Background and objective Trigeminal neuralgia (TN) is a debilitating disorder characterized by acute episodic attacks of pain that significantly impair patients\' quality of life and overall functioning. Initial therapeutic strategies to treat this condition include pharmacological options, particularly carbamazepine. In cases with resistance to dose escalation and polypharmacy, interventional procedures may be warranted. The primary aim of this study was to compare the efficacy of trigeminal ganglion (TG) radiofrequency thermocoagulation (RFT) and ultrasound (US)-guided maxillary/mandibular (max/mand) nerve pulsed radiofrequency (PRF) for treating TN, based on the findings at six months post-treatment. The secondary aims were to assess the impact of these interventions on drug consumption and interventional safety based on adverse events. Methods This prospective, randomized, single-blind study was conducted at a single pain clinic. Forty-four patients were randomized into two groups. Group RFT received TG RFT at 60 °C, 65 °C, and 70 °C for 60 seconds each, whereas Group PRF received max/mand PRF for 240 seconds. Pain relief was assessed by using the numeric rating scale (NRS) and intervention effectiveness on medication consumption was evaluated by using the Medication Quantification Scale III (MQS III). The rates of intervention-related adverse events were also compared. Results Both RFT and PRF significantly alleviated pain at one and six months post-treatment compared to baseline (p<0.05). No statistical differences were found in the NRS and MQS III scores between the groups. At six months, 77.3% of RFT patients and 63.9% of PRF patients experienced at least 50% pain relief, with no statistically significant difference. Hypoesthesia occurred in two RFT patients, and masseter weakness was observed in one patient, while no adverse events were reported in the PRF group. Conclusions TG RFT and max/mand PRF are effective treatments for TN. US-guided max/mand PRF, which avoids RFT-associated complications and radiation exposure, may be the superior and preferable option. In this study, the potential space between the coronoid process and maxilla was used to access the maxillary nerve during the maxillary block and PRF procedures, in contrast to the classical approach through the mandibular notch. Further large-scale randomized controlled trials are required to gain deeper insights into the topic.

BACKGROUND: Although the maxillary nerve block (MNB) provides adequate pain relief in cleft palate surgery, it is not routinely used globally, and reported techniques are heterogeneous. This study aims to describe relevant anatomy and to present the preferred technique of MNB administration based on the current literature and the expert opinion of the authors.
METHODS: First, a survey was sent to 432 registrants of the International Cleft Palate Master Course Amsterdam 2023. Second, MEDLINE (PubMed interface) was searched for relevant literature on maxillary artery (MA) anatomy and MNB administration in pediatric patients.
RESULTS: Survey response rate was 18% (n=78). Thirty-five respondents (44.9%) used MNB for cleft palate surgery before the course. A suprazygomatic approach with needle reorientation towards the ipsilateral commissure before incision was most frequently reported, mostly without the use of ultrasound. Ten and 20 articles were included on, respectively, MA anatomy and MNB administration. A 47.5% to 69.4% of the MA\'s run superficial to the lateral pterygoid muscle and 32% to 52.5% medially. The most frequently described technique for MNB administration is the suprazygomatic approach. Reorientation of the needle towards the anterior aspect of the contralateral tragus appears optimal. Needle reorientation angles do not have to be adjusted for age, unlike needle depth. The preferred anesthetics are either ropivacaine or (levo)bupivacaine, with dexmedetomidine as an adjuvant.
CONCLUSIONS: Described MNB techniques are heterogeneous throughout the literature and among survey respondents and not routinely used. Further research is required comparing different techniques regarding efficacy and safety.

The nerve block is a safe and effective method to theat trigeminal neuralgia (TN). In terms of the V2 trigeminal neuralgia, the most difficult procedure in nerve block is accurate and fast greater palatine foramen (GPF) insertion. In this study, we developed a new technique using a personalised digital tooth-supported guide plate to increase insertion accuracy and success rates and reduce the pain of patients during injection. A total of 18 patients with TN (11 female and 7 male) were enrolled and treated between September 2020 and June 2022. Before injection, the guide plate was designed via Mimics three-dimensional (3D) reconstruction technology and printed via 3D printer. Then, all patients underwent maxillary nerve block with a guide plate for each injection. In this study, placement of all guide plates was completed within one minute and all punctures were successful the first time. The depth of the injection needle was over 2.5 cm in all cases and the guide plate was stability-supported by the maxillary teeth. The various pain scores had an obvious improvement. No patients presented symptoms of local anaesthetic toxicity or onset of new neurological sequelae. Using this new technology, we can significantly reduce the difficulty of GPF insertion and decrease patient pain during injection. The enhanced success rate of nerve block can achieve better therapeutic effect. For surgeons, personalised digital tooth-supported guide plates make the operation easier, especially for novice surgeons.

