Local anesthesia in oral and maxillofacial surgery: A review of current opinion

Expediting the reversal of inferior alveolar nerve block anesthesia in children with photobiomodulation therapy

In pediatric dentistry, complications arising from extended soft tissue anesthesia can negatively impact patient comfort and trust in dental care. This study evaluates the clinical efficacy of diode laser-based photobiomodulation therapy (PBMT) in expediting the resolution of anesthesia in children aged 6-9 receiving inferior alveolar nerve block (IANB) injections. In this split-mouth double-blind randomized clinical trial, 36 pediatric subjects aged 6-9, requiring pulpotomy procedures on both sides of the mandible, received IANBs (single cartridge of 2% lidocaine/1:100,000 epinephrine). PBMT and sham laser were alternately applied to each side of the mandible, in two separate sessions, with the envelope method determining treatment allocation and intervention side on the first treatment day. During the laser session, laser (808 nm, 250 mW, 23s continuous, 0.5 cm², 11.5 J/cm², direct contact) irradiated two points at the injection site, five intra-oral and five extra-oral points along the infra-alveolar nerve's pathway. Soft tissue anesthesia reversal was quantified through tactile assessment. Soft tissue trauma was also assessed by the researcher and reported by parents 24 h post-dental visit. All data were analyzed using IBM SPSS Statistics v25.0 via Paired T-test, two-way repeated measures ANOVA, and McNemar's test. The laser group exhibited a mean lip anesthesia duration of 122.78 ± 2.26 min, while the sham laser group experienced 134.44 ± 21.8 min, indicating an 11.66-minute reduction in anesthesia duration for the laser group. (P < 0.001) Soft tissue trauma occurred in two sham laser group patients and one laser group patient, with no significant difference. (P = 1) The findings indicate that employing laser with defined parameters can reduce the length of IANB-induced anesthesia.

Assessing the Efficacy of Buffered Versus Nonbuffered Lidocaine in Dental Extractions: A Double-Blinded Randomized Controlled Trial

BACKGROUND

Injections using buffered lidocaine may decrease discomfort, have a quicker onset, and be a more efficacious local anesthetic. Previous studies have been inconclusive in the oral context.

PURPOSE

To address if bicarbonate buffered 2% lidocaine can decrease pain from the use of local anesthesia, has a quicker onset time, and is more efficacious.

STUDY DESIGN

The design was a single-center double-blinded randomized control trial, set in an outpatient oral and maxillofacial clinic housed in the University of Cincinnati Medical Center. Inclusion criteria for the study were patients requiring a single tooth extraction due either to caries or periodontal disease.

PREDICTOR VARIABLE

The predictor variable was the local anesthetic used either nonbuffered 2% lidocaine with 1:100,000 epinephrine (control) or bicarbonate buffered 2% lidocaine with 1:100,000 epinephrine (study) was randomly assigned.

MAIN OUTCOME VARIABLES

Primary outcome variables were injection pain score, and postoperative pain, time to anesthetic onset, and the number of rounds of injections required to achieve adequate anesthesia.

COVARIATES

The covariates were jaw involved, age, sex, and race, American Society of Anesthesiologists score, body mass index, current tobacco use, history of psychiatric illness, chronic pain, and preoperative pain score.

ANALYSES

Test statistics were calculated using Wilcoxon rank-sum test, Kruskal-Wallis test, Spearman rank correlation test, χ2 test for bivariate analyses, and Fisher's exact test. P values ≤ .05 were considered statistically significant.

RESULTS

The final sample was 114 subjects. The mean age of the sample was 42.97 years, standard deviation ±13.43 years. The sample was 39.47% male. The racial demographics were Caucasian (62.28%) and African American (33.33%). Buffered lidocaine did not have a statistically significant relationship with any of the outcomes. The jaw involved had a statistically significant association to the injection pain score (P value = .006), and the number of rounds of anesthetic required (P value = .047). Age showed a statistically significant association to injection pain score (P value = .032), and the number of rounds of anesthetic required (P value = .027). Finally, preoperative pain had a statistically significant relationship with injection pain score (P value = < .001).

CONCLUSION AND RELEVANCE

In this study, bicarbonate buffered lidocaine did not exhibit any discernible advantages over nonbuffered lidocaine for any study outcomes.

