Failure Of Inferior Alveolar Nerve Block Research Articles

Retromolar Canal Diagnosed by Cone-Beam Computed Tomography and its Influence in Inferior Alveolar Nerve Block

The aim of this study was to observed the anesthetic efficacy of the alveolar nerve block on nine patients that CBCT diagnosed unilateral retromolar canal on a double-blind, split-mouth approach. The assessments of patient response to thermal (pulp vitality test) and pressure (compression of soft tissue) stimuli were carried out before and 5 minutes after the inferior alveolar nerve block procedure, using both visual analog scale (VAS) and Mc Gill pain questionnaires (McG). The mean percentage of patient response decreased after alveolar nerve block, according to both VAS and McG, and was statistically similar among hemi mandibles with and without retromolar canal (Wilcoxon>0.05); however, those without retromolar canal presented greater reduction in patient response in 6 out of 9 cases. Therefore, the retromolar canal is not a determinant factor of inferior alveolar nerve block failure.

COMPARISON OF CLINICAL EFFICACY OF MANDIBULAR NERVE ANESTHESIA

Introduction: Being the best at managing pain is an essential but difficult aim for oral and maxillofacial surgeons. The relatively high rate of failure of the inferior alveolar nerve block (IANB) may be attributed to a variety of factors. The capacity of the different mandibular nerve block procedures to address the precise causes of IANB failure is what makes them valuable.
 Objective: This research compared the effectiveness of Gow-Gates Nerve Block Technique with Conventional Inferior Alveolar Nerve Block Technique for Mandibular Nerve Anesthesia.
 Results: The average time it took for anaesthesia to start for the traditional inferior alveolar block approach was 3 minutes, 17 seconds, but the average time it took for the Gow-Gates technique was much longer, at 4 minutes, 15 seconds.
 Conclusion: The results of the current investigation found no statistically significant differences between the Gow Gates approach as well as the traditional inferior alveolar nerve block in terms of anaesthetic efficacy.

A Morphometric Study of the Mandibular Foramen in Dry Adult Human Mandibles in a Black Malawian Population

The inferior alveolar nerve block (IANB) technique is a common technique performed on patients in dental surgery, placement of mandibular implants and other procedures involving the mandible. Precise identification of the mandibular foramen (MF) is essential for dental surgeons to accurately administer local anesthetics. Inaccurate localization of the mandibular foramen may result in IANB failure and injury to neurovascular tissues. Therefore, this study aimed at investigating the precise location of the MF from various anatomical land marks in dry adult human mandibles of Malawian population. The study was conducted on 29 dry adult human mandibles of unknown sex of Malawian origin from the Anatomy Division collection of human skeletons housed in the Biomedical Sciences Department, College of Medicine, University of Malawi. To determine the position of the mandibular foramen, distances from mandibular foramen to anterior margin, posterior margin, mandibular notch, gonial angle and mandibular base using a Vernier caliper were measured. The mean distance of the MF from posterior margin of mandibular ramus was 11.26±1.22 mm (right side) and 11.47±1.35 mm (left side), from the anterior margin 20.85±3.12 mm (right side) and 20.85±3.22 mm (left side) mandibles. The mean distance between mandibular notch (MN) and MF was 23.87±2.61 mm (right side) and 23.53 ± 2.65 mm (left side). The mean distance between mandibular base (MB) and MF for the right and left were 28.47 ± 2.90 mm and 27.85 ± 2.99 mm respectively. The inferior limit of the mandibular foramen was located at 24.69 ± 3.65 mm (right side) and 24.25 ± 2.77 mm (left side) to the angle (AG) of the mandible. The findings of this study show that the anterior margin mean distance from the MF for both right and left mandibles seem to be bilateral symmetrical suggesting the interpretation that the needle for IANB could be inserted at about 21 mm from the anterior margin to the MF in an adult of Malawian origin during surgery.

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.

