INCIDENCE OF COMPLICATIONS OF INFERIORALVEOLAR NERVE BLOCK INJECTION
BDS, OMFS, DSC. Nasser Nooh^"BDS, MSC, PhD, Walid A. Abdullah^
^Associate Professor; Head Division and Consultant of oral and maxillofacial surgery,Faculty of dentistry, King Saud University (KINGDOM OF SAUDI ARABIA)
^Assistant Professor; Consultant of Oral and Maxillofacial Surgery, Faculty of dentistry,King Saud University (Kingdom of Saudi Arabia), and lecturer of Oral and Maxillofacial Surgery,
Faculty of dentistry, Mansoura University (EGYPT)•Corresponding author; nnooh6(Q)qmail.com
ABSTRACT
Objective: The aim of this study was to assess the immediate complications after injection of inferior alveolarnerve block (lANB) using a modified indirect technique. Patients and Methods: A total of 5000 lANB injections wasperformed by an oral and maxillofacial surgeon for a total of 3454 adults. Patients with hyperthyroidism were excludedfrom the study. The following data were collected; name, age, sex, and side of the lANB. Furthermore, the presence ofany complication was noted as well as its type, persistence, and severity. All data were analyzed using SPSS (SPSSInc., Chicago, IL), and descriptive statistics were generated. Results: Failures of lANB and the need for secondinjections were seen in 48 patients (1%). Positive aspirations were noted in 84 patients (1.7%). Blanching of the cheekwas found in four patients (0.08%), which persisted for about 5 minutes. Two patients (0.04%) had electrical painradiating to the tongue. In addition, facial paralysis was seen in one patient (0.02%), persisting about 4 hours, andthere were two cases of blurred vision (0.04%) Conclusion: Based on the results and within the limitations of thestudy, the following can be concluded; This technique shows lower failure rate, lower positive aspiration rate, and lowerincidence of facial paralysis than the standard technique described by Malamed. In addition, aspiration is importantbefore the deposition of the anesthetic solution in lANB,
Key words: immediate complications, inferior alveolar nerve block, oral and maxillofacial surgery
INTRODUCTION
Probably one of the most common procedures in dentistry is the administration of local anesthetic,^ The inferioralveolar nerve block (lANB) is the most frequently used mandibular injection technique for achieving looal anesthesiafor restorative and surgical procedures,'^
In 1884, Halsted and Hall described the first inferior alveolar regional nerve block by injecting an anestheticsolution ( cocaine) into the area of the mandibular foramen ^ Then, Fischer , described the classic technique which,was modified later by many authors." Nowadays, most of the dentists all-around the world are using a techniquesimilar to the one described by Jorgensen and Hayden in 1967, which targeting the mandibular nerve. '̂ although,there are some complications associated with this standard lANB technique, it is still considered by many authors asthe technique with the least complications, safest administration, and least discomfort to the patients.
An anesthetic complication can be defined as any deviation from the normally expected pattern during or afterthe injection of local anesthesia.^ Complications of local anesthesia can be classified as local or systemic. Thesecomplications may include local and/or systemic immediate post-injection, as failure, needle breakage, penetration of ablood vessel, hematoma, nerve damage, facia! nerve paresis, blanching, and reactions (eg, overdose, allergy,idiosyncrasy).^^
Different techniques are used in lANB. Therefore, the aim of this study was to assess the incidence, types, andseverity of the complication(s) of lANB injection given using a modified, indirect injection technique. This study issimitar to research by Joseph et a l \ this current study focused only on the inferior alveolar nerve injection with a largernumber of injections for more reliable and accurate results.
PATIENTS AND METHODS
PatientsThis study period was from March 2001 to November 2008 with 3,454 adults Saudi patients who received a
total of 5000 lANB injections. Only patients with hyperthyroidism were excluded. The study involved 1841 females and1613 males between 17 to 56 years old with a mean age of 36. The reasons for lANB injections were extractions ofwisdom teeth (74.7%) and extractions of other mandibular posterior teeth (25.3%) (Table 1). Only patients who aretreated at Oral and Maxillofacia! surgery clinic are included in this study. All patients are Saudi referred for extraction ofthe lower Molar teeth.
lANB TechniqueAll the lANB injections were done by one experienced oral and maxillofacial surgeon using the same syringe
design and Icng 27-gauge needles (Fig.1). The needle was inserted from the opposite premolar to touch the antero-medial aspect of the ramus 1.5 cm above the occlusion level (Fig.2), then the needle was redirected by moving thesyringe to the same side of injection above the occlusion level (Fig. 3). Then the needle was advanced in contact withthe bone 75% of the needle length should be inserted( about 30 to 34 mm ) (Figs- 4,5).
