Anesthetic efficacy of the mylohyoid nerve block and combination inferior alveolar nerve block/mylohyoid nerve block

An Ancient Science to Improve Today's Clinical Practice: Oral Surgery Meets Human Anatomy

Human body dissection was a ubiquitous practice in the past, to better understand anatomy and to develop medicine. Today, its role could still be important to answer everyday clinical queries and help surgeons. The example of the possible lack of anesthesia during symphysis surgeries can emphasize the usefulness of dissection. The mandibular symphysis usually receives innervation from inferior alveolar nerve terminations, but, in some rare cases, a particular anastomosis involves the lingual nerve and the nerve to the mylohyoid. The anatomical knowledge resulting from body dissections could help oral surgeons to understand the reason why the patient could feel pain during the surgery, and ensure performance of the right lingual nerve block to obtain complete anesthesia. This clinical situation shows the educational role of an ancient, yet still valid, practice, human dissection, and the importance of anatomical studies to improve surgical skills, to provide better treatment for the patient.

Dual innervation of the mylohyoid muscle by the trigeminal and hypoglossal nerves: A case report

During the routine dissection of a cadaveric specimen, the left mylohyoid muscle was found to be innervated by both the trigeminal and hypoglossal nerves. This variation was found unilaterally. To our knowledge this dual innervation of the mylohyoid muscle is an extremely rare variation. The possibility of these variants may lead to clinical consequences such as anesthesia failure and iatrogenic injury during surgical procedures in this region. We discuss this anatomical variation and possible developmental etiologies.

Anomalies and Clinical Significance of Mylohyoid Nerve: A Review

Background

The mylohyoid nerve is a branch of the inferior alveolar nerve (IAN), which is a branch of the posterior division of the mandibular nerve (MN). It is the source of motor nerve supply to the mylohyoid and anterior belly of the digastric muscle. At times, it provides sensory innervation to the mandibular teeth and skin below the chin. Since the location, anatomical variation and communications of the mylohyoid nerve are varied, it becomes clinically important to have an in-depth knowledge when treating patients for dental and maxillofacial procedures. Such anatomical variations of the mylohyoid nerve innervations may account for failure of the nerve blocks and hence, knowledge is very important for the practitioner.

Materials and Methods

A thorough literature search was done using the key words mandibular nerve, communications of the mylohyoid nerve, inferior alveolar nerve, lingual nerve, failure of dental anaesthesia, mylohyoid nerve and dental implants "from the Databases - PubMed, Scopus Embase and Web of Science (years 1952-2020)".

Results

The mylohyoid nerve may contain motor and sensory fibres, it may pass through the mylohyoid groove or canal and communicate with other nerves, which is clinically significant. Such anatomical variations may be one of the reasons for the failure of the inferior alveolar nerve block.

Conclusion

Awareness of these variations is very significant in planning treatment and avoiding any unnecessary steps. The most frequently encountered anatomic variation of the mylohyoid nerve was innervation of the submental skin and the anterior teeth.

Comparison of three anesthetic techniques for the removal of posterior mandibular teeth with 2% lidocaine: a systematic review

OBJECTIVES

The present systematic review aimed to evaluate whether the IANB (conventional inferior alveolar nerve block) technique is superior to the VA (Vazirani-Akinosi) or GG (Gow-Gates) techniques for anesthesia in the removal of posterior mandibular teeth.

MATERIALS AND METHODS

This systematic review was structured according to the PICO strategy, adhered to the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) checklist, and was recorded on the international prospective register of systematic reviews (PROSPERO-CRD42020153130). Studies were included based on the eligibility criteria and data from the included studies were collected by one author, while another reviewed the compilation.

RESULTS

Eight studies were included, all of which were randomized controlled trials. Three studies tested the techniques by exclusively performing lower third molar removal; the others covered other posterior lower teeth. All studies used the same local anesthetic and the same vasoconstrictor: lidocaine 2% with epinephrine/adrenaline. A total of 1056 patients were evaluated.

CONCLUSIONS

Some differences were observed between the techniques. Because of the heterogeneity between studies, clinical trials with more specific methodologies, such as comparisons of GG and VA with IANB for mandibular tooth removal, and the same clinical homogeneity will be worthwhile.

CLINICAL RELEVANCE

A systematic review of which anesthetic technique is most effective for mandibular teeth removal may positively impact the population's life. There are no systematic reviews which approach this theme in a well-structured perspective.

[Root dislocation into the mouth floor as a complication of lower impacted third molar extraction]

Root dislocation into soft tissues during lower jaw third molar extraction belongs to clinically rare complications. The thickness of the cortical plate on the third molar lingual side does not exceed 1.5 mm. Working with an elevator, or headpiece, it is possible to push the roots into the adjacent soft tissue. It is not possible to remove displaced tooth fragment through the socket, it requires additional surgical access from the lingual side. The authors described three clinical cases of root dislocation during third molar removing. Successful surgical treatment was done.

