Nitrous Oxide in Pediatric Dentistry: A Clinical Handbook

© Springer Nature Switzerland AG 2020

K. Gupta et al. (eds.)Nitrous Oxide in Pediatric Dentistryhttps://doi.org/10.1007/978-3-030-29618-6_1

1. Rationale for Using Nitrous Oxide in Pediatric Dentistry

Kunal Gupta¹   and Priyanshi Ritwik²  

(1)

Children’s Dental Center, Gurugram, India

(2)

Department of Pediatric Dentistry, LSUHSC School of Dentistry, New Orleans, LA, USA

Kunal Gupta (Corresponding author)

Priyanshi Ritwik

Email: [email protected]

1.1 Understanding Fear and Anxiety

1.2 Purpose of Nitrous Oxide in Children

1.3 Indications of Using Nitrous Oxide in Pediatric Dentistry

1.4 Contraindications for the Use of Nitrous Oxide in Children

1.5 Advantages of Using Nitrous Oxide in Children

1.6 Disadvantages of Nitrous Oxide in Children

1.7 Conclusion

References

Electronic Supplementary Material

The online version of this chapter (https://​doi.​org/​10.​1007/​978-3-030-29618-6_​1) contains supplementary material, which is available to authorized users.

Keywords

Dental fear/anxietyObjectives of nitrous oxideIndications/contraindications of nitrous oxideAdvantages/disadvantages of nitrous oxideBehavior guidance in children

Learning Objectives

1.

Comprehending fear and anxiety in children which forms the basis for using nitrous oxide in children

2.

Understanding the purpose of using nitrous oxide in children which will help in increasing its use in children

3.

Studying about the indications of using nitrous oxide in children which assists in case selection

4.

Knowing contraindications which will help in making this technique more efficacious and safe

5.

Realizing the advantages of this technique over other modes of sedation

6.

Appreciating the disadvantages of this technique in order to know its limitations

A visit to a dental clinic is always considered to be nerve-racking whether for adults or children. The smell, the sounds, and the general atmosphere all add up to create an atmosphere which is not exactly perceived to be pleasant by most people. If you add crying children and stressed out parents to the mix, as in case with pediatric dental offices, then the situation becomes even more complex. This means that pediatric dentistry can be demanding for all the people involved and most importantly for child patients. Understanding the basics of fear and anxiety is a stepping stone towards the successful use of nitrous oxide in children as a behavior management tool. The purpose of using nitrous oxide should be clear to the pediatric dentists, in order to ensure that this technique is practiced effectively and efficaciously. It is more of a behavior guidance tool rather than a sedative tool. In this chapter, the indications and contraindications of using nitrous oxide in children shall be discussed as well as the advantages and disadvantages of its use in a pediatric dental office. A thorough knowledge about these will instill confidence in the pediatric dentists about its use in majority of their child patients.

1.1 Understanding Fear and Anxiety

The knowledge and understanding of fear and anxiety not only lays the foundation of our ability to provide the best possible care for children but more importantly allows us to establish a healthy and long-term relationship with them. It helps dentists recognize the signs of fear and anxiety, understand the underlying etiology, and enable them in developing a strategy to interact with such children. It is only after a thorough understanding of fear and anxiety that a dentist can use basic behavior guidance techniques individualized to each pediatric patient and introduce nitrous oxide in an effective manner.

1.1.1 What Is Fear?

Fear is a natural part of a child’s development. Overcoming fear helps a child successfully engage and overcome a difficult situation. A child who is able to overcome a fearful situation develops a sense of achievement and becomes more confident. On the other hand, a child who gets overwhelmed by fear often chooses to run away from the situation. In our case, it means leaving the operatory or if he chooses to stay, he does not allow the dentist to examine or treat him. Such a patient continues to remain scared of dentists and becomes more insecure as time passes. This perpetuates future anxiety and reluctance in accepting dental care.