Fig. 1. Syringe design and long 27'gaugeneedle used in the study
Fig. 2. The needle was inserted from the oppositepremolar to touch the antero-medial aspect of the
ramus 1.5 cm above the occlusion level
Fig. 3. The needle was redirected by moving thesyringe to the same side of injection above the
occlusion level
Fig. 4. The needle was advanced in contactwith the bone 75% of the needle length
(about 30 to 34 mm)
Fig. 5. Showing the length of the needle thatshould be inserted before deposition of the
Table 1. Demographic characteristics of participating subjects
Male
Female
total
number
1613
1841
3454
Age
18;56yMean (37y)
17;52yMean (35y)
Mean (36y)
BilaterallANB
582(1164injections)
964(1928injections)1546(3092injections)5000 lANB
UnilaterallANB
1031
877
1908
injections
Cause(wisdomteethextractions)1718
2017
3735
74.7 %
Cause(other lower posteriorteeth extractions)
477
788
1265
25 3%
If there is no bone contact, the needle is withdrawn and redirected until having bone contact, we never injectunless we have a bone contact. Aspiration was performed, and then 1.8 cc of local anesthesia solution (2% lidocainewith 1;100,000 epinephrine 1.8 cc cartridge) was deposited for the anesthesia of inferior alveolar and lingual nerves.Then 0.3 cc of 2% lidocaine with 1;100,000 epinephrine solutions was injected in the buccal sulcus opposing to theaffected tooth as an infiltration to the long buccal nerve.
We used only one 18 cc cartridge of (2% lidocaine with 1;100,000 epinephrine) in all patients as lANB at thestart of the procedure, then if patients showed improper anesthetic effect for extraction we injected with a secondcartridge and considered as a failure in the first injection trail.
Data Collection and Statistical AnalysisIn all patients, the following data were collected: name, age, sex, and side of the lANB The presence of any
complications was noted, including type, persistence, and severity. All data were analyzed using SPSS, anddescriptive statistics were generated. . • •
RESULTS
A total of 5000 lANB injections were administered during the study period. Failures and the need for a secondinjection occurred in 48 patients (1%). Positive aspirations were noted in 84 patients (1.7%). Blanching of the cheekwas seen in four patients (0.08%), which persisted about 5 minutes. Two cases of blurred vision (0.04%) wererecorded in two female patients, both on the right side (lANB), and both patients showed complete improvement afterabout 7 minutes. Two patients (0.04%) had electrical pain radiating to the tongue. One person had facial paralysis(0.02%), which persisted about 4 hours.
Needle breakage, overdose, allergy or idiosyncrasy, and persistent nerve damage were not found in anypatient. Table 2 summarizes the incidence of compiications and their duration in all patients.
Table 2. Number (%) of complications encountered following lANB
Complication
FailurePositive aspirationBlanching
Blurred visionFacial paralysisElectrical pain
Incidence number
48844
212
percentage
= 1 %17%0.08 %0.04 %0.02%0.04 %
duration
=4 minutes
= 7 minutes4 hours
DISCUSSION
According to failure rate, this study showed lANB failure was present in =1% of lANB injections. These resultswere significantly different from previous studies.^•^•'' Wong and Jacobsen ^ reported a failure rate of 5% to 15%. Inaddition, Malamed^ identified the inferior alveolar nerve block as the injection with the highest clinical failure rate (15%to 20%) when properly administered. Furthermore, Malamed attributed failure to a high degree of variation in themorphology of the mandibular ramus and the location of the mandibular foramen; however, improper technique is themost common reason for failure.^'^ ̂ Because of the specialty in which lANB is given, the authors' results showed lowerfailure rate (1%) when compared with the results of Cohen et al^ and Nusstein et al̂ '̂ who reported that the failure rateof lANB to be between 38% and 75% of the time in their endodontic clinical trails-
Most of the time, success rates are reportedly higher when a single individual's first demonstration ofanesthesia success is published. A random prospective trial would be required using a standard technique forconnparison.
