Hypnosis on acute dental and maxillofacial pain relief: A systematic review and meta-analysis.

INTRODUCTION/OBJECTIVES: The effects of hypnosis on acute pain have been discussed recently, resulting in increased attention in the dental/maxillofacial field offering new perspectives, especially in emergency situations, trauma, or acute inflammatory situations where conventional pharmaceuticals are contraindicated due to allergies or intolerance reactions. DATA: To systematically evaluate and assess the effects of hypnosis on acute dental/facial pain relief. Randomized controlled trials, cohort studies, controlled clinical trials, cross-sectional studies, evaluation, and validation studies, following the PRISMA guidelines, of human subjects of all ages were included. SOURCES: Five electronic databases (Cochrane, Embase, MEDLINE via PubMed, LILACS, Scopus) were screened for studies published between 1989 - 2021. A NIH quality-assessment-tool was performed. STUDY SELECTION/RESULTS: 27 papers have been included and a meta-analysis was performed. Hypnosis has been reported to reduce intraoperative and postoperative pain as well as the use of analgesics in various dental procedures such as tooth extraction. Highly hypnotizable subjects generally respond better to hypnosis. Different hypnosis techniques were used for pain relief and relaxation. The studies show a large heterogeneity. CONCLUSION: Although there are only a small number of studies on the subject so far, evidence can be confirmed for the effects of hypnosis on acute pain relief in dental/maxillofacial area. Despite the promising results, further research is needed. CLINICAL SIGNIFICANCE: Hypnosis offers a possible alternative to conventional pain medications for acute dental and maxillofacial pain, especially in cases of allergies or contraindications; it can be easily applied by a trained practitioner.

Efficacy of Hypnosis on Dental Anxiety and Phobia: A Systematic Review and Meta-Analysis.

Hypnosis is a commonly used therapy option in dentistry and medicine for fear and pain reduction. Nevertheless, it is viewed very critically, as there is still insufficient evidence for a treatment effect. Specific phobia of dental treatment and dental anxiety are prevalent conditions that can cause an oral health impairment. This paper critically reviews 19 clinical trials aimed at reducing dental anxiety and fear avoidance in adults, published in peer-reviewed journals between 1979 and 2021. The search identified 257 papers; 223 were selected after removing duplicates. A total of 188 articles were excluded after title and abstract evaluation; 35 full text articles were assessed for eligibility. Another 10 papers were discharged after full text evaluation, as these were case reports and questionnaires. Six papers were discharged due to the lack of a comparable scale to measure dental anxiety. The following treatment techniques were reviewed: various forms of cognitive-behavioral therapy (CBT), relaxation training, benzodiazepine premedication, self-hypnosis by audio therapy, hypnotherapy, hypnosis, and nitrous oxide sedation. CBT delivered in a variety of formats, including one-session treatment, showed the most evidence for the efficacy of reducing anxiety. A wide heterogeneity of methods allowed only the inclusion of five studies to the performed meta-analysis, showing contrasting results for the application of hypnosis. The main reason for this issue is the great variety in methods used, making a distinct assessment of hypnotic interventions difficult. However, the results of the systematic review are promising in that hypnosis can also be regarded as powerful and successful method for anxiety reduction, while there are also studies with a small or even slightly negative effect. Therefore, further research is needed. Within the limitations of the current study, a more consistent use of methods to examine anxiety for hypnosis research is recommended.

Hypnosis and Sedation for Anxious Children Undergoing Dental Treatment: A Retrospective Practice-Based Longitudinal Study.

To assess whether the treatment of children with oral midazolam and pediatric hypnosis techniques can improve the compliance in consecutive sessions, a retrospective longitudinal practice-based observational study was designed and carried out. A total of 311 children between 3 and 12 years of age were treated under hypnosis and sedation with midazolam (0.40 mg/kg body weight). Treatments were performed in one to a maximum of three sessions. A total of 183 children received one, 103 received two and 25 children received three treatment sessions. The behavior of the children during the sessions was examined by means of the Venham score. The self-evaluation of the children was based on the Wong−Baker Scale. Child behavior using midazolam and hypnosis techniques showed little difference and good compliance between the sessions. Venham scores did not increase significantly regarding total treatment from the first (0.99 ± 1.41) to the second (1.17 ± 1.39) and to the third session (1.27 ± 1.20) (p > 0.05). However, considering the highest Venham scores that occurred in each case, the behavior of the children worsened significantly (p < 0.01) during the three treatment sessions, from 1.37 ± 1.31 (first) to 1.87 ± 1.74 (second) to 2.32 ± 1.33 (third). In 6.11% of the children, treatment was discontinued in the first session (n = 19), 0.96% in the second (n = 3) and 0% in the third. Treatment with low-dose midazolam, combined with hypnosis techniques, showed to be an effective option for dental treatment in children. Within the limitations of the current study, and with consideration of highest possible compliance, no more than two treatment sessions for pediatric dental treatment should be performed.

