Environmental, Emotional, and Cognitive Determinants of Dental Pain
- Acute orofacial pain shares similarities but also has unique aspects, relative to other forms of bodily pain.
- The experience and expression of orofacial pain is determined by a multitude of factors that can be conceptualized across environmental, emotional, and cognitive domains.
- The dental setting is a unique environment with important social and relational aspects that impact pain.
- Emotional factors, particularly dental care-related anxiety and fear, are closely intertwined with orofacial pain.
- Cognitive processing is an important consideration in dental pain, as catastrophizing and memory of pain have been found to relate to the experience and expression of pain.
- Individual patient characteristics, including genetics, age, gender, culture, and other psychosocial factors, affect orofacial pain.
Pain is common, even ubiquitous, for all human beings throughout life, and pain associated with the oral cavity is part of that experience; however, oral pain has some unique qualities relative to other types of bodily pain. Oral pain may be different, in part, due to the way in which the teeth are innervated compared to the rest of the body. Additionally, the dental setting is a unique environment which factors into the pain experience. The social and psychological functions of the oral cavity and orofacial region also contribute to special meaning and significance associated with dental pain. While there are differences, however, all pain experiences share some common elements. A person’s cognitive interpretations, as well as behavioral and emotional responses to nociceptive sensations, are driven by basic biological predispositions, social and other environmental factors, and psychological considerations, among a myriad of other possible influences.
Among other types of acute dental pain, patients can experience toothache and can seek relief through oral health care. Patients can experience pain prior to procedures; during procedures such as injections, restorations, extractions, root canal treatments, and other services; and postprocedure during recovery (e.g., Pak & White, 2011). While the occurrence of pain during procedures may be low (i.e., affecting less than 25% of general dental practice patients, according to Tickle et al. 2012), public perceptions are that dental care is highly associated with pain. Consequently, dental care-related anxiety and fear are inextricably intertwined with oral pain (see Chapter 12 in this volume).
When considering pain involving the oral cavity, the general context of pain in the orofacial region should be considered. Any pain conditions in the hard and soft tissues of the head, face, neck, and intraoral cavity are considered orofacial pain, as defined by the American Academy of Orofacial Pain (de Leeuw, 2008); however, dental pain as regarded by a layperson most commonly is associated with toothache; injury to the teeth, jaw, or face; or procedural pain related to restoration, extraction, endodontic therapy, orthodontics, or periodontal surgery.
Pain is described as “an unpleasant sensory and emotional experience associated with actual or potential tissue damage, or described in terms of such damage” (International Association for the Study of Pain Task Force on Taxonomy [IASP], 1994, p. 211). While this definition provides a rudimentary description, it does not fully describe the psychological experience of pain. The IASP asserts that while aversive stimuli do in fact activate the nociceptive response, that itself is “not pain.” The perception of pain also is an affective experience, due to its unpleasantness. It is based on an individual’s biological predisposition and prior experience (IASP, 1994). The unpleasantness of pain, its cause(s), and future implications contribute to the emotional reaction, which is used as a cue to either escape the situation and/or to avoid it in the future, if possible (MacDonald & Leary, 2005). The painful sensation is the warning signal to the body and may produce a reflexive response. The affect, or emotional response that is associated with pain, varies depending on the stimulus, the environment, and the individual.
From a biological perspective, dental pain often is caused by inflammatory diseases involving the dental pulp or periodontal tissues (Holland, 2001), but it also can be related to other disease processes or injury. Holland suggests that dental pain can be of pulpal origin (e.g., hypersensitivity to dentin, reversible pulpitis, irreversible pulpitis) or periodontal origin (e.g., pericoronitis, periadicular periodontitis, postendodontic pain, cracked tooth syndrome, postextraction pain). This pain, however, can spread to other sites from the teeth (e.g., masticatory muscles), or be referred from/to the teeth from other regions. For example, somatoform disorders, including pain syndromes, can be manifested in toothache, without a clear nociceptive etiology (e.g., “phantom tooth pain” or atypical odontalgia; Holland, 2001). Atypical odontalgia is a chronic form of dental pain without a clear cause (Melis et al., 2003; Baad-Hansen, 2008). There are several theories presented in the literature; however, most evidence supports atypical odontalgia as a neuropathic pain condition (Baad-Hansen, 2008).