The authors of this current study saw a reasonably tow positive aspiration rate (1.7%) compared with the resultsof previous studies.^^•''^TaghaviZenouz et a l " reported an incidence of 15.3%, while Blanton and Roda ^̂ stated thatthey had a positive aspiration rate of 10% to 15%. This relatively high percentage was decreased in the Gow-Gatestechnique to 1.6% to 1,9%''^
Garcia et al^^ and Brodsky and Dower̂ ** indicated the lANB method is superior to the Gow-Gates technique inpercentages of mtravascular puncture, this is related to the large quantity of vascular elements present in thepterygomandibular space. For this reason, it has been stated that the lANB technique is risky for patients who havesome kind of blood dyscrasias.''^ From this point, the authors consider their technique to be more superior to thestandard regular lANB injection method, as it has a significantly different positive aspiration rate and a comparableresult with Gow-Gates.
Although there is a significant difference between the authors' study results regarding positive aspiration (1.7%)and those of Frangiskos et al̂ ® (20%), the authors of this paper agree with them that intravascular injection of localanaesthetic during inferior alveolar nerve block is more or less a common complication. So aspiration is mandatorybefore the solution deposition during lANB. However, the authors disagree with Mariis et al,̂ *" who stated thataspiration is not necessary because complications from intravascular injection of local anesthesia are uncommon.Because even if the incidence is very low, yet the complication ( if happened) is serious , so we have to do ourprecautions to avoid this low incidence complication by making aspiration prior to each lANB injection.
Visual problems include blurnng of vision or blindness, which can be temporary or permanent. Motor problemsinclude mydriasis, palpebra! ptosis, and diplopia. Horner-like manifestations involving ptosis, enophthalmos and miosisof the eye also have been reported.''^"^° Fortunately, most complications in the eye are transient. Rood ^̂ reported acase in which 1.5 mL of lidocaine with epinephrine (1:80,000) in lANB, immediate loss of vision developed in theipsilateral eye. along with upper-eyelid ptosis. Yet, within 5 minutes to 45 minutes, all symptoms had disappeared.Unfortunately, cases of permanent complications also have been reported.^°'^^ In this study, the incidence of blurredvision was (0.04%), which was improved completely within 7 minutes. This result is in agreement with what wasreported by Ngeow et al.^^
The authors agree with Uckan et aP that blanching and ischemia are reported as rare local complications oflocal anesthesia Blanching incidence in the current study was (0.08%) Few articles document patients and clinicalphotographs.
Needle breakage was not seen during the study, and the authors agree with Lustig and Zusman^ who reportedneedles now are made of one piece of metal tube with a soft piastic hub. Occurrences of needle breakage are reportedanecdotally; better manufacturing techniques and single use may account for this.
The incidence of temporary facial palsy in this study (0.02%) was less than Keetley and Moles' results,^" whichfound a 0.3% rate. The facial nerve is embedded in the substance of the parotid gland, which has a deep lobeextending around the posterior ramus oî the mandible and projecting forward on the medial surface of the ramus. If theinjection is made too far posteriorly, the anesthetic solution may be injected into the substance of the parotid gland andcould involve the facial nerve. If this happens, the patient will complain immediately of an inability to blink the eye.followed by a sense of paralysis on the same side of the face.^^
CONCLUSION
The authors' technique shows lower failure rate, lower positive aspiration rate, and lower incidence of facialparalysis compared with the standard technique described by Malamed.^ Aspiration is important before the depositionof the anesthetic solution in lANB.
REFERENCES
1. Lustig JP, Zusman SP. Immediate complications of local anesthetic administered to 1,007consecutive patients. J Am Dent Assoc 1999; 130(4):496-499.
2. Hannan L, Reader A. Nist R, et al. The use of ultrasound for guiding needle placement for inferioralveolar nerve blocks. Ora! Surg Oral Med Oral Pathol Oral Radiol Endod 1999;87(6):658-665.