Mylohyoid foramen of mandible: a rare exit point of intra-mandibular origin of nerve to mylohyoid

Nerve to mylohyoid is a branch of inferior alveolar nerve. It arises in the infratemporal fossa and runs in the mylohyoid groove of mandible to reach the submandibular region, where it supplies the anterior belly of digastric and mylohyoid muscles. Though sensory distribution of this nerve have been described, it is predominantly a motor nerve. Here, a rare intra-mandibular origin of nerve to mylohyoid has been presented. This nerve arose from the inferior alveolar nerve inside the mandible and came out to the submandibular region by passing through a small foramen present on the medial surface of the body of the mandible. It ended by supplying the anterior belly of digastric and mylohyoid muscles. The knowledge of this variation could be of importance to maxillofacial surgeons and radiologists.

Clinical anatomy of the nerve to the mylohyoid

The nerve to the mylohyoid (NM) originates from the mandibular division of the trigeminal nerve. The NM provides motor control to the mylohyoid and the anterior belly of the digastric. Its sensory component, as a variation of this nerve, has scantly been described in the literature. We discuss the current clinical implications of the NM based on its anatomical variations of the with the hopes of benefiting patients who are undergoing invasive maxillofacial procedures.

Unusual array of neural communications in the infratemporal fossa: Useful for skull base surgery

Variations in the branching pattern of the mandibular nerve frequently accounts for failure to obtain adequate local anesthesia in routine oral and dental procedures, and also for unexpected injury to the nerves during surgery. The knowledge of the neurovascular relationships of the infratemporal region is relevant in odontostomatology practice. In this article we present a rare case of atypical communication between the inferior alveolar nerve and lingual nerve and the mylohyoid and lingual nerves. Further, the clinical implications of these communications on the development of the supplementary innervation and their possible role in anesthesia is discussed in detail. The communication between mylohyoid and lingual nerve was found in this case near the submandibular ganglion after the lingual nerve passes in close relation to third molar tooth, which makes it more susceptible to injury during third molar extractions. The communicating branch between the mylohyoid nerve and lingual nerve may also innervate the tongue, and surgeons should be aware of this variation to avoid post- operative complcations after oral surgeries. Thus the precise anatomy of structures of infratemporal region and its variations may prove beneficial to clinicians, especially to oral and maxillofacial surgeons.

Injectable local anaesthetic agents for dental anaesthesia

BACKGROUND

Pain during dental treatment, which is a common fear of patients, can be controlled successfully by local anaesthetic. Several different local anaesthetic formulations and techniques are available to dentists.

OBJECTIVES

Our primary objectives were to compare the success of anaesthesia, the speed of onset and duration of anaesthesia, and systemic and local adverse effects amongst different local anaesthetic formulations for dental anaesthesia. We define success of anaesthesia as absence of pain during a dental procedure, or a negative response to electric pulp testing or other simulated scenario tests. We define dental anaesthesia as anaesthesia given at the time of any dental intervention.Our secondary objective was to report on patients' experience of the procedures carried out.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL; the Cochrane Library; 2018, Issue 1), MEDLINE (OVID SP), Embase, CINAHL PLUS, WEB OF SCIENCE, and other resources up to 31 January 2018. Other resources included trial registries, handsearched journals, conference proceedings, bibliographies/reference lists, and unpublished research.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) testing different formulations of local anaesthetic used for clinical procedures or simulated scenarios. Studies could apply a parallel or cross-over design.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methodological approaches for data collection and analysis.

