A Systematic Review on Nerve-Related Adverse Effects following Mandibular Nerve Block Anesthesia

Introducing a novel intraoral mandibular nerve block technique for loco-regional analgesia in camels (Camelus dromedarius): a cadaveric study using computed tomography

The aim of this study was to introduce a novel intraoral technique for performing mandibular nerve blocks in dromedary camels (Camelus dromedarius). In this study, 18 adult camel skulls of varying ages and breeds were examined to determine the position of the mandibular foramen. Using a Vernier caliper, three dimensions in millimeters were measured: (1) the distance between the mandibular foramen (MF) and the caudal edge of the third molar tooth at the occlusal surface level, (2) the distance between the MF and the rostral edge border of the mandible's ramus (RER) at the occlusal surface level, and (3) the distance between the MF and the ventral margin border of the mandible (VM). The technique was evaluated using five intact camel cadaver heads (n = 5), and a total of ten mandibular nerve blocks were described. An 18-gauge 80-mm Tuohy needle was inserted into the mouth commissure and advanced caudally while injecting a saline-methylene blue solution. The accuracy of the injection was confirmed through the infiltration of the contrast dye into the target area using computed tomography (CT) and post procedural dissection. Anatomical study of the mandibular nerve site was performed to aid the blind insertion of the needle. The findings contribute to the development of veterinary anesthesia techniques and provide anatomical considerations for clinicians performing oral surgeries in sedated camels. The results demonstrated the successful implementation of the intraoral technique, highlighting its efficacy and reliability in achieving local anesthesia for oral surgeries involving the lower jaw and teeth in sedated camels. Further research studies are needed to evaluate the long-term efficacy and safety of the technique and to compare it with existing approaches.

Interventional pain blocks in Ontario: a population-based cross-sectional study on 2019 procedural volumes, clustering, and physician billings

PURPOSE

Multidisciplinary chronic pain management includes pharmacologic, psychological, and interventional strategies. In Canada, the use of interventional pain blocks (PBs) has increased in recent years. We sought to determine the distribution and clustering of PBs among physicians in Ontario, and to examine differences in the patient and physician characteristics by volume of PBs administered.

METHODS

We conducted a population-based cross-sectional study of PBs administered for chronic pain to Ontario residents between 1 January and 31 December 2019. Our primary outcome was the total number of PBs administered in an outpatient setting for chronic pain by eligible physicians. We used Lorenz curves, overall and stratified by PB type and physician specialty, to examine clustering of PBs among physicians, and compared patient and physician characteristics using standardized differences.

RESULTS

Among physicians who provided PBs, provision was highly clustered, with the top 1% of physicians providing 39% of blocks. In these high-volume PB providers, the majority of whom were general practitioners (88.4%), PBs made up the vast majority (median [interquartile range (IQR)], 87% [84-89]) of their billings, with the majority of the patients in their practices (63.0%) receiving at least one PB in 2019. Patients who received a PB from a high-volume provider had a higher annual frequency of visit for PBs (median [IQR], 10 [3-23]) and number of PBs administered per visit (median [IQR], 5 [4-6]).

CONCLUSION

Pain block administration is highly clustered in Ontario, with many patients receiving PBs in ways that are not supported by best evidence. Further research is required to determine whether the Ontario fee-for-service model of billing has created a suboptimal use of these health care resources.

Comparison of Efficacy of Lidocaine and Articaine as Inferior Alveolar Nerve Blocking Agents in Patients with Symptomatic Irreversible Pulpitis: Randomized Controlled Trial

Background and Objectives: Lidocaine Hydrochloride has been the standard choice for local anesthesia in dentistry and Articaine's unique structure and growing popularity make it a viable alternative. Due to contradictory results in prior research and a scarcity of trials conducted in the Pakistani population, this study aims to compare the anesthetic efficacy of Lidocaine with Articaine for inferior alveolar nerve blocks in patients with symptomatic irreversible pulpitis. Materials and Methods: This double-blinded, randomized controlled trial included 152 patients who were selected by consecutive non-probability sampling. The participants included patients who presented with symptomatic irreversible pulpitis in mandibular posterior teeth (molars and premolars) and depicted normal apical tissue radiographically. The patients were equally and randomly divided into two groups. The control group received 2% Lidocaine Hydrochloride injections, and the experiment group received 4% Articaine Hydrochloride injections. Participants scored their pain on the HP-VAS both before and after the administration of anesthesia. A value of 54 mm or less on the scale indicated effective anesthesia. The data obtained were analyzed using SPSS. Chi-square test was applied to analyze data for statistical significance. Results: There was no statistically significant difference in the efficacy of the two anesthetic agents. During access cavity preparation, Lidocaine demonstrated a success rate of 93%, whereas Articaine exhibited a slightly higher success rate of 97%. During initial instrumentation, the success rates for Lidocaine and Articaine were 72% and 71%, respectively. This suggests that both Lidocaine and Articaine were effective in achieving anesthesia during the dental procedure in patients with symptomatic irreversible pulpitis, with Articaine showing a slightly better success rate, although the difference was not statistically significant. Conclusions: The anesthetic efficacy of Articaine is similar to that of lidocaine in subjects with symptomatic irreversible pulpitis. Hence, Articaine can serve as an alternative to Lidocaine for local anesthesia administration in dentistry.