3. Johnson TM, Badovinac R, Shaefer J. Teaching alternatives to the standard inferior alveolar nerveblock in dental education: outcomes in clinical practice. J Dent Educ. 2007;71(9): 1145-1152.
4. Waikakul A, Punwutikorn J. A comparative study of the extra-intraoral landmark technique and thedirect technique for inferior alveolar nerve block. J Oral Maxillofac Surg. 1991,49(8) 804-808.
5. Malamed SF. Handbook of Local Anesthesia.AXh ed. St. Louis, MO: C.V. Mosby Co.; 1997.6. Bennett RC. Monheim's Local Anesthesia and Pain Control in Dental Practice.lXh ed St. Louis, MO:
C.V. Mosby Publishing, 1984.7. Wong MK, Jacobsen PL. Reasons for local anesthesia failures. J Am Dent Assoc 1992-123(1)-69-
73.8. Madan GA, Madan SG, Madan AD. Failure of inferior alveolar nerve block: exploring the alternatives.
9. Cohen HP, Cha BY, Spängberg LS. Endodontic anesthesia in mandibular molars: a clinical study. JEndod. 1993;19(7):370-373.
10. Nusstein J, Reader A, Nist R, et al. Anesthetic efficacy of the supplemental intraosseous injection of2%!idocaine with 1:100,000 epinephrine in irreversible pulpitis. J Endod. 1998;24(7):487-491.
11. Zenouz AT, Ebrahimi H, Mahdipour M, et al. The incidence of intravascular needle entrance duringinferior alveolar nerve block injection. Journal of Dental Research Dental Clinics Dental Prospects.2008;2(1):38-41.
12. Blanton PL, Roda RS. The anatomy of local anesthesia. J Calif Dent Assoc. 1995,23(4):55-58.13. Apolinar GP, Blanca GM, José MMJ. Risks and complications of local anaesthesia in dental office:
current situation. RCOE. 2003;8(1):41-63. ( article in Spanish).14. Brodsky CD, Dower JS Jr. Middle ear problems after a Gow-Gates injection. J Am Dent Assoc.
2001;132(10):1420-1424.15. Piot B, Sigaud-Fiks M, Huet P, et al. Management of dental extractions in patients with bleeding
disorders. Oral Surg Oral Med Oral Pathol Oral Radio! Endod. 2002;93(3):247-250.16. Frangiskos F, Stavrou E, Merenditis N, et al. Incidence of penetration of a blood vessel during
inferior alveolar nerve block. BrJOral Maxillofac Surg. 2003;41(3):188-18917- Martis C, Karabouta-Voulgaropoulou E, Marti K. Aspiration in inferior alveolar nerve block.
Stomatologia. 1986;43:273-278.18. Ngeow WC, Shim CK, Chai WL. Transient loss of power of accommodation in 1 eye following inferior
alveolar nerve block: report of 2 cases. J Can Dent Assoc. 2006;72(10):927-93119- Webber B, Orlansky H, Lipton C, et al. Complications of an intra-arterial injection from an inferior
alveolar nerve block. J Am Dent Assoc. 2001; 132(12):1702-170420. Tomazzoli-Gerosa L, Marchini G, Monaco A. Amaurosis and atrophy of the optic nerve: an unusual
complication of mandibular-nerve anesthesia. Ann Ophthalmol. 1988;20(5): 170-171.21 Rood JP. Ocular complication of inferior dental nerve block, A case report. Br Dent J.
1972;132(1):23-24.22. Peñarrocha-Diago M, Sanchis-Bielsa JM. Ophthalmologic complications after intraoral local
anesthesia with articaine. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2000;90(1 ):21-24.1. 23 Uckan S, Cilasun U, ErkmanO. Rare ocular and cutaneous complication of inferior alveolar nerve
block. J Oral Maxillofac Surg. 2006;64(4):719-721.23. Keetley A, Moles DR A clinical audit into the success rate of inferior alveolar nerve block analgesia
in general dental practice. Prim Dent Care.2001i8(4):139-142.24. Blanton PL, Jeske AH; ADA Council on Scientific Affairs; ADA Division of Science. Avoiding
complications in local anesthesia induction: anatomical considerations. J Am Dent Assoc.2003;134(7):888-893.
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