15 Future Research and Applications


Future Research and Applications

Lars-Göran Öst and Erik Skaret

Symptoms, Clinical Characteristics and Consequences

Patients attending special clinics for dental phobia (DP) have poor oral health (Agdal et al. 2008; Wide Boman et al. 2010) compared to the general population. However, Agdal et al. (2010) found that patients with intra-oral injection phobia (IOIP) had much better oral health than DP patients. They went to the dentist more regularly and were focusing on preventive strategies that would postpone a situation with need for oral injections. Variation in oral health for the DP patients is great and it makes sense that people in this group are also focusing on preventive strategies, at least in the beginning of their avoidance period. We can hypothesize that the differences in oral health between the DP and the IOIP groups are due to the difference in avoidance. However, we do not understand the differences within the groups. What is characterizing the group of DP patients that have good oral health?

Research generally focuses on the negative aspects of having a phobia like DP or IOIP. Do some patients have positive secondary effects of their phobia? Will treatment open up ­problems that the phobia ‘protected’ them from, for example negative interpersonal relationships/­partnerships and losing sympathy from other people? In such a case this is probably related to motivation for treatment and represents barriers for anxiety treatment.


Regarding research on the epidemiology of dental anxiety and phobia, the current situation is far from satisfactory. Most studies investigating the prevalence of dental phobia have simply used a self-report scale, most commonly the Dental Anxiety Scale (DAS) and decided on a certain cut-off for diagnosis (e.g. 13 or 15 points). There are no epidemiology studies using state-of-the-art methodology in this area, e.g. as in the National Comorbidity ­Survey-Replication (Kessler et al. 2012), in which randomly selected individuals are interviewed with the help of a specific interview schedule in order to ascertain if they fulfil any psychiatric diagnoses. Thus, we recommend that researchers interested in the prevalence of dental phobia and anxiety should collaborate with psychiatric epidemiologists and ensure that the questions necessary to arrive at a diagnosis are included in the interview schedule.


The first question when it comes to assessment concerns diagnosis and differential diagnosis. As far as we can see today this has to be done by a psychologist (or psychiatrist) trained in carrying out diagnostic interviews with the help of a structured or semi-structured interview schedule, e.g. the Structured Clinical Interview for DSM-IV (SCID-I) or the Anxiety Disorders Interview Schedule for DSM-IV (ADIS-IV). One important question for future research is whether it is possible to develop a self-report questionnaire that can give equally reliable information as the diagnostic interviews.

Another important issue is to develop a battery of assessment methods to be used in randomized controlled trials (RCTs) and a smaller version of this battery to be used in clinical work. This battery should cover all important aspects of dental phobia and employ more than self-report scales, e.g. behavioural approach/avoidance tests (BAT) as in the Haukebø et al. (2008) and Vika et al. (2009) studies. During a BAT simple psychophysiological assessment, e.g. of heart rate and blood pressure, could also be made (e.g. Lundgren et al. 2006). Furthermore, an independent dentist could rate the patient’s behaviour (e.g. Berggren and Linde 1984) while in the dentist chair undergoing dental treatment after anxiety therapy. Finally, different aspects of the dental phobia should be covered via self-report scales, e.g. beliefs (Milgrom et al. 1995), cognitions (De Jongh et al. 1995), coping strategies (Bernson et al. 2007), dental experiences (Oosterink et al. 2008) and satisfaction with dental visits (Hakeberg et al. 2000).

It goes without saying that all of these measures must go through a psychometric evaluation before being used in research and clinical settings. The final hurdle then is to get researchers and clinicians to use this kind of a battery. Editors of scientific journals can help by only accepting studies for publication if they use a broad battery of assessment instruments. Clinicians need to be informed, e.g. in continuing education courses, that their treatment of DP patients will be made easier and the outcome improved by using the assessment battery. We also recommend that clinicians continuously evaluate their treatment of these patients by at least employing self-report instruments before and after therapy. This enables a comparison with the therapy effects obtained in randomized clinical trials.