MAIN RESULTS

We included 123 studies (19,223 participants) in the review. We pooled data from 68 studies (6615 participants) for meta-analysis, yielding 23 comparisons of local anaesthetic and 57 outcomes with 14 different formulations. Only 10 outcomes from eight comparisons involved clinical testing.We assessed the included studies as having low risk of bias in most domains. Seventy-three studies had at least one domain with unclear risk of bias. Fifteen studies had at least one domain with high risk of bias due to inadequate sequence generation, allocation concealment, masking of local anaesthetic cartridges for administrators or outcome assessors, or participant dropout or exclusion.We reported results for the eight most important comparisons.Success of anaesthesiaWhen the success of anaesthesia in posterior teeth with irreversible pulpitis requiring root canal treatment is tested, 4% articaine, 1:100,000 epinephrine, may be superior to 2% lidocaine, 1:100,000 epinephrine (31% with 2% lidocaine vs 49% with 4% articaine; risk ratio (RR) 1.60, 95% confidence interval (CI) 1.10 to 2.32; 4 parallel studies; 203 participants; low-quality evidence).When the success of anaesthesia for teeth/dental tissues requiring surgical procedures and surgical procedures/periodontal treatment, respectively, was tested, 3% prilocaine, 0.03 IU felypressin (66% with 3% prilocaine vs 76% with 2% lidocaine; RR 0.86, 95% CI 0.79 to 0.95; 2 parallel studies; 907 participants; moderate-quality evidence), and 4% prilocaine plain (71% with 4% prilocaine vs 83% with 2% lidocaine; RR 0.86, 95% CI 0.75 to 0.99; 2 parallel studies; 228 participants; low-quality evidence) were inferior to 2% lidocaine, 1:100,000 epinephrine.Comparative effects of 4% articaine, 1:100,000 epinephrine and 4% articaine, 1:200,000 epinephrine on success of anaesthesia for teeth/dental tissues requiring surgical procedures are uncertain (RR 0.85, 95% CI 0.71 to 1.02; 3 parallel studies; 930 participants; very low-quality evidence).Comparative effects of 0.5% bupivacaine, 1:200,000 epinephrine and both 4% articaine, 1:200,000 epinephrine (odds ratio (OR) 0.87, 95% CI 0.27 to 2.83; 2 cross-over studies; 37 participants; low-quality evidence) and 2% lidocaine, 1:100,000 epinephrine (OR 0.58, 95% CI 0.07 to 5.12; 2 cross-over studies; 31 participants; low-quality evidence) on success of anaesthesia for teeth requiring extraction are uncertain.Comparative effects of 2% mepivacaine, 1:100,000 epinephrine and both 4% articaine, 1:100,000 epinephrine (OR 3.82, 95% CI 0.61 to 23.82; 1 parallel and 1 cross-over study; 110 participants; low-quality evidence) and 2% lidocaine, 1:100,000 epinephrine (RR 1.16, 95% CI 0.25 to 5.45; 2 parallel studies; 68 participants; low-quality evidence) on success of anaesthesia for teeth requiring extraction and teeth with irreversible pulpitis requiring endodontic access and instrumentation, respectively, are uncertain.For remaining outcomes, assessing success of dental local anaesthesia via meta-analyses was not possible.Onset and duration of anaesthesiaFor comparisons assessing onset and duration, no clinical studies met our outcome definitions.Adverse effects (continuous pain measured on 170-mm Heft-Parker visual analogue scale (VAS))Differences in post-injection pain between 4% articaine, 1:100,000 epinephrine and 2% lidocaine, 1:100,000 epinephrine are small, as measured on a VAS (mean difference (MD) 4.74 mm, 95% CI -1.98 to 11.46 mm; 3 cross-over studies; 314 interventions; moderate-quality evidence). Lidocaine probably resulted in slightly less post-injection pain than articaine (MD 6.41 mm, 95% CI 1.01 to 11.80 mm; 3 cross-over studies; 309 interventions; moderate-quality evidence) on the same VAS.For remaining comparisons assessing local and systemic adverse effects, meta-analyses were not possible. Other adverse effects were rare and minor.Patients' experiencePatients' experience of procedures was not assessed owing to lack of data.

AUTHORS' CONCLUSIONS

For success (absence of pain), low-quality evidence suggests that 4% articaine, 1:100,000 epinephrine was superior to 2% lidocaine, 1:100,000 epinephrine for root treating of posterior teeth with irreversible pulpitis, and 2% lidocaine, 1:100,000 epinephrine was superior to 4% prilocaine plain when surgical procedures/periodontal treatment was provided. Moderate-quality evidence shows that 2% lidocaine, 1:100,000 epinephrine was superior to 3% prilocaine, 0.03 IU felypressin when surgical procedures were performed.Adverse events were rare. Moderate-quality evidence shows no difference in pain on injection when 4% articaine, 1:100,000 epinephrine and 2% lidocaine, 1:100,000 epinephrine were compared, although lidocaine resulted in slightly less pain following injection.Many outcomes tested our primary objectives in simulated scenarios, although clinical alternatives may not be possible.Further studies are needed to increase the strength of the evidence. These studies should be clearly reported, have low risk of bias with adequate sample size, and provide data in a format that will allow meta-analysis. Once assessed, results of the 34 'Studies awaiting classification (full text unavailable)' may alter the conclusions of the review.

A Randomized Controlled Study Comparing Efficacy of Classical and Gow-Gates Technique for Providing Anesthesia During Surgical Removal of Impacted Mandibular Third Molar: A Split Mouth Design

INTRODUCTION

Reliable profound mandibular block anesthesia is questionable when depositing the anesthetic solution at the lingula. The Gow-Gates technique is an useful alternative to the classical inferior alveolar nerve block and the incidence of unsuccessful anesthesia may be as high as classical technique. The aim of this study is to compare the clinical efficacy, degree of patient acceptability, advantages, disadvantages and limitations of the classical and Gow-Gates techniques for providing anesthesia in patients undergoing bilateral symmetrical surgical removal of impacted mandibular third molar under local anesthesia.

MATERIAL AND METHODS

The split mouth design study was conducted on 100 patients aged between 20 to 40 years undergoing surgical removal of bilateral symmetrical impacted mandibular third molar performed by the same maxillofacial surgeon. 2 ml of 2 % lignocaine hydrochloride with 1:80,000 adrenaline was used as a standard local anesthetic solution in all the cases. By using four-digit numbers from a random number table, either Gow-Gates or classical inferior alveolar nerve block were randomly assigned to either left or right sides in each patient. The injections were administered by another surgeon who was blinded to the experiment. The patient was assessed for Pain experienced during injection, frequency of positive aspirations, Onset and duration of anesthesia and Nerves anesthetized.

