Transorbital Endoscopic Approach to the Foramen Rotundum for Infraorbital Nerve Stripping.

PURPOSE: To develop and evaluate a transorbital endoscopic approach to the foramen rotundum to excise the maxillary nerve and infraorbital nerve branch. METHODS: Cadaveric dissection study of 10 cadaver heads (20 orbits). This technique is predicated upon 1) an inferior orbital fissure release to facilitate access to the orbital apex and 2) the removal of the posterior maxillary wall to enter the pterygopalatine fossa (PPF). Angulations along the infraorbital nerve were quantified as follows: the first angulation was measured between the orbitomaxillary segment within the orbital floor and the pterygopalatine segment suspended within the PPF, while the second angulation was taken between the pterygopalatine segment and maxillary nerve as it exited the foramen rotundum. With refinement of the technique, the minimum amount of posterior maxillary wall removal was quantified in the final 5 cadaver heads (10 orbits). RESULTS: The mean distance from the inferior orbital rim to the foramen rotundum was 45.55 ± 3.24 mm. The first angulation of the infraorbital nerve was 133.10 ± 16.28 degrees, and the second angulation was 124.95 ± 18.01 degrees. The minimum posterior maxillary wall removal to reach the PPF was 11.10 ± 2.56 mm (vertical) and 11.10 ± 2.08 mm (horizontal). CONCLUSIONS: The transorbital endoscopic approach to an en bloc resection of the infraorbital nerve branch up to its maxillary nerve origin provides a pathway to the PPF. This is relevant for nerve stripping in the context of perineural spread. Other applications include access to the superior portion of the PPF in selective biopsy cases or in concurrent orbital pathology.

Endoscopic endonasal treatment of maxillary nerve (V2) painful neuropathy: cadaveric study with clinical correlation.

BACKGROUND: Surgical access to the second (V2, maxillary) and third (V3, mandibular) branches of the trigeminal nerve (V) has been classically through a transoral approach. Increasing expertise with endoscopic anatomy has achieved less invasive, more efficient access to skull base structures. The authors present a surgical technique using an endoscopic endonasal approach for the treatment of painful V2 neuropathy. METHODS: Endoscopic endonasal dissections using a transmaxillary approach were performed in four formalin-fixed cadaver heads to expose the V2 branch of the trigeminal nerve. Relevant surgical anatomy was evaluated and anatomic parameters for neurectomy were identified. RESULTS: Endoscopic endonasal transmaxillary approaches completed bilaterally to the pterygopalatine and pterygomaxillary fossae exposed the V2 branch where it emerged from the foramen rotundum. The anatomy defined for the location of neurectomy was determined to be the point where V2 emerged from the foramen rotundum into the pterygopalatine fossa. The technique was then performed in 3 patients with intractable painful V2 neuropathy. CONCLUSIONS: In our cadaveric study and clinical cases, the endoscopic endonasal approach to the pterygopalatine fossa achieved effective exposure and treatment of isolated V2 painful neuropathy. Important surgical steps to visualize the maxillary nerve and its branches and key landmarks of the pterygopalatine fossa are discussed. This minimally invasive approach appears to be a valid alternative for select patients with painful V2 trigeminal neuropathy.

Cleft Palate Repair: A New Maxillary Nerve Block Approach.

