Anesthetic efficacy of unilateral and bilateral inferior alveolar nerve blocks to determine cross innervation in anterior teeth

Prevalence, Patterns and Variations of Anterior Loop of Inferior Alveolar Nerve-A CBCT Based Retrospective Study

The fragment of inferior alveolar nerve (IAN) existing anterior to the mental foramen (MF), before dividing the canal, is known as the "Anterior Loop of the IAN". The presence of anterior loop (AL) is important when placing the implant in inter foraminal area of the mandible or during any other surgical procedure. It is imperative to precisely determine the position and dimensions of these anatomical variations on a cone-beam CT (CBCT) scan. To estimate the prevalence and pattern of anterior loop of IAN and establish any corelation between dimension of the MF with length and angulation of the AL of the IAN. Total 178 CBCT samples were collected fulfilling the inclusion criteria from a private diagnostic centre in Bhubaneswar, Odisha. The greatest diameter of the mental foramen was measured along with anterior loop length and angulation in the panoramic section of the CBCT scan. The angulation formed and the length was corelated with the greatest diameter of the mental foramen and analysed. Our study reveals that the AL was more frequently seen among males, predominantly on the left side of the mandible. The relationship between length of the anterior loop and diameter of the mental foramen demonstrated a mild negative corelation. There was no possible corelation present between angle formed by anterior loop with inferior alveolar canal and diameter of mental foramen. A small positive corelation was established between length of anterior loop and angle formed by the anterior loop with inferior alveolar canal. CBCT scans should be recommended for pre-surgical evaluation of anatomical variations in the mandibular region. Also, a safe margin of 3-4 mm anterior to mental foramen should be maintained while working in the premolar area.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12070-021-02691-w.

[Terminological and debatable issues of the intraosseous organization of the anterior part of the mandible]

In the scientific literature, one can find conflicting assumptions about the presence of «proper mental bone» and «upper and lower lingual canals», which make up a separate ossified area in the chin of the mandible and the system of blood supply and innervation. However, calling these lesions «lingual canals» or «incisal canals», as is often found in various articles, is incorrect based on the position of International Anatomical Terminology. This is due to the lack of topographic reference in the term, which can equally be understood as the canal of the tongue, the neurovascular bundle of the same name, and the root canal system of the teeth of the lower jaw and can also be associated with the maxilla. We searched for information in English, without time limits, in the PubMed Central database, and searched on Google and analyzed the bibliography, relevant studies and reviews. The selection of publications was carried out by request «mental spine canals», 58 articles were found in PubMed, of which 21 were relevant. For the analysis, publications were selected that described in detail the anatomical, clinical and radiological features of the structure of the anterior part of the mandible. As a result of previous studies and the study of literature data, the intraosseous structures of the anterior part of the lower jaw were refined and classified, which solve not only terminological disputes, but also are important clinical guidelines for endodontic treatment, dental implantation and local anesthesia.

Stumbling block for inferior alveolar nerve block in predoctoral students: An analytical observational study and review of literature of mandibular nerve block techniques

Introduction:

Dentists earnestly try to practice painless treatment. Conventional inferior alveolar nerve block technique is preferred by most of the dentists despite its various modifications.However its failure rate as per literature is quite high. Inexperienced dentists face difficulty in obtaining effective anesthesia. This may be due to limited access to inferior alveolar nerve,greater density of alveolar bone,bulky soft tissues,damage to nerve or due to risk of intravascular injection.

Aim:

The aim of this study is to review and clinically assess the factors causing difficulty or failure of inferior alveolar nerve block in predoctoral students and to review the mandibular nervve blocks.

Material and methods:

Dental interns of riyadh elm university were monitored during administration of inferior alveolar nerve block for difficulty factors influencing inferior alveolar nerve block. Onset of anesthesia, efficacy anesthesia of inferior alveolar nerve, lingual nerve and long buccal nerve were ascertained. Difficulty index was used to assess the “item difficulty” with a score of 0.0 which indicates that none of the dental interns anesthetised correctly to 1.0 suggesting all the dental interns anesthetised correctly.

Results:

Complete failure of inferior alveolar nerve block was noticed in 2.4% of predoctoral students. The most common cause for inferior alveolar nerve block failure was attributed to the difficulty in palpating the landmarks (77%), 22% of the patients refused multiple needle penetrations,and 19% of inferior alveolar nerve block failure was due to the fear of potential complications by the predoctoral students.