Fear is defined as an unpleasant emotional response to a real or perceived immediate external threat or danger [1]. Fear comprises of psychological and psychophysiological responses. In simple terms, fear is the emotion one experiences, when there is an imminent threat of harm [2]. Fear is a protective emotion and integral to human experience. Fear is caused by specific stimuli in a context-dependent way [3].

Inability to handle a difficult situation leads to the development of fear.

1.1.2 Ages and Stages of Fear

Fears vary across ages and stages of child development (Fig. 1.1). Typically, fears vary in frequency, intensity, and duration. Fears wax and wane as a child grows; they also tend to differ based on the objects which evoke them in an age-specific and transitory way [4]. Children’s fears at various age groups has been detailed in Appendix I. Knowledge about age-specific fears can be useful for the dentists when dealing with children. For eg: In a dental office, separation from parents should not be done for preschoolers as it may induce fear.

Fig. 1.1

Different kinds of fear at various age groups in a growing child

1.1.3 Development and Physiology of Fear

The neurobiology of fear remains in its infancy. From an evolutionary perspective, fear is a protective mechanism and enables one to respond appropriately when faced with danger or harm. Fear is considered as an innate function of the subcortical brain, and the amygdala is referred to as the hub of the fear circuit [2]. The role of the amygdala in processing and expressing fear is summarized in Fig. 1.2.

Fig. 1.2

Location and Role of the amygdala in processing and expressing response to fear

Amygdala is the core of fear circuit in the brain.

A child’s fear has been explained by several theories. It may be related to the emotional involvement with their parents [5, 6] or may be a conditioned response involving learning, unlearning, and modification of fear through environmental experiences. Gesell states that children [7] go through a series of fears as they mature. Jeffrey Derevensky stated that children’s fears are not unrealistic or imaginary [8].

Fear in children is mostly learned through experiences or taught by parents, teachers, siblings, or friends.

1.1.4 Responses to Fear

Stimuli that evoke fear unravel a complex cascade of behavioral, autonomic, endocrine, and cognitive responses. Broadly speaking, fear results in inner feeling/cognitive response, outer behavioral expression, and accompanying physiological changes [4]. The responses to fear are summarized in Fig. 1.3.

Fig. 1.3

Different responses to fear

Inner feeling/cognitive Response: Negative statements or statements regarding possible danger from fearful situation (e.g., I feel scared, The dog will bite me!).

Behavioral Response: Avoidance or escape from the fearful situation, crying, clinging to parents, physical combativeness. The dentist usually has to manage this behavioral response while trying to deliver dental care to a fearful child (Figs. 1.4, 1.5, and 1.6).

Fig. 1.4

A crying child

Fig. 1.5

A fearful child clinging to mother and covering his mouth

Fig. 1.6

A fearful child wanting to go out of the operatory

A clinician can recognize a fearful child based on behavioral responses.

Physiological: Increased heart rate and respiratory rate, sweating, dryness of mouth, trembling, shaking, changes in respiration.

The emotional response to fear varies from a person to person and is more subjective. The subjective emotional reaction translates to behavioral changes manifesting in characteristic facial expressions, flight, fright, freeze, and/or avoidance [9]. In the long run, stimuli causing fear also lead to the development of particular adaptive behaviors within an individual to avoid or cope with the threat [3].

1.1.5 Types of Fear

Since fear is evolutionarily related to prevention from harm, there are innate fears, which occur in children, irrespective of their past experiences. Innate fear is not conditioned. It drives the individual’s defense when faced by a threat, much like the flight or fright reaction of an animal when it sights its predator. However, an individual’s lifetime experiences also shape the development of other fears. Over the course of life, individuals acquire fears. Figure 1.7 provides a visualization of classification of fear into innate and acquired fears in children [10]. The acquired fears are discussed below as conditioned, objective, and subjective fears.

