Evaluation of ultrasound-guided suprazygomatic maxillary nerve block in functional endoscopic sinus surgery for postoperative pain relief: A randomised controlled trial.

Background and Aims: Postoperative pain can impede functional recovery and delay hospital discharge after functional endoscopic sinus surgery (FESS). The study aimed to assess the efficacy of ultrasound (USG)-guided suprazygomatic maxillary nerve block (SZMNB) for postoperative pain in FESS. Methods: Forty-eight adult patients between 18 and 65 years of age with American Society of Anesthesiologists physical status I and II and scheduled to undergo FESS were enroled in this randomised controlled study. Patients were randomly allocated to either receive USG-guided SZMNB with general anaesthesia (n = 24) or general anaesthesia alone (n = 24). The numerical rating scale (NRS) pain score in the immediate postoperative period was recorded as the primary outcome. A total of 24 h postoperative rescue analgesic consumption, surgeon satisfaction score, postoperative haemodynamics, and postoperative complications were noted as secondary outcomes. Results: The median (interquartile range) of the NRS pain score in the immediate postoperative period was 0 (0-0.25)[95% confidence interval (CI): 0, 0.08] in the block group compared to 2 (1.75-3) [95% CI: 1.60, 2.40] in the control group, P < 0.001]. Pain scores were significantly reduced at all time intervals till 24 h after surgery (P < 0.001). None of the patients required rescue analgesia in the block group. In contrast, eight patients required diclofenac 75 mg intravenous as rescue analgesia within 1 h of surgery and ten patients within 1-6 h of surgery in the control group. Other secondary outcomes were comparable between groups (P > 0.05). Conclusion: The USG-guided SZMNB provides excellent postoperative analgesia for patients undergoing FESS without significant side effects.

Effectiveness and Distribution of Anesthesia for a Modified Extra Oral Maxillo-Mandibular Nerve Block for Dento-Alveolar Procedures: A Prospective Cohort Study.

Aim: To evaluate the effectiveness of a modified maxillo-mandibular nerve block technique that includes anesthetizing the maxillary and mandibular nerve with single injection. Materials and Methods: A prospective, clinical cohort study was carried out including patients who presented for surgical removal of maxillary and mandibular third molars. All patients were administered maxilla-mandibular nerve block through a single injection on one side. Three clinical neurosensory tests were used for mapping the area of anesthesia and to assess and grade objectively the effect of the block. Light touch (LT), two-point discrimination (TPD), pin prick (PP) and Electric pulp testing (EPT) were used for all branches of maxillary and mandibular nerve. An extra oral mapping chart for depth of anesthesia was maintained for each patient to categorize the grades as nil, intermediate and highly anesthetized areas. Results: 62 patients were assessed in the study. EPT showed greater depth of pulpal anesthesia in posterior teeth than the anterior in both maxilla and mandible. PP and TPD tests also showed that the anesthetic effect varied between posterior divisions demonstrating extreme anesthesia compared to the anterior divisions. Conclusion: This technique was found to be successful for surgical extractions involving the maxillary and mandibular regions. Supplementary Information: The online version contains supplementary material available at 10.1007/s12663-022-01755-w.

Ultrasound-Guided Maxillary Nerve Block and Superficial Cervical Plexus Block During Surgery for Maxillary Malignancy: A Case Report.

We report a case of ultrasound-guided craniocervical nerve blocks performed with ropivacaine for perioperative local/regional anesthesia in a patient who underwent right partial maxillary resection and neck dissection under general anesthesia. The patient was an 85-year-old woman with multiple medical comorbidities in whom analgesia using nonsteroidal anti-inflammatory drugs and opioids was expected to increase the risk of postoperative complications. Bilateral ultrasound-guided maxillary (V2) nerve blocks and a right superficial cervical plexus block were performed, which provided adequate perioperative anesthesia and avoided postoperative complications. The use of ultrasound-guided craniocervical nerve blocks with ropivacaine can be an effective approach for providing prolonged perioperative local anesthesia and analgesia, minimizing the need for other potentially problematic analgesics.

Evaluation of Three Methods of Sensory Function Testing for the Assessment of Successful Maxillary Nerve Blockade in Horses.

