Efficacy and complications associated with a modified inferior alveolar nerve block technique. A randomized, triple-blind clinical trial

Efficacy of Different Techniques of the Inferior Alveolar Nerve Block for Mandibular Anesthesia: A Comparative Prospective Study

Background The inferior alveolar nerve block (IANB) is a commonly employed technique in oral surgery for achieving profound anesthesia in the mandibular teeth and associated structures. Several techniques have been developed to enhance the success rate and patient comfort during the IANB. The aim of this study was to compare and evaluate the efficacy of different IANB techniques for mandibular anesthesia.  Materials and methods The participants included in the study were adults requiring surgical extraction of an impacted mandibular third molar teeth. A total of 100 participants were randomly assigned to five different groups representing various techniques of IANB, i.e., conventional Halsted technique, Vazirani-Akinosi technique, Gow-Gates technique, Fischer 1-2-3, and extraoral Kurt-Thoma technique, with 20 participants in each group. The participants were evaluated for the onset of anesthesia using subjective and objective methods, pain perception during the administration of local anesthesia using a 10-point visual analogue scale (VAS), and the incidence of trismus postoperatively. Data were analyzed using IBM SPSS Statistics for windows, version 23.0 (released 2015; IBM Corp Armonk, United States) with p-values less than 0.05 considered as statistically significant. Descriptive statistics, Kruskal-Wallis, and post-hoc tests were included in the data analysis for intergroup comparisons. Results The primary outcomes evaluated were the onset of anesthesia, the patient's perception of pain during the administration of local anesthesia, and the secondary outcome included in the incidence of trismus. In this study, it was found that the Kurt-Thoma technique had the fastest onset of anesthesia (2.25 minutes), higher incidence of trismus (25%), and higher pain perception (6.5 score on VAS). The conventional Halstead technique (3.55 minutes), Fischer 1-2-3 technique (3.5 minutes), and Vazirani-Akinosi technique (3.1 minutes) had an almost similar mean duration of anesthesia. The onset of anesthesia was delayed in the Gow-Gates technique (5.1 minutes). Patient perception of pain during administration of local anesthesia was higher in the Kurt-Thoma (6.5) and Gow-Gates techniques (4.95), and it was least in the Fischer 1-2-3 technique (0.75) in the VAS scores. The incidence of trismus was highest with the Kurt-Thoma technique (25%), then the Gow-Gates technique (20%), followed by the conventional Halstead technique (5%).  Conclusion In this study, it was found that the conventional Halsted technique was the best among the different techniques of IANB and remains the gold standard.

The performance of inferior alveolar nerve block technique among undergraduate students

AIMS

This study aimed at evaluating the ability to feel bone touch, positive aspirations, and frequency of the success rate during the direct inferior alveolar nerve block (IANB) among dental students.

METHODS

This prospective cross-sectional study involved 203 cases of IANB injections for patients requiring extraction of mandibular posterior teeth who visited student dental clinics at Ajman University, Fujairah Campus. Students' performance of direct IANB including ability to perceive bone touch, frequency of positive aspirations, and success rate were reported.

RESULTS

Students reported feeling bone contact in 148 (72.9%), 43 (21.2%), and 12 (5.9%) of the first, second, and third attempts during the IANB, respectively. Positive aspiration was found in 46 (22.7%) of the injections. The success was in 195 (96.1%) of the total injections. Spearman's correlation coefficient indicated that there was no significant correlation between the success rate and the result of aspiration (rho = .054, p = .440). Additionally, there was no correlation between attempts to touch the bone and the outcome of the aspiration (rho = -.091, p = .198) or success rate (rho = -.083, p = .240).

CONCLUSION

There is a relatively high success rate of direct IANB technique among dental students. This confirms the inclusion of this technique in the curriculum. Furthermore, the high rate of positive aspiration reflects the awareness and competency of dental students with the aspiration technique. In turn, this will reduce the failure of anaesthesia and the subsequent systemic complications.

Comparison of Clinical Efficacy of Classical Inferior Alveolar Nerve Block and Vazirani-Akinosi Technique in Bilateral Mandibular Premolar Teeth Removal: A Split-Mouth Randomized Study

Purpose

To compare the clinical efficacy of classical inferior alveolar nerve block (CIANB) and Vazirani-Akinosi (VA) injection technique in patients indicated for bilateral mandibular premolar teeth extraction for orthodontic treatment.