RESULTS

Results were statistically analyzed by Mann-Whitney and chi square test. A 'P' value of less than 0.05 was considered for statistical significance. Higher mean pain during injection was recorded in classical group, was found to be statistically significant. No significant association was observed between aspiration and the groups. Higher mean onset of anesthesia was recorded in Gow-gates group, was found to be statistically significant. Higher mean duration of anesthesia was recorded in Gow-gates group, was not statistically significant. Higher success rate was recorded in Gow-gates group and was statistically significant.

CONCLUSION

If we ignore delayed onset of anesthesia of Gow gates technique, it is found to be more reliable, beneficial and have higher success rate than classical inferior alveolar nerve block technique.

Articaine and mepivacaine buccal infiltration in securing mandibular first molar pulp anesthesia following mepivacaine inferior alveolar nerve block: A randomized, double-blind crossover study

Aims:

A crossover double-blind, randomized study was designed to explore the efficacy of 2% mepivacaine with 1:100,000 adrenaline buccal infiltration and 4% articaine with 1:100,000 adrenaline buccal infiltration following 2% mepivacaine with 1:100,000 adrenaline inferior alveolar nerve block (IANB) for testing pulp anesthesia of mandibular first molar teeth in adult volunteers.

Materials and Methods:

A total of 23 healthy adult volunteers received two regimens with at least 1-week apart; one with 4% articaine buccal infiltration and 2% mepivacaine IANB (articaine regimen) and another with 2% mepivacaine buccal infiltration supplemented to 2% mepivacaine IANB (mepivacaine regimen). Pulp testing of first molar tooth was electronically measured twice at baseline, then at intervals of 2 min for the first 10 min, then every 5 min until 45 min postinjection. Anesthetic success was considered when two consecutive maximal stimulation on pulp testing readings without sensation were obtained within 10 min and continuously sustained for 45 min postinjection.

Results:

In total, the number of no sensations to maximum pulp testing for first molar teeth were significantly higher after articaine regimen than mepivacaine during 45 min postinjection (267 vs. 250 episodes, respectively, P < 0.001), however, both articaine and mepivacaine buccal infiltrations are equally effective in securing anesthetic success for first molar pulp anesthesia when supplemented to mepivacaine IANB injections (P > 0.05). Interestingly, volunteers in the articaine regimen provided faster onset and longer duration (means 2.78 min, 42.22 min, respectively) than mepivacaine regimen (means 4.26 min, 40.74 min, respectively) for first molar pulp anesthesia (P < 0.001).

Conclusions:

Supplementary mepivacaine and articaine buccal infiltrations produced similar successful first molar pulp anesthesia following mepivacaine IANB injections in volunteers. Articaine buccal infiltration produced faster onset and longer duration than mepivacaine buccal infiltration following mepivacaine IANB injections.

Mannitol an adjuvant in local anaesthetic solution: recent concept & changing trends (review)

Various adjuncts have been utilized with lignocaine to decrement tourniquet pain and prolong postoperative analgesia and its efficacy during dental extraction and various other restorative procedures in dentistry. An obligatory part of the dental process is to sanction a patient to feel comfortable and pain-free during operational and remedial dental procedures. The most popular local anaesthetic injection for lower teeth is the inferior alveolar nerve (IAN) block. Instead of this the percentage of ineffectiveness is higher is inferior alveolar nerve block as compared to other local anaesthetic nerve block. The goal of cumulating different drugs is to engender the best therapeutic effects with the fewest or no unpropitious effects. There are fewer researches and evidence present which recommend and promote the application and effectiveness of mannitol other than in the administration in decreasing raised intracranial pressure. It is paramount to know how the drug interacts with each other to minimize the unexpected or perilous effects.

Anesthetic efficacy of a combination of 0.9 M mannitol plus 68.8 mg of lidocaine with 50 μg epinephrine in inferior alveolar nerve blocks: a prospective randomized, single blind study

The purpose of this prospective randomized, single blind study was to determine the anesthetic efficacy of 68.8 mg of lidocaine with 50 μg epinephrine compared to 68.8 mg lidocaine with 50 μg epinephrine plus 0.9 M mannitol in inferior alveolar nerve (IAN) blocks. Forty subjects randomly received 2 IAN blocks consisting of a 1.72-mL formulation of 68.8 mg lidocaine with 50 μg epinephrine and a 5-mL formulation of 68.8 mg lidocaine with 50 μg epinephrine (1.72 mL) plus 0.9 M mannitol (3.28 mL) in 2 separate appointments spaced at least 1 week apart. Mandibular anterior and posterior teeth were blindly electric pulp tested at 4-minute cycles for 60 minutes postinjection. No response from the subject to the maximum output (80 reading) of the pulp tester was used as the criterion for pulpal anesthesia. Total percent pulpal anesthesia was defined as the total of all the times of pulpal anesthesia (80 readings), for each tooth, over the 60 minutes. One hundred percent of the subjects had profound lip numbness with both inferior alveolar nerve blocks. The results demonstrated that the 5 mL-formulation of 68.8 mg lidocaine with 50 μg epinephrine plus 0.9 M mannitol was significantly better than the 1.72-mL formulation of 68.8 mg lidocaine with 50 μg epinephrine for all teeth, except the lateral incisor. We concluded that adding 0.9 M mannitol to a lidocaine with epinephrine formulation was significantly more effective in achieving a greater percentage of total pulpal anesthesia (as defined in this study) than a lidocaine formulation without mannitol. However, the 0.9 M mannitol/lidocaine formulation would not provide 100% pulpal anesthesia for all the mandibular teeth.

