College of Dentistry, The Ohio State University, Columbus, Ohio 43210, USA.
J Am Dent Assoc. 2010 Feb;141(2):185-92. doi: 10.14219/jada.archive.2010.0137.
The efficacy of the extraoral infraorbital nerve block has not been studied sufficiently to ensure its appropriate clinical use. To compare the local anesthetic efficacy of the extraoral versus the intraoral infraorbital nerve block, the authors conducted a prospective, randomized crossover study.
Forty adult participants randomly received extraoral infraorbital nerve blocks of 1.8 milliliters of 2 percent lidocaine with 1:100,000 epinephrine at one appointment and intraoral infraorbital nerve blocks of 1.8 mL of 2 percent lidocaine with 1:100,000 epinephrine at another appointment in a crossover design. After administering the injections, the authors used an electric pulp tester to assess the maxillary central and lateral incisors, canine, premolars and first molar for pulpal anesthesia in four-minute cycles for 60 minutes. They considered anesthesia to be successful when the participant had no response to two consecutive 80 readings (the maximum output) with the electric pulp tester.
The authors found that the extraoral and intraoral infraorbital nerve blocks were ineffective in providing profound pulpal anesthesia of the maxillary central incisor (15 percent success rate) and lateral incisor (22 percent success rate). The pulpal anesthesia success rate was 92 percent for the canine for both types of nerve blocks, 80 to 90 percent for first and second premolars and 65 to 70 percent for the first molar, with no significant differences (P < .05) between the two nerve blocks. Pulpal anesthesia did not last for an hour in any of the teeth. Needle insertion pain and postoperative sequelae were more common after the extraoral infraorbital nerve block was administered.
Both nerve blocks would be ineffective in the central and lateral incisors. Both nerve blocks would be somewhat successful in the canine and premolars but not in the first molar.
眶下神经的眶外注射的疗效尚未得到充分研究，无法确保其在临床上的合理应用。为比较眶外和眶内注射的局部麻醉效果，作者进行了一项前瞻性、随机交叉研究。
40 名成年参与者在交叉设计中，随机在一次就诊时接受 1.8 毫升 2%利多卡因加 1:100000 肾上腺素的眶外神经阻滞，另一次就诊时接受 1.8 毫升 2%利多卡因加 1:100000 肾上腺素的眶内神经阻滞。注射后，作者使用电活力计在 60 分钟内每 4 分钟评估上颌中切牙、侧切牙、尖牙、前磨牙和第一磨牙的牙髓麻醉情况，共评估 60 分钟。当参与者用电活力计连续两次 80 读数（最大输出）均无反应时，作者认为麻醉成功。
作者发现眶外和眶内神经阻滞均无法有效提供上颌中切牙（成功率 15%）和侧切牙（成功率 22%）的深度牙髓麻醉。两种神经阻滞的尖牙牙髓麻醉成功率均为 92%，第一和第二前磨牙为 80%至 90%，第一磨牙为 65%至 70%，两种神经阻滞之间无显著差异（P<.05）。任何牙齿的牙髓麻醉均未持续 1 小时。眶外神经阻滞后，针插入疼痛和术后后遗症更为常见。
两种神经阻滞在中切牙和侧切牙均无效。两种神经阻滞在尖牙和前磨牙中会有些效果，但在第一磨牙中无效。
