Knowledge of the potential adverse reactions to mandibular block anesthesia is important in the practice of dentistry. This article presents a complication in the middle ear not previously reported.
Case Description
Unusual middle ear symptoms immediately followed the administration of 1.8 milliliters of 3 percent mepivacaine for a Gow-Gates mandibular block injection. Over the course of 10 days, the patient had complaints of inner ear pressure, inability to equilibrate ear pressure, decreased hearing, pain and severe headache before returning to normal without further complaints and complications.
Conclusions
The cause of the complications was either a hematoma, a technique problem causing trauma and inflammation, an anatomical variation or any combination of these.
Clinical Implications
Proper technique, knowledge of the anatomy of the injection area and familiarity with potential complications are important in the administration of local anesthetic.
Section snippets
CASE REPORT
During a local anesthetic practice exercise at the University of the Pacific School of Dentistry, San Francisco, a healthy 22-year-old male dental student was administered a Gow-Gates injection that resulted in complete anesthesia of the inferior alveolar, lingual and auriculotemporal nerves. A classmate, carrying out the procedure under one-on-one supervision from a trained and experienced faculty dentist, had noted a positive aspiration on needle insertion and thus adjusted the needle until a
DISCUSSION
The deposition site for the Gow-Gates mandibular block is approximately 1 millimeter from the neck of the condyle, below the insertion of the lateral pterygoid muscle in a relatively avascular fatty area.15 There have been inconsistent reports on the frequency of positive aspirations with the Gow-Gates injection. In 1977, Gow-Gates and Watson16 reported a 1.6 percent incidence of positive aspiration with this injection, far lower than the 7.9 percent average in eight studies in which a total of
CONCLUSIONS
Whether one is an inexperienced novice or an accomplished practitioner, proper technique is a very important aspect of administering local anesthetic. Without proper technique, the clinician may inflict pain on patients and incur complications unnecessarily. Therefore, when performing the Gow-Gates technique, the clinician should be sure to orient the syringe properly before puncturing the mucosa.2 One of the keys to mastering this technique is the lateral angulation of the needle, which must
The first is incomplete aspiration of the injection technique. One study has reported that the positive aspiration ratio of the inferior alveolar nerve block is only 7.9%.22 In addition, a needle can deviate out of the first injection point if the patient moves.
Many types of complications occur after intraoral local anesthesia; however, visual loss is a rare one. There have been only a few case reports of visual disturbance after intraoral local anesthesia. A 67-year-old man with systemic hypertension complained of visual disturbance after a dental local injection for circumzygomatic and circum-mandibular wire removal. Forty-nine days later, he had partly recovered his vision. To date, the exact mechanism of visual loss after dental injection remains unclear. This rare case could provide another clue to the etiology and caution against similar complications.
2012, Oral Surgery, Oral Medicine, Oral Pathology and Oral Radiology
Intraoral administration of local anesthetics is one of the most common dental procedures. Ophthalmologic complications can occur after maxillary as well as mandibular local anesthetic injections and may be underreported and sometimes misinterpreted. A review of the literature from the years 1936-2011 shows 131 cases with this type of complication. This case report presents a patient with right lateral rectus muscle palsy and blurred vision after bimaxillary anesthesia. Signs, symptoms, and pathophysiologic hypotheses of these complications are presented.
The Gow-Gates technique is said to have several advantages over traditional techniques to achieve mandibular nerve anesthesia; however, its routine use is quite limited, mainly due to complications during visual alignment of reference landmarks. The purpose of this study was to verify the validity and accuracy of a new method to reach the injection site.
Fifteen magnetic resonance images were captured. Distances from the ideal injection point in the condylar neck (puncture ideal) to the injection points located in the α and β plane intersection (puncture Gow-Gates and puncture modified) were measured and compared.
Positive and significant (P ≤ .003) Pearson correlations between landmarks and injection points confirmed the validity of the modified technique. Paired t test showed that the segment line puncture ideal–puncture modified, 5.17 mm, was 3 times shorter (P < .001) than the segment line puncture ideal–puncture Gow-Gates, 17.91 mm. As calculated by linear regression, establishing the injection point of the modified technique depended only on the anteroposterior and lateromedial condyle positions.
The modified technique proved to be valid and precise and has a determined and an effective injection site.
Dentists administer thousands of local anesthetic injections every day with few reports of serious complications. However, misjudging the anatomy involved during local anesthetic administration can result not only in inadequate or incomplete anesthesia, but in other complications such as paresthesia, bleeding or hematoma formation, or in serious systemic complications.
The authors discuss anatomical considerations that dentists should keep in mind when administering local anesthetic injections. In particular, they discuss ways in which dentists can minimize the risk of nerve or vascular injury, as well as systemic complications.
Even the most experienced practitioner can benefit from a periodic review of the anatomy associated with local anesthesia. This article offers dentists the opportunity to consider needle placement with regard to location of nerves, blood vessels and glands, and to review injection protocols that can minimize the risk of complications.
Dr. Dower is an associate professor, Restorative Dentistry, and the director, Local Anesthesia Curriculum, University of the Pacific School of Dentistry, 2155 Webster St., San Francisco, Calif. 94115-2333