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.

Effect of massage on the efficacy of the mental and incisive nerve block

The purpose of this trial was to assess the effect of soft tissue massage on the efficacy of the mental and incisive nerve block (MINB). Thirty-eight volunteers received MINB of 2.2 mL of 2% lidocaine with 1 : 80,000 epinephrine on 2 occasions. At one visit the soft tissue overlying the injection site was massaged for 60 seconds (active treatment). At the other visit the crowns of the mandibular premolar teeth were massaged (control treatment). Order of treatments was randomized. An electronic pulp tester was used to measure pulpal anesthesia in the ipsilateral mandibular first molar, a premolar, and lateral incisor teeth up to 45 minutes following the injection. The efficacy of pulp anesthesia was determined by 2 methods: (a) by quantifying the number of episodes with no response to maximal electronic pulp stimulation after each treatment, and (b) by quantifying the number of volunteers with no response to maximal pulp stimulation (80 reading) on 2 or more consecutive tests, termed anesthetic success. Data were analyzed by McNemar, Mann-Whitney, and paired-samples t tests. Anesthetic success was 52.6% for active and 42.1% for control treatment for lateral incisors, 89.5 and 86.8% respectively for premolars, and 50.0 and 42.1% respectively for first molars (P = .344, 1.0, and .508 respectively). There were no significant differences in the number of episodes of negative response to maximum pulp tester stimulation between active and control massage. A total of 131 episodes were recorded after both active and control massage in lateral incisors (McNemar test, P = 1.0), 329 (active) versus 316 (control) episodes in the premolars (McNemar test, P = .344), and 119 (active) versus 109 (control) episodes respectively for first molars (McNemar test, P = .444). Speed of anesthetic onset and discomfort did not differ between treatments. We concluded that soft tissue massage after MINB does not influence anesthetic efficacy.

Anesthetic efficacy of a combination of 0.5 M mannitol plus 127.2 mg of lidocaine with 50 μg epinephrine in inferior alveolar nerve blocks: a prospective randomized, single-blind study

The purpose of this prospective, randomized, single-blind study was to determine the anesthetic efficacy of 127.2 mg lidocaine with 50 μg epinephrine compared to 127.2 mg lidocaine with 50 μg epinephrine plus 0.5 M mannitol in inferior alveolar nerve (IAN) blocks. Forty subjects randomly received 2 IAN blocks consisting of a 3.18 mL formulation of 127.2 mg lidocaine with 50 μg epinephrine and a 5 mL formulation of 127.2 mg lidocaine with 50 μg epinephrine (3.18 mL) plus 0.5 M mannitol (1.82 mL) in 2 separate appointments spaced at least 1 week apart. Mandibular anterior and posterior teeth were blindly electric pulp tested at 4-minute cycles for 60 minutes postinjection. Pain of solution deposition and postoperative pain were also measured. No response from the subject to the maximum output (80 reading) of the pulp tester was used as the criterion for pulpal anesthesia. Total percent pulpal anesthesia was defined as the total of all the times of pulpal anesthesia (80 readings) over the 60 minutes. One hundred percent of the subjects had profound lip numbness with both inferior alveolar nerve blocks. The results demonstrated that a 5 mL formulation of 127.2 mg lidocaine with 50 μg epinephrine plus 0.5 M mannitol was significantly better than the 3.18 mL formulation of 127.2 mg lidocaine with 50 μg epinephrine for all teeth. Solution deposition pain and postoperative pain were not statistically different between the lidocaine/mannitol formulation and the lidocaine formulation without mannitol. We concluded that adding 0.5 M mannitol to a lidocaine with epinephrine formulation was significantly more effective in achieving a greater percentage of total pulpal anesthesia than a lidocaine formulation without mannitol.

Transverse cervical nerve: implications for dental anesthesia

The inferior alveolar nerve block (IANB) has the highest failure incidence of any dental anesthetic technique. Many authors have outlined potential reasons for these failures in permanent lower molars, including accessory innervations from the mylohyoid and mental foramen. However, the potential accessory innervation of posterior mandibular teeth from the transverse cervical nerve (TCN), a branch of ventral rami from the C2-C3 spinal nerves from the cervical plexus (CP), has been difficult to assess as a result of the small size and thickness of the mandibular accessory foramina and nerve branches, as well as due to the dissection technique performed. The goal of this study was to identify and trace the CP branches from fresh human cadaver tissue samples using the Sihler's technique. Two fresh human cadaver samples were used. Samples were fixed in neutralized formalin, macerated in potassium hydroxide, decalcified in acetic acid, stained in Ehrlich's hematoxylin, destained in acetic acid, and cleared in glycerin. Both specimens skin was dissected. The Sihler's technique delineated all nerves three dimensionally and helped to disclose structures of small size and thickness. The TCN from the CP, stained in blue, innervated the posterior mandible in one of the two samples. These results confirmed that the CP may supply accessory innervation to the inferior border of the posterior mandible through the TCN. These findings illustrate variations of anatomy that may account for IANB failures in posterior mandibular teeth and allows for clinical decisions for implementing supplemental anesthetic techniques.