This chapter focuses on the social and psychological factors that influence the experience of oral pain, with particular emphasis on the complex interplay among environmental, emotional, and cognitive dynamics, and how they interact with individual differences. First, conceptual issues in understanding dental pain will be presented, followed by environmental determinants of pain. In the third and fourth sections, emotional and cognitive determinants, respectively, will be considered. The chapter will conclude with information specific to individual differences, gender, cultural, and lifespan issues. While the biological aspects of dental pain cannot be overlooked, neither can the contributions of psychological and environmental factors when working to prevent or ameliorate the distress associated with pain-related experiences.
Conceptual Issues in Understanding Dental Pain
Pain terminology is used differently across cultures; however, there are fundamental aspects of pain that are universal. From an evolutionary perspective, pain is a warning signal with adaptive and motivational functions (McNeill & Dubner, 2001). Pain is, in part, an affective experience that exists along a continuum as a warning signal of possible illness or injury. It may be a manifestation of an advancing or receding pathological state, but it is largely symptomatic. It acts as a means to indicate potential injury, illness, or danger. From this perspective, dental pain is a functional means to signal the possibility of a developing or ongoing disease state that requires attention to determine the effect on intraoral structures and on overall systemic health. Of course, persistent pain that extends beyond an expected recuperative period is considered chronic and nonfunctional, as in temporomandibular disorder or atypical odontalgia (see Chapter 9). In such cases, emotional and environmental factors often strongly influence the pain experience, and require in-depth examination and attention.
Pain has the ability to alter behavior and motivate individuals to seek treatment. When a person is experiencing dental pain, particularly when it is intense, the pain can become a consuming sensory experience, making it difficult for the individual to maintain normal functioning throughout the day or to sleep at night. When dental pain is experienced by a patient with dental care-related fear and/or phobia, stimulus intensity may be the primary factor in determining how that patient responds (Vowles et al., 2006) and at what point they seek care. Pain intensity, in part, determines the rapidity with which a person seeks dental care; whether an individual is someone who receives regular preventative oral health care or seeks dental care only symptomatically, pain acts as an equalizer, prompting and at times even demanding intervention.
Pain typically is experienced when an aversive stimulus activates myelinated A-delta or unmyelinated C-fibers that send signals to the brain; however, dental pain, specifically pain from tooth pulp, is uniquely different. Tooth pulp seems to be innervated differently compared to other areas of the body, with the A-delta fibers ending within the inner third of the dentinal tubules and the C-fibers ending in the tooth pulp (Hildebrand et al., 1995; Fried, Sessle, & Devor, 2011). Exposing skin to air puffs or water spray typically does not result in a nociceptive response, but when that same stimulation is applied to tooth pulp (exposed dentin), the result is (often intensely) painful. The unique nature of dental pain makes it difficult to generalize to other forms of bodily pain. It may be that an individual could endure intense or longer duration painful stimulation in other areas of the body and less in the oral cavity, or vice versa. Nevertheless, there is some evidence that the way that a person views other forms of bodily pain (e.g., via a cold pressor test) are predictive of postoperative dental pain after a surgical extraction (Mobilio et al., 2011). Currently, there is a need for further research that compares painful stimulation in different parts of the body, including the oral cavity.
In addition to the physical sensations of dental pain being unique, specific verbal descriptors have been found to be associated with toothache. Melzack’s (1975) research with the McGill Pain Questionnaire found that toothache is associated with sensory words: “throbbing, boring, and sharp”; an affective word: “sickening”; evaluative word: “annoying”; and temporal words: “constant and rhythmic” (Dubuisson & Melzack, 1976). These verbal descriptors are specific to the experience of one form of dental pain (i.e., toothache) and may differentiate between irreversible disease versus a potentially treatable condition, based on the type of description the patient offers (Grushka & Sessle, 1984).