Retrospective Evaluation of the Effects of Local Anesthesia Before Tooth Extraction Procedures under General Anesthesia on Physiologic Parameters and Postoperative Bleeding in Children

BACKGROUND

Studies have been conducted to evaluate changes in hemodynamics, postoperative bleeding, and pain in pediatric dental patients receiving general anesthesia (GA). However, a limited number of studies have evaluated the effects of local anesthetics (LA) on tooth extraction procedures during GA. There is no consensus in the literature regarding LA application in the perioperative period for dental treatments performed within the scope of GA.

AIM

This study aimed to determine the retrospective physiologic effects of fluctuations in vital signs and postoperative bleeding in children who did or did not receive LA for tooth extraction under GA.

METHODS

A retrospective evaluation of 77 patients aged 5.16 ± 1.85 years who had the extraction of primary posterior teeth with or without LA under GA were reviewed in the post-anaesthesia care unit (PACU) for postoperative bleeding and the effects of intraoperative LA on fluctuations in postoperative parameters such as mean arterial pressure (MAP), heart rate (HR), peripheral oxygen saturation (SpO2), respiratory rate (RR), and the end-tidal carbon dioxide (EtCO2). These were compiled from the patient records of the procedures.

RESULTS

Significant differences between the baseline and peak MAP (P < 0.001), HR (P = 0.011), and EtCO2 (P = 0.002) were noted in children without LA compared to those who had LA. In addition, substantial variations were observed between the baseline and peak values for MAP (P < 0.001) and HR (P = 0.037) in children who had tooth extraction in the mandibular region. Statistically significant differences were noted between the baseline and peak values for patients who did not receive LA before the extraction of the first primary molar in terms of MAP (P < 0.02) and EtCO2 (P = 0.032). Similarly, significant differences in MAP (P < 0.02) and EtCO2 (P = 0.034) were noted in the extraction of the second primary molar. In addition, there was a significant difference in bleeding based on the number of tooth extractions in those who did not receive LA (P = 0.020).

CONCLUSION

This study showed that in children who underwent tooth extraction under GA, additional LA application minimized changes in HR, MAP, and EtCO2, whereas a lack of LA application produced significant fluctuations from baseline to peak values of HR, MAP, and EtCO2. In addition, LA application reduced postoperative bleeding.

The effects of Anchusa azurea methanolic extract on burn wound healing: Histological, antioxidant, and anti-inflammatory evaluation

Anchusa azurea one of the medicinal plants that has been traditionally used for treat burn wounds. However, the traditional claim that A.azurea can hasten burn wound healing has not been supported by scientific studies. This experiment used a male Wistar rats model to investigate the activity of A. azurea aerial parts methanolic extract in burn wound healing. To determine their ability to help in healing burn wounds in rat models, the active components of the aerial parts of A. azurea were extracted with 80% methanol, then, 1% and 10% ointments were prepared from the extract, and applied topically. The LCMS chromatography of A. azurea plant extract showed different active ingredients, including phenolic compounds, flavonoids, fatty acids, and others. The plant extract's investigated as anti-inflammatory, antioxidant, and histological effects on the burn wound healing process. The results showed a significant (p-value < 0.025) rate of burn wound healing with 78.6% and 84.8% contraction, respectively using 1% and 10% (w/w) extract ointments after 12 days. These results were corroborated by histological observations such as collagen deposition, re-epithelialization, and repair of the remaining skin tissues without any sign of cutaneous toxicity. The plant extract showed significant (p-value < 0.025) antioxidant effect at the highest tested dose of 500 µg/mL, scavenging 89.78% of the DPPH with an IC50 of 213.6 µg/mL. These results confirmed by histological changes observations of collagen deposition, re-epithelialization, and reformation of remaining skin tissues without any signs of dermal toxicity. The plant extract exhibited significant (p-value < 0.025) level of antioxidant agents, by scavenging 89.78% of the DPPH at 500 µg/mL with IC50 of 213.6 µg/mL. Additionally, all pro-inflammatory cytokines examined, including IL-6 and IL-10, the results exhibited reduction in IL-6 level and increase IL-10 level. The aerial extract of the A. azurea plant revealed a wealth of several significant active ingredients, including phenolic compounds, flavonoids, fatty acids, and others, suggesting the potential for anti-inflammatory, burn wound-healing, and antioxidant medications. These findings can open an avenue to find new therapeutics for burn wounds healing, anti-inflammatory and antioxidant properties.