Conclusion:

Clinical skill of predoctoral students need adequate training in nerve blocks. Revising the current literature on alternative inferior alveolar nerve block techniques or use of evidence based dentistry to update and practice alternative nerve block techniques would aid in improving the clinical skills and treatment outcome which would therefore enable to remove the stumbling blocks in successful anesthesia.

Anesthetic Efficacy of an Alternative Inferior Alveolar Nerve Block Technique Using an Extra-Short Needle: A Double-Blind Randomized Non-Inferiority Trial

PURPOSE

Inferior alveolar nerve block (IANB) is a frequently used anesthetic technique for restorative and surgical procedures in the mandible and its success rate usually ranges from 80 to 85%. Thus, this study aimed to compare the anesthetic efficacy of an alternative technique named superficial nerve block (SNB)-which consists of a modified approach using an extra-short needle inserted 10 mm deep and on a higher injection site to the conventional technique (CT) for IANB in healthy individuals.

METHODS

About 20 participants received both SNB and CT with 1.8 mL of 2% lidocaine and 1:100,000 epinephrine. Thermal tests were performed 6 times, every 2 min, on the inferior canine and first molar to determine the success rate and anesthesia onset. Assessments were repeated at 20, 40, and 60 min to determine anesthesia duration. Sensitivity of lips and tongue was tested by clamp pressure. Pain perception during injection was assessed by a 100 mm visual analog scale (VAS).

RESULTS

The success rate in accordance with anatomical location was molars (SNB = 90%; CT = 85%), canines (SNB = 25%; CT = 70%), lips (SNB = 45%; CT = 95%), and tongue (SNB = 85%; CT = 95%). Significant differences were found for canines (P = .012) and lips (P < .002). Moreover, median anesthesia onset was: molars (SNB = 6 min; CT = 4 min), canines (SNB = 6 min; CT = 6 min), lips (SNB = 10 min; CT = 6 min), and tongue (SNB = 8 min; CT = 4 min), whereas median duration was molars (SNB = 60 min; CT = 60 min), canines (SNB = 20 min; CT = 60 min), lips (SNB = 60 min; CT = 60 min), and tongue (SNB = 60 min; CT = 60 min). A significant difference was found for anesthesia onset on molars (P = .024) and lips (P = .009). Pain scores on VAS were SNB (median = 8.5 mm) and CT (median = 10.0 mm) (P = .398).

CONCLUSIONS

In healthy individuals, the anesthetic effects of SNB were noninferior to CT in molars and tongue, although efficacy was considerably inferior in anterior teeth and lips.

Volume of Anesthetic Agents and IANB Success: A Systematic Review

The aim of this study was to provide an evidence-based answer to the question: "Is 3.6-mL volume of an anesthetic agent more effective than 1.8-mL volume in providing anesthesia for mandibular molars?" Following formulation of research question and keyword selection, a comprehensive search of the following databases was conducted: Cochrane library, PubMed, Scopus, Google Scholar, ProQuest, and Clinicaltrials.gov. Three-phase eligibility appraisal and quality assessment of the studies were carried out by 2 independent reviewers. To reduce clinical heterogeneity, the included studies were divided into 2 groups: studies on healthy teeth and studies on teeth with pulpitis. The data of included studies were statistically combined through meta-analysis using a fixed-effects model. A total of 20,778 records were initially retrieved from the search. Following screening and eligibility assessment, 8 studies met the eligibility criteria and were included for qualitative synthesis. Of those, 5 studies were qualified for meta-analysis. In the irreversible pulpitis group, increasing the volume of anesthetic agent from 1.8 to 3.6 mL significantly increased the success rate of inferior alveolar nerve block (risk ratio = 2.45, 95% CI: 1.67-3.59, p < .001). However, there was insufficient evidence to draw a conclusion regarding healthy teeth.