OBJECTIVE: To introduce a different approach for maxillary nerve block (MNB), in cleft palate repair. To reduce the use of opioids during surgery and to prevent frequent respiratory complications by means of an adequate intra and postoperative pain relief. PATIENTS AND METHODS: A prospective clinical trial was planned, to collect scientific evidences between 2 groups of patients with primary cleft palate, receiving surgery in 2 Pediatric centers of Buenos Aires, utilizing a different protocol.Sixty patients undergoing primary cleft palate repair in both hospitals, from January 2017 to July 2018, by senior surgeons and the same expert anesthesiologists' team, were included.Syndromic and secondary cases, and patients whose parents rejected to participate of this study were excluded. The first group called Hospital A included 45 children, the second group identified as Hospital B was formed by 15 patients.A combination of general whit local anesthesia and a bilateral regional MNB, was used in all the patients of the Hospital A. Utilizing an aspirating syringe, children received 0.15 ml/kg of lidocaine clorhidrate 2% with epinephrine 1:50.000, under direct vision through the spheno palatine holes, just before surgery. A traditional general anesthesia procedure plus local anesthesia, was utilized in all the patients treated at the Hospital B Medial blood pressure and cardiac frequency parameters were tested during induction, along the surgical procedure and in the immediate post op, to detect any sign of pain (12). After surgery, patient reactivity, airway depression symptoms, time of initial feeding and discharge time, were also monitored (13).This study was approved by the Hospitals Ethics Committees of both hospitals, and is in accordance with the 1975 Helsinki Declaration, as amended in 1983. The parents have signed an informed consent form for all the patients included. RESULTS: Patients of both groups did not show any significant variant in the monitored parameters to detect signals of pain, along the surgery. The rest of controls during and after surgery showed significant differences in favor of the patients of Hospital A. CONCLUSIONS: Bilateral regional MNB, under direct vision trough the spheno palatine holes results an effective, easy, and safe method for pain relief during and after primary cleft palate repair surgeries.The combination of slight general anesthesia with local anesthesia and regional blocks, results a good option to reduce opioids utilization, to prevent neurotoxicity, respiratory depression, sickness, and vomiting facilitating early feeding and patient discharge.

Infraorbital Foramen Decompression Surgery for the Infraorbital Nerve Hypoesthesia in Patients With Isolated Fracture of Maxillary Sinus Anterior Wall.

Isolated fracture of maxillary sinus anterior wall is relatively uncommon. If the extent of fracture is minimal, only conservative care is amenable, however, there is no agreement on whether infraorbital nerve dysfunction can be used as an indication for surgical intervention. This study was conducted to verify the effect of decompression surgery of infraorbital foramen for recovery of hypoesthesia. A total of 26 patients with unilateral fracture of maxillary sinus anterior wall were enrolled. Ten who received only conservative therapy were allocated in the control group, while sixteen patients were assigned to the decompression group. Pre- and post-treatment sensory assessment using visual analogue scale (VAS) was recorded. Overall treatment satisfaction was also evaluated by means of global assessment scale (GAS). Both absolute VAS value and score increment showed statistical difference only at 4 weeks (P = 0.010 and P = 0.021, respectively), but no significant difference at 1, 12, and 24 weeks. GAS score also showed no statistical significance (P = 0.386). Decompression surgery of infraorbital foramen does not have a significant effect on hypoesthesia recovery in isolated fracture of maxillary sinus anterior wall. Therefore, it is not recommended to perform the operation when the infraorbital nerve hypoesthesia is the only indication for the open reduction.

Long-term Follow-up of Patients Treated with Percutaneous Radiofrequency Thermocoagulation via the Foramen Rotundum for Isolated Maxillary Nerve Idiopathic Trigeminal Neuralgia.

OBJECTIVE: The purpose of this study is to evaluate the effectiveness and safety of percutaneous radiofrequency thermocoagulation (PRT) via the foramen rotundum (FR) for the treatment of isolated maxillary (V2) idiopathic trigeminal neuralgia (ITN) and assess the appropriate puncture angle through the anterior coronoid process to reach the FR. METHODS: Between January 2011 and October 2016, 87 patients with V2 ITN refractory to conservative treatment were treated by computed tomography (CT)-guided PRT via the FR at our institution. The outcome of pain relief was assessed by the visual analog scale (VAS) and Barrow Neurological Institute (BNI) pain grade and grouped as complete pain relief (BNI grades I-III) or unsuccessful pain relief (BNI grades IV-V). Recurrence and complications were also monitored and recorded. The puncture angle for this novel approach was assessed based on intraoperative CT images. RESULTS: Of the 87 treated patients, 85 (97.7%) achieved complete pain relief, and two patients (2.3%) experienced unsuccessful pain relief immediately after operation. During the mean follow-up period of 44.3 months, 15 patients (17.2%) experienced recurring pain. No severe complications occurred, except for hypoesthesia restricted to the V2 distribution in all patients (100%) and facial hematoma in 10 patients (11.5%). The mean puncture angle to reach the FR was 33.6° ± 5.7° toward the sagittal plane. DISCUSSION: CT-guided PRT via the FR for refractory isolated V2 ITN is effective and safe and could be a rational therapy for patients with V2 ITN.