Oftentimes, external observers (e.g., dentists, hygienists) attempt to understand an individual’s pain experience, while trying to prevent or ameliorate it, and may make a judgment that the pain is less or more intense or emergent, relative to the level of expression. Assuming that pain is actually being experienced (and the patient is not malingering), the external observer may be accurate, or may underestimate or overestimate; however, it does not change the person’s experience. The expression of pain may be utilized to communicate to others one’s level of discomfort; however, it also may function to modify the behavior of others. Report of the onset of new acute pain (Ow!) during a procedure likely elicits a more attentive and rapid response by a dentist than a patient’s report about being fearful. For example, when the patient in the dental chair says “Ouch!,” the dentist typically will respond by stopping what she or he is doing. Therefore, a patient learns that by expressing pain to the dentist, he or she can change the present course of action and temporarily avoid the dental procedure. A highly dentally fearful patient may utilize pain expressions (even nonconsciously) as a means of escape or avoidance, when in reality the person is experiencing a state that external observers would regard as fear, not pain. Pain and fear (as well as anxiety) are inextricably linked in the dental operatory (McNeil & Berryman, 1989; McNeil et al., 2011; Wilson et al., 2013). Importantly, communication from patients within healthcare settings functions not only to relate meaning, but also to elicit certain clinician behaviors and outcomes, such as stopping the dental drill.
Aspects of the environment are powerful and distinctive determinants of dental pain. Within the dental operatory, and the dental clinic, there are a myriad of stimuli that signal, or cue, to the patient that a particular event is about to occur. The stimuli within the dental operatory and clinic typically are infrequently experienced by patients, and so are unique and may even retain novelty over time. The social aspects of the dental environment are important signaling factors that are influential in patients’ overall experience. From the behavior of the receptionist, to the ambiance in the waiting room, and of course including the interactions with hygienists and dentists, social interactions and communication contribute to the general environment in the dental setting that affects patients’ processing, conceptualization, and response to nociception. The dental environment and the cues therein “set the occasion” for anticipation of sensations during dental care. Some cues likely sensitize certain patients, making them more vulnerable. In other cases, however, they allow realistic expectations, such that there is a higher threshold and tolerance for pulp stimulation, for example, in a dental setting than in a psychological laboratory (Dworkin & Chen, 1982). These factors, as well as other aspects of the environment, such as predictability and control, are presented with consideration of their impact on pain.
Dentists, hygienists, assistants, and even receptionists, just like other “stimuli” in the dental office, such as dental chairs, can be associated with pain and may elicit a fear response in highly fearful patients. Similar to links in a chain, there may be several degrees of separation from seeing the receptionist to injection or drilling, but the conditioning that occurs in this environment can, and often does, pair with preceding stimuli. Patients may respond with verbal reports of distress, psychophysiological responding, or may choose to escape the situation entirely as a result of coming into contact with these environmental cues, or even anticipating them. A dental cartoon from the popular press portrays a patient saying “ouch” even as a dentist merely enters the treatment room (Shepherd, 1991). This cartoon exemplifies the blend of fear and pain that often is experienced during dental care (McNeil & Berryman, 1989; McNeil et al., 2011).
While all dental personnel may be viewed as potential “fear stimuli,” dentists may be the most negatively viewed, given that they conduct the most (potentially) painful procedures. They even can be regarded as “purveyors of pain,” yet may be seen (even simultaneously) as a means to relief and an end to suffering. When a dentist provides relief from ongoing dental pain, the process of “negative reinforcement” occurs, in that the dentist has removed or reduced pain for the patient, thus increasing the likelihood he or she will visit the dentist for this problem in the future. Nevertheless, the patient may not consistently have positive experiences, or the positive experiences may not override a highly fearful patient’s prior experiences, but each positive encounter has the potential to help alleviate some of the fear and other discomfort associated with dental care.
Relationships with Oral Healthcare Providers and Communication
The social aspects of the relationship between dental patient and oral healthcare provider may seem to be secondary to procedures that are employed in the operatory vis-à-vis pain. Nevertheless, these relationships significantly impact the experience and expression of pain, and affect the maintenance of oral health behaviors (Grembowski, Andersen, & Chen, 1989; Kent & Blinkhorn, 1991). A patient’s view of the quality of this relationship predicts a number of outcomes, including treatment adherence, appointment attendance, and satisfaction (Sandell, Camner, & Sarhed, 1994; Sinha, Nanda, & McNeil, 1996). Lower reported pain levels are associated with greater social support (e.g., active or passive) during the pain experience, as compared to experiencing the pain alone (Brown, Sheffield, & Robinson, 2003). Individuals who experience painful stimulation in a group setting have been shown to match the responding of others in the group (Craig & Weiss, 1971). The concept of social modeling suggests that others can be influential on one’s behavior, which includes pain responding. For example, adolescent patients who received attentive care and more attention from parents recovered more slowly from oral surgery (Gidron, McGrath, & Goodday, 1995).