Ultrasound-Guided Suprazygomatic Maxillary Nerve Block Is Effective in Reducing Postoperative Opioid Use Following Bimaxillary Osteotomy

BACKGROUND

Ultrasound-guided maxillary nerve block has recently been described, though its impact upon bimaxillary osteotomy has not been formally investigated.

PURPOSE

The present study was carried out to determine whether the addition of ultrasound-guided maxillary nerve block in subjects undergoing bimaxillary osteotomy reduces opioid use.

STUDY DESIGN, SETTING, SAMPLE

A randomized clinical trial was carried out in adults undergoing bimaxillary osteotomy between April 2019 and January 2020 at Teknon Medical Center (Barcelona, Spain).

PREDICTOR VARIABLE

The predictor variable was the treatment technique used (maxillary nerve block or no block). The subjects were randomized to either receive (test group) or not receive (control group) bilateral ultrasound-guided suprazygomatic maxillary nerve block (5 ml of 0.37% ropivacaine) before surgery.

MAIN OUTCOME VARIABLE(S)

The primary outcome variable was the intravenous methadone requirements in the first two postoperative hours. The secondary outcome variables were postoperative pain, rescue subcutaneous methadone, intravenous remifentanil used intraoperatively, the incidence of postoperative nausea-vomiting, and complications derived from maxillary nerve block.

COVARIATES

Subject age, sex, weight, height, and anesthetic risk, and the duration of surgery were recorded.

ANALYSES

Descriptive and inferential analyses were performed using the χ2 test and Mann-Whitney U test. Statistical significance was considered for P < .05.

RESULTS

The baseline sample consisted of 68 subjects scheduled for bimaxillary osteotomy. The follow-up sample comprised 60 subjects: 30 in the control group (10 females and 20 males, aged 34.0 ± 10.2 years) and 30 in the test group (13 females and 17 males, aged 29.8 ± 10.8 years). The subjects who received maxillary nerve block showed less intravenous methadone use in the first 2 hours postsurgery (median 2.0 mg control group vs 0 mg test group; P < .001), lower pain levels at any time during the first 18 hours postsurgery (median visual analog score 4 control group vs 2 test group; P < .001), and a lesser percentage required methadone (33.3% control group vs 0% test group; P < .01) at 4-18 hours postsurgery.

CONCLUSION AND RELEVANCE

The results obtained suggest that ultrasound-guided maxillary nerve block is a promising anesthetic technique capable of reducing intraoperative and postoperative opioid use, with greater patient comfort in bimaxillary osteotomy.

Rapid production of the anaesthetic mepivacaine through continuous, portable technology

Local anaesthetics such as mepivacaine are key molecules in the medical sector, so ensuring their supply chain is crucial for every health care system. Rapid production of mepivacaine from readily available commercial reagents and (non-dry) solvents under safe conditions using portable, continuous apparatus could make an impactful difference in underdeveloped countries. In this work, we report a continuous platform for synthesising mepivacaine, one of the most widely used anaesthetics for minor surgeries. With a focus on sustainability, reaction efficiency and seamless implementation, this platform afforded the drug in 44% isolated yield following a concomitant distillation-crystallisation on a gram scale after N-functionalisation and amide coupling, with full recovery of the solvents and excess reagents. The use of flow chemistry as an enabling tool allowed the use of "forbidden" chemistry which is typically challenging for preparative and large scale reactions in batch mode. Overall, this continuous platform presents a promising and sustainable approach that has the potential to meet the demands of the healthcare industry.

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.

Structurally compromised teeth. Part II: A novel approach to peripheral build up procedures

OBJECTIVE

To introduce the "Peripheral Build-Up technique - PBUt" as a foundation restoration strategy for structurally compromised teeth (SCT).