Failure of molar anesthesia in endodontics : A systematic review

Introduction: Failure of molar anesthesia is commonly encountered in our clinical practice ranging around 15% in normal pulps and 44%–81% in inflamed pulps. Effective pain management is challenging in such situations. The aim of the present systematic review was to enlist the reasons for local anesthesia failure in mandibular molars during root canal treatment and to assess the effectiveness of supplementary methods along with the conventional inferior alveolar nerve block (IANB) in achieving profound anesthesia. Materials and Methods: A literature search on Pubmed and Google scholar database from the year 1990–2020 was conducted using the keywords: “Molar anesthesia,” “Local anesthesia failure,” “Hot tooth,” “irreversible pulpitis.” The articles pertaining to the failure of IANB during endodontic treatment of mandibular molars and the techniques for the improved success of molar anesthesia were reviewed. The data were analyzed in terms of author, year, type of study design, study population and type of intervention, method of assessment of outcome, outcome assessed, result and clinical recommendations. Results: The search yielded 9090 articles, from which the specific articles relevant to the topic were reviewed. The articles were reviewed independently by two authors. Finally, a total of 7 randomized controlled trials fulfilling the eligibility criteria were analyzed and subjected to qualitative assessment. Conclusion: The failure of IANB could be attributed to several reasons such as anatomical variations, Operator Technique, Presence of inflammation, and Psychological reasons. In addition, there is a positive association in using adjuncts for achieving effective anesthesia in mandibular molars.

Effect of pre-operative medication with paracetamol and ketorolac on the success of inferior alveolar nerve block in patients with symptomatic irreversible pulpitis: a double-blind randomized clinical trial.

BackgroundThe efficacy of local anesthesia decreases in patients with symptomatic irreversible pulpitis. Therefore, it was proposed that the use of premedication with an anti-inflammatory drug might increase the success rate of pulpal anesthesia in mandibular posterior teeth with vital inflamed pulp.MethodsOne hundred thirty-four patients who were actively experiencing pain willingly participated in this study. The Heft Parker (HP) visual analog scale (VAS) was used to record the initial pain intensity. Patients were randomly allocated to receive a placebo, 10 mg of ketorolac, and 650 mg of paracetamol. The standard inferior alveolar nerve block (IANB) was administered to all patients using 2% lidocaine with 1:200,000 adrenaline after one hour of medication. After 15 min, the patient was instructed to rate the discomfort during each step of the treatment procedure, such as access to remaining dentin, access to the pulp chamber, and during canal instrumentation on the HP VAS. IANB was considered successful if the patient reported no or mild pain during access preparation and instrumentation. Moderate or severe pain was classified as a failure of IANB and another method of anesthesia was used before continuing the treatment.ResultsThe rate of successful anesthesia in the placebo, paracetamol, and ketorolac groups was 29%, 33%, and 43%, respectively, and no statistically significant difference was found between the groups.ConclusionPreoperative administration of paracetamol or ketorolac did not significantly affect the success rate of IANB in patients with irreversible pulpitis. No significant difference was observed between the paracetamol and ketorolac groups.

Study of mandibular foramen in relation to various landmarks on ramus of mandible along with its clinical significance in people of Gujarat region

Introduction: Mandibular foramen has its clinical importance in giving inferior alveolar nerve block very commonly give n in various dental procedures like removal of third molar tooth, Dental pain, Dentoalveolar trauma, Dry socket, Periapical abscess and in painful procedure on mandible or lower lip/chin. So it is very essential to know the anatomy of mandible particularly mandibular foramen which is situated just above the centre of the medial surface of the ramus of the mandibl e. Mandibular foramen gives passage to inferior nerve and vessels to sup ply the teeth of lower jaw. Mandibular foramen provides an important anatomical land mark. The inferior nerve block is the commonest local anaesthetic technique in clinical practice in dental procedures. There are chances of failure of Inferior alveolar nerve block failure due to its variations in position of. So it requires detailed anatomical study of mandibular foramen. This study aims to determine the exact position of mandibular foramen in relation to various landmark on mandible. We have studied dry adult human mandibles of people of Gujarat region. Materials and Methods: The material for the present study includes 100 adult dry human mandibles of unknown sex. These were collected from Govt. Medical College, Bhavnagar. All measurements were recorded using a sliding vernier caliper. Measurements were taken using below mentioned bony landmarks on the mandible. Results: The study shows mean distance of mandibular foramen to anterior border of ramus 17.052.70mm on right side and 17.353.00mm on left side, to posterior border of ramus was 10.412.13mm on right side and 9.722.06 mm on left side, to mandibular notch 21.502.81mm on right side and 21.883.31 mm on left side, base of man dible or inferior border was 22.203.28 mm on right side and 25.304.2mm on left side. Conclusion: The present study gives knowledge of the position of mandibular foramen and provides useful information for successful local anaesthesia (inferi

Pulpal anesthesia in pediatric patients following supplemental mandibular buccal infiltration in vital permanent mandibular molars with deep caries.