The Efficacy of Mylohyoid Nerve Anesthesia in Dental Implant Placement at the Edentulous Posterior Mandibular Ridge

The aim of this study is to evaluate the anesthetic efficacy of mylohyoid and buccal nerve anesthesia at the posterior edentulous mandible versus regional anesthetic block to the inferior alveolar nerve in dental implant surgery. The study was composed of 2 groups. In the first group (group A), 14 voluntary adults (7 female and 7 male) received local infiltrations of 1 mL articaine HCl 4% with epinephrine 1/200 000 to the ipsilateral mylohyoid and buccal nerves. In the second group (group B, control; 9 female and 5 male adults), the inferior alveolar and the buccal nerve blocks were performed. Visual analog scales were obtained from patients to determine the level of pain during incision, drilling, implant placement, and suturing stages of implant surgery. A combination of buccal and mylohyoid nerve block offered an acceptable level of anesthesia. Two patients from group A stopped the ongoing surgery and had extraregional anesthesia by inferior alveolar nerve block. In group B, patients were operated on successfully. Local anesthetic infiltrations of the mylohyoid and the buccal nerve may be considered alternative methods of providing a convenient anesthetic state of the posterior mandibular ridge.

Anesthetic efficacy of combinations of 0.5 m mannitol and lidocaine with epinephrine in inferior alveolar nerve blocks: a prospective randomized, single-blind study

The purpose of this prospective, randomized, single-blind study was to determine the anesthetic efficacy of lidocaine with epinephrine compared to lidocaine with epinephrine plus 0.5 M mannitol in inferior alveolar nerve (IAN) blocks. Forty subjects randomly received an IAN block in 3 separate appointments spaced at least 1 week apart using the following formulations: a 1.8 mL solution of 36 mg lidocaine with 18 µg epinephrine (control solution); a 2.84 mL solution of 36 mg lidocaine with 18 µg epinephrine (1.80 mL) plus 0.5 M mannitol (1.04 mL); and a 5 mL solution of 63.6 mg lidocaine with 32 µg epinephrine (3.18 mL) plus 0.5 M mannitol (1.82 mL). Mandibular teeth were blindly electric pulp tested at 4-minute cycles for 60 minutes postinjection. No response from the subject to the maximum output (80 reading) of the pulp tester was used as the criterion for pulpal anesthesia. Mean percent total pulpal anesthesia was defined as the total of all the times of pulpal anesthesia (80 readings) over the 60 minutes. Pain of solution deposition and postoperative pain were also measured. The results demonstrated that 2.84 mL of lidocaine with epinephrine plus 0.5 M mannitol was significantly better than 1.8 mL of lidocaine with epinephrine for the molars and premolars. The 5 mL of lidocaine with epinephrine plus 0.5 M mannitol was statistically better than 1.8 mL of lidocaine with epinephrine and 2.84 mL of lidocaine with epinephrine plus 0.5 M mannitol for all teeth except the central incisor. Solution deposition pain and postoperative pain were not statistically different among the mannitol formulations and the lidocaine formulation without mannitol. We concluded that adding 0.5 M mannitol to lidocaine with epinephrine formulations significantly improved effectiveness in achieving a greater percentage of total pulpal anesthesia compared with a lidocaine formulation without mannitol for IAN block.

The efficacy of infiltration anaesthesia for adult mandibular incisors: a randomised double-blind cross-over trial comparing articaine and lidocaine buccal and buccal plus lingual infiltrations

AIM

To compare the efficacy of 2% lidocaine and 4% articaine both with 1:100,000 adrenaline in anaesthetising the pulps of mandibular incisors.

METHODS

Thirty-one healthy adult volunteers received the following local anaesthetic regimens adjacent to a mandibular central incisor: 1) buccal infiltration of 1.8 mL lidocaine plus dummy lingual injection (LB), 2) buccal plus lingual infiltrations of 0.9 mL lidocaine (LBL), 3) buccal infiltration of 1.8 mL articaine plus dummy lingual injection (AB), 4) buccal plus lingual infiltrations of 0.9 mL articaine (ABL). Pulp sensitivities of the central incisor and contralateral lateral incisor were assessed electronically. Anaesthetic efficacy was determined by two methods: 1) Recording the number of episodes with no responses to maximal electronic pulp tester stimulation during the course of the study period, 2) recording the number of volunteers with no response to maximal pulp tester stimulation within 15 min and maintained for 45 min (defined as sustained anaesthesia). Data were analysed by McNemar, chi-square, Mann-Whitney and paired t-tests.