Fig. 1.7

Types of fear and their acquisition in children

Conditioned fear is the development of fear responses according to the classic Pavlovian conditioning. Classic fear conditioning is described in a historical experiment where a little boy was presented with a white rabbit. At the same time, a suspended steel bar was struck with a hammer to produce a frightening loud noise. The noise caused the boy to tremble and cry. After several pairings of the white rabbit and the noise, the little boy became visibly upset at the sight of the rabbit alone. He also generalized his conditioned emotional reaction to other white, furry objects [11, 12]. Such experiments would no longer be possible to conduct ethically. However, the implications of conditioned fear in pediatric dentistry are significant. In the dental setting, an example of conditioned fear is the use of topical anesthesia prior to local anesthetic injection. During the first appointment, the child learns that the injection follows the application of topical anesthetic. During the second appointment, the child is conditioned to expect the injection after the application of topical anesthetic and may become fearful immediately after the application of topical anesthesia.

Objective fears develop based on one’s own experiences. General impatience on part of the dentist while treating a child or lack of clinical skills may instill fear or anxiety in children [13]. An example is the child with an acute dental abscess who may have had a difficult extraction. Should this child need another extraction in the future, he/she will likely have a fear of extraction based on their direct experience at the previous dental visit. In fact, unbearable pain at their first visit to a dentist is a predictor of children developing long-term anxiety and apprehension towards dentists and dental treatment [14].

A dentist’s manner of communication with a child, patience, clinical skills, and use of other behavior management techniques can help in reducing acquired fear in a child.

On the other hand, subjective fear develops based on the experiences or narratives of others. An example would be a child who hears negative feedback from a sibling about the dental treatment. A child’s fear can also be initiated on hearing negative words about dental experiences from parents. Many a times, parents tell their children casually that if you don’t brush well, you will end up with a dentist pulling out your teeth. The child now may be fearful at his/her own first dental appointment based on indirect experience or comments of somebody else (child may think that the dentist’s job is to pull out teeth). This is similar to developing high levels of fear for a friendly animal for which parents have told threatening narratives to their child.

Mothers who are scared of dentists, often have children who are anxious and fearful about the same [15] and is another example of subjective fear in children.

It has been found that subjective fears are stronger determinants of dental fears in children than objective fears.

Classification of dental fears into four groups has been carried out by the Seattle system (Table 1.1) (Milgrom 1985) [16]

Table 1.1

Table showing types of dental fear (Milgrom 1985)

1.1.6 Levels of Fear

Humans and other species have developed fear as a protective adaptation for survival in response to danger. For most of us, the level of fear is commensurate with the level of threat, and fear response is a dynamic process, adapting to the severity of the threat with effective coping skills. An example is an individual who is fearful of dental procedures, yet he/she decides to receive dental care because the benefits of dental treatment outweigh the threat from the procedure. However, for others, fear is disproportionate to the threat. When fear interferes with normal functions, it leads to maladaptive behaviors, such as avoidance. An example is a child who is extremely fearful of dental procedures and hence avoids dental care until the last moment; this could adversely influence treatment, as a restorable tooth may become non-restorable due to disease progression.

1.1.7 Strategies of Dealing with Fear

Clinicians should be well versed with the developmental aspects of children’s fear which are age and stage appropriate [7]. Some important clinically applicable concepts are as follows:

Never make fun of a child’s fear.

Positive reinforcement for a child’s good behavior. Ending the dental appointment on a positive endnote enables a child to remember something positive, even about a difficult dental appointment. Constantly highlighting desired behavior can be a much more effective way of promoting the desired behavior and enhancing a child’s confidence (Fig. 1.8).

Try to be supportive and empathetic while talking to a fearful child (Fig. 1.9).

Help child explore strategies to overcome their fears. Breathing exercises, visual imagery, art therapy, music, and suggestive hypnosis are examples of techniques which can be implemented in the dental clinic (Fig. 1.10).

Fig. 1.8

Positive reinforcement—praising child verbally

Fig. 1.9

Communicating in a supportive and empathetic manner while talking to a fearful child

Fig. 1.10

Using music to overcome a child’s fear

A dentist should always make an effort to encourage the child to talk about their fear and its associated feelings.

Three categories of treatment to enable a child overcome dental fear are as follows [7]:

1.