Maxillary nerve blocks (MNBs) commonly facilitate dental surgeries in standing horses. The goal of this prospective, blinded, cross-over design trial including 15 client-owned horses was to evaluate 3 methods of sensory function testing for confirming a successful MNB. Testing was performed bilaterally before sedation, 5 min after sedation, and 15 and 30 min after MNB with 0.5% bupivacaine and involved a needle prick dorsal to each naris, hemostat clamping of each nostril, and gingival algometry (measuring sensitivity to pain). Responses to stimulation were numerically scored and scores were summed up to a total score. Total score increases on the blocked side by ≥ 2 between baseline and 30 min Post MNB recordings signified a successful MNB. Sedation in the preceding 6 h, presence of sino-nasal disease, side of dental pathology, age, butorphanol administration, and detomidine dosing (µg/kg/min) throughout the tooth extraction procedure were recorded. In 73% of horses, MNB was successful. Sedation in the preceding 6 h (P = .732), age (P = .936), side of pathology (P = .516), and sino-nasal disease (P = .769) were not associated with total scores. Detomidine dosage and butorphanol use did not differ between horses in which the MNB was considered successful and for those in which it was not (P = .967 and P = .538, respectively). Scores obtained with gingival algometry were less closely associated with total scores (rho = .649) than those obtained with needle prick and nostril clamping (rho = .819 and .892, respectively). Therefore, needle prick and nostril clamping are considered the more reliable methods for use in clinical practice to determine the success of an MNB.

Morphometric study of incisive, greater and lesser palatine foramina: a novel point of maxillary nerve block in a Thai population / Estudio morfométrico del foramen palatino incisivo, mayor y menor: un punto novedoso de bloqueo del nervio maxilar en una población tailandesa

SUMMARY: To study the morphometric location of the incisive, greater, and lesser palatine foramina for maxillary nerve block. Two hundred Thai dry skulls were randomly organized from the Forensic Osteology Research Center. The distances of the parameters were measured via Vernier caliper.: Thedistances from the incisive foramen to the incisive margin of the premaxilla were 10.93?2.42 mm in males and 10.98?2.06 mm in females. From the left side, the incisive foramen to the greater palatine foramen (GPF) was39.07?2.23mm in males and 38.57?2.41 mm in females, and from the right side were 39.81?2.37 mm in males and 38.62?2.53mm in females. From the left side, the incisive foramen to the lesser palatine foramen (LPF) was 43.16?2.23 mm in males and 41.84?2.42mm in females and from the right side were 42.93?2.14 mm in males and 41.76?2.61 mm in females. The GPF found at medial to the maxillary third molar were 94-95 % in males and 84 % in females. These findings suggest that the medial position to the third molar teeth be used as a landmark for a palatine nerve block in Thais. These findings will help dentists to perform local anesthetic procedures, especially the nasopalatine and greater palatine nerve blocks, more effectively.

RESUMEN: El objetivo de este trabajo fue estudiar la localización morfométrica de los forámenes palatinos incisivos, mayores y menores para el bloqueo del nervio maxilar. Se organizaron al azar doscientos cráneos secos tailandeses del Centro de Investigación de Osteología Forense. Las distancias de los parámetros se midieron mediante un calibre Vernier. Las distancias desde el foramen incisivo hasta el margen incisivo de la premaxila fueron 10,93 ? 2,42 mm en hombres y 10,98 ? 2,06 mm en mujeres. Desde el lado izquierdo, el foramen incisivo al foramen palatino mayor (FPM) fue de 39,07 ? 2,23 mm en los hombres y 38,57 ? 2,41 mm en las mujeres, y del lado derecho fue de 39,81 ? 2,37 mm en los hombres y 38,62 ? 2,53 mm en las mujeres. Del lado izquierdo, el foramen incisivo al foramen palatino menor (LPF) fue de 43,16 ? 2,23 mm en hombres y 41,84 ? 2,42 mm en mujeres y del lado derecho 42,93 ? 2,14 mm en hombres y 41,76 ? 2,61 mm en mujeres. El FPM encontrado medial al tercer molar maxilar fue 94-95 % en hombres y 84 % en mujeres. Estos hallazgos sugieren que la posición medial de los terceros molares se utilice como punto de referencia para un bloqueo del nervio palatino en individuos tailandeses. Estos hallazgos ayudarán, de manera más eficaz, a los dentistas a realizar procedimientos anestésicos locales, especialmente los bloqueos nasopalatinos y del nervio palatino mayor.

The effects of maxillary nerve block, ethmoidal nerve block and their combination on cardiopulmonary responses to nasal stimulation in anesthetized Beagle dogs.