CLINICAL CONSIDERATIONS

Several strategies have been proposed over time (cervical marginal relocation, doughnut, and preformed ring techniques) to enable the management of restorative procedures in challenging situations such as the presence of deep subgingival defects. The PBUt is a versatile, completely additive direct technique that share some strategical concepts with these techniques to approach critical clinical situations while supplying a wider field of application thanks to distinct operative expedients. The clamp insertion modality, the extension of the proximal wall and the matrix customization/stabilization strategies adopted in PBUt endorse the possibility to manage the most apical and peripheral border of the residual tooth structure when located up to >1.5 mm above the bone crest. The periodontal response has to be then monitored over time. Moreover, thanks to the peripheral and apically-extended addictive approach, it allows a massive preservation of residual sound tooth structure and improves the resistance and retentive physical/geometrical features of the abutment tooth. The PBUt operative workflow is herein explained.

CLINICAL SIGNIFICANCE

The Peripheral-Build-Up technique (PBUt) advocates some innovative clinical restorative steps for the management of SCT with coronal and deep subgingival defects.

Inflammatory signal transduction pathways induced by prilocaine toxicity in cultured ARPE-19 cells

Prilocaine (PRL) is a common local anesthetic. Despite the successful use of regional anesthesia for intraocular surgery, there are associated side effects that may affect the retina in case of accidental intravitreal injection. This study examined the signal transduction pathways activated by PRL toxicity and determined the protective role of nitric oxide synthase-2 (NOS2) inhibition in cultured human-derived retinal pigment epithelial cells (ARPE-19). Toxicity analysis was performed using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay to detect the toxic dose of PRL and protective effectiveness of asperglaucide (ASP), an NOS2 inhibitor. Nuclear factor kappa B p65 (NF-κB p65), phosphorylated NF-κB p65, phospho-protein kinase B (AKT), NOS2, nitrotyrosine, and cleaved caspase-3 protein levels were evaluated by immunofluorescence staining and/or western blot analysis. Interleukin-6 (IL-6) and nitrated protein levels were quantified using an immunoassay, whereas caspase-3 activity and nitrite/nitrate levels were measured using a fluorometric method. A significant increase in NF-κB p65, and phosphorylated NF-κB p65 and AKT levels due to PRL toxicity was observed. Similarly, IL-6, NOS2, nitrite/nitrate, and nitrotyrosine levels were significantly higher in PRL-treated cells than in control cells. Application of ASP to PRL-treated cells reduced NF-κB p65, and phosphorylated NF-κB p65 and AKT to basal levels. IL-6, NOS2, nitrite/nitrate, and nitrotyrosine levels also considerably decreased following ASP treatment in cells experiencing PRL-induced toxicity. Moreover, the caspase-3-dependent apoptotic pathway was not activated. Our results indicate that ASP could ameliorate PRL-induced activation of NF-κB p65 that led to inflammation in cultured ARPE-19 cells.

Additional pre-extubation local anaesthetic application to improve the postoperative course in orthognathic surgery: a randomised controlled trial

A clinical trial was performed to assess the analgesic efficacy of adding ropivacaine pre-extubation for pain management after bimaxillary osteotomy. Forty-eight patients were assigned to receive general anaesthesia followed by either a single pre-incisional infiltration with lidocaine (control group, n = 24) or the same pre-incisional infiltration with lidocaine and an additional second infiltration with ropivacaine before awakening (test group, n = 24). Postoperative pain was assessed subjectively using a visual analogue scale and objectively based on the frequency of postoperative rescue opioid consumption. The dose of opioids (methadone) consumed and frequency of postoperative-nausea-vomiting were also recorded. Patients who received the two infiltrations of local anaesthetic had better results in terms of lesser pain during the first 8 hours postoperative (P<0.001 at 2 and 4 hours; P = 0.028 at 8 h), a lesser need for rescue opioids (P = 0.020) and lower doses of rescue opioids (P = 0.011), and consequently a lesser incidence of postoperative-nausea-vomiting (0-4 hours postoperative, P<0.03). The results obtained suggest that the infiltration of an additional dose of local anaesthetic is a simple strategy for reducing pain perception and opioid use, and for ensuring greater patient comfort after bimaxillary osteotomy.