Methods

This split-mouth comparative study was conducted on 20 patients randomly selected for bilateral extraction of mandibular premolar indicated for orthodontic treatment to receive CIANB and VA injection technique alternatively. The clinical parameters evaluated were pain during injection, onset of anesthesia, duration of anesthesia, quality of anesthesia, nerve anesthetized with single nerve block, need for re-injection and frequency of positive aspiration.

Results

No statistically significant differences were observed regarding the onset of anesthesia, duration of anesthesia, quality of anesthesia, nerves anesthetized with single nerve block and need for re-injection. However, pain experienced during injection was statistically significant and was lesser in VA technique than CIANB. Positive aspiration was not found in both the injection techniques.

Conclusion

VA technique showed a statistically significant difference in terms of less pain experienced during injection than CIANB. However, though not significant, VA technique was more clinically superior over the CIANB in terms of duration of anesthesia, quality of anesthesia and the need for re-injection. Also in this study, there were no complications associated with any of the injection techniques and the prevalence of positive aspiration was not found in both the techniques.

[Constructions of the scale of difficulty in the extraction of impacted mandibular third molars by using Delphi method]

OBJECTIVE

To evaluate the relevant indicators affecting difficulty in the extraction of impacted mandibular third molars and score difficulty of different operation and risk indicators, so as to build an intuitive and accurate scale to help operators make more accurate analysis and prediction of difficulty before the operation.

METHODS

Based on literature and the clinical review, the difficulty indicators of tooth extraction were summarized. Firstly, 10 doctors from Peking University School and Hospital of Stomatology who had been engaged in alveolar surgery for a long time established an expert nominal group, and then rated whether the summarized indicators needed to be retained in the form of face-to-face questionnaires. A level 1 and 2 item frame for evaluating difficulty in the tooth extraction was formed after discussion; Then Delphi method was used to send a questionnaire to 30 experts by e-mail. After two rounds of scoring and modification, the scale of difficulty in the extraction of impacted mandibular third molars was formed.

RESULTS

The recycling rate of two rounds of questionnaires was 100.0%, which showed that the experts were very enthusiastic about the study; The authority coefficients (Cr) of the two rounds of Delphi expert consultation were both 0.92, which showed that the results were representative and authoritative. After two rounds of grading and revision, the variable coefficient (CV) decreased and the Kendall's concordance coefficient (W) increased, which were statistically significant: In the first round, the CV was 0.24 and W was 0.56 (P < 0.001), and in the second, the CV was 0.19 and W was 0.72 (P < 0.001), which indicated that there was a good convergence among the expert opinions. Finally, a scale of difficulty in the tooth extraction containing 12 items at level A and 37 items at level B was formed, including operation difficulty indicators, risk difficulty indicators and common difficulty indicators.

CONCLUSION

Based on comprehensive literature retrieval, the study has put forward the concept that difficulty in the extraction of impacted mandibular third molars is composed of operation difficulty and risk difficulty. Using Delphi method, the long-term clinical experience and professional knowledge of experts are transformed into quantitative indicators as a scoring scale. The scale has certain representativeness and authority.

[Constructions of the scale of difficulty in the extraction of impacted mandibular third molars by using Delphi method]

OBJECTIVE

To evaluate the relevant indicators affecting difficulty in the extraction of impacted mandibular third molars and score difficulty of different operation and risk indicators, so as to build an intuitive and accurate scale to help operators make more accurate analysis and prediction of difficulty before the operation.

METHODS

Based on literature and the clinical review, the difficulty indicators of tooth extraction were summarized. Firstly, 10 doctors from Peking University School and Hospital of Stomatology who had been engaged in alveolar surgery for a long time established an expert nominal group, and then rated whether the summarized indicators needed to be retained in the form of face-to-face questionnaires. A level 1 and 2 item frame for evaluating difficulty in the tooth extraction was formed after discussion; Then Delphi method was used to send a questionnaire to 30 experts by e-mail. After two rounds of scoring and modification, the scale of difficulty in the extraction of impacted mandibular third molars was formed.

