亚甲蓝对大鼠眶下神经作用的实验研究

目的：观察在大鼠眶下神经周围应用20g/L亚甲蓝后其形态学变化,并对其可能的作用机制进行探讨。方法：直视下采用眶下神经周围注药法注射后,分别于术后3d、2、4、8、14周切取标本作光镜和透射电镜观察。结果：光镜观察：术后3d、2周时,可见神经纤维发生瓦勒氏变性,4周后,可见少量神经纤维再生,14周后,瓦勒氏变性仍然存在,再生纤维增多。电镜观察：早期,有髓神经纤维髓鞘扭曲、增厚、套叠,致密溶解;轴突不规则,收缩变小,轴突内出现溶酶体,空泡性变。无髓神经纤维变化不如有髓神经纤维明显。晚期,出现壁薄、形态较规整的新生纤维。雪旺细胞变化不明显。结论：20g/L亚甲蓝引起神经髓鞘及轴突的变化,可能是其发挥止痛作用的主要原因。     

Effects of glycerol on the rat infraorbital nerve: an experimental study

Glycerol was injected into the infraorbital canal of 12 rats to determine neurolytic effects on the peripheral trigeminal nerve. Saline and 90% ethanol were injected in control animals. One week after the injection, histopathological changes were noted in both glycerol and alcohol groups. In the former group, axonolysis and demyelination were restricted to the outer zone of the nerve bundles. Centrally located axons remained undamaged. A total destruction of all axons was found in the alcohol group. Four weeks after the injection in the glycerol group, small sized axons with thin myelin replaced damaged axons at the periphery of the bundle. No signs of regeneration were noted in the alcohol group. A possible mode of action of glycerol injected at the peripheral trigeminal nerve in relieving trigeminal neuralgia is described.     

Neurolytic effects of ampicillin on the rat infraorbital nerve

J Oral Pathol Med (2012) 41 : 268–271 Purpose: The aim of this study was to investigate the histomorphological changes of the infraorbital nerve of rats treated with ampicillin. Materials and Methods: The infraorbital nerve was approached through the infraorbital foramen, and 0.01 ml of ampicillin dissolved in distilled water was injected taking care not to damage the nerve. Saline solution was used in control animals. Nerves were dissected and after routine histology processing analysed by light microscopy. Results: Cross‐section of the nerve treated with ampicillin showed damaged axons with disintegration of heavily myelinated fibres, while thinly myelinated fibres remain unaffected. In the saline group, no damage was observed. The signs of regeneration of the damaged infraorbital nerves were detected on the fourth post‐operative week. Conclusion: Ampicillin can cause peripheral nerve damage when injected perineurally.     

Surgical treatment of maxillary nerve injuries. The infraorbital nerve

Although inferior alveolar and lingual nerve injuries appear to occur more often, there are undoubtedly cases of ION injury that require evaluation and possible surgical intervention by the oral and maxillofacial surgeon. Patients with ION injuries will require a neurosensory examination for the determination of the level of sensory impairment, or the localization of pain of peripheral origin (centrally mediated pain will not benefit from peripheral nerve surgery). The surgical management of ION injury might be as relatively simple as decompression of the nerve by reduction of a zygomatic complex fracture, or may require extensive mobilization of the nerve and surrounding soft tissue and bone to allow for primary anastomosis or a nerve autograft. In specific instances, improvement in ION sensory function or alleviation of pain within the distribution of the ION can be expected.     

Branching patterns of the infraorbital nerve and topography within the infraorbital space

The infraorbital nerve (ION) is the terminal branch of the maxillary nerve; it supplies the skin and mucous membranes of the middle portion of the face. This nerve is vulnerable to injury during surgical procedures of the middle face. Severe pain and loss of sense are noted in patients whose infraorbital nerve is damaged. In the study presented here, we investigated the branching pattern and topography of the ION, about which little is currently known, by dissecting 43 hemifaces of Korean cadavers. In most cases, the infraorbital artery was located in the middle (73.8%) and superficial to the ION bundle (73.8%) at its exit from the infraorbital canal. The ION produced four main branches, the inferior palpebral, internal nasal, external nasal, and superior labial branches. The superior labial branch was the largest branch of the ION produced the most sub-branches. These sub-branches were divided into the medial and lateral branches depending upon the area that they supplied. We were able to classify four types of branching pattern of the external and internal nasal branch and the medial and lateral sub-branches of the superior labial branch of the ION at the site of their emergence through the infraorbital foramen (types I-IV). Type I, where all four branches are separated occurred the most frequently (42.1%). These findings will help to preserve the ION while performing certain types of maxillofacial surgery, such as removal of a tumor from the upper jaw and fracture of the upper jaw.     