The canalis sinuosus is an anatomical variation whereby the infraorbital canal sometimes generates a small, lateral branch (canal) close to its midpoint, to allow the passage of the anterior superior alveolar neurovascular bundle in the anterior maxilla. This article focuses on an incidental finding of this variant, in a 74-year-old Trinidadian female of Afro-Caribbean descent with an endodontic presenting complaint. The canalis sinuosus shadow on conventional radiography resulted in uncertainty as to the offending tooth until a 3-dimensional scan was undertaken in this region. This report will discuss the implications of the presence of this canal from radiologic, endodontic, and surgical perspectives.

Rhinogenic headache (RH), arising from nasal and sinus pathologies, present a diagnostic challenge due to their diverse etiologies. This study investigates a unique case where RH coincides with infraorbital nerve dehiscence, delving into the intricate relationship between sinonasal anatomy and neurovascular complications. The infraorbital nerve contacted a cyst in the maxillary sinus. Centripetal endoscopic sinus surgery was performed to open the maxillary sinus and remove the cyst. After 3 months of follow-up, the patient had a notable improvement in symptoms with a reduced headache. This case highlights the significance of considering uncommon anatomic variations, such as infraorbital nerve dehiscence, within the context of RH. Diligent history-taking and appropriate use of radiologic investigations are pivotal for guiding clinicians toward an accurate diagnosis and determining the most appropriate course of treatment.

A 20-year-old quarter horse gelding was presented for routine dental examination. Periodontal disease and luxation of tooth 108 was diagnosed and oral extraction was planned. After an unsuccessful blind maxillary nerve block, it was elected to perform the procedure under total intravenous anesthesia. Following recovery, a focal superficial corneal ulcer, severe retrobulbar swelling, mild exophthalmos, and marked swelling and prolapse of the third eyelid (nictitating membrane) were observed. Clinical signs persisted beyond 48 h despite the use of systemic anti-inflammatories and topical ocular anti-inflammatories and antibiotics. A temporary tarsorrhaphy was subsequently done at 48 h and the horse was discharged after 5 d of hospitalization and regression of clinical signs. Although it is very useful for easing dental extractions, the blind maxillary nerve block is associated with potential complications due to inadvertent vascular puncture. This case report describes a rare complication of prolapse of the third eyelid in a horse after a maxillary nerve block and successful treatment with a temporary tarsorrhaphy. Key clinical message: This case report explains how nictitating membrane swelling and prolapse can occur following a blind maxillary nerve block in the horse and describes treatment with a temporary tarsorrhaphy.
Hématome orbitaire sévère avec gonflement de la troisième paupière et prolapsus à la suite d’un bloc du nerf maxillaire à l’aveugle chez un cheval. Un hongre quarter horse de 20 ans a été présenté pour un examen dentaire de routine. Une maladie parodontale et une luxation de la dent 108 ont été diagnostiquées et une extraction orale a été planifiée. Après l’échec d’un bloc du nerf maxillaire à l’aveugle, il a été décidé d’effectuer la procédure sous anesthésie intraveineuse. Après la guérison, un ulcère cornéen superficiel focal, un gonflement rétrobulbaire sévère, une légère exophtalmie ainsi qu’un gonflement et un prolapsus marqués de la troisième paupière (membrane nictitante) ont été observés. Les signes cliniques ont persisté au-delà de 48 heures malgré l’utilisation d’anti-inflammatoires systémiques et d’anti-inflammatoires oculaires topiques et d’antibiotiques. Une tarsorraphie temporaire a ensuite été réalisée à 48 heures et le cheval est sorti après 5 jours d’hospitalisation et de régression des signes cliniques. Bien qu’il soit très utile pour faciliter les extractions dentaires, le bloc du nerf maxillaire à l’aveugle est associé à des complications potentielles dues à une ponction vasculaire involontaire. Ce rapport de cas décrit une complication rare de prolapsus de la troisième paupière chez un cheval après un bloc nerveux maxillaire et un traitement réussi par tarsorraphie temporaire.Message clinique clé:Ce rapport de cas explique comment un gonflement et un prolapsus de la membrane nictitante peuvent survenir à la suite d’un bloc du nerf maxillaire à l’aveugle chez le cheval et décrit le traitement par tarsorraphie temporaire.(Traduit par Dr Serge Messier).