Behavioral procedures

Systematic desensitization

Modeling (Fig. 1.11)

Contingency management

2.

Cognitive behavioral interventions

It is a structured and brief psychological treatment based on a combination of psychoeducation, exposure, and homework exercises [17].

It is based on changing distorted thinking and dysfunctional behavior. Clinicians should help children learn to identify their triggers, understand how anxiety affects their behavior, and how to replace distorted thoughts using cognitive reframing. Children are taught to replace negative thoughts with positive ones and separate realistic thoughts from unrealistic ones.

3.

Behavioral family interventions

This requires involvement of the family, especially the parents. The process involves identifying the problem, trigger for anxiety, and finding a possible solution. It involves stepwise achievement of goals. Positive reinforcement is an integral part of this. Parents need to allocate specific time during the day for this intervention.

Fig. 1.11

Modeling being done on parent to enable child overcome fear

1.1.8 Anxiety

Often, the terms fear and anxiety are used loosely or interchangeably. However, while fear is a phasic and transient response to an imminent or immediate threatening stimulus, anxiety is a sustained tonic state, based on the prediction of a threatening stimulus. The term anxiety is used to describe the feeling which occurs when the source of harm is either uncertain or distant in time or space. An individual’s emotional response to anxiety and to fear is similar. The difference in fear and anxiety is illustrated in Fig. 1.12.

Fig. 1.12

Figure illustrating difference in fear and anxiety

Fig. 1.13

(a) Anxious child crying without reason. (b) Anxious child not making eye contact with the clinician

A patient is dentally anxious when he feels that getting dental treatment will result in a negative outcome, and moreover he feels that if and when that happens he will not be able to control the outcome [18]. Dental anxiety has been attributed to factors such as personality characteristics, traumatic or painful past dental experiences in childhood (conditioned experiences), learned attitude towards dental care from fearful family members or peers, perception of body image, fear of bodily injury, coping styles, and pain reactivity [19].

Clinical anxiety in a child regarding a dental visit is a strong predictor of uncooperative behavior [14].

An important distinction between fear and anxiety is that fear is short lived and subsides after the threat or danger passes, while anxiety does not dispel as quickly.

There are various reasons for anxiety in children, as listed below [20]:

Temperamental disposition

Physical illness or disability

Family problems

(A Disagreement between parents, recent parental divorce, parental illness, parents seeking reassurance from children, and parents using excessive threats to control their condition.)

School/academic worries

Problems with friends, social circles, and activities out of school

Temperament is a distinct personality of a child. It is an inborn trait which reflects the approach of a child towards the world. Children with different temperaments will have different approaches towards their visit to a dental practice and their acceptability of dental treatment.

Thomas and Chess (1987, 1991) [21] categorized children into three clusters of temperament.

1.

Easy—Child is usually in positive mood and adapts easily to new experiences.

2.

Difficult—Child reacts negatively, cries frequently, and does not accept new situations easily.

3.

Slow to warm up—Child has low activity level and takes time to get adapted to new circumstances.

Rothbart et al. [22] develop Children’s Behavior Questionnaire (CBQ) and its derivative Children’s Behavior Questionnaire Short Form (CBQ-SF) which serves as an aid to evaluate child’s temperament. As per this scale, children with easy temperament which includes children with high effort control (can easily stop an activity when he or she is told no), high soothability (easy to soothe when the child gets upset), and low frustration (does not become angry when he or she is asked to go to bed), low activity, and impulsivity (is not in a hurry to get from one place to another or rushing into an activity without thinking about it) will show more success with nitrous oxide sedation.

The physical manifestations of anxiety in children are listed in Table 1.2.

Table 1.2

Physical signs of anxiety in children presenting for a dental appointment

1.1.9 Phobia

Phobia is different from fear in that it is out of proportion, unreasonable, and persistent [23]. Dental phobia is a severe type of dental anxiety which is characterized by marked and persistent anxiety in relation to discernible dental situations/objects (e.g., injections, high-speed handpiece) or to dental situations in general. Dental anxiety and dental phobia represent different points on a continuum, varying from mild dental anxiety on one end to dental phobia on the extreme end of the continuum [24, 25].

