behaviors may allow them to explore factors that increase or decrease internal motivation. Internal motivation is needed for sustained health behavior change. When clinicians attempt to impose motivation (e.g., through direct persuasion or advice given from an expert source), patients often respond with a guilt-induced transient change or simply sustain the current behavior. People may also respond by subtly pushing back and becoming more resistant to change. It is only when behaviors are internally directed and valued by the patient that sustained changes are possible. When healthy behaviors are sustained over time, better health outcomes are possible.

Originating in the addiction fields, many healthcare providers are now trained and using MI in primary care as well as dentistry. Bray and colleagues demonstrated that MI can be effectively learned and utilized by dental hygiene students.¹⁸ The effectiveness of the MI approach for more lasting behavior change with consequent improvements in health outcomes has is documented in over 900 clinical trials and across a variety of health behaviors and providers. MI improves oral health outcomes related to brushing frequency,¹⁹ plaque control,²⁰ periodontal outcomes,²⁶ dental caries and dental visits. One of the largest and most highly rated studies on MI and oral health consisted of a longitudinal study of children 0-5 years old and their caregivers.¹² At the 2 year follow-up, the group receiving MI had a significantly higher proportion of children brushing seven nights per week at bedtime compared to the traditional health education group 35.45% to 25.33% respectively. While a higher proportion of the MI group (61.2%) assured children were bushing 2 times a day compared to 56% in the health education the result was not statistically significant.

A recent systematic review of high fidelity MI and oral health examined the outcomes in 16 well designed studies. MI outperformed conventional health education in improving at least one outcome in four studies on preventing early childhood caries. With regard to periodontal health, superior effect of MI on oral hygiene was found in five trials and was absent in two trials.²⁷ It is worth noting that, among the five trials that showed a superior effect of MI, the follow-up period varied with some for 2 months except for two trials that followed the participants for >6 months. Questions remain regarding the validity of MI provided in oral health studies as oral health providers trained in MI are uncommon and the fidelity of the delivery is often omitted.

Additionally, for some patients, multiple sessions of MI might be necessary for behavior change to occur. The concept of the potential dose-response of MI for behavior change was further supported by a recent meta-analysis.²⁴