Personality Styles of Dentists Practicing Hypnosis Confirm the Existence of the Homo Hypnoticus.

Several publications with healthcare professionals, such as psychotherapists, have shown a significant difference in personality styles in practitioners using hypnosis compared to those not using hypnosis. To investigate differences in personality styles, dentists were contacted to participate in a personality-inventory [Personality Style and Disorder Inventory (PSDI)] online survey. Dentists using hypnosis (HYP DGZH) (n = 418) were compared to dentists not using hypnosis (NONHYP DENT) (n = 162). Results show that hypnosis-practicing dentists score significantly higher in the intuitive/schizotypal ST personality style (p < 0.001) compared to non-hypnosis-practicing dentists. Female dentists scored significantly higher in intuitive/schizotypal ST and unselfish/self-sacrificing SL in the HYP DGZH sample but only in unselfish/self-sacrificing SL in the NONHYP DENT sample. The percentage of women was similar in both samples (68.2%; 67.3%). Intuitive/schizotypal ST was found to be the predominant personality style of men who are interested in or use hypnosis, metaphorically so-called "homo hypnoticus." Within the limitations of this cross-sectional non-interventional observational online-questionnaire study, results expand this notion to the so-called "homo hypnoticus dentalis." However, further research on the subject is needed to investigate and confirm this personality type in other than the German-speaking DACH countries.

Functional Changes in Brain Activity Using Hypnosis: A Systematic Review.

Hypnosis has proven a powerful method in indications such as pain control and anxiety reduction. As recently discussed, it has been yielding increased attention from medical/dental perspectives. This systematic review (PROSPERO-registration-ID-CRD42021259187) aimed to critically evaluate and discuss functional changes in brain activity using hypnosis by means of different imaging techniques. Randomized controlled trials, cohort, comparative, cross-sectional, evaluation and validation studies from three databases-Cochrane, Embase and Medline via PubMed from January 1979 to August 2021-were reviewed using an ad hoc prepared search string and following the Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) guidelines. A total of 10,404 articles were identified, 1194 duplicates were removed and 9190 papers were discarded after consulting article titles/abstracts. Ultimately, 20 papers were assessed for eligibility, and 20 papers were included after a hand search (ntotal = 40). Despite a broad heterogenicity of included studies, evidence of functional changes in brain activity using hypnosis was identified. Electromyography (EMG) startle amplitudes result in greater activity in the frontal brain area; amplitudes using Somatosensory Event-Related Potentials (SERPs) showed similar results. Electroencephalography (EEG) oscillations of θ activity are positively associated with response to hypnosis. EEG results showed greater amplitudes for highly hypnotizable subjects over the left hemisphere. Less activity during hypnosis was observed in the insula and anterior cingulate cortex (ACC).

Current neuroscientific research database findings of brain activity changes after hypnosis.

Using multi-modal brain imaging techniques we found pronounced changes in neuronal activity after hypnotic trance induction whereby state changes seem to occur synchronously with the specific induction instructions. In clinical patients, hypnosis proved to be a powerful method in inhibiting the reaction of the fear circuitry structures. The aim of the present paper is to critically discuss the limitations of the current neuroscientific research database in the light of a debate in defining relevant hypnotic constructs and to suggest ideas for future research projects. We discuss the role of hypnotic suggestibility (HS), the impact of hypnotic inductions and the importance of the depth of hypnotic trance. We argue that future research on brain imaging studies on the effects of hypnosis and hypnotherapy should focus on the analysis of individual cross-network activation patterns. A most promising approach is to simultaneously include physiological parameters linked to cognitive, somatic, and behavioral effects.

Caries treatment in a four-year-old boy using hypnosis - a case report.