Role of intraseptal anesthesia for pain-free dental treatment

Pain control during the dental procedure is essentials and challenging. A complete efficacious pulp anesthesia has not been attained yet. The regional anesthesia such as inferior alveolar nerve block (IANB) only does not guarantee the effective anesthesia with patients suffering from irreversible pulpitis. This main aim of this review was to discuss various aspects of intraseptal dental anesthesia and its role significance in pain-free treatment in the dental office. In addition, reasons of failure and limitations of this technique have been highlighted. Literature search was conducted for peer-reviewed articles published in English language in last 30 years. Search words such as dental anesthesia, pain control, intraseptal, and nerve block were entered using a web of knowledge and Google scholar databases. Various dental local anesthesia techniques were reviewed. A combination of block anesthesia, buccal infiltration and intraligamentary injection resulted in deep anesthesia (P = 0.003), and higher success rate compared to IANB. For pain-free management of conditions such as irreversible pulpitis, buccal infiltration (4% articaine), and intraosseous injection (2% lidocaine) are better than intraligamentary and IANB injections. Similarly, nerve block is not always effective for pain-free root canal treatment hence, needing supplemental anesthesia. Intraseptal anesthesia is an efficient and effective technique that can be used in maxillary and mandibular adult dentition. This technique is also beneficial when used in conjunction to the regional block or local dental anesthesia.

Anesthetic efficacy of meperidine in teeth with symptomatic irreversible pulpitis

Achieving adequate pulpal anesthesia in mandibular teeth is always a challenge. Supplementary injections and using drugs in combination are some methods implemented to overcome this hurdle. In this randomized clinical trial, use of meperidine in conjunction with lidocaine in intraligamentary injection did not exhibit significant improvement in anesthesia.

[Scientific anatomical rationalefor lower teeth local anesthesia]

The article presents clinical recommendation for the choice of local anesthesia techniques in dental treatment of lower teeth based both on original research and literature review. Several localanesthesiatechniques are described for various teeth group, as well as intraosseousdiffusionoflocal anesthetic at various sites of mandible bone and possible anatomical reasons for local anesthesia failures. Theresultsofauthor's anatomical and clinical studies confirm that branches of buccal and lingual nerve can provide lower teeth innervation. Several local anesthesia techniques which may be useful for overcoming the mandibular block failure are proposed.

Periodontal intraligament injection as alternative to inferior alveolar nerve block--meta-analysis of the literature from 1979 to 2012

OBJECTIVES

In a first meta-analysis, inferior alveolar nerve block (IANB) and periodontal intraligamentary injection anesthesia (ILA) were compared with focus on the failure rate of local anesthesia, pain during injection, additional injections, cardiovascular disturbances (CVD), and method-inherent differences (unwanted side effects, latency time, amount of anesthetic solution, duration of anesthesia) in adult patients.

MATERIALS AND METHODS

Prospective and retrospective studies with clinical comparison of both injection techniques considering the relevant outcome parameters in adult patients from 1979 to 2012 were included. A specific tool for assessing risk of bias in each included study was adopted. Data were assessed for methodological reliability and extracted and supplemented by sensitivity analysis by two independent reviewers.

RESULTS

Seven studies were included [evidence grade Ib (n=1), IIb (n=3), and III (n=3)]. For other parameter than CVD, the significant heterogeneity of the random effects did not allow the reporting of pooled summary effect estimates. CVD were found significantly more often after IANB [odds ratio (OR): 0.12 (0.02-0.69)]. Further analysis revealed less injection pain in cases of ILA [OR: 0.32 (0.1-1)]. For failure rates as well as for needed additional injections, no significant differences were detected. IANB showed a latency of >3 min, whereas ILA had nearly none. The effect of IANB is longer than for ILA.

CONCLUSIONS

Methodological and reporting flaws were consistently observed in the included articles. Except for CVD, it could not be shown that ILA is neither superior nor inferior compared to IANB.

CLINICAL RELEVANCE

IANB as "gold standard" for routine dental treatments should be discussed.

Supplemental pulpal anesthesia for mandibular teeth

Clinical pulpal anesthesia is dependent on the interaction of three major factors. (1) the dentist (2) the patient and (3) local anesthesia. Many patients fear endodontic treatment due to a concern about pain. Although pain treatment is well managed in many endodontic patients, there exists a group of patients who do not receive adequate local anesthesia. The purpose of this review article is to discuss the possible reasons for pulpal anesthetic failures and also to focus on the measures for developing effective approaches for the same.