A Cadaver Study to Assess the Feasibility of a Cross-Nerve Transfer of the Infraorbital Nerve for Patients With Peripheral Infraorbital Nerve Injury.

BACKGROUND: Patients with facial fracture or head and neck surgery sometimes suffer from infraorbital nerve injury. This injury results in severe hemilateral numbness in the midfacial area. The infraorbital nerve ends with two major branches; the infra nasal branch (INB) and superior labial branch (SLB). In this study, we assessed the feasibility of cross-nerve transfer of the INB and SLB based on a cadaver study. METHODS: The INB/SLB from a total 20 sides of 10 cadavers (2 men and 8 women; average age, 79.9 years) were dissected. The distribution patterns of the INB and SLB, the distance between the INB/SLB and the piriform aperture, and the shortest distance between the INB/SLB were estimated. RESULTS: Three distribution patterns of the INB and SLB were observed, that is type A (65%); only the INB is thick enough for a nerve transfer, type B (20%); only the SLB is thick enough for a nerve transfer, and a combination of types A and B (15%). The distance between the INB, SLB and the piriform aperture was on average 8.61 and 10.81 mm in each. The shortest distance between the INB and SLB was on average 11.34 ± 3.7 mm. CONCLUSIONS: The INB and SLB existed in all the specimens and could be found approximately 1 cm below the piriform aperture. The average distance between the INB and SLB was approximately 11 mm. These results imply the feasibility of a cross-nerve transfer of the distal part of the infraorbital nerve.

Transantral endoscopic approach for the treatment of lesions affecting the maxillary nerve.

BACKGROUND: Surgical approaches to skull base lesions that affect the maxillary nerve are complex, due to deep location and presence of relevant neurovascular structures surrounding this area. METHOD: We propose the transantral endoscopic approach (TEA) for the treatment of lesions affecting the maxillary nerve or its vicinity. More specifically, the ones that are located anterior to the foramen rotundum. CONCLUSIONS: This technique represents a minimally invasive treatment option for these kind of cranial base lesions. It offers optimal visualisation similar to the endonasal approach, whereas less dissection is required.

Posttraumatic Midface Pain: Clinical Significance of the Anterior Superior Alveolar Nerve and Canalis Sinuosus.

BACKGROUND: Posttraumatic midface pain secondary to injury of the anterior superior alveolar nerve (ASAN) is characterized as pain localized to the central and lateral incisors, canines, and maxilla. This nerve is susceptible to injury and subsequent formation of neuromas after midface trauma. Surgical intervention requires an accurate and precise understanding of the course of the ASAN. METHODS: Dissections of 12 human cadaver heads were conducted to identify the course of the ASAN through the canalis sinuosus (CS). Fifty 1-mm slice face computed tomographic scans were evaluated to document the dimensions and course of the CS. RESULTS: The ASAN branched laterally from the infraorbital nerve before reaching the infraorbital rim in all cadavers. The bifurcation occurred 18 mm posterior to the infraorbital rim (range, 10-30 mm). At a point 25 mm inferior to the infraorbital rim, the ASAN is found 3.4 mm lateral to the piriform aperture (range, 3-4 mm). Radiographic analysis demonstrated a 12.9-mm horizontal length of the CS across the anterior maxilla (SD, 2.2 mm), a distance of 4.8 mm between the piriform aperture and the CS (SD, 1.2 mm), and 11.7 mm vertical length of the CS along the piriform aperture (SD, 3.0 mm). CONCLUSIONS: The ASAN maintains consistent coordinates at specific points along its course through the midface. An improved understanding of the course of the ASAN will guide future diagnosis of injury to this nerve and surgical intervention for patients with posttraumatic midface pain secondary to ASAN injury.

Trigeminal Neuralgia: Evaluation of the Relationship Between the Region of Neuralgic Manifestation and the Site of Neurovascular Compression Under Endoscopy.