Paresthesia in dentistry: The ignored neurotoxicity of local anesthetics

Local anesthetics are frequently used by dentists to relieve localized discomfort of the patient and improve treatment conditions. The risk of paresthesia after local anesthesia is frequently encountered in dental clinics. The neurotoxicity of local anesthetics is a disregarded factor in paresthesia. The review summarizes the types of common local anesthetics, incidence and influencing factors of paresthesia after local anesthesia, and systematically describes the neurotoxicity mechanisms of dental local anesthetic. Innovative strategies may be developed to lessen the neurotoxicity and prevent paresthesia following local anesthesia with the support of a substantial understanding of paresthesia and neurotoxicity.

Physiology of pregnancy and oral local anesthesia considerations

Background

Safe and effective local anesthesia is a prerequisite for emergency oral surgeries and most dental treatments. Pregnancy is characterized by complex physiological changes, and increased sensitivity to pain. Pregnant women are particularly vulnerable to oral diseases, such as caries, gingivitis, pyogenic granuloma and third molar pericoronitis. Maternally administered drugs can affect the fetus through the placenta. Therefore, many physicians and patients are reluctant to provide or accept necessary local anesthesia, which leads to delays in the condition and adverse consequences. This review is intended to comprehensively discuss the instructions for local anesthesia in the oral treatment of pregnant patients.

Methodology

An in-depth search on Medline, Embase, and the Cochrane Library was performed to review articles concerned with maternal and fetal physiology, local anesthetic pharmacology, and their applications for oral treatment.

Results

Standard oral local anesthesia is safe throughout the pregnancy. At present, 2% lidocaine with 1:200,000 epinephrine is considered to be the anesthetic agent that best balances safety and efficacy for pregnant women. Maternal and fetal considerations must be taken into account to accommodate the physiological and pharmacological changes in the gestation period. Semi-supine position, blood pressure monitoring, and reassurance are suggested for high-risk mothers to reduce the risk of transient changes in blood pressure, hypoxemia, and hypoglycemia. For patients with underlying diseases, such as eclampsia, hypertension, hypotension, and gestational diabetes, the physicians should use epinephrine cautiously and control the dose of anesthetic. New local anesthesia formulations and equipment, which contribute to minimizing injection pain and relieving the anxiety, have and are being developed but remain understudied.

Conclusions

Understanding the physiological and pharmacological changes during pregnancy is essential to ensure the safety and efficiency of local anesthesia. Optimal outcomes for the mother and fetus hinge on a robust understanding of the physiologic alterations and the appropriate selection of anesthetic drugs and approaches.

Comparison of the anesthetic effect of alkalized lidocaine versus non-alkalized lidocaine administered at a slow rate in mandibular primary molars

Background

There are several invasive dental procedures that require local anesthetics. However, its infiltration is usually associated with anxiety and fear, increasing the perception of pain in pediatric patients. For this reason, it is important to evaluate different strategies for its application. We compared the anesthetic effect of the administration of 2% lidocaine with epinephrine 1:80000 non-alkalized at slow speed and alkalized at fast speed to block the inferior alveolar nerve in deciduous molars.

Methods

A crossover clinical trial was carried out whose sample consisted of 38 patients between 6-10 years who required bilateral pulp treatment in their first mandibular primary molars. At the first appointment, they received 2% lidocaine with 1:80000 alkalinized epinephrine administered at a fast rate, and at the second appointment, 2% lidocaine with 1:80000 non-alkalized epinephrine administered at a low speed. We evaluated the onset of action, duration of the anesthetic effect, and intensity of pain during its infiltration.

Results

We found that non-alkalized lidocaine at slow speed had a shorter onset time of action (57.21±22.21 seconds) and longer duration of effect (170.82±43.75 minutes) compared to administration of alkalinized lidocaine at fast speed (74.03±22.09 seconds, 148.24±36.24 minutes, respectively). There was no difference in the level of pain intensity.

Conclusion

In this study, the slow administration of the non-alkalized local anesthetic showed a shorter onset time of action and a longer duration of the anesthetic effect in comparison with the alkalized local anesthetic administered at a rapid rate in the blockade of the inferior alveolar nerve in deciduous molars.

Pain perception following computer-controlled versus conventional dental anesthesia: randomized controlled trial

Background

The administration of local anesthesia (LA) in dental practice requires an injection which is the leading cause of patients’ fear and anxiety. Computer-controlled local anesthetic injector, designed to reduce the pain of performing local anesthesia by controlling the speed of injection. This single-blind randomised control trial aimed to compare the pain perception after computer-controlled local anesthesia (CCLA) and conventional LA.