The efficacy of pre-operative oral medication of paracetamol, ibuprofen, and aceclofenac on the success of maxillary infiltration anesthesia in patients with irreversible pulpitis: A double-blind, randomized controlled clinical trial

AIM

To determine the effect of preoperative administration of paracetamol (PARA), ibuprofen (IBUP), or aceclofenac (ACEC) on the success of maxillary infiltration anesthesia in patients with irreversible pulpitis in a double-blinded randomized controlled trial.

MATERIALS AND METHODS

One hundred and twenty patients with irreversible pulpitis of a maxillary first molar participated. Patients indicated their pain scores on a Heft Parker visual analog scale, after which they were randomly divided into four groups (n = 30). The subjects received identical capsules containing 1000 mg PARA, 800 mg IBUP, 100 mg ACEC or cellulose powder (placebo, PLAC), 1 h before administration of maxillary infiltration anesthesia with 2% lidocaine containing 1:200,000 epinephrine. Access cavities were then prepared and success of anesthesia was defined as the absence of pain during access preparation and root canal instrumentation. The data were analyzed using chi-squared tests.

RESULTS

The success rates in descending order were 93.3% (IBUP), 90% (ACEC), 73.3% (PARA), and 26.5 % (PLAC). A significant (P < 0.001) difference was found between the drug groups and the PLAC group.

CONCLUSIONS

Pre-operative administration of PARA, IBUP, and ACEC significantly improved the efficacy of maxillary infiltration anesthesia in patients with irreversible pulpitis.

A prospective, randomized, double-blind study of the anesthetic efficacy of sodium bicarbonate buffered 2% lidocaine with 1:100,000 epinephrine in inferior alveolar nerve blocks

The authors, using a crossover design, randomly administered, in a double-blind manner, inferior alveolar nerve (IAN) blocks using a buffered 2% lidocaine with 1:100,000 epinephrine/sodium bicarbonate formulation and an unbuffered 2% lidocaine with 1:100,000 epinephrine formulation at 2 separate appointments spaced at least 1 week apart. An electric pulp tester was used in 4-minute cycles for 60 minutes to test for anesthesia of the first and second molars, premolars, and lateral and central incisors. Anesthesia was considered successful when 2 consecutive 80 readings were obtained within 15 minutes, and the 80 reading was continuously sustained for 60 minutes. For the buffered 2% lidocaine with 1:100,000 epinephrine/sodium bicarbonate formulation, successful pulpal anesthesia ranged from 10-71%. For the unbuffered 2% lidocaine with 1:100,000 epinephrine formulation, successful pulpal anesthesia ranged from 10-72%. No significant differences between the 2 anesthetic formulations were noted. The buffered lidocaine formulation did not statistically result in faster onset of pulpal anesthesia or less pain during injection than did the unbuffered lidocaine formulation. We concluded that buffering a 2% lidocaine with 1:100,000 epinephrine with sodium bicarbonate, as was formulated in the current study, did not statistically increase anesthetic success, provide faster onset, or result in less pain of injection when compared with unbuffered 2% lidocaine with 1:100,000 epinephrine for an IAN block.

Local anesthesia strategies for the patient with a "hot" tooth

Attaining local anesthesia for the treatment of teeth diagnosed with irreversible pulpitis ("hot" tooth) can be a challenge. This article looks at the strategies a dentist can use to help achieve adequate pulpal anesthesia for the patient, thereby eliminating or reducing treatment pain.

Frequency of localization of the painful tooth by patients presenting for an endodontic emergency

INTRODUCTION

Endodontic pain patients sometimes have difficulty in accurately identifying the painful tooth. We determined the frequency in which patients presenting with endodontic pain can correctly localize the painful tooth and the effect of periradicular symptoms.

METHODS

The frequency of localization of the painful tooth in 79 endodontic emergency patients was assessed by using patient and dentist assessment of presenting pain along with the verbal numeric rating scale (VNRS).

RESULTS

The results show that patients presenting with odontogenic pain can localize the painful tooth 73.3% of the time. Patients experiencing periradicular pain can localize the painful tooth (89%) significantly more often than patients with pain without periradicular symptoms (30%, p < 0.0001).

CONCLUSIONS

The presence of periradicular pain increases the accuracy of pain localization. The VNRS is highly correlated with other pain scales and is an acceptable initial pain-assessment tool for endodontic emergency patients.