This study aimed to evaluate the relationship among the pain region, branches of trigeminal nerve, and the neurovascular compression (NVC) location. A total of 123 consecutive patients with trigeminal neuralgia (TN) underwent endoscope-assisted microvascular decompression according to positive preoperative tomographic angiography. V2 alone was in 51 cases and V3 alone was in 64 cases. The location of NVC was classified into cranial, caudal, medial, or lateral sites. Some patients with multiple regions were recorded as medial + cranial, lateral + cranial, medial + caudal, and lateral + caudal. Twenty-eight (71.8%) of 39 patients with TN (V2) had their NVC at the medial site of the nerve. Twenty-seven (64.3%) of 42 patients with TN (V3) had their NVC at the lateral site of the nerve. There was a statistically significant difference (P = 0.0011 < 0.01, χ2 test). Sixteen (69.6%) of 23 patients with TN(V2) had their NVC at the cranial site of the nerve. Thirty-four (69.4%) of 49 patients with TN (V3) had their NVC at the caudal site of the nerve. There was no statistical difference (P = 0.3097 > 0.01). Evaluation of the relationship between the pain region and the NVC location by endoscopic images during microvascular decompression is more accurate. The second branch is mostly distributed in the medial area, and third branch is mainly distributed in the lateral area.

Neonatal infraorbital nerve crush-induced CNS synaptic plasticity and functional recovery.

Infraorbital nerve (ION) transection in neonatal rats leads to disruption of whisker-specific neural patterns (barrelettes), conversion of functional synapses into silent synapses, and reactive gliosis in the brain stem trigeminal principal nucleus (PrV). Here we tested the hypothesis that neonatal peripheral nerve crush injuries permit better functional recovery of associated central nervous system (CNS) synaptic circuitry compared with nerve transection. We developed an in vitro whisker pad-trigeminal ganglion (TG)-brain stem preparation in neonatal rats and tested functional recovery in the PrV following ION crush. Intracellular recordings revealed that 68% of TG cells innervate the whisker pad. We used the proportion of whisker pad-innervating TG cells as an index of ION function. The ION function was blocked by ∼64%, immediately after mechanical crush, then it recovered beginning after 3 days postinjury and was complete by 7 days. We used this reversible nerve-injury model to study peripheral nerve injury-induced CNS synaptic plasticity. In the PrV, the incidence of silent synapses increased to ∼3.5 times of control value by 2-3 days postinjury and decreased to control levels by 5-7 days postinjury. Peripheral nerve injury-induced reaction of astrocytes and microglia in the PrV was also reversible. Neonatal ION crush disrupted barrelette formation, and functional recovery was not accompanied by de novo barrelette formation, most likely due to occurrence of recovery postcritical period (P3) for pattern formation. Our results suggest that nerve crush is more permissive for successful regeneration and reconnection (collectively referred to as "recovery" here) of the sensory inputs between the periphery and the brain stem.

Perineural invasion of cutaneous squamous cell carcinoma along the zygomaticotemporal nerve.

The vast majority of periocular squamous cell carcinoma spreads intraorbitally along the supraorbital and infraorbital nerves into the cavernous sinus. A patient presented with a history of resected squamous cell carcinoma and pain in the zygomatic distribution. She was found to have temporalis involvement of the malignancy and invasion of the zygomaticotemporal nerve by histopathology. She underwent aggressive resection and adjuvant treatment with no evidence of recurrence at 8-month follow up. This case illustrates an uncommon route of squamous cell carcinoma spread through the zygomaticotemporal sensory nerve distribution.

Maxillary Nerve as Landmark for Exposure of the Internal Maxillary Artery in Extracranial-Intracranial Bypass Surgery.

OBJECTIVE: To establish a new method for fast exposure of the internal maxillary artery (IMA) during extracranial-intracranial bypass surgery. METHODS: To explore the positional relationship between the IMA and the maxillary nerve and pterygomaxillary fissure, 11 formalin-fixed cadaveric specimens were dissected. Three bone windows of the middle fossa were created for further analysis. Then the IMA length that could be pulled up above the middle fossa was measured after different degrees of removal of bony structure. The IMA branches under each bone window were also explored in detail. RESULTS: The top of the pterygomaxillary fissure was located 11.50 mm anterolateral to the foramen rotundum. The IMA could be identified just inferior to the infratemporal segment maxillary nerve in all specimens. After drilling of the first bone window, the IMA length that could be pulled above the middle fossa bone was 6.85 mm. After drilling of the second bone window and further mobilization, the IMA length that could be harvested was significantly longer (9.04 mm vs. 6.85 mm; P < 0.001). Removal of the third bone window did not significantly improve the IMA length that could be harvested. CONCLUSIONS: The maxillary nerve could be used as a reliable landmark for the exposure of the IMA in the pterygopalatine fossa. With our technique, the IMA could be easily exposed and sufficiently dissected without zygomatic osteotomy and extensive middle fossa floor removal.