RESULTS

For both test teeth, the number of episodes of no sensation on maximal stimulation was significantly greater after articaine than lidocaine for both techniques. The split buccal plus lingual dose was more effective than the buccal injection alone for both solutions (p <0.001). 4% articaine was more effective than 2% lidocaine when comparing sustained anaesthesia in both teeth for each technique (p <0.001), however, there was no difference in sustained anaesthesia between techniques for either tooth or solution.

CONCLUSIONS

4% articaine was more effective than 2% lidocaine (both with 1:100,000 adrenaline) in anaesthetising the pulps of lower incisor teeth after buccal or buccal plus lingual infiltrations.

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.

Design and development of a device for facilitation of Gow-Gates mandibular block and evaluation of its efficacy

INTRODUCTION

The Gow-Gates technique is a useful alternative to the inferior alveolar nerve block whenever the latter fails to provide adequate anesthesia. The main disadvantage of this technique is that the incidence of unsuccessful anesthesia may be as high as that for the inferior alveolar nerve block until the administrator gains clinical experience with it.

OBJECTIVES

The aim of this study was to develop a device that facilitates the Gow-Gates technique and to increase its success rate even for administrators who are unfamiliar with this procedure.

MATERIALS AND METHODS

Ninety patients participated in our study. Forty-five patients received Gow-Gates mandibular block with device, and 45 patients received it without instrument (control group). Ninety 5th-year dental students who had no previous clinical experience with the Gow-Gates technique injected the patients.

RESULTS AND DISCUSSION

The success rate of anesthesia of inferior alveolar nerve, lingual nerve, buccal nerve, and auriculotemporal nerve were 93.3%, 93.3%, 91.1%, and 91.1%, respectively, in the study group and 68.9%, 68.2%, 68.9%, and 68.2%, respectively, in the control group.

CONCLUSION

We concluded that our device facilitates the Gow-Gates technique and increases its success rate irrespective of the gender of the patient, the side of the mandible being injected, and the experience of the administrator who uses the instrument.

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.

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.

Sensory innervation of mandibular teeth by the nerve to the mylohyoid: Implications in local anesthesia

Traditionally, the nerve to the mylohyoid has been considered a motor nerve. However, dissection and clinical studies have challenged this dogma implicating the nerve to the mylohyoid as a nerve of accessory sensory innervation to mandibular teeth. Within the infratemporal fossa, the nerve to the mylohyoid branches from the inferior alveolar nerve and may be anesthetized with an inferior alveolar nerve block. However, because of the variability in location of branching and the potential barriers formed by both the pterygomandibular fascia and the sphenomandibular ligament, the nerve to the mylohyoid may escape anesthesia in an inferior alveolar nerve block. This may prevent profound local anesthesia of the mandibular teeth and may account, at least in part, for the high failure rate of the inferior alveolar nerve block. Alternative local anesthesia procedures may be employed to ensure adequate anesthesia of the nerve to the mylohyoid is achieved. This review provides a background of anatomical and clinical research of the nerve to the mylohyoid and outlines techniques suggested for providing a neural blockade of the nerve to the mylohyoid.

Pulpal anaesthesia for mandibular permanent first molar teeth: a double-blind randomized cross-over trial comparing buccal and buccal plus lingual infiltration injections in volunteers

AIM

To compare the efficacy of buccal and buccal plus lingual infiltration anaesthesia for permanent mandibular first molars.

METHODOLOGY

Thirty one healthy adult volunteers received each of the following methods of anaesthesia for a mandibular first molar tooth in a randomised order, 1) Buccal infiltration of 1.8 mL and needle penetration lingually. 2) Buccal infiltration of 0.9 mL, plus lingual infiltration of 0.9 mL. Two percent lidocaine with 1:100,000 epinephrine was used. Electrical pulp testing was performed before, and every 2 minutes for 30 minutes after injection. A successful outcome was recorded as the absence of pulp sensation on two or more consecutive maximal pulp tester stimulations (80 microA). Injection discomfort was assessed using visual analogue scales. Data were compared with McNemar and Wilcoxon Signed Ranks tests.

RESULTS

Buccal infiltration was successful in 38.7% of cases compared to 32.3% after combined infiltrations; the difference was not significant (P = 0.63). Buccal infiltration produced more episodes of no response to maximum stimulation than buccal and lingual infiltrations (129 and 114 respectively), this difference was not significant (P = 0.11). Peak anaesthetic effect occurred around 10-14 minutes after injection. There was no difference in injection discomfort between buccal injections of 0.9 mL and 1.8 mL of solution (P = 0.90). Lingual injection was more uncomfortable than lingual penetration (P = O.O02).

CONCLUSIONS

Buccal and buccal plus lingual infiltrations did not differ in their efficacy in producing anaesthesia of permanent first molar teeth.