OBJECTIVE: To describe an approach for ethmoidal nerve block (EBLOCK) and to compare the effects of a maxillary nerve block (MBLOCK), EBLOCK and their combination (M-EBLOCK) on heart rate (HR), systolic (SAP), mean (MAP), diastolic (DAP) arterial pressures and respiratory rate (fR) during nasal stimulation in dogs. STUDY DESIGN: Prospective, blinded, randomized, crossover placebo-controlled study. ANIMALS: Beagle dogs (five cadavers, nine live dogs), with a median (interquartile range) weight of 10.5 (10.3-11.0) kg. METHODS: The accuracy of iohexol injections (each 1 mL) at the maxillary and ethmoidal foramina in cadavers was evaluated using computed tomography. Then, anesthetized dogs were administered four bilateral treatments separated by 1 week, saline or 2% lidocaine 1 mL per injection: injections of saline at the maxillary and ethmoidal foramina (Control), injections of lidocaine at the maxillary foramina and saline at the ethmoidal foramina (MBLOCK), injections of saline at the maxillary foramina and lidocaine at the ethmoidal foramina (EBLOCK) and injections of lidocaine at all foramina (M-EBLOCK). The ventral nasal meatus was bilaterally stimulated using cotton swabs, and HR, SAP, MAP, DAP and fR were continuously recorded. Values for each variable were compared before and after stimulation using Wilcoxon signed-rank test. Changes in variables among treatments were analyzed using Mann-Whitney U and Kruskal-Wallis tests (p ≤ 0.05). RESULTS: Computed tomography revealed iohexol distribution around the openings of the target foramina in all cadavers. In living dogs, HR, SAP, MAP, DAP and fR significantly increased after stimulation within each treatment (p < 0.03). Physiologic responses were significantly attenuated, but not absent, in the M-EBLOCK [HR (p = 0.019), SAP, MAP, DAP and fR (all p ≤ 0.001)] compared with those in the Control. CONCLUSIONS AND CLINICAL RELEVANCE: Concurrent injections of lidocaine at the maxillary and ethmoidal foramina attenuated HR, arterial pressure and fR responses to nasal stimulation in Beagle dogs.

Clonidine as an Adjuvant to Bupivacaine for Suprazygomatic Maxillary Nerve Blocks in Cleft lip and Palate Repair: A Randomized, Prospective, Double-Blind Study.

OBJECTIVES: Does clonidine, as adjuvant to bupivacaine for suprazygomatic maxillary nerve blocks, reduce emergence agitation in patients undergoing cleft lip and cleft palate surgery? DESIGN: Randomized, controlled, and double-blind study. SETTING: Guwahati Comprehensive Cleft Care Center, Guwahati (Assam, India). PARTICIPANTS: A total of 124 patients; with a median age of 5 years in the clonidine group (CLG) and 7 years in the control group (CG), who underwent cleft lip or cleft palate surgery were included. Exclusion criteria included lack of consent from patients or their guardians, allergy to local anesthetics, coagulation disorders, local infection at the puncture site before performing the block, and language difficulties or cognitive disorders. INTERVENTIONS: Patients were randomized into 2 groups to receive bilateral suprazygomatic maxillary nerve blocks with either a bupivacaine/clonidine mixture for the CLG or bupivacaine alone in the CG. MAIN OUTCOME MEASURE: The primary end point was the incidence of emergence agitation. RESULTS: There was a statistically significant difference in the incidence of emergence agitation (30.2% in the CG compared to 15.2% in the CLG; difference of incidences: 15%, 95% CI: 0.1-30.1). The percentage of patients requiring intraoperative Fentanyl was lower in the CLG (10.6% compared to 26.4%; difference of incidences: 15.8%, 95% CI: 1.8-29). No other differences were observed. Further research in a more typically aged children population undergoing cleft surgery is needed. CONCLUSIONS: The use of clonidine as an adjuvant to bupivacaine in maxillary nerve block reduces the incidence of emergence agitation and intraoperative opioid consumption without hemodynamic or sedative side effects in patients undergoing cleft lip and palate surgery.

Suprazygomatic maxillary nerve block: an ultrasound and cadaveric study to identify correct sonoanatomical landmarks.