Preauricular transzygomatic anterior infratemporal fossa approach for tumors in or around infratemporal fossa lesions.

Various surgical approaches to the infratemporal fossa (ITF) have been reported. Among them, the preauricular transzygomatic anterior ITF approach (anterior ITF approach) has been used for exposure of the antero-superior part of the ITF. The purpose of this article is to show anatomical dissections using the anterior ITF approach and to evaluate our surgical experience using this approach. An anatomical study of the anterior ITF approach was performed using six sides of three cadaveric heads. Clinical course was retrospectively reviewed for 34 patients who underwent microsurgical resection of tumor in or around the ITF using this approach. Medical, surgical, and neuroimaging records of these patients were evaluated. The key point of this approach was mobilization of the second and third divisions of the trigeminal nerve after drilling of the lateral loop between the foramina rotundum and ovale. After mobilization of the trigeminal nerve, the auditory tube, tensor veli palatini muscle, and pharyngobasilar membrane could be seen. Removal of the pterygoid muscles and plates allowed surgical access to the ITF, orbit, maxillary sinus, pterygopalatine fossa, and parapharyngeal space. We used this approach in 31 patients with skull base tumors between 1994 and 2007. Gross total removal was achieved in 27 of the 31 patients. No mortality or severe morbidity was encountered. Therefore, the anterior ITF approach provides easy access to the ITF and adjacent regions without destruction of important organs.

Tacr3 in the lateral habenula differentially regulates orofacial allodynia and anxiety-like behaviors in a mouse model of trigeminal neuralgia.

Trigeminal neuralgia (TN) is debilitating and is usually accompanied by mood disorders. The lateral habenula (LHb) is considered to be involved in the modulation of pain and mood disorders, and the present study aimed to determine if and how the LHb participates in the development of pain and anxiety in TN. To address this issue, a mouse model of partial transection of the infraorbital nerve (pT-ION) was established. pT-ION induced stable and long-lasting primary and secondary orofacial allodynia and anxiety-like behaviors that correlated with the increased excitability of LHb neurons. Adeno-associated virus (AAV)-mediated expression of hM4D(Gi) in glutamatergic neurons of the unilateral LHb followed by clozapine-N-oxide application relieved pT-ION-induced anxiety-like behaviors but not allodynia. Immunofluorescence validated the successful infection of AAV in the LHb, and microarray analysis showed changes in gene expression in the LHb of mice showing allodynia and anxiety-like behaviors after pT-ION. Among these differentially expressed genes was Tacr3, the downregulation of which was validated by RT-qPCR. Rescuing the downregulation of Tacr3 by AAV-mediated Tacr3 overexpression in the unilateral LHb significantly reversed pT-ION-induced anxiety-like behaviors but not allodynia. Whole-cell patch clamp recording showed that Tacr3 overexpression suppressed nerve injury-induced hyperexcitation of LHb neurons, and western blotting showed that the pT-ION-induced upregulation of p-CaMKII was reversed by AAV-mediated Tacr3 overexpression or chemicogenetic inhibition of glutamatergic neurons in the LHb. Moreover, not only anxiety-like behaviors, but also allodynia after pT-ION were significantly alleviated by chemicogenetic inhibition of bilateral LHb neurons or by bilateral Tacr3 overexpression in the LHb. In conclusion, Tacr3 in the LHb plays a protective role in treating trigeminal nerve injury-induced allodynia and anxiety-like behaviors by suppressing the hyperexcitability of LHb neurons. These findings provide a rationale for suppressing unilateral or bilateral LHb activity by targeting Tacr3 in treating the anxiety and pain associated with TN.

Investigation of infraorbital nerve injury following zygomaticomaxillary complex fractures.

