1.A Novel Method Of Inferior Alveolar Nerve Block Anesthesia And Its Anesthetic Effect 2.Preemptive Analgesia In Mandibular Third Molar Extractions

Part I A novel method of inferior alveolar nerve block anesthesia and its anesthetic effectBackground: Inferior alveolar nerve block(IANB)is one of the most important techniques in clinical treatment.Due to anatomical differences,the success rate of inferior alveolar nerve(IAN)block anesthesia is low in some patients.In recent years,with the development of anatomy,neurophysiology,immunology,pharmacology and other disciplines,the technique of inferior alveolar nerve block anesthesia has also been developed significantly.In terms of anatomy,domestic and foreign experts have conducted in-depth studies on the anatomical structure of the mandibular nerve canal through imaging techniques such as cone beam computed tomography(CBCT)and magnetic resonance imaging(MRI),so as to better understand the anesthesia of the inferior alveolar nerve block can be performed more accurately.The experimental research of neurophysiology has also been used to study the conduction mechanism of the inferior alveolar nerve and to better understand the signal transmission process of the nerve in order to improve the success rate of inferior alveolar nerve block anesthesia.In addition,different types of anesthetic drugs and their mechanisms of action were studied,and the safety of different types of anesthetic drugs in inferior alveolar nerve block anesthesia was investigated,so that the implementation of inferior alveolar nerve block anesthesia could be better mastered and the incidence of anesthetic complications could be effectively reduced.In conclusion,this study proposes a new method of inferior alveolar nerve block anesthesia basing the mandibular second molar.Objective: The purpose of this study was to obtain anatomic data related to inferior alveolar nerve block through imaging analysis,and to compare the anesthetic effects of the new method and the conventional method of inferior alveolar nerve block anesthesia.Methods: 1.Data from 30 CBCT images taken at the CT laboratory of Lishui College in 2018 were selected for the study.The CBCT data were imported into3 DSlicer 4.13.0 software to create a 3D model of the mandible(voxel size: 0.2 mm,slice thickness: 0.2 mm).The horizontal distance from the distal mesiobuccal cusp of the mandibular second molar to the mandibular lingula was measured using a line tool.And this horizontal distance was used as the reference distance for needle insertion in the new method.2.A total of 131 dentistry students from the class of 2020 Lishui College of Dentistry were included in the study.The conventional method and the new method were used to perform inferior alveolar nerve block anesthesia in the mandible bilaterally,and the success rate of anesthesia,the onset time of anesthesia,the duration of anesthesia and the rate of positive aspiration were compared.The t-test was used for the enumeration data,and the χ2 or Fisher exact test was used for the measurement data.A value of p<0.05 was considered to indicate statistical significance.Results: The mean horizontal distance from the distal mesiobuccal cusp of the mandibular second molar to the mandibular lingula was 29.98 ± 3.11 mm,31.45 ±2.92 mm in men and 28.50 ± 2.62 mm in women.the success rate of anesthesia by the conventional method was 86.3%(113/131)and by the new method was 86.3%(113/131).The anesthesia onset time was 3.4±2.4 min for the conventional method and2.9±2.6 min for the new method(p=0.13).The duration of anesthesia was 119.7±47.4min for the conventional method and 121.7±54.4 min for the new method(p=0.77).There were 3 positive cases of retraction in the conventional method and 1 positive case of retraction in the new method.There were no hematomas,restricted mouth opening,tinnitus,temporary facial paralysis or other anesthetic complications in all cases.There were no significant differences between the new method and the conventional method in terms of anesthesia success rate,anesthesia onset time,anesthesia duration,and positive retraction rate.Conclusion:This novel method of inferior alveolar nerve block anesthesia with the mandibular second molar as the landmark has the characteristics of obvious and stable anatomical landmark,not affected by the patient’s mouth opening degree,easy to learn,and the anesthetic efficiency is not inferior to the traditional method.This novel method can be used as the main anesthesia method for patients with difficult mouth opening and as an alternative method when inferior alveolar nerve block anesthesia fails,and deserves further study.Part II preemptive analgesia in mandibular third molar extractionBackground :With the development of economy and civilization,the food in people’s daily life has become more refined.With the degeneration of masticatory organs,the number of patients with obstructed mandibular third molars is increasing.As a result,extraction of mandibular obstructed third molars has become one of the most commonly performed procedures in clinical practice.During the preoperative and intraoperative period,the patient’s fear mainly comes from the intraoperative pain and postoperative complications.Preemptive analgesia(PA),as a preventive measure,has been shown to be effective in reducing postoperative pain.Currently,preemptive analgesia is used in all aspects of clinical care.However,its application,dosage and duration of use are still controversial.Objective: To investigate the value of preemptive analgesia in the clinical management of maxillofacial surgery by observing the degree of postoperative swelling and pain in patients undergoing extraction of mandibular third molar with immediate postoperative injection of a mixture of dexamethasone and lidocaine.Methods: Five patients requesting extraction of mandibular obstructed third molars were included in the study,and all of the obstructed third molars were horizontally obstructed on preoperative imaging.All of these patients required extraction of the mandibular obstructed third molar after incision and flap debridement.A mixture of dexamethasone and lidocaine was injected 1.5 m L immediately after the completion of the extraction of the mandibular obstructed third molar,and the degree of postoperative swelling and pain was recorded.Results: The maximum swelling of the patients was 1.1 cm at 48 h postoperatively,and the maximum pain score was 7 at 7 days,which were within the acceptable range.No postoperative complications such as infection and numbness occurred after the extraction.Conclusion: Local injection of a mixture of dexamethasone and lidocaine after extraction of complex obstructive mandibular third molar can effectively reduce postoperative complications such as swelling,pain,and mouth opening restriction,and is worthy of clinical promotion and application.