Anesthetic efficacy of buccal and lingual infiltrations of lidocaine following an inferior alveolar nerve block in mandibular posterior teeth

The authors, using a crossover design, randomly administered, in a single-blind manner, 3 sets of injections: an inferior alveolar nerve block (IANB) plus a mock buccal and a mock lingual infiltration of the mandibular first molar, an IANB plus a buccal infiltration and a mock lingual infiltration of the mandibular first molar, and an IANB plus a mock buccal infiltration and a lingual infiltration of the mandibular first molar in 3 separate appointments spaced at least 1 week apart. An electric pulp tester was used to test for anesthesia of the premolars and molars in 3-minute cycles for 60 minutes. Anesthesia was considered successful when 2 consecutive 80 readings were obtained within 15 minutes following completion of the injection sets, and the 80 reading was continuously sustained for 60 minutes. For the IANB plus mock buccal infiltration and mock lingual infiltration, successful pulpal anesthesia ranged from 53 to 74% from the second molar to second premolar. For the IANB plus buccal infiltration and mock lingual infiltration, successful pulpal anesthesia ranged from 57 to 69% from the second molar to second premolar. For the IANB plus mock buccal infiltration and lingual infiltration, successful pulpal anesthesia ranged from 54 to 76% from the second molar to second premolar. There was no significant difference (P > .05) in anesthetic success between the IANB plus buccal or lingual infiltrations and the IANB plus mock buccal infiltration and mock lingual infiltration. We conclude that adding a buccal or lingual infiltration of 1.8 mL of 2% lidocaine with 1:100,000 epinephrine to an IANB did not significantly increase anesthetic success in mandibular posterior teeth.

Effectiveness of nasopalatine nerve block for anesthesia of maxillary central incisors after failure of the anterior superior alveolar nerve block technique

The purpose of this study was to assess the effectiveness of nasopalatine nerve block for anesthesia of maxillary central incisors after failure of the anterior superior alveolar nerve (ASAN) block technique. Secondarily, the possible innervation of the maxillary central incisors by the nasopalatine nerve was also investigated. Twenty-seven healthy, young adult volunteers (age: 17-26 years; gender: 9 males and 18 females) were enrolled in this study. All participants were undergraduate dental students of the University of Vale do Rio Verde de Três Corações. The volunteers had the anterior superior alveolar nerves anesthetized and a thermal sensitivity test (cold) was performed on the maxillary central incisors. The volunteers that responded positively to cold stimulus received a nasopalatine nerve block and the thermal sensitivity test was repeated. All participants were anesthetized by a single operator. Three patients presented sensitivity after both types of bilateral blocks and were excluded from the percentage calculations. In the remaining 24 patients, 16 had their maxillary central incisors anesthetized by the anterior superior alveolar block and 8 remained with sensitivity after the ASAN block. All these 8 patients had their maxillary central incisors successfully anesthetized by the nasopalatine block. In this study, 33.3% of the subjects had the innervation of one or both maxillary central incisors derived from the nasopalatine nerve, whilst most subjects (66.7%) had such teeth innervated by the anterior superior alveolar nerve. The nasopalatine nerve block was effective in anesthetizing the maxillary central incisors when the anterior superior alveolar nerve block failed.

Anesthetic efficacy of lidocaine/meperidine for inferior alveolar nerve blocks

The authors, using a crossover design, randomly administered, in a single-blind manner, inferior alveolar nerve blocks using 36 mg of lidocaine with 18 microg of epinephrine or a combination of 36 mg of lidocaine with 18 microg epinephrine plus 36 mg meperidine with 18 microg of epinephrine, at 2 separate appointments, to 52 subjects. An electric pulp tester was used to test for anesthesia, in 4-minute cycles for 60 minutes, of the molars, premolars, and central and lateral incisors. Anesthesia was considered successful when 2 consecutive 80 readings were obtained within 15 minutes and the 80 reading was continuously sustained for 60 minutes. Using the lidocaine solution, successful pulpal anesthesia ranged from 8 to 58% from the central incisor to the second molar. Using the lidocaine/meperidine solution, successful pulpal anesthesia ranged from 0 to 17%. There was a significant difference (P < .05) between the lidocaine and lidocaine/meperidine solutions for the lateral incisors through the second molars. We conclude that the addition of meperidine to a standard lidocaine solution does not increase the success of the inferior alveolar nerve block.