The aim of this study was to investigate the severity of infraorbital nerve injury following zygomaticomaxillary complex fractures and to estimate the treatment methods facilitating its functional recovery. A total of 478 patients with unilateral zygomaticomaxillary complex fractures were treated. Infraorbital nerve sensory disturbances were diagnosed in 64.4% of the patients. Injury of the infraorbital nerve was expressed as asymmetry index, which was calculated as a ratio between the affected side and the intact side electric pain detection thresholds at the innervation zone skin before treatment and 14 days, 1, 3, 6 and 12 months postoperatively. A mean asymmetry index of 0.6 +/- 0.03 and 1.9 +/- 0.5 was registered for 57 (11.9%) patients with hyperalgesia and for 251 (52.5%) patients with hypoalgesia, respectively. As a result of retrospective analysis of infraorbital nerve sensory disturbances and its functional recovery, infraorbital nerve injury severity was classified as mild, moderate and severe. It was found that the dynamics and outcome of the functional infraorbital nerve recovery depend on the severity of the injury and the presence of infraorbital canal damage. Function was completely recovered within 3 months after treatment in cases with mild nerve injury. In moderate cases, complete recovery was seen within 6 months and in 34.6% of the severe cases, within a 12-month period after treatment when infraorbital nerve decompression was performed according to the stated indication. Treatment based on infraorbital nerve injury classification offers a better prognosis for complete recovery of the infraorbital nerve function.

Endoscopic Endonasal Transrotundum Middle Fossa Exposure: Technique of Transpterygoid Maxillary Nerve Transposition.

OBJECTIVE: Middle fossa floor access can be challenging. Open skull base approaches have associated morbidity and yield suboptimal working angles around the temporal lobe. Endoscopic endonasal approaches to the middle fossa are poorly described, but provide an improved angle. I hypothesized that the length of the maxillary nerve can be transposed out of the foramen rotundum to provide a path to expose the full width of the middle fossa floor through the anterolateral and anteromedial triangle. METHODS: Endoscopic endonasal transpterygoid dissections to expose the middle fossa were performed bilaterally on 2 silicone-injected cadaveric heads (4 sides). Transposition of V2 was then performed on all sides, and additional middle fossa exposure was achieved. High-resolution computed tomography imaging was obtained to quantify the extent of exposure. A transzygomatic approach was also performed for comparison. RESULTS: The maxillary nerve was successfully transposed in each dissection. A periosteal fold was identified to assist in the mobilization of the infraorbital nerve. The average middle fossa exposure achieved without transposition was 50% (of the medial to lateral width). Transposition increased that to 95%. Comparison with the open transzygomatic approach demonstrated superior surgical trajectory (inferior to superior) with the endonasal route. CONCLUSIONS: Endoscopic endonasal transpterygoid approaches with or without transposition of the maxillary nerve provide a reasonable option for sequentially exposing the entire medial to lateral extent of the anterolateral triangle. It provides an advantageous inferior to superior surgical angle and can be considered for treatment of select middle fossa floor pathology.

Functional role of lingual nerve in breastfeeding.

Functional role of lingual nerve in breastfeeding was investigated in rat pups during the suckling period. DiI, a postmortem neuronal tracer, was used to confirm the immature lingual nerve (LN) responsible for tongue sensation and resulted in successful fiber labeling anterogradely to the tongue, which showed different distribution patterns from fiber labeling derived from the hypoglossal nerve. Unilaterally LN-injured pups did not show suckling disturbance with absence of any shortening (P11 pups: 559+/-16s; 105% of the control value) in nipple attachment time and the survival rate remained high (P11: 100%). Bilaterally LN-injured pups showed suckling disturbance with marked shortening (P11 pups: 220+/-54 s; 42% of the control value) in nipple attachment time and a low survival rate (P1: 33%; P11: 41%). Bilaterally infraorbital nerve-injured or bilaterally bulbectomized pups did not show any nipple attachment at all and there were no survivors, confirming the crucial roles of upper lip sensation and olfaction in suckling. Based on these findings, we conclude that tongue sensation is very important, but not essential for suckling.

Transmaxillary exploration of the intracranial portion of the maxillary nerve in malignant perineural disease. Technical note.