RESULTS

The recycling rate of two rounds of questionnaires was 100.0%, which showed that the experts were very enthusiastic about the study; The authority coefficients (Cr) of the two rounds of Delphi expert consultation were both 0.92, which showed that the results were representative and authoritative. After two rounds of grading and revision, the variable coefficient (CV) decreased and the Kendall's concordance coefficient (W) increased, which were statistically significant: In the first round, the CV was 0.24 and W was 0.56 (P < 0.001), and in the second, the CV was 0.19 and W was 0.72 (P < 0.001), which indicated that there was a good convergence among the expert opinions. Finally, a scale of difficulty in the tooth extraction containing 12 items at level A and 37 items at level B was formed, including operation difficulty indicators, risk difficulty indicators and common difficulty indicators.

CONCLUSION

Based on comprehensive literature retrieval, the study has put forward the concept that difficulty in the extraction of impacted mandibular third molars is composed of operation difficulty and risk difficulty. Using Delphi method, the long-term clinical experience and professional knowledge of experts are transformed into quantitative indicators as a scoring scale. The scale has certain representativeness and authority.

Is it possible to extract lower third molars with infiltration anaesthesia techniques using articaine? A double-blind randomized clinical trial

OBJECTIVE

To compare the efficacy and safety of inferior alveolar nerve blocks (IANB) with additional buccal infiltration (standard technique) and of buccal and lingual anaesthetic infiltration (experimental technique) for lower third molar (L3M) extractions.

STUDY DESIGN

A randomised, double-blind clinical trial involving 129 L3M extractions was conducted. In the IANB group, an IANB was performed using the conventional approach, followed by a buccal injection in the extraction area. In the infiltration group (INF), an infiltration was performed in the buccal and lingual areas of the lower second molar. A 4% articaine solution was employed in all cases. The main outcome variable was anaesthetic efficacy. Other variables like intraoperative and postoperative pain, onset time and adverse events were also recorded. Descriptive and bivariate analyses of the data were made.

RESULTS

120 patients were randomised. The IANB group showed significantly higher anaesthetic efficacy than the INF group (64.4 vs. 45.8%) (odds ratio = 0.47; 95% confidence interval = 0.22-0.97; p = 0.042). No complications were observed.

CONCLUSIONS

IANB with additional buccal infiltration is more suitable than the experimental technique for achieving adequate analgesia in L3M extractions. Moreover, the standard method is safe and provides a shorter onset time and lower initial postoperative pain levels.

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.

Which is the most suitable local anaesthetic when inferior nerve blocks are used for impacted mandibular third molar extraction? A network meta-analysis

The aim of this study was to compare the efficacy and safety of the different local anaesthetic agents for the extraction of impacted lower third molars. A network meta-analysis was performed of all published reports of randomized controlled clinical trials assessing efficacy (anaesthetic success and absence of need for supplementary anaesthesia during the surgical procedure) and/or safety (number of adverse events) of anaesthetic agents. Three electronic databases were searched, from their earliest records up to April 2019. Additionally, the grey literature was searched to identify further potential candidates for inclusion. Anaesthesia had to be delivered by an inferior alveolar nerve block, complemented with infiltration anaesthesia of the buccal nerve. The quality of the studies was assessed using the Cochrane Collaboration tool. This study included a total of 21 trials (2021 molars) assessing the efficacy and 19 trials (1977 molars) assessing the safety of 11 anaesthetic solutions. Seven of the studies included were considered to have a high risk of bias. The most effective local anaesthetic for the extraction of impacted mandibular third molars appeared to be 4% articaine, with significant differences when compared with 2% lidocaine, 0.5% bupivacaine, and 1% ropivacaine. Lidocaine is the safest local anaesthetic, although all investigated solutions can be used safely.

Development of a New Index to Assess the Difficulty Level of Surgical Removal of Impacted Mandibular Third Molars in an Asian Population

PURPOSE

This study aimed to develop a straightforward and accurate index of impacted third molar removal difficulty through analyzing various factors to assess the difficulty level of impacted mandibular third molar (IMTM) extraction.

MATERIALS AND METHODS

This prospective cohort study included 203 patients who required IMTM extraction. All patients were selected using the preset selection criteria. The present study assessed operation difficulty with operating time. A mathematical model and regression analysis were performed to explore 6 main factors (age, number of roots, degree of bone impaction, shape of roots, and impaction angle and its relation). Appropriate correction coefficients were obtained to formulate a new IMTM removal difficulty predictive index. Consistency of the κ value was checked to evaluate performance.