In 1920 John Watson published his famous study on little Albert who was taught to be afraid of white animals by being subjected to classical conditioning in the laboratory; pairing the presence of the animal with a loud scary noise (Watson and Rayner 1920). Some American researchers followed in Watson’s footsteps up until the 1950s when these kinds of studies were no longer accepted by ethical committees.

One alternative when studying aetiological factors is to carry out longitudinal studies. These need to start with a large group of young children, before the normal age of onset for dental phobia, and assess them with a large battery of parameters. Then the sample has to be followed up frequently enough to be able to catch the various onset circumstances, while it is fresh in their memory, for the 3–5 per cent of the sample that is supposed to develop dental phobia. This kind of research is costly and also suffers from the restriction that only those factors assessed at the start of the study, or at a previous assessment, can be used as a predictor.

As far as we can conclude from research (e.g. Öst 1985) the way a phobia has been acquired does not seem to be of any importance when it comes to treatment. Rachman (1977) described three known pathways to fear or phobia: (i) direct conditioning; (ii) modelling and (iii) instruction or transformation of information. In addition, there might be other ways that have not yet been discovered. Irrespective of which of these pathways patients ascribed the onset of their phobias to, common CBT methods seem to be about equally effective. One should also keep in mind that most patients are in their mid-30s when applying for treatment and have had dental phobia for more than 20 years on average. Since a therapy for any type of psychiatric disorder cannot change the original causes (i.e. the onset circumstances) the focus needs to be on the factors that currently maintain the disorder, e.g. the strong belief or conviction that a catastrophe will happen if one sees a dentist to obtain dental treatment.

Intra-Oral Injection Phobia

Very little research has been undertaken regarding IOIP so far. The field needs experimental laboratory studies to investigate the relationships between this phobia and injection phobia (IP) in general, DP and blood-injury phobia (BIP). What behavioural, cognitive and physiological responses do these phobias have in common and what responses differ significantly between the phobias?

From a diagnostic point of view the degree of overlap between IOIP, IP, DP and BIP is of great interest. This also leads to the question of comorbidity between various combinations of phobias in this area. How common is comorbidity and does it predict outcome negatively? Recent research in specific phobias (Ollendick et al. 2010; Öst et al. 2001) and social phobia (Öst et al. in press) in youth indicates that: (i) comorbidity does not impede the outcome of the primary disorder and (ii) the comorbid disorders improve significantly without being focused on in treatment. However, it remains to be seen if this also holds true for the current group of specific phobias in adults.

As a clinician an important question for future research is whether any of the phobias in this quartet is always the ‘lead singer’, i.e. the motor that drives the other and thus needs to be treated first, or if this varies from patient to patient.

Dental Anxiety in Children and Adolescents

Problems concerning prevalence are the same for the younger age groups as for the adult population; often based on self-reports and certain cut-offs for diagnoses. The instruments used generally lack adequate or sufficiently explained theoretical foundations (Armfield 2010).

Treatment studies in children with behaviour management problems and/or dental anxiety often focus on how to modify the child’s behaviour to make it easier to perform the dental treatment. Examples of techniques include relaxation, distraction, hypnosis and a focus on increasing control and predictability. Methodological issues involve differences in age, culture, sampling methods and validity of measures (e.g. dental anxiety (DA) and dental behaviour management problems (DBMP)) and should be more theory driven (Klingberg and Broberg 2007). Many studies include pharmacological methods or combinations of a psychological and a pharmacological approach. Greater focus and effort should be directed towards psychological interventions that will reduce the child’s anxiety in the long run without the need for pharmacological support. There are few RCTs comparing different approaches in children (Porritt, Marshman and Rodd 2012). There are, however, studies showing effective treatment of children with other phobic disorders (Öst et al. 2001; Seligman and Ollendick 2011), but as far as we know there are no RCTs testing treatment of children with DP or IOIP. Since the mean age of onset for DP is 11–12 years (Öst 1987) it is important to intervene and reverse the dental anxiety problem at/>

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Jan 20, 2015 | Posted by in General Dentistry | Comments Off on 15 Future Research and Applications
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