OBJECT: Achieving microscopically tumor-free margins during resection of skull base malignancies has consistently been identified as a positive prognostic factor for patient survival. When malignancies extend perineurally into the major nerves traversing the skull base and entering the cavernous sinus, achieving tumor-free margins can be challenging and typically necessitates performing a craniotomy to access the lateral wall of the cavernous sinus. This report describes a novel technique used to access and resect malignancy extending perineurally into the intracranial portion of V2 via the maxillary sinus. METHODS: Seven patients with maxillary sinus tumors and perineural extensions along V2, who underwent resection of the primary tumor and transmaxillary intracranial exposure and dissection of the maxillary nerve to achieve maximal tumor resection, were analyzed. Prospectively collected data, including symptoms, clinical signs, diagnostic imaging data, pathological diagnosis, incidence and nature of complications, adjuvant therapies, and oncological outcomes, were retrospectively analyzed. RESULTS: All patients in this cohort had trigeminal nerve symptomatology as well as abnormal enhancement in the pterygopalatine fissure as noted on magnetic resonance imaging. The transmaxillary exploration of the maxillary nerve technique was used in all seven patients, resulting in gross-total resection of the tumors in every patient. At the last follow-up (mean 30 months, range 13-58 months, in four of seven patients for > 2 years), six patients were alive without evidence of local disease. One patient with squamous cell carcinoma died of progressive infratemporal fossa and regional neck disease 26 months after resection. No intracranial or cavernous sinus disease was present. CONCLUSIONS: This technique extended the limits of resection without the need for a craniotomy and improved local tumor control in this patient cohort.

The anatomic branch pattern of the axillary nerve.

The purpose of this study is to determine the surgical anatomy and innervation pattern of the branches of the axillary nerve and discuss the clinical importance of the presented findings. We dissected 30 shoulders in 15 fixed adult cadavers under a microscope through anterior and posterior approaches. The axillary nerve was examined in 2 segments in relation to the underlying subscapularis muscle. The axillary nerve gave off no branches in the first segment in 85% of cases. When the posterior approach was used, the axillary nerve and its branches were observed to be in a triangular-shaped area. The mean distance from the posterolateral corner of the acromion to the axillary nerve and its branches was 7.8 cm. In all cases, the posterior branch of the axillary nerve gave off its first muscular branch to innervate the teres minor. The joint branch of the axillary nerve was observed to branch out in 3 different patterns. The acromial and clavicular parts of the deltoid muscle were observed to be innervated from the anterior branch of the axillary nerve in all cases. The posterior part of the deltoid muscle was observed to be innervated in 3 different patterns. The posterior part of the deltoid was innervated from the branch or branches coming only from the posterior branch in 70% of cases, from the anterior and posterior branches in 26.7% of cases, and from the anterior branch in 3.3% of cases. The findings of this study are useful for identifying each of the branches of the axillary nerve and have implications for surgeries related with selective innervation.

Effect of surgical denervation on orthodontic tooth movement in rats.

INTRODUCTION: Tooth movement through bone depends on local inflammatory reactions of the dentoalveolar tissues. Mechanical signals cause sensory afferent nerves to liberate inflammatory peptides around the teeth, creating local inflammation. Relationships between neurogenic inflammation and tooth movement are poorly understood. The objective of this study was to measure the differences in orthodontic tooth movement between rats treated with and without surgical transection of the maxillary nerve. METHODS: Forty-two Sprague-Dawley rats were divided into 3 groups: (1) those with surgical transection of the maxillary nerve, (2) those with sham surgeries, and (3) those without surgery. After a 2-week healing period, a closed-coil spring appliance was activated to produce a 50 g mesial tipping force on the maxillary first molar. Diastema sizes distal to the first molar were measured in triplicate by using vinyl polysiloxane impression material and stone model pour-ups at 14 and 28 days of tooth movement. Images were captured and measured with a charge coupled device (CCD) microscope camera (Leeds Precision, Minneapolis, Minn) and Optimas measurement software (Media Cybernetics, Newburyport, Mass), respectively. Two-way repeated-measures ANOVA was used for statistical analysis. RESULTS: Both weight and diastema size increased for all animals throughout the study. Although there were no significant differences between groups at any time point (log diastema, P = .43), the maxillary nerve transection surgery group had a significantly smaller increase in log diastema from 14 to 28 days than either the sham surgery or the nonsurgery group (P = .045). CONCLUSIONS: This study suggests that surgical denervation causes little net effect on orthodontic tooth movement at these force levels.