Methods

Dental students were both test and operator group versus an experienced dentist as additional operator of the LA. Data were collected regarding gender, age, medical condition, smoking habits. Additionally, operator feedback about the handling, pain at insertion and during infiltration, excitement (Dental Anxiety Scale), and complications were assessed.

Results

Out of the 60 included participants, the majority were females (n = 41; 68.3%), medically healthy (n = 54; 90%), and did not receive medications (n = 54; 90%). While the participating students administered 62 (51.7%) injections, the experienced dentist administered 58 (48.3%) injections. The difference in pain perception on puncture between CCLA and conventional injections was not statistically significant (Sig. = 0.285); however, pain perception during injection was significantly different (Sig. = 0.029) between CCLA (1.65 ± 1.93) and conventional injections (2.49 ± 2.31).

Conclusion

The professional experience influenced the pain perception while applying the LA. CCLA did not reduce pain on puncture significantly; however, pain perception during the injection was significantly reduced in the case of using CCLA devices compared to the conventional syringe.

A Comparative Study on Sedation Efficacy Between General and Regional Anesthesia with Dexmedetomidine in Patients Under Maxillofacial Surgery

BACKGROUND AND OBJECTIVE

Securing the airway in the surgery of maxillofacial disorders and traumas is fundamental during the operation. The present study aims to investigate the beneficial sedative effects of dexmedetomidine (DEX) in patients who underwent maxillofacial surgery with regional anesthesia compared to general anesthesia.

METHODS

Fifty patients, aged 20-45 years old were randomly divided into two groups of regional anesthesia (RA) and general anesthesia (GA) (each n=25). The group RA received regional block with sedation (DEX: 1 μg/kg infused over 10 min followed by the maintenance dose of 0.5 μg/kg/h) and the group GA underwent general anesthesia (DEX: 0.1 μg/kg/min over 10 min followed by 0.4-0.7 μg/kg/h). Postoperative pain scores, anesthesia outcomes, hemodynamic parameters, the time of the post-anesthesia care unit (PACU) discharge and intra and postoperative complications were comparatively assessed in both groups.

RESULTS

The baseline characteristics of the patients (age, gender, BMI, and ASA physical status) showed no differences between the two groups (P>0.05). Although the duration of surgery and recovery time showed no differences between the groups, the duration of anesthesia and extubation time was remarkably lower in the RA group than in the GA group (P<0.01). Administration of nerve blocks demonstrated less pain and longer sleep time in the postoperative phase as compared to the GA group. Heart rate and mean arterial blood pressure were significantly less in the RA group at the end of the loading dose of DEX and incision time (P<0.05). SpO2, respiration rate and Ramsay sedation scale did not exhibit any significant differences between the two groups at all-time points (P>0.05). No significant differences were observed with regard to the adverse events between the two groups (P>0.05).

CONCLUSIONS

Although our findings revealed that both methods are suitable and safe methods for maxillofacial surgery, the outcomes of anesthesia with regional block and sedation include less pain in the postoperative phase, shorter extubation time and earlier discharge from the PACU demonstrated that this method is more reliable for maxillofacial surgery. Further controlled studies are needed to compare the effectiveness and safety profiles of two RA and GA techniques and also to compare DEX with other anesthetic agents to achieve optimum outcomes in maxillofacial surgeries.

Comparative Preclinical Study of Lidocaine and Mepivacaine in Resilient Hyaluronic Acid Fillers

Background: Hyaluronic acid-based filler injections are now well-established aesthetic procedures for the correction of skin tissue defects and volume loss. Filler injections are becoming increasingly popular, with a growing number of injections performed each year. Although classified as a minimally invasive procedure, the introduction of a needle or a canula may remain painful for the patient. A major improvement was achieved with the incorporation of local anesthetics into the formulation for pain relief. Methods: In this study, two well-known anesthetics, lidocaine and mepivacaine, were systematically compared to assess their influence on filler mechanical and biological features. The impact of each anesthetic was monitored in terms of gel rheological properties, stability, durability, and degradation. The release profiles of each anesthetic were also recorded. Finally, the pharmacokinetics of each anesthetic in rats were assessed. Results: For all the rheological and biological experiments performed, lidocaine and mepivacaine influences were comparable. The addition of either anesthetic into a soft-tissue filler showed no significant modifications of the stability, durability, and degradability of the gel, with similar release profiles and pharmacokinetics at an equivalent concentration. Conclusions: Substituting lidocaine with mepivacaine does not impact the properties of the gels, and thus both can be equally incorporated as anesthetics in soft-tissue fillers.