Cutaneous distribution of infraorbital nerve

The aim of this study is to elucidate precisely the cutaneous distribution of the infraorbital nerve. Ten hemifaces of five Korean adult cadavers (2 males and 3 females) were subjected to the dissection. The cutaneous branches of the infraorbital nerve were distributed over the infraorbital area, which bounds on superiorly the lower eyelid margin, inferiorly the horizontal line crossing the mouth corners, medially 0.5 cm to midline, and laterally 2 cm lateral to the temporal canthus of the eyes. The infraorbital nerve had 19.5 branches (range, 15-24 branches). The mean area supplied by the infraorbital nerve was 25.8 cm2 (range, 24.0-28.2 cm2). The mean area of the superior labial branch was 13.1 cm2 (range, 11.2-14.3 cm2) and broader than either the 7.5 cm2 (range, 6.6-8.8 cm2) of the lower palpebral branch or the 7.6 cm2 (range, 6.7-9.3 cm2) of the external nasal branch. The external nasal branch was overlapped with the lower palpebral and superior labial branch, but the last two branches do not overlap each other. The nonoverlapped branch of the infraorbital nerve exhibits a restricted anesthesia, but the overlapped branch sustains sensory perception to some extent when being damaged.     

Evaluation of cutaneous sensibility on infraorbital nerve area

Normal facial sensibility on the area of the infraorbital nerve was determined in 24 healthy subjects. The measurement of two points discrimination distance and the evaluation of cutaneous pressure threshold were assessed on both sides on the zygomatic, paranasal, and superior labial skin. Cutaneous sensibility varied from region to region but was consistent from one normal individual to another. Cutaneous sensibility of the superior labial skin was more accurate than zygomatic and paranasal skin in all tests. Sex and dominant sides did not have significant influence on the results. The measurement of two point discrimination distance and the evaluation of cutaneous pressure threshold provided reliable and reproducible data that can be used as a standard to determine facial cutaneous sensibility.     

上颌骨前牵引对犬眶下神经的影响

目的:观察犬双侧上颌骨前牵引的不同时期眶下神经组织学结构的改变,探讨其对眶下神经的影响。方法:选12周龄杂种犬13只为实验对象,实验组12只,用特制牵引器进行上颌骨前牵引;对照组1只,未配戴牵引器。牵引过程包括15d牵引期和20d固定期,牵引力为800g。于术后不同时间点分组处死动物,取双侧眶下神经,制成常规切片,光镜下观察不同时期的神经组织形态。结果:随着牵引的进行,上颌骨明显前移,眶下神经出现明显病理变化,牵引结束时神经损伤最严重;固定期神经出现修复性变化。结论:双侧上颌骨前牵引对眶下神经可产生一定的损伤,但这种损伤是暂时的、可逆的,随着时间的延长,神经的形态结构可恢复正常。     

颧上颌复合体骨折中眶下神经损伤的研究现状

颧上颌复合体（ZMC）骨折是颌面部最常见的骨折类型之一,除了面部凹陷、复视等临床症状外,还常常因损伤邻近的眶下神经导致患侧下睑、颧面部、鼻、上唇皮肤及黏膜的感觉异常。本文对眶下神经损伤的解剖基础、ZMC骨折中眶下神经损伤的诊断和评估、治疗及预后进行综述。     

A comparative study of normal sensibility of the inferior alveolar nerve and the infraorbital nerve

In order to assess the degree of similarity of the infraorbital nerve and inferior alveolar nerve, thirty subjects with no history of sensory injury were examined by a battery of neurosensory tests including: light touch, brush stroke direction, two-point discrimination, and thermal disk temperature assessment. In a matched sample experimental design, the sensibility of the inferior alveolar nerve (lower lip) was compared to the inferior orbital nerve (upper lip). The product moment correlations revealed a significant relationship (degree of sameness) between the upper and lower lip. The comparison of the upper and lower lip appear to be acceptable for retrospective tests for detection of neurosensory injury of the inferior alveolar nerve. Of these tests, light touch appears to be the most consistent while remaining sensitive to individual variation. The thermal disk assessment was least sensitive in that no individual variation could be demonstrated. In addition, there appear to be greater variations in men than in women.     

Paraesthesia of the infraorbital nerve following fracture of the zygomatic complex

68 patients with fractures of the zygomatic complex were studied. Of these, 56 had sensory disturbances of the infraorbital nerve. 50 patients were operated on and in 42% (21) some degree of persisting hypesthesia was found. No significant difference in outcome was found between the different methods of indirect reduction used. However, in 10 out of 12 patients in which direct fixation with transosseous wiring of the infraorbital margin was performed, persisting hypesthesia was encountered. In 3 out of 4 patients where the nerve was also explored primarily, the sensation returned totally. A secondary nerve deliberation was also found to be beneficial in 4 out of 5 patients with persisting total loss of sensation.     