A double-blind comparison of a supplemental interligamentary injection of fentanyl and mepivacaine with 1:200,000 epinephrine for irreversible pulpitis

The analgesic efficacy of supplemental interligamentary fentanyl injection for management of endodontic debridement patients was investigated through a randomized, double-blind study. Forty patients who presented with acute symptomatic irreversible pulpitis of the upper first molar tooth participated in the study. Patients were scheduled for endodontic debridement, for which infiltration anesthesia with 1.8 ml of 2% mepivacaine with epinephrine 1:200,000 was the standard primary anesthetic technique. Patients were randomly divided into two equal groups. The first group received supplemental interligamentary injection with 0.4 ml fentanyl 0.05 mg/ml, while the second group received supplemental interligamentary injection with 0.4 ml mepivacaine with epinephrine 1:200,000. The intraligamental-injected drug was given as 0.2 ml on the mesial and 0.2 ml on the distal aspect of the tooth. Results indicated that fentanyl provided relatively greater analgesia, yielding satisfactory relief during different stages of the procedure, including access cavity preparation, pulpotomy, and pulp extirpation. Fentanyl is effective when used in conjunction with local anesthetics to provide adequate analgesia during endodontic debridement, and this finding provides strong evidence that peripheral actions are involved in the analgesia produced by opioid drugs in inflammatory pain.

Speed of Injection Influences Efficacy of Inferior Alveolar Nerve Blocks: A Double-Blind Randomized Controlled Trial in Volunteers

This randomized double-blind crossover trial investigated the efficacy and discomfort associated with slow (60 seconds) and rapid (15 seconds) inferior alveolar nerve blocks (IANB) using 2.0 ml of 2% lidocaine with 1:80,000 epinephrine in securing mandibular first molar, premolar and lateral incisor pulp anesthesia in 38 healthy adult volunteers. Episodes of maximal stimulation (80 microA) without sensation on electronic pulp testing were recorded. Injection discomfort was self-recorded by volunteers on 100 mm visual analogue scales. Data were analyzed by McNemar, Friedman, Wilcoxon Signed Ranks, and paired t tests. Slow IANB produced more episodes of no response to maximal pulp stimulation than rapid IANB in molars (220 episodes versus 159, p < 0.001), premolars (253 episodes versus 216, p = 0.003) and lateral incisors (119 episodes versus 99, p = 0.049). Slow IANB was more comfortable than rapid IANB (p = 0.021).

Articaine and Lidocaine Mandibular Buccal Infiltration Anesthesia: A Prospective Randomized Double-Blind Cross-Over Study

This randomized crossover double-blind trial compared the efficacy of buccal infiltration with 4% articaine and 2% lidocaine (both with 1:100,000 epinephrine) in securing mandibular first molar pulp anesthesia. Injections were given at least 1 week apart in 31 healthy adult volunteers. Electronic pulp testing was undertaken at baseline and at 2 minute intervals until 30 minutes postinjection. A successful outcome was recorded in the absence of pulp sensation on two consecutive maximal pulp tester stimulations (80 muA). 64.5% of articaine and 38.7% of lidocaine infiltrations were successful (p = 0.008). Articaine infiltration produced significantly more episodes of no response to maximum stimulation in first molars than lidocaine (236 and 129, respectively, p < 0.001). Mandibular buccal infiltration is more effective with 4% articaine with epinephrine compared to 2% lidocaine with epinephrine. Both injections were associated with mild discomfort.

The key to profound local anesthesia: neuroanatomy

BACKGROUND

To achieve profound dental local anesthesia, it is necessary for the dentist to have a thorough knowledge of the details of sensory innervation to the maxilla and mandible. Since the early 1970s, dentistry has experienced a resurgence of interest in the neuroanatomical basis of local anesthesia, resulting in numerous scientific reports on the subject.

OVERVIEW

Current studies afford a more detailed knowledge of the branching of various divisions of the trigeminal nerve, the great sensory nerve of the head region. In this article, the authors provide an update of the peripheral distribution of the trigeminal nerve to enhance induction of safe and effective dental local anesthesia.

CONCLUSIONS AND PRACTICAL IMPLICATIONS

An understanding of the potential variations in innervation should help the dentist improve his or her ability to induce profound local anesthesia.