An important component of the provider–patient relationship is communication. One study demonstrated that patient attitudes about the quality of a past appointment were significantly different between patients who discussed an orofacial problem with a healthcare provider versus with a layperson (e.g., spouse, relative, friend). Interestingly, those patients who perceived poorer quality relationships with healthcare providers, and were less likely to discuss a pain problem with the provider, were at greater risk for developing health problems associated with not receiving appropriate dental care (Riley, Gilbert, & Heft, 2004). In addition, two facets of communication content have been found to have an effect on pain responding: provider confidence and provider behavior that is described as “warm and friendly” (Gryll & Katahn, 1978). Patients indicated that when providers communicated confidence in an intervention, they reported less pain than when the provider was ambivalent about the treatment approach. Patients also reported less pain when the provider was “warm and friendly” and actively elicited discussion and questions from patients, relative to providers who were more neutral and less talkative. Therefore, communication quality and content of communications between patient and provider, like other aspects of the overall environment in the dental office, affects not only the relationship but the experience and expression of pain as well.
Distraction, or shifting the patient’s attention away from environmental procedural cues, and away from the sensory aspects of a painful situation to another more pleasant stimulus, has long been successful in lessening pain (Kent & Blinkhorn, 1991). Due to the acute and transient nature of procedure-related dental pain, the use of distraction often is quite successful, as it moves the focus away from the current environment. Distraction may be as simple as listening to music or as technologically advanced as virtual reality; however, it seems to be increasingly effective as more sensory systems are involved. Seyrek, Corah, and Pace (1984) found that watching a television program or playing a video game was more effective at reducing patient discomfort than listening to an audiotape. Both simple and complex virtual reality systems have been implemented as a means of distraction. Frere et al. (2001) found that dental prophylaxis patients experienced less pain when exposed to positive and distracting virtual reality versus treatment as usual. Hoffman et al. (2001) compared the use of an immersive virtual reality distraction, a movie distraction, and no distraction during periodontal scaling and root planing. Higher pain ratings were found during the movie and the no-distraction conditions, while little to no pain was indicated during the virtual reality intervention.
As another form of distraction, hypnosis is helpful to many dental patients. Hypnosis, however, is likely to be more than a distraction in many cases, as there are broader and different conceptualizations, including relaxation, suggestibility, and trance states. Hypnosis has been shown to be effective in altering the experience of pain. As an example, one study involved giving participants a hypnotic suggestion for anesthesia of the right mandibular arch that was to last during and after pain stimulation with a pulp tester. Pain threshold was measured before, during, and after the hypnotic suggestion. During and after hypnosis, pain threshold was significantly higher than in the prehypnosis condition (Facco et al., 2011). There is a long history of effective use of hypnosis for pain control in dental settings (see Chapter 6 in this volume).
Predictability is the degree to which the presence or absence of an environmental signal indicates the onset, offset, duration, or intensity of a stimulus or event; in the case of dental care, it is whether or not the patient knows what will occur during dental treatment, how and when it will happen, and for how long. Predictability (along with controllability) impacts the experience and expression of pain and distress during dental care. Affective states, including fear and anxiety, impact patients’ ability to accurately predict dental pain experiences (e.g., Van Buren & Kleinknecht, 1979). Moreover, as fearful individuals in general overpredict aversive events, presumably as protection from potential harm (Arntz & Hopmans, 1998), predictability in the dental setting is extremely important as pain can be highly influenced by fear and anxiety. The primary approach to increasing dental patients’ predictability has been the provision of information by providers. The type and amount of information provided to dental patients is important, as is the patient’s preference for it. Providing information about both the potential procedural and sensory experience appears to be the most beneficial for patients (Corah, Gale, & Illig, 1979). Nevertheless, simply providing information does not insure that the patient will listen (or read), encode the facts, or understand them (Sorrell et al., 2009).
There has been considerable investigation of providing information about procedures to dental patients. Patients lacking predictability about a tooth extraction procedure, for example, displayed greater pain behavior compared to patients who were informed and able to predict what would occur in treatment (Auerbach et al., 1976). Relatedly, giving information about nitrous oxide enhanced its pain control effects in tooth pulp shock (Dworkin et al., 1984). As root canal therapy is portrayed so negatively and is associated with intense pain in the popular press, some work has been devoted to studying the impact of corrective information. Sorrell et al. (2009) found that even viewing a 5-minute film yields greater knowledge among endodontic patients. Additionally, positively written information about endodontic therapy was found to produce reduced fear of dental pain (van Wijk & Hoogstraten, 2006).