​PURPOSE: Suprazygomatic maxillary nerve blocks (SMB) are used in adult and pediatric patients to provide analgesia for midface surgery and chronic maxillofacial pain syndromes. The ultrasound-guided SMB technique ensures visualisation of the needle tip, avoidance of the maxillary artery and confirmation of local anesthetic spread. The goal of this study was to correctly identify SMB sonoanatomical landmarks to ensure the nerve block is performed safely and effectively. METHODS: Following an ultrasound-guided SMB with dye injection on 2 embalmed cadavers, pre-tragal face-lift style incision with a full thickness flap dissection was performed allowing accurate visualization of the bony landmarks being used for sonography and identification of the location of the injected dye. RESULTS: This study identifies the correct sonoanatomic landmarks as the maxilla and the coronoid process of the mandible which suggests that the block needle tip and local anesthetic injection are within the infratemporal fossa as opposed to the previously reported pterygopalatine fossa. CONCLUSION: An improved understanding of the sonoanatomy will aid clinicians who are learning, performing and teaching the ultrasound-guided suprazygomatic approach to the maxillary nerve block.

Standing Sedation and Iocoregional Analgesia in Equine Dental Surgery.

Procedural sedation has become popular for describing a semiconscious state that allows patients to be comfortable during certain surgical or diagnostic procedures. Sedation may be enhanced by locoregional anesthetic techniques to produce sufficient analgesia and muscle relaxation for surgery to occur. Sedation and local anesthesia for standing diagnostic and surgical procedures on the horse's head circumvents the potential complications of general anesthesia (particularly, complications related to recovery). However, the implementation of a locoregional anesthetic technique requires a thorough understanding of the anatomy to maximize success and minimize possible complications.

Ultrasound-Guided Local Anesthetic Nerve Blocks in a Forehead Flap Reconstructive Maxillofacial Procedure.

Head and neck reconstructive surgery involving tissue flaps is often complex requiring the development of an individualized anesthetic plan. The following case report describes the anesthetic management of an 87-year-old man considered at high risk for postoperative delirium due to advanced age and blindness undergoing general anesthesia for resection of squamous cell carcinoma of the right side of the nose and reconstructive surgery with a scalping forehead flap. Ultrasound-guided local anesthetic maxillary and supraorbital nerve blocks were successfully used perioperatively to reduce the need for alternative analgesics associated with higher risks of complications such as postoperative nausea, vomiting, and delirium.

Computed Tomography Analysis of the Feline Infraorbital Foramen and Canal.

Feline skull anatomic variation is plain to see with casual observation. Obtaining an in-depth understanding of this anatomic variability is critical to performing safe and effective regional anesthesia for dental procedures and maxillofacial surgeries. Maxillofacial anatomic variability is proven to impact the placement and efficacy of nerve blocks in dogs and horses, but similar studies have not been performed in cats. This study's main objective was to evaluate the anatomy of the infraorbital foramen and canal in relation to regional anatomic landmarks in brachycephalic and mesaticephalic cats. Significant anatomic variability was identified, particularly among cats with brachycephalic skulls.

Morphometric evaluation and clinical implications of the greater palatine foramen, greater palatine canal and pterygopalatine fossa on CBCT images and review of literature.

INTRODUCTION: The pterygopalatine fossa (PPF) infiltration is performed to reduce blood flow during endoscopic sinus surgery and septorhinoplasty, as well as to control posterior epistaxis and provide regional anesthesia in dental procedures. PPF infiltration performed with consideration of the morphometrics of greater palatine foramen (GPF), greater palatine canal (GPC) and PPF would increase the success of the procedure and reduce the risk of complications. The aim of this study is to investigate the GPF, GPC, lesser palatine foramen (LPF), lesser palatine canal (LPC) and PPF morphology via the images obtained by CBCT, to provide information for interventional procedures. MATERIALS AND METHODS: GPF, GPC, LPF, LPC and PPF were morphometrically evaluated retrospectively in CBCT images of 75 female and 75 male cases by Planmeca Romexis program. The 19 parameters were measured on these images. RESULTS: These parameters were evaluated statistically. The comparison of these parameters by genders revealed significant differences in distances between GPC-PC, PC-IOF, LPC-GPF, GPF-MS in the coronal and transverse planes, the distance between GPF and the occlusal plane of the teeth, GPF-PNS, GPF-IF and TD-GPF, and in the area of GPF. The number of LPF was found ranging from 1 to 5. CONCLUSION: Our results may help to insert to needle properly for application of maxillary nerve block with a high success rate and minimal complication. We recommend that the needle should be inserted 14-15 mm lateral to the midsagittal plane, 19-20 mm over the occlusal plane of the teeth and on the same line with the third molar teeth. For PPF infiltration through the GPF, the needle should be pushed forward 28 mm upward at 66° angle on the transverse plane and 14°-15° angle on the vertical plane.