Communication of infraorbital nerve and facial nerve: anatomic and histologic study

The maxillary nerve, second division of the trigeminal nerve, is entirely sensory. It has been reported that drooling may occur later in the event of fracture of the zygoma in which hypesthesia prevails. The aim of the study is to elucidate additional detailed anatomy of the infraorbital plexus, consisting of the superior labial branch of the infraorbital nerve and facial nerve in the cheek. The authors dissected infraorbital nerves and facial nerves in 16 cadavers. Most terminals of the zygomatic branch of the facial nerve emerged from under the levator labii superiors and zygomatic muscle and infraorbital nerve. A hazardous zone of infraorbital plexus is found in a circle 36 mm in diameter. Its center is located 22 mm below the inferior orbital foramen. This hazardous zone of infraorbital plexus should be kept in mind when performing any procedures related to zygoma, maxilla, or deep cheek injuries.     

Idiopathic thrombocytopenic purpura presenting with infraorbital nerve paraesthesia

A case of severe chronic idiopathic thrombocytopenic purpura is reported which presented with infra-orbital paraesthesia and haemorrhagic bullae of the oral mucosa.     

面中骨折术后眶下神经损伤恢复的临床观察

目的：观察面中骨折后眶下神经损伤的恢复状况。方法：对28例面中骨折后眶下神经损伤的患者,术后通过患者自述、针剌检测、两点辨别觉及直流感应电测仪测定眶下神经的恢复状况及恢复时间。采用SPSS12．0软件包对数据进行t检验。结果：25例患者的眶下神经损伤得到恢复,神经恢复时间在4-6个月,平均25周：3例患者未能恢复．成为永久性损伤。未发现慢性神经性疼痛患者。结论：大部分骨折后眶下神经损伤是暂时的、可恢复的,极少数为永久性损伤。对伤后6个月神经功能仍未恢复的患者,可考虑行眶下神经减压术。     

面中骨折术后眶下神经损伤恢复的临床观察

目的:观察面中骨折后眶下神经损伤的恢复状况.方法:对28例面中骨折后眶下神经损伤的患者,术后通过患者自述、针刺检测、两点辨别觉及直流感应电测仪测定眶下神经的恢复状况及恢复时间.采用SPSS12.0软件包对数据进行t检验.结果:25例患者的眶下神经损伤得到恢复,神经恢复时间在4～6个月,平均25周;3例患者未能恢复,成为永久性损伤.未发现慢性神经性疼痛患者.结论:大部分骨折后眶下神经损伤是暂时的、可恢复的,极少数为永久性损伤.对伤后6个月神经功能仍未恢复的患者,可考虑行眶下神经减压术.     

Investigation of infraorbital nerve injury following zygomaticomaxillary complex fractures

Summary 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.     

Prospective study on post-traumatic and postoperative sensory disturbances of the inferior alveolar nerve and infraorbital nerve in mandibular and midfacial fractures.

In a prospective study (January 1999 to December 1997), 34 patients with 26 mandibular and 20 midfacial fractures were investigated. All the fractures were managed by osteosynthesis. To evaluate the incidence and duration of recovery of post-traumatic and postoperative sensory disturbances, the following tests were carried out: sharp/blunt testing, and the two-point discrimination test as conventional clinical examination methods, and electromyographic recording of the masseter reflex to calibrate the clinical findings. To establish the sensory status of the inferior alveolar and the infraorbital nerves in the region of the fracture, and on the intact and control sides, the tests were performed pre-operatively and postoperatively on the seventh day, after 4 weeks and after 3, 6 and 12 months. The incidence of post-traumatic sensory disturbance was 46% for mandibular fractures and 65% for fractures to the midface (sharp/blunt test, two-point discrimination test). The rate of postoperative sensory disturbance in surgical treatment of mandibular fracture involving the region of the intra bony course of the inferior alveolar nerve, including the post-traumatic sensory disturbance, was 76.9%, and 55% following surgical treatment of midfacial fractures. The incidence of persistent sensory disturbances following surgical treatment was 7.7% in the case of mandibular fractures, and 15% in the case of midfacial fractures (sharp/blunt test, two-point discrimination test, masseter reflex). Recovery of neurological function is delayed in the presence of a displaced fracture (> 1 mm) as compared with non-displaced fractures. For the postoperative calibration of sensory disturbances, electromyographic recording of the masseter reflex from the fourth postoperative week onwards has proved useful.     

Technical innovation: transfacial approach for infraorbital nerve exploration and orbital-maxillary surgery.

A transfacial approach for infraorbital nerve exploration and maxillary surgery has been developed, allowing for good visual access as far posteriorly as the foramen rotundum and anterior maxillary region. This allows for infraorbital osteotomies, peripheral nerve grafting, neurolysis procedures, or combined maxillofacial-neurosurgical procedures with gasserian ganglion exploration and/or grafting. The procedure affords maximum surgical accessibility with good postoperative healing and minimal concerns about potential oral contamination.