Evaluation of mandibular block using a standardized method

The purpose of this prospective randomized study was to investigate the manifestations and efficiency of mandibular block (MB) using a standardized method. In this study, 123 patients requiring MB were randomly assigned to receive MB using a repeated measures design. Mandibular block was administered in each patient by using 2.1 mL of 2% lidocaine with 1:100 000 epinephrine for the inferior alveolar nerve, lingual nerve, and/or buccal nerve. Clinical parameters including the electric pulp test and test for soft tissue sensation using a sharp dental explorer were assessed on both the operated side and contralateral side before and 5, 10, and 15 minutes after injection, and at the end of surgical procedure. Results of the test of the contralateral tooth served as the control group. No response to the electric pulp test at a maximum output (80 readings) was used as the criterion for pulpal anesthesia. Results obtained with electric pulp test and sharp explorer test were not significantly different during various intervals on the contralateral side, indicating the reliability of this standardized method for assessing MB. The MB technique achieved a high rate of subjective numbness (100%) according to the perception of the patients of overall numbness and lip numbness. Overall anesthetic success rates of pulpal anesthesia were 5.7% for the central incisor, 38.2% for the canine, 55.3% for the first premolar, and 90.2% for the first molar. No significant difference was found in the efficiency of anesthesia related to sex or age of the patients. A slower onset of pulpal anesthesia after MB was found for the anterior teeth than for the posterior teeth. This study suggests that the use of a standardized method might produce a clearer and more comprehensive evaluation of the efficiency and manifestations of MB.

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.

Pulpal anaesthesia for mandibular central incisor teeth: a comparison of infiltration and intraligamentary injections

AIM

This study compared the anaesthetic efficacy of infiltration and intraligamentary injections in the permanent mandibular central incisor.

METHODOLOGY

Twelve healthy volunteers received each of the following methods of anaesthesia for one of their mandibular central incisors over four visits. 1 Labial infiltration of 1.0 mL. 2 Lingual infiltration of 1.0 mL. 3 Labial infiltration of 0.5 mL plus lingual infiltration of 0.5 mL. 4 Intraligamentary injection of (118 mL. Two percent lidocaine with 1: 80 000 adrenaline and 30 gauge needles were used throughout. Electrical pulp testing was performed before injection and every 2 min up to 30 min after the injection. Injection discomfort was recorded on a 100-mm visual analogue scale. Data were compared with ANOVA, Student's t-test and chi2 tests.

RESULTS

Anaesthesia varied between techniques(F = 9.3, P < 0.001). The incidence of anaesthesia at any time was as follows: 50% success for labial infiltration; 50% success for lingual infiltration: 92% success for combined labial and lingual infiltration; 0% success for intraligamentary injections (chi2 = 20; P < 0.001). The mean (+/-SD) VAS score for intraligamentary injection discomfort was 28 +/- 12 mm, for buccal infiltrations 17 +/- 8 mm and for lingual infiltrations 16 +16 mm. Intraligamentary injections were more uncomfortable than buccal (t = 3.7: P < 0.01) and lingual infiltrations (t = 2.67: P < 0.05).

CONCLUSIONS

The most reliable method of the techniques investigated for obtaining pulpal anaesthesia in mandibular permanent central incisors was a combination of labial and lingual infiltration. Intraligamentary injections were unreliable and were more uncomfortable than infiltrations in the mandibular central incisor region.

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

OBJECTIVE

The purpose of this prospective randomized study was to measure the degree of anesthesia obtained with unilateral and bilateral inferior alveolar nerve blocks to determine whether cross innervation occurs in anterior teeth.

STUDY DESIGN

Through use of a repeated-measures design, 38 subjects randomly received unilateral or bilateral inferior alveolar nerve blocks at two separate appointments. Each inferior alveolar nerve block used 3.6 mL of 2% lidocaine with 1:100,000 epinephrine. Mandibular anterior teeth were blindly pulp-tested at 4-minute cycles for 60 minutes' postinjection. No response from the subject to the maximum output (80 reading) of the pulp tester was used as the criterion for pulpal anesthesia. Anesthesia was considered successful when 2 consecutive 80 readings were obtained.

RESULTS

One hundred percent of the subjects had lip numbness with each of the inferior alveolar nerve block techniques. Anesthetic success rates of the unilateral inferior alveolar nerve block were 39% for the central incisor, 50% for the lateral incisor, and 68% for the canine. For the bilateral inferior alveolar nerve blocks, success rates were 66% for the central incisor, 74% for the lateral incisor, and 76% for the canine. The bilateral inferior alveolar nerve block success rates were significantly (P <.05) higher for the central and lateral incisors when compared with the success rates of the unilateral inferior alveolar nerve block.

CONCLUSIONS

Cross innervation does seem to occur in mandibular central and lateral incisors. However, the success rates in these teeth with bilateral inferior alveolar nerve blocks were below 75%. The failure of the inferior alveolar nerve blocks to anesthetize the anterior teeth was the overriding reason for failure. Clinically, bilateral inferior alveolar nerve blocks to provide profound pulpal anesthesia in mandibular anterior teeth are not recommended on the basis of the results of this study.