A clinician guide to patients afraid of dental injections and numbness.SAAD Dig. 2011 Jan; 27:33-9.SD
Fears of dental injections remain a clinical problem often requiring cognitive behavioural psychology counselling and sedation in order to carry out needed dental treatment. This study, based on a national survey in Australia, compared patient concerns about numbness caused by local anaesthesia and fears of the injection itself. It also examined associations between dental fearfulness and avoidance associated with patient self-reported negative experiences and treatment need. Clinical advice on how to approach such patients is offered. Relatively high levels of dental anxiety and fear have been reported in several industrialised Western societies (McGrath & Bedi, 2004; Armfield, Spencer & Stewart, 2006; Lahti et al., 2007; Enkling, Marwinski Jöhren, 2006). In the U.K., almost one in three adults consider themselves to always be anxious about going to the dentist (Nuttall et al., 2001). Of concern is that this dental fear may be passed on to the children of anxious adults (Nuttall, Gilbert & Morris, 2008), leading to an inter-generational perpetuation of the problem. There is considerable evidence that dental fear is related to poorer oral health, reduced dental attendance and increased treatment stress for the attending dentist. There are many aspects of going to a dentist that might elicit feelings of apprehension, concern or anxiety in prospective patients (Liddell & Gosse, 1998; Oosterink, de Jongh & Aartman, 2008). One of the most commonly reported concerns relates to receiving injections. Indeed, fear of needles and the treatment of injection fear has been an important focus of a research in the U.K. (Boyle, Newton & Milgrom, 2010). Needle fear, in particular, is a major issue given that the delivery of local anaesthesia via injection is the central plank of pain relief techniques in dentistry (Malamed, 2009) and dentists as well as patients often avoid difficult injections as a consequence, resulting in poor pain control. A less well described anxiety of receiving dental treatment is fear of numbness associated with the dental injection (Morse & Cohen, 1983). Certainly, many dentists believe that their patients avoid local anaesthesia because of a wish to avoid the disturbing effects of numbness (Moore et al., 1998). Milgrom et al. (1997) found that fears about the numbness associated with receiving local anaesthesia significantly differentiated avoiders and non-avoiders of dental treatment. However, these concerns appeared to be much less common than those concerning the perceived pain of injections and fear of bodily injury resulting from the injection (Milgrom et al., 1997; Kaako et al., 1998). Consistent with these findings, whereas 43% of English patients asked to imagine undergoing future third molar surgery expressed concerns primarily about pain, only 6% of patients indicated concern about numbness as their worst fear (Earl, 1994). More recently, a study of Dutch people found that the feeling of numbness from the anaesthesia was rated as the 41st most feared dental stimulus out of a list of 67 possible stimuli, and that only 1.5% of the general population regarded numbness as extremely anxiety provoking (Oosterink, de Jongh & Aartman, 2008). However, it is important for a clinician to differentiate between those who dislike the sensation of temporary numbness versus those who may worry that it may never wear off. Such problem thinking can be an issue irrespective of whether a patient overcomes the fear of needles with sedation or not. A large number of patients dislike the sensation of numbness enough for manufacturers to respond with a partial antidote in alpha adrenergic receptor antagonist phentolamine mesylate (OraVerse Sanofi-Aventis, Hersh & Lindemeyer, 2010). Approval of this agent, which shortens the length of soft tissue anaesthesia after inferior alveolar block, is pending in the UK and other European countries. In other cases, dentists resort to using local anaesthetics without vasoconstrictors to shorten the period of anaesthesia (Fiset, Getz, Milgrom & Weinstein, 1989). While the association between dental fear and fear of injections has received considerable attention, the relationship between dental fear and numbness has received less attention. In particular, the nature of the associations between dental fear and avoidance and anxiety over numbness has not been studied. There has also been no research into whether or not concerns over numbness are independent of injection concerns. Finally, the association between fear of numbness and injections and dental avoidance and treatment needs has not been investigated. This study, based on survey work in Australia, aimed to compare patient concerns about numbness caused by receiving anaesthesia to that of anxiety over the receipt of needles and injections. Associations with dental fear and avoidance as well as negative experiences and treatment needs were also explored.