Inferior alveolar nerve block (IANB) does not always provide adequate pulpal anesthesia, and supplemental techniques have been investigated in adults. This study aimed to pre- and intraoperatively evaluate the success of pulpal anesthesia following supplemental mandibular buccal infiltration (SMBI) after failure of IANB in permanent mandibular molars with deep caries of pediatric patients. Following IANB, preoperative pulpal anesthesia was assessed using the cold test, and success was defined when there was a negative response. In cases with failed IANB, SMBI was administered, and pulpal anesthesia was re-evaluated. A maximum of three SMBIs was allowed. After achieving successful preoperative pulpal anesthesia, treatment was then initiated. Intraoperatively, success of pulpal anesthesia was determined when the Wong-Baker FACES Pain Rating Scale reported by the patients was ≤ four. Sixty molars of patients aged 9.6 ± 2.3years were included in the study. The success of preoperative pulpal anesthesia following IANB was 33.3%. The overall cumulative preoperative pulpal anesthesia after three SMBIs was 95%. However, the success of intraoperative pulpal anesthesia was only 66.7%. SMBI greatly improved the success of preoperative pulpal anesthesia after failure of IANB. However, the success of preoperative pulpal anesthesia, confirmed by the cold test, does not always guarantee intraoperative pulpal anesthesia, especially in teeth with irreversible pulpitis. IANB produced low pulpal anesthesia in vital permanent mandibular molars with deep caries of pediatric patients. Clinicians should always prepare for supplemental injection both pre- and intra-operatively.

Morphological alterations in the position of the mandibular foramen in dentate and edentate mandibles.

The technique of inferior alveolar nerve (IAN) block must be based on precise anatomical knowledge regarding the correct position of the mandibular foramen (MF). The aim of the investigation reported here was to determine the anatomic and topographic localization of the MF according to mandibular ramus anatomic landmarks and to identify morphological alterations in the position of the MF and size and shape of the ramus in terms of the impact of tooth socket loss in the molar and premolar region. Seventy-three dry human adult mandibles were divided into two groups according to dental status. These were measured to determine the distances from the anterior and posterior ramus border (AB, PB) to the midpoint of the MF fossa, and from the mandibular notch (MN) and inferior ramus border (IB) to the MF entering point. A number of relevant ramus anatomic features were analyzed, such as ramus width (RW), height (RH), and thickness (RT). The MF was closer to the PB and IB in edentate mandibles (right/left mean PB-MF 10.66±1.84/11.06±2.05mm; right/left mean IB-MF 21.77±3.23/21.8±2.27mm) compared to dentate mandibles (right/left mean PB-MF 11.87±2.08/12.04±1.94mm; right/left mean IB-MF 22.94±3.09/22.74±3.74mm). Edentate mandibles demonstrated reduced RW (right/left mean RW 26.03±3.53/26.49±3.90mm), significantly reduced (p=0.03) right RH (right/left mean RH 43.56±4.74/45.43±4.86mm), and significantly reduced (p<0.05) RT in the area of the MF fossa depression (right/left mean RT 5.52±1.21/5.21±0.91mm) compared to dentate mandibles (right/left mean RW 27.34±3.84/27.48±3.80mm; right/left mean RH 46.33±4.52/47.40±4.20mm; right/left mean RT 7.86±1.98/8.10±1.92mm). Alterations in MF position and mandibular ramus anatomic features in edentate mandibles increase the potential risk of complications and failure of IAN block.

Failure rate of inferior alveolar nerve block among dental students and interns.