Dental phobia is an extreme form of dental anxiety.

1.1.10 Dental Fear and Anxiety in Children

Dental fear and anxiety have been recognized as a public health dilemma in many countries [18, 26].

Dental fear and anxiety eventually lead to disease progression and exacerbation of the underlying dental problem due to avoidance of dental visits.

Fear of pain is an important predictor of dental anxiety [18]. The nature of fear prominent in a child’s life corresponds to the child’s age, cognitive ability, and stage of development [18]. In a pre-school child, attachment and separation anxiety play an important role. These children are less likely to become anxious if their parent and favorite toy accompany them into the dental operatory. In children older than 8 years of age, the fear of bodily injury is prominent. The fear of extraction is exaggerated in children in this age group. Teenagers manifest fear of dental treatment, likely due to issues of control and autonomy [18]. Most of these fears in children decrease or disappear as they grow older due to cognitive development and learning appropriate coping skills [18, 26]. Indeed, the prevalence of dental fear and anxiety is higher in younger children [26].

The pooled prevalence of dental fear in children across different countries varies between 10 and 20% [26]. The prevalence and level of dental fear and anxiety in Northern European pediatric populations are lower than in other geographic areas such as Southern Europe, Asia, and the USA. This implies that cultural factors influence dental fear and anxiety. While fear and anxiety in other contexts are socially unacceptable, dental fear is widely accepted and carries little social stigma [27]. Dental fear and anxiety are higher in girls than in boys [26].

Fear of dental treatment in children results in treatment difficulties [18]. Children with dental fear and anxiety exhibit behavioral problems, which can result in a stressful and unpleasant experience for the child, the parents, and the treating dental practitioner [24]. Such behavioral problems are often related to dental factors such as previous negative treatment experiences, particularly extraction, restorative procedures, and injection, which cause the most negative emotional load [18]. Conditioning is an important contributor to dental fear in children of 5–11 years of age [28]. Individuals with dental fear and anxiety have a high likelihood of cancelling dental appointments or failing to show up for scheduled dental appointments [24].

Dental fear leads to avoidance of treatment and high dental anxiety leads to poor oral health-related quality of life.

1.1.11 Etiology of Dental Fear in Children

Dental fear in children can be traced to five basic factors which play a role in its etiology. Dentists treating children should understand the underlying cause of fear as the basis of the uncooperative/fearful behavior exhibited by the child in the dental clinic [29]. These basic root causes of dental fears are summarized in Fig. 1.14.

Fig. 1.14

Etiology of fearful behaviors by children during dental appointments

Fear of Pain or Its Anticipation

Dental fear is related to anticipated pain or misinterpreted pain. A logical explanation to the child that pain is different from touch or pressure can help the child in dissociating anticipated or misinterpreted pain from fear. For example, if the child complains of pain even after administering local anesthesia, then use of a probe, to let the child feel the difference in anesthetized and non-anesthetized area, assures the child that he/she will not experience pain.

Lack of Trust or Fear of Betrayal

Trust of the dentist is an important factor in dental fear among adults. However, there is no evidence-based data to demonstrate this in children [29]. Conventional wisdom and classic child psychology literature support building trust between the child and the dentist as the building block to successful dental appointments. Lack of trust in a child may be due to a previous negative experience with a dentist, or medical personnel, and/or learned from behavior/statements of parents, siblings, or peers.

Mistrust can be reduced by proper and honest communication with children. TLC or tender loving care is empathetic non-judgmental communication with the child, acknowledging the child’s feelings. This mistrust can be reduced by asking the child about his/her feelings. The dentist should ask open-ended questions without words with negative connotations. Therefore, instead of asking the child are you feeling scared?, the dentist can ask how are you feeling today?. If the child responds I am scared, the dentist can ask further open-ended questions such as can you tell me more about why are you feeling scared today or