This clinical case report demonstrates the successful application of hypnosis in an anxious four-year-old boy in whom two primary molars were treated with a composite filling. The almost 16-minute pediatric dental treatment was performed without complications and without interruptions. It could be shown that hypnosis can be used for the pediatric dental treatment of decayed primary tooth lesions. In the specific individual case hypnosis was not only used adjuvant but as an alternative to local anesthesia. A dental anxiety reducing effect and an elimination of pain perception were observed, so that the treatment was possible without anesthesia. It was also found that the communication and rapport between the practitioner and the four-year-old child were improved using hypnosis. There is still a need for high quality studies on the numerous positive effects that hypnosis has on pediatric dental treatment.

FUNCTIONAL CHANGES IN BRAIN ACTIVITY AFTER HYPNOSIS: Neurobiological Mechanisms and Application to Patients with a Specific Phobia-Limitations and Future Directions.

Studies of brain-plasticity changes in hypnosis using functional magnetic resonance imaging (fMRI), positron-emission-tomography (PET) and electroencephalography (EEG) were reviewed. The authors found evidence in those studies that hypnosis is a powerful and successful method for inhibiting the reaction of the fear circuitry structures. Limitations of the studies were critically discussed, and implications for future research were made. The authors are currently using a portable fNIRS apparatus to integrate the scanning device into real life situations in medical practice. Their aim is to disentangle the neuronal mechanisms and physiological correlates in patients with severe fear of medical treatments when directly confronted with anxiety-provoking stimuli and to assess the effects of a brief hypnosis. Drawing on evidence from several technological modalities, neuroimaging and physiological studies pave the road to a better scientific understanding of neural mechanisms of hypnosis.

Hypnosis and Local Anesthesia for Dental Pain Relief-Alternative or Adjunct Therapy?-A Randomized, Clinical-Experimental Crossover Study.

This prospective randomized clinical crossover trial was designed to compare hypnosis and local anesthesia for experimental dental pain relief. Pain thresholds of the dental pulp were determined. A targeted standardized pain stimulus was applied and rated on the Visual Analogue Scale (0-10). The pain threshold was lower under hypnosis (58.3 ± 17.3, p < .001), maximal (80.0) under local anesthesia. The pain stimulus was scored higher under hypnosis (3.9 ± 3.8) than with local anesthesia (0.0, p < .001). Local anesthesia was superior to hypnosis and is a safe and effective method for pain relief in dentistry. Hypnosis seems to produce similar effects observed under sedation. It can be used in addition to local anesthesia and in individual cases as an alternative for pain control in dentistry.

Effectiveness of Self-Hypnosis on the Relief of Experimental Dental Pain: A Randomized Trial.

This randomized, controlled clinical trial evaluates the effectiveness of self-hypnosis on pain perception. Pain thresholds were measured, and a targeted, standardized pain stimulus was created by electrical stimulation of the dental pulp of an upper anterior tooth. Pain stimulus was rated by a visual analogue scale (VAS). The pain threshold under self-hypnosis was higher (57.1 ± 17.1) than without hypnotic intervention (39.5 ± 11.8) (p < .001). Pain was rated lower on the VAS with self-hypnosis (4.0 ± 3.8) than in the basal condition without self-hypnosis (7.1 ± 2.7) (p < .001). Self-hypnosis can be used in clinical practice as an adjunct to the gold standard of local anesthesia for pain management, as well as an alternative in individual cases.

Functional changes in brain activity after hypnosis in patients with dental phobia.

Visiting the dentist is often accompanied by apprehension or anxiety. People, who suffer from specific dental phobia (a disproportional fear of dental) procedures show psychological and physiological symptoms which make dental treatments difficult or impossible. For such purposes, hypnosis is often used in dental practice as an alternative for a number of treatments adjuvant or instead of sedation or general anaesthetics, as medication is often associated with risks and side effects. This is the first study to address the effects of a brief dental hypnosis on the fear processing structures of the brain in dental phobics using functional magnetic resonance imaging (fMRI). 12 dental phobics (DP; mean 34.9years) and 12 healthy controls (CO; mean 33.2years) were scanned with a 3T MRI whole body-scanner observing brain activity changes after a brief hypnotic invervention. An fMRI event-related design symptom provocation task applying animated audio-visual pseudorandomized strong phobic stimuli was presented in order to maximize the fearful reactions during scanning. Control videos showed the use of familiar electronic household equipment. In DP group, main effects of fear condition were found in the left amygdala and bilaterally in the anterior cingulate cortex (ACC), insula and hippocampu (R