Ophthalmic complications following ocular penetration during routine dentistry in 13 cats.

CASE HISTORY Thirteen cats developed ophthalmic complications following dental procedures in Australia and New Zealand between December 2014 and February 2018. All cats had at least one maxillary tooth extracted and some received a transoral maxillary nerve block. CLINICAL FINDINGS Ocular signs were identified at a median of 1.5 (min 0, max 14) days following elective dental procedures and included fibrin in the anterior chamber, aqueous flare, vision loss and miosis. Response to medical management was poor overall, with 7/13 (54%) cats undergoing subsequent enucleation and one cat was subjected to euthanasia shortly after the dental procedure due to ocular disease. The remaining five cats were managed medically. Of these, four exhibited signs of persistent inflammation at the last ophthalmic assessment, and one was subsequently subjected to euthanasia due to reasons unrelated to ocular health. Active inflammation resolved in one cat, however the lesions caused by previous inflammation persisted. PATHOLOGICAL FINDINGS Assessment of six enucleated globes showed a variety of pathological changes, with marked fibrinous exudation and suppurative inflammation as predominant features. A scleral penetration site was identified in three globes. Four globes had lens capsule rupture and phacoclastic uveitis. DIAGNOSIS Endophthalmitis following iatrogenic globe penetration during routine dental procedures. CLINICAL RELEVANCE This case series demonstrates that globe penetration during dental procedures carries a poor prognosis for the eye. Clinicians should be aware of the risks of ocular trauma during dental procedures in cats and great care should be taken to avoid ocular penetration, particularly during tooth extractions. Transoral maxillary nerve blocks should be avoided or used with extreme caution in cats.

Comparison of Frontozygomatic versus Sigmoid Notch Approach for Extraoral Maxillary Nerve Block Anesthesia: A Prospective Clinical Trial.

BACKGROUND: With definitive indications, extraoral techniques of achieving regional nerve blocks are a boon to oral and maxillofacial surgical practice. Though less commonly practiced, since general anesthesia is more favored, certain medical conditions favor the use of regional nerve blocks over general anesthesia. To block the maxillary nerve extraorally, sigmoid notch approach and frontozygomatic approach have been previously described in the literature, but a clinical trial comparing these techniques is sparse. This study attempts to compare both the approaches for their efficacies while paying an equal attention to the associated complications. MATERIALS AND METHODS: Two hundred patients aged between 40-90 years of ASA 1 and 2 category were equally divided into two groups and underwent extraction of maxillary teeth under local anesthesia using 2% lignocaine with 1:80,000 adrenaline. Frontozygomatic approach to reach the foramen rotundum was employed in group A (n = 100) and sigmoid notch approach in group B (n = 100). Pain during injection, time required for onset of subjective and objective symptoms of anesthesia and duration of anesthesia were the study parameters. Associated complications were documented and discussed. Student's unpaired t test was used for statistical evaluation. RESULTS: Although both the techniques were found to be feasible, statistical evaluations favored the frontozygomatic approach with respect to faster onset and a longer duration of the anesthetic effect. The anatomical considerations in either techniques suggested that the incidence of potential complications of accidental entry of the needle into the orbit, skull and vessel injuries was higher when using sigmoid notch approach as against the frontozygomatic approach. CONCLUSION: Though sigmoid notch approach, described widely in the literature, can be employed successfully, certain anatomical considerations and technical modifications in the frontozygomatic approach have made the latter a more practical and feasible approach. When both the maxillary and the mandibular nerves need to be blocked simultaneously, sigmoid notch may be employed, but isolated maxillary nerve block is better achieved using frontozygomatic approach.

Impact of age on the anatomy of the pediatric pterygopalatine fossa and its relationship to the suprazygomatic maxillary nerve block.