While more information generally increases predictability and decreases the experience of pain and anxiety, some individuals prefer less information to cope with potentially painful situations. This individual difference is based on two different types of coping styles known as monitoring and blunting (Miller, 1995). Patients who prefer more detailed information (i.e., “monitors”) often are more concerned and distressed with their medical condition, experience greater side effects, are more knowledgeable about their situation, and are less satisfied and more demanding about the psychosocial aspects of care as compared to patients characterized as “blunters.” These blunters prefer less information and if provided with too much detail may experience disruption in their avoidance coping. As a related example, when tooth extraction patients had a preference to receive procedure- and sensory-related information and then received information about treatment, pain and distress responding was significantly reduced compared to patients who received information but had no such preference for it (Auerbach, Martelli, & Mercuri, 1983).
Numerous studies have examined the influence of coping styles and information in healthcare settings (van Zuuren et al., 2006; Forys & Dahlquist, 2007; Kola et al., 2013). Forys and Dahlquist (2007) examined the effect of matching an individual’s coping style to a coping strategy (i.e., distraction or sensation monitoring) during a laboratory pain induction study. By matching coping style to the appropriate coping strategy, both pain threshold and tolerance were increased, but without reductions to pain intensity, affect, or anxiety. While there are a number of other ways in which coping style can be conceptualized (e.g., emotion-focused, problem-focused, or passive), the monitoring-blunting dimension is helpful in understanding the amount and type of information that is provided to dental patients anticipating potentially painful procedure(s). Because of the connection between anxiety/fear and pain, research suggests that by matching patients’ coping style to the appropriate amount and/or type of information or coping strategy, they may experience reduced anxiety and perhaps less pain.
Warning patients about potential pain, and responding to a patient’s direct question about whether a procedure will be painful, are classic examples of information provision in dentistry. Authenticity and honesty are, of course, important in terms of the relationship between the provider and patient. Nevertheless, labeling an anticipated sensation as painful likely will insure that the patient experiences it as pain. Focusing on the specific sensations patients likely will experience, rather than on the broader experience of pain, helps them to label the experience in a more positive way (cf. Neiberger, 1978).
Considering patients’ anticipation or prediction of pain (or comfort) during dental care, van Wijk and Hoogstraten (2005) have focused on fear of dental pain, and have developed a specific measure of that construct, based on the Fear of Pain Questionnaire-III (McNeil & Rainwater, 1998). Patients with high degrees of fear of dental pain have been found, during dental injections, to feel more pain and to experience it for longer periods (van Wijk & Hoogstraten, 2009). Pain during third molar extraction is predicted by fears of dental pain (van Wijk, de Jongh, & Lindeboom, 2010). This fear of dental pain construct is a heuristic for the understanding of the intersection of dental pain and fear/anxiety. This area of investigation has a significant benefit in that assessment instruments with known psychometric properties are available and have been translated into various languages (e.g., McNeil & Rainwater, 1998; van Wijk & Hoogstraten, 2003).
The ability of a patient to alter the onset, offset, duration, or intensity of a dental experience, in essence, whether or not the patient is able to influence what happens during treatment, defines controllability (Arntz & Schmidt, 1989; Foa, Zinbarg, & Rothbaum, 1992; Zvolensky, Lejuez, & Eifert, 2000). Controllability can be conceptualized in terms of actual control and perceived control; actual control involves responding which leads to an environmental change, while perceived control refers to the belief that an event can be structured, contained, or altered (Walker, 2001). Giving control, or increasing perceptions of control, during pain stimulation can increase pain tolerance (Kanfer & Goldfoot, 1966; Kanfer & Seidner, 1973; Haythornthwaite et al., 1998). Encouraging patients to raise a hand as a “stop signal” if they experience pain is a classic chairside method that has been shown to reduce reports of pain (Wardle, 1982), which likely is mediated through fear reduction. The pain-reducing effects of actual control are dependent on the patient’s own locus of control, which exists along a continuum from internal (“If I brush regularly, I can prevent cavities.”) to external (“My mother had all her teeth extracted by the time />