RESULTS

Degree of bone impaction had the highest correlation coefficient (0.576), followed by shape of roots (0.359), and the lowest correlation coefficient was for number of roots. The Pederson index for these 203 patients showed that 75, 76, and 52 patients had low, moderate, and high difficulty levels, respectively, whereas the new index categorized 78, 85, and 40 patients as having low, moderate, and high difficulty. Comparison of the Pederson index and new index with operating time showed κ agreements of 65.30 and 77.9% (P < .01), suggesting that the prediction results of the new index are more objective and accurate.

CONCLUSION

The newly proposed index is straightforward and efficient and exhibited promising results in κ agreement. Because of its straightforward nature, it is better suited for Chinese public hospitals with a large volume of patients who require alveolar surgery. The detection of predictor variables could be useful for graduate students, professionals, and general dental practitioners contemplating IMTM removal to assess the difficulty level of IMTM extraction.

Intense, Instantaneous, and Shooting Pain During Local Anesthesia for Implant Surgery

Administration of local anesthetics is daily routine for most dental practitioners. Normally, the effect is achieved, and no adverse effects are seen. In this article, the authors describe the complications of immediate, intense and shooting pain, numbness, and marked pallor of the cheek, which occurred during infiltration of a local anesthetic in buccal vestibule infiltration. The patients moved suddenly because of pain and marked pallor of the cheek near the root of the nose and lower eyelid pallor was observed. The pain was very short and the injection was performed again after a few minutes. Two patients also reported an alteration of vision or paralysis of the extra-ocular muscles and drooping eyelid due to paralysis of the levator palpebrae superioris muscle and signs of numbness in the infraorbital area on the same side as the anesthesia. While 3 patients were also apprehensive and started to scare with heart palpitations, as they did not understand what was happening. Probably the anesthetic solutions were injected into an intravascular artery and passed from the extraosseous branch of posterior superior alveolar artery through to the infraorbital artery, which could produce the clinical signs observed in the present study. At the same time, the inoculation of anesthetic in the artery could be grounds for legal disputes for the dentist. In fact, in the absence of vascular disease, anomalies documented by the dentist, they would, however, respond to professional liability and be liable for damages caused to the patient. In conclusion, despite the fact that this condition requires no treatment, it could lead to the recognition of clinical signs in patient with injection of local anesthesia into the artery. At the same time, the inoculation of anesthetic in the artery could be grounds for legal disputes for the dentist.

A randomized controlled trial comparing nerve block and mandibular infiltration techniques in posterior mandible implant surgeries

Background

To compare global surgical pain under nerve block and mandibular infiltration anesthesia techniques, and to evaluate pain during drilling and the distance to the mandibular canal in posterior mandible implant surgeries.

Material and Methods

A prospective, randomized, controlled, double-blind, clinical trial was conducted to compare nerve block (Group A) to mandibular infiltration (Group B) techniques for dental implant placement. Global surgical pain (VAS = visual analogue scale), pain during drilling or implant placement (MPQ = McGill pain questionnaire) and distance to the mandibular canal (Image J) were statically analyzed. Age, gender, anxiety levels, tooth to be replaced, implant size, adjacent teeth and duration of surgery were also analyzed.

Results

172 patients were included and 283 dental implants were analyzed. VAS values were significantly higher in Group B (p<0.05). In Group A, 99% of the surgeries were performed painlessly during drilling and implant placement, but in Group B, 11.6% of implant placements (17 implants) felt pain during these surgical steps. Mean distance to mandibular canal (3.8 mm, range: 0.0 to 7.0) in those 17 implants placed under mandibular infiltration was clinically and statistically similar to the mean distance (3.0 mm, range: 0.0 to 9.0) of 130 implants placed painless (p=0.10). Pain during drilling under mandibular infiltration was significantly associated with the duration of surgery (p<0.05) and to both adjacent teeth being present (p<0.05).

Conclusions

Although both techniques are safe and effective for placing implants in the posterior mandible, nerve block provides a more profound analgesia than mandibular infiltration. When placing implants under mandibular infiltration, as getting closer to the canal does not increase the feeling of pain, it is not recommended to use the presence of pain as a preventive resource to avoid inferior alveolar nerve injuries. Key words:Dental implant, mandibular infiltration anesthesia, nerve block, pain, nerve injury.