Animal models remain necessary tools to study neuropathic pain. This manuscript describes the distal infraorbital nerve chronic constriction injury (DIoN-CCI) model to study trigeminal neuropathic pain in mice. This includes the surgical procedures to perform the chronic constriction injury and the postoperative behavioral tests to evaluate the changes in spontaneous and evoked behavior that are signs of ongoing pain and mechanical allodynia. The methods and behavioral readouts are similar to the infraorbital nerve chronic constriction injury (IoN-CCI) model in rats. However, important changes are necessary for the adaptation of the IoN-CCI model to mice. First, the intra-orbital approach is replaced by a more rostral approach with an incision between the eye and the whisker pad. The IoN is thus ligated distally outside the orbital cavity. Secondly, due to the higher locomotor activity in mice, allowing rats to move freely in small cages is replaced by placing mice in custom-designed and constructed restraining devices. After DIoN ligation, mice exhibit changes in spontaneous behavior and in response to von Frey hair stimulation that are similar to those in IoN-CCI rats, i.e., increased directed face grooming and hyperresponsiveness to von Frey hair stimulation of the IoN territory.

BACKGROUND: The foramen rotundum and anterior cavernous sinus have traditionally been accessed by transcranial approaches that are limited by the high density of critical neurovascular structures. The transmaxillary approach provides an entirely extradural route to the foramen rotundum and anterior cavernous sinus.
METHODS: This patient with neurofibromatosis and facial pain with trigeminal schwannoma at the foramen rotundum was successfully treated by transmaxillary resection of the tumor. This approach allowed for a direct extradural access to the pathology, with bony decompression and tumor resection, avoiding transcranial routes.
CONCLUSIONS: The transmaxillary approach provides a safe and entirely extradural corridor to access smaller localized skull base lesions at and surrounding the cavernous sinus.

Experimental maxillofacial surgery is commonly performed in pigs; however, locoregional anesthesia of this area has not been described. This study evaluated the feasibility of a novel maxillary nerve block approach. In part I, cadavers were used to determine anatomic landmarks and assess maxillary nerve dye staining by using 0.03 mL kg-1 of a 1:10 mixture of commercial food dye and 0.5% bupivacaine. In part II, 10 additional pig cadavers underwent bilateral ultrasound-guided maxillary nerve blocks by using trans-infraorbital canal needle placement. The maxillary nerve was harvested and scored based on degree of staining (0 and 1, absent or incomplete staining; 2, staining; >1 cm circumferentially). Intracranial and intraconal spread of dye was evaluated. A Kruskal-Wallis test was used to compare infraorbital canal length estimated either externally via landmarks, internally via ultrasound, or actually measured after dissection. In 18 of 20 (90%) injections, successful staining (score = 2) of maxillary nerves was obtained for a nerve length of 2.4 ± 0.3 cm. Two of 20 cases (10%) had inadequate staining (score <2). At dissection of these 2 cases, the needle tip was observed to have collided with an unerupted tooth (third molar). No intracranial or intraconal spread of dye was observed. We detected no statistical differences between the estimated external, estimated internal, or actual dissection methods for measurement of infraorbital canal length (P = 0.3). Ultrasound-guided trans-infraorbital maxillary nerve block in pigs is a feasible technique, warranting further work to evaluate its in vivo efficacy and safety.

Variant foramina of the skull can lead to misdiagnosis on medical imaging and potentially, intraoperative complications if not appreciated. Here, we report an unusual foramen found superior to the frontozygomatic suture. The foramen was located on the left side at the superolateral rim of the orbit, 2.36 cm inferolateral to the supraorbital foramen. It was positioned 2.5 mm superior to the frontozygomatic suture. The foramen had a length of 3.1 mm and a width of 1.3 mm. The internal opening of the foramen was located 1.45 cm superolateral to the zygomaticotemporal foramen. We suggest that this foramen is a pathway for either a branch of the zygomatic nerve or lacrimal nerve and/or their vascular bundles. Although the prevalence of such a finding cannot be confirmed, such a case is of archival value as a comparison for future similar cases.