Analgesic efficacy of the inferior alveolar nerve block for maxillofacial cancer surgery under general anaesthesia - A randomised controlled study

Background and Aims

Mandibular resection during maxillofacial cancer surgery evokes a strong sympathetic response requiring high doses of opioids. We studied the effect of the inferior alveolar nerve block (IANB) for analgesia in maxillofacial cancer surgeries.

Methods

This randomised controlled study was conducted over five months in a tertiary care cancer hospital following Institutional Ethics approval and trial registration. Fifty consenting adult patients belonging to the American Society of Anesthesiologists (ASA) physical status I and II requiring maxillofacial cancer surgery with unilateral mandibular resection were recruited. Twenty-five patients in the study arm received ipsilateral IANB; a mock injection was given to the control group. Fentanyl requirement and haemodynamic parameters during primary tumour excision were the primary and secondary endpoints. Student's t-test was applied to compare primary and secondary endpoints.

Results

Forty-nine patients completed the study. Both arms were comparable with respect to age, gender distribution, ASA physical status and baseline heart rate (HR) and blood pressure (BP). The mean (standard deviation) intravenous fentanyl requirement during primary tumour excision in the IANB arm was 70(32) µg, significantly lower than 183(48) µg in the control arm, P < 0.001. The mean maximum HR during primary tumour excision was 82 and 99 per minute in the IANB and control arms, respectively (P < 0.001) whereas the maximum mean BP was 88 and 101 mm Hg, respectively (P < 0.001).

Conclusion

IANB significantly reduced intraoperative fentanyl requirement and caused fewer haemodynamic changes during maxillofacial cancer surgery requiring unilateral mandibular excision.

Clinical Application of Inferior Alveolar Nerve Block Device for Safe and Secure IANB by Any Operator

The inferior alveolar nerve block (IANB) is an established technique with a success rate of 60-80%; however, large errors have been reported among operators. Some dentists do not prefer to use IANB because of the risk of complications. Nevertheless, it is a useful technique for pain control, and a secure IANB offers significant benefits to operators and patients. This case series study aimed to investigate the efficacy of the "IANB Device," a nerve block guide for IANB, and the adverse events associated with its use in clinical practice. IANB was performed using the device on five patients who had undergone detailed computed tomography examination for chronic orofacial pain in the third division of the trigeminal nerve. Lidocaine 1% (1 mL, no adrenaline added) was used as the local anesthetic. IANB was performed by three dentists with 2, 5, and 11 years of experience in orofacial pain treatment. Thus, the data were collected in triplicate for each patient. The primary endpoints were whether adjustment of the IANB device was required, changes in the sensation threshold of the lower lip, the time to disappearance of pain, the presence or absence of tongue sensation ("Do you have numbness in your tongue?": "Yes/No"), and discomfort (visual analog scale). The incidence of any other adverse events was recorded. The procedure was judged to be successful if the pain disappeared and an elevation in the sensation threshold of the lower lip was observed. Adjustment of the IANB device was not required in any patient. A significant elevation in the sensation threshold of the lower lip and the disappearance of pain were observed in all patients. Three of the five patients reported experiencing tongue numbness. Discomfort with the use of the IANB device was less than 30 mm on the visual analog scale. No notable complications were observed. The appropriate type, concentration, and dosage of the local anesthetic must be considered during general dental treatment and oral surgical procedures. Our findings suggest that the IANB device is useful for eliminating errors between operators, enhancing safety, and improving the success rate.

Knowledge, Practice and Self-Reported Confidence Level of Croatian Dentists in the Use of Local Anesthesia: A Cross-Sectional Study

Objectives: To provide safe and effective local anesthesia, dentists must have knowledge of neuroanatomy, anesthesia agents, techniques, equipment, and proper use of local anesthetics. This study aims to explore the knowledge, practices, and confidence regarding local anesthetics and anesthetic techniques in dentistry. Material and Methods: The online cross-sectional questionnaire was conducted via social media, and yielded 441 responses from across the country (69.8% women and 30.2% men; 70.7% general dentists; and 29.3 specialists). The data collected included sociodemographic characteristics, knowledge, and practices pertaining to the usage of local anesthesia. The questionnaire also documents their self-assessed confidence level in applying different local anesthetic techniques and experiences with adverse reactions. The obtained data were processed by description and using a generalized linear model for regression. Results: The respondents had a median knowledge score of 6 out of a possible 14 points regarding local anesthetics in dental medicine, and their median self-confidence level in the successful application of various techniques of local anesthesia was 54 out of a maximum of 85 points. The results showed that a higher knowledge level was associated with the female gender (OR 1.83, CI 1.13-2.98, p = 0.014) and specialization in oral surgery (OR 7.04, CI 1.71-29.07, p = 0.007). In contrast, a lack of confidence in using various local anesthetic techniques was also associated with the female gender (OR 0.63, CI 0.41-0.99, p = 0.047) and specialization in orthodontics (OR 0.16, CI 0.03-0.88, p = 0.035). Of the respondents, 81.4% (n = 371) experienced a local complication, and 42.2% (n = 186) experienced a systemic complication during local anesthesia. The complications experienced cannot be associated with a lack of knowledge or self-confidence (p > 0.05). The majority of respondents (364 of the 441 total-82.5%) expressed interest in receiving further education on the topic of local anesthesia. Conclusions: The research results show that the dentists involved in the study have poor knowledge of local anesthetics and moderate self-reported confidence levels in using various local anesthetic techniques. Moreover, dentists' self-confidence in applying different techniques of local anesthesia is not related to their knowledge. Therefore, it would be necessary for dentists to undergo a continuing dental education program that enables them to enhance their skills and knowledge in local anesthesia.