Photocatalytic degradation of pharmaceuticals by pore-structured graphitic carbon nitride with carbon vacancy in water: Identification of intermediate degradants and effects of active species

Pharmaceuticals are increasingly used in daily life and have been massively discharged to the aquatic environment. The removal of pharmaceuticals from water by various nanomaterials including graphitic carbon nitride (g-C₃N₄) has received extensive attention. Herein, we synthesized a carbon-defective carbon nitride with pore structure through a simple thermal polymerization method for photodegradation of lidocaine, mepivacaine and ropivacaine (typical amide local anesthetics). The results showed that the degradation process conformed to the pseudo-first-order reaction kinetics, and the degradation rate constant of organic pollutants using CCN-600 (i.e., g-C₃N₄ synthesized at 600 °C) reached 5.05 × 10^-2 min^-1, about 2.5 times higher than that of the prototype g-C₃N₄ (2.09 × 10^-2 min^-1). The capture experiment of active species and the electron paramagnetic resonance (EPR) test demonstrated that superoxide radical (O₂^-) played a major role in the degradation process. Based on the possible photodegraded intermediate products identified, the degradation pathways were deduced. This study provides not only a new strategy for fabrication of pore-structured g-C₃N₄ with carbon vacancy, but also a reference method for the treatment of pharmaceuticals in water bodies.

Design of hydroxy-α-sanshool loaded nanostructured lipid carriers as a potential local anesthetic

Hydroxy-α-sanshool (HAS), extracted from Zanthoxylum piperitum, is commonly used in oral surgery to relief pain. However, the application of HAS is limited in clinical practice due to its poor stability. This study focuses on the design of a novel nano-formulation delivery system for HAS to improve its stability and local anesthetic effect. Hydroxy-α-sanshool loaded nanostructured lipid carriers (HAS-NLCs) were prepared by melting emulsification and ultra-sonication using monostearate (GMS) and oleic acid (OA) as lipid carriers, and poloxamer-188 (F68) as a stabilizer. Besides, the formulation was optimized by response surface methodology (RSM). Then, the best formulation was characterized for particle size, polydispersity index (PDI), zeta potential, entrapment efficiency (EE%), drug loading (DL%), differential scanning calorimetry (DSC), and morphology (transmission electron microscopy, TEM). The obtained HAS-NLCs were homogeneous, near spherical particles with high DL% capacity. The stability of HAS-NLCs against oxygen, light, and heat was greatly improved over 10.79 times, 3.25 times, and 2.09 times, respectively, compared to free HAS. In addition, HAS-NLCs could exhibit sustained release in 24 h following a double-phase kinetics model in vitro release study. Finally, HAS-NLCs had excellent anesthetic effect at low dose in formalin test compared with free HAS and lidocaine, which indicated HAS-NLCs were a potential local anesthesia formulation in practice.

A Systematic Review on Nerve-Related Adverse Effects following Mandibular Nerve Block Anesthesia

Inferior alveolar nerve (IAN) block injections are commonly used in clinical practice, but they are not free from complications. The aim of the present systematic review is to assess the nerve-related adverse effects of IAN block anesthesia. A structured and systematic search was performed on the major electronic databases (PubMed, Cochrane Library, Web of Science, Scopus and CINAHL) for studies published in English until 30 September 2021. A total of 131 articles were identified through database searching using combinations of keywords. Fifteen papers were included and assessed for eligibility. Overall, nerve damage following an IAN block anesthesia injection is a rare occurrence, probably due to the direct nerve trauma of the needle, a neurotoxic effect of the used anesthetic solution and/or a combination of them. From a medico-legal point of view, a balanced discussion prior to nerve block anesthesia should be pursued in order to avoid patients' reluctance to undergo necessary dental treatment due to the remote eventuality of nerve injury.