OBJECTIVES: The suprazygomatic maxillary nerve block is associated with improved post-operative pain management after select craniofacial surgical procedures. This study's objective is to better define the impact of pediatric facial skeletal growth on techniques for accessing the pterygopalatine fossa (PPF). METHODS: Pediatric patients with prior thin-slice maxillofacial computed tomography imaging were identified in an institutional radiology database. Aquarius image-processing software (Ver. 4.4.11, TeraRecon, Inc., Foster City, CA) was used to measure from the suprazygomatic skin to the greater wing of the sphenoid where the needle is then re-oriented in an anterior and inferior trajectory allowing it to advance into the PPF. RESULTS: A total of 90 patients ranging from 0 to ≤18 years of age were included in the study. The mean distance from the suprazygomatic skin to the foramen rotundum in patients 0 to ≤12 months of age and >13 to ≤18 years of age was 38.6 (SD ±â€¯4.7) and 47.1 (SD ±â€¯3.2) mm, respectively (p < .0001). The statistical analysis demonstrated a positive correlation between age in years and all of the measured distances (p = .0001). With respect to the plane of the needle entry site, the anterior and inferior angles required for passage into the PPF in the 0 to ≤12 months age group were 11 (SD ±â€¯2.1) and 9.0 (SD ±â€¯2.5) degrees, respectively, compared to those in the >13 to ≤18 years of age group at 12.4 (SD ±â€¯1.9) and 12.1 (SD ±â€¯3.2) degrees, respectively. These data reveal that patients in the oldest compared to the youngest pediatric age groups require significantly greater needle insertion, yet the angles of needle re-orientation are clinically similar between these two pediatric age groups varying by up to only 3°. CONCLUSION: As expected, the distance from the skin to the foramen rotundum increases significantly with age; however, the angles of re-orientation with respect to the original needle entry site demonstrated up to only 3° of variability between the youngest and oldest age groups evaluated in this pediatric cohort.

Anatomical characteristics of greater palatine foramen: a novel point of view.

PURPOSE: Anatomy of greater palatine foramen is important for maxillary nerve blocks, haemostatic procedures, and the treatment of neuralgia; although metrical data are available about its collocation, still several aspects need to be explored, such as the influence of the cranium size. METHODS: The position of greater palatine foramen was assessed on 100 skulls through six measurements (distances from intermaxillary suture, posterior palatal border, posterior nasal spine, and incisive foramen; palatal length; relative position on palatal length) and two angles (angles at incisive foramen and greater palatine foramen). Maximum cranial length, maximum cranial breadth, cranial height and bizygomatic breadth, horizontal cephalic index, and Giardina Y-index were evaluated. Possible differences according to sex and side were assessed through two-way ANOVA (p < 0.05). Measurements showing sexual dimorphism were further assessed through one-way ANCOVA including cranial parameters as covariates (p < 0.05). RESULTS: Distances of the greater palatine foramen from intermaxillary suture, incisive foramen, posterior palatal border, posterior nasal spine, palatal length, and position of the greater palatine foramen on the palatal length were statistically different according to sex (p < 0.05), independently from general cranial dimensions but for the distance from the posterior palatal border. The angle at the incisive foramen and distances from intermaxillary suture and from posterior nasal spine showed statistically significant differences according to side (p < 0.05). CONCLUSIONS: Results highlight that most of sexually dimorphic measurements useful for pinpointing the greater palatal foramen do not depend upon the cranium size. A more complete metrical assessment of the localization of the greater palatine foramen was provided.

Retrograde maxillary nerve perineural injection: A tomographic and anatomical evaluation of the infraorbital canal and evaluation of needle type and size in equine cadavers.

The aim of this study was to investigate a new approach for equine maxillary nerve blocks, which can facilitate several orofacial surgeries. Current techniques aim at the maxillary foramen and approach via the zygomatic arch, conferring the risk of injury to several delicate structures in the target area. To investigate the feasibility of a retrograde approach from the infraorbital foramen, an anatomic study of the infraorbital canal and its surrounding structures was performed on 13 cadaveric skulls using computed tomography and anatomical dissection. Measurements included canal length and volume, its conformation and relationship with the enclosed structures, and infraorbital foramen diameters. The technical approach to simulate the distribution of local anaesthetic within the infraorbital canal was further defined, including needle selection among seven different needles, evaluating ease of insertion, trauma to surrounding tissues and spread of contrast medium toward the target area. To validate the technique, two Tuohy needles were randomly inserted at 12 infraorbital foramina and 10 mL of contrast medium was injected. CT verified the spread of the solution and possible complications. Each canal had a serpentine-curved pathway. Anatomical dissections evidenced gaps between the infraorbital nerve, vessels and the infraorbital canal. The integrity of these structures had been preserved from the passage of the selected Tuohy needles. This study suggests a feasible approach to the maxillary nerve block within the infraorbital canal providing an appropriate needle selection and technique to limit complications.