Paresthesia in dentistry: The ignored neurotoxicity of local anesthetics

Local anesthetics are frequently used by dentists to relieve localized discomfort of the patient and improve treatment conditions. The risk of paresthesia after local anesthesia is frequently encountered in dental clinics. The neurotoxicity of local anesthetics is a disregarded factor in paresthesia. The review summarizes the types of common local anesthetics, incidence and influencing factors of paresthesia after local anesthesia, and systematically describes the neurotoxicity mechanisms of dental local anesthetic. Innovative strategies may be developed to lessen the neurotoxicity and prevent paresthesia following local anesthesia with the support of a substantial understanding of paresthesia and neurotoxicity.

Choosing the optimal mandible position for inferior alveolar nerve block (IANB) using finite element analysis

BACKGROUND

One of the most popular methods of local anesthesia in dentistry, inferior alveolar nerve block (IANB) involves the blockade of the inferior alveolar nerve (IAN) and lingual nerve (LN) in the pterygomandibular space. Despite the large number of works describing the contents of this space, the spatial displacements of the anatomical structures of this area at different positions of the mandible have not been sufficiently studied. The aim of our study was to study the spatial movements of the IAN and inferior alveolar artery (IAA) at various positions of the mandible using computer simulation and finite element analysis to find the safest way to conduct IANB.

MATERIALS AND METHODS

Reverse engineering was used to create a model of the cranial base and the mandible based on computed tomography (CT) data obtained from patient N (male, 24 years old), the arteries of the head and neck were designed from the data of multiphase angiography of patient M (female, 61 years old). Masticatory muscles, sphenomandibular ligament, temporomandibular joint and mandibular nerve were modeled in the SolidWorks software package based on an open database of anatomical structures. The finite element grid was generated in the Solidworks software. In the first series of experiments, the displacement of the mandible was modeled along the vertical axis down by 48 mm (maximum opening of the mouth), in the second series, the jaw was displaced vertically by 48 mm with a simultaneous transversal movement of 10 mm, in the third series, the jaw was displaced along the vertical axis down by 34 mm and transversally by 22 mm.

RESULTS

The largest distance between IAN and IAA was noted in the third series of experiments. The distance between the nerve and the vessel was minimal in the first series, with an open mouth without lateral displacements.

CONCLUSION

The generated computer model opens new possibilities for studying the dynamic anatomy of the pterygomandibular space. The results of this study can be used for further experimental and clinical trials to find the safest approach to the implementation of IANB, as well as applied in the practice of the educational process.

Evaluation of Intraligamentous and Intraosseous Computer-Controlled Anesthetic Delivery Systems in Pediatric Dentistry: A Randomized Controlled Trial

Computer-controlled local anesthetic delivery systems (CDS) represent one of the resources that have progressed the most in recent years, but their efficacy and applicability in pediatric dentistry is still the subject of certain controversies. This randomized, controlled, split-mouth clinical trial assessed two CDS in children (n = 100) with deep caries in the temporary dentition that required invasive therapeutic procedures, using inferior alveolar nerve block as the gold standard. Half of the patients (n = 50) underwent the intraligamentary technique (Wand STA^®) on one side of the mouth and conventional inferior alveolar nerve block on the contralateral side, while the other half (n = 50) underwent the intraosseous technique (QuickSleeper^®) on one side of the mouth and conventional inferior alveolar nerve block on the contralateral side. The following were considered covariates: age, sex, type of dental procedure and the applied local anesthesia system. The outcome variables were the pain caused by the anesthesia injection, the physical reaction during the anesthesia injection, the need for anesthetic reinforcement, pain during the therapeutic procedure, the overall behavior during the visit, the postoperative morbidity and, lastly, the patient's preference. In conclusion, we confirmed the efficacy of intraligamentary and intraosseous techniques administered using a CDS for conducting invasive dental treatments in children, their advantages compared with inferior alveolar nerve block in terms of less pain generated by the anesthesia injection and less postoperative morbidity, as well as the pediatric patients' preference for CDS versus conventional techniques.