Objectives:To report the failure rate of inferior alveolar nerve block (IANB) among dental students and interns, causes of failure, investigate awareness of different IANB techniques, and to report IANB-associated complications.Methods:A 3-page questionnaire containing 13 questions was distributed to a random sample of 350 third to fifth years students and interns at the College of Dentistry, King Saud University, Riyadh, Saudi Arabia on January 2011. It included demographic questions (age, gender, and academic level) and questions on IANB failure frequency and reasons, actions taken to overcome the failure, and awareness of different anesthetic techniques, supplementary techniques, and complications.Results:Of the 250 distributed questionnaires, 238 were returned (68% response rate). Most (85.7%) of surveyed sample had experienced IANB failure once or twice. The participants attributed the failures most commonly (66.45%) to anatomical variations. The most common alternative technique used was intraligamentary injection (57.1%), although 42.8% of the sample never attempted any alternatives. Large portion of the samples stated that they either lacked both knowledge of and training for other techniques (44.9%), or that they had knowledge of them but not enough training to perform them (45.8%).Conclusion:To decrease IANB failure rates for dental students and interns, knowledge of landmarks, anatomical variation and their training in alternatives to IANB, such as the Gow-Gates and Akinosi techniques, both theoretically and clinically in the dental curriculum should be enhanced.

The influence of mandibular skeletal characteristics on inferior alveolar nerve block anesthesia.

BackgroundThe inferior alveolar nerve block (IANB) is the most common anesthetic techniques in dentistry; however, its success rate is low. The purpose of this study was to determine the correlation between IANB failure and mandibular skeletal characteristicsMethodsIn total, 693 cases of lower third molar extraction (n = 575 patients) were examined in this study. The ratio of the condylar and coronoid distances from the mandibular foramen (condyle-coronoid ratio [CC ratio]) was calculated, and the mandibular skeleton was then classified as normal, retrognathic, or prognathic. The correlation between IANB failure and sex, treatment side, and the CC ratio was assessed.ResultsThe IANB failure rates for normal, retrognathic, and prognathic mandibles were 7.3%, 14.5%, and 9.5%, respectively, and the failure rate was highest among those with a CC ratio < 0.8 (severe retrognathic mandible). The failure rate was significantly higher in the retrognathic group than in normal group (P = 0.019), and there was no statistically significant difference between the other two groups.ConclusionsIANB failure could be attributable, in part, to the skeletal characteristics of the mandible. In addition, the failure rate was found to be significantly higher in the retrognathic group.

Alternative mandibular nerve block techniques: A review of the Gow-Gates and Akinosi-Vazirani closed-mouth mandibular nerve block techniques

and Overview. The limited success rate of the standard inferior alveolar nerve block (IANB) has led to the development of alternative approaches for providing mandibular anesthesia. Two techniques, the Gow-Gates mandibular nerve block and the Akinosi-Vazirani closed-mouth mandibular nerve block, are reliable alternatives to the traditional IANB. The Gow-Gates technique requires the patient's mouth to be open wide, and the dentist aims to administer local anesthetic just anterior to the neck of the condyle in proximity to the mandibular branch of the trigeminal nerve after its exit from the foramen ovale. The Akinosi-Vazirani technique requires the patient's mouth to be closed, and the dentist aims to fill the pterygomandibular space with local anesthetic. Both techniques are indicated for any type of dentistry performed in the mandibular arch, but they are particularly advantageous when the patient has a history of standard IANB failure owing to anatomical variability or accessory innervation. Having the skill to perform these alternative anesthetic techniques increases dentists' ability to provide successful local anesthesia consistently for all procedures in mandibular teeth.

Failure of inferior alveolar nerve block in endodontics.

Analgesia is essential for successful completion of modern dental procedures. Standard inferior alveolar nerve block (IANB) is the primary method used to achieve mandibular analgesia. Difficulty experienced in obtaining satisfactory analgesia after IANB, especially of an acutely inflamed mandibular molar, remains a common clinical problem. Even when a proper technique is employed, clinical studies show that IANB fails in approximately 30% to 45% of cases. The reasons for failure are not fully understood. Anatomical considerations and abnormal physiological responses in the presence of inflammation as explanations for IANB failure are discussed in this paper.