See discussions, stats, and author profiles for this publication at: https://www.researchgate.net/publication/7425936 Nerve injury caused by mandibular block analgesia Article in International Journal of Oral and Maxillofacial Surgery · June 2006 DOI: 10.1016/j.ijom.2005.10.004 · Source: PubMed CITATIONS READS 135 208 2 authors: Søren Hillerup Rita Helen Jensen University of Copenhagen Oslo and Akershus University College of Appli… 81 PUBLICATIONS 977 CITATIONS 138 PUBLICATIONS 5,826 CITATIONS SEE PROFILE SEE PROFILE All in-text references underlined in blue are linked to publications on ResearchGate, Available from: Søren Hillerup letting you access and read them immediately. Retrieved on: 16 November 2016 Int. J. Oral Maxillofac. Surg. 2006; 35: 437–443 doi:10.1016/j.ijom.2005.10.004, available online at http://www.sciencedirect.com Clinical Paper Oral Medicine S. Hillerup1, R. Jensen2 Nerve injury caused by 1Department of Oral and Maxillofacial Surgery, Rigshospitalet, University of Copenhagen, Denmark; 2Danish Headache Center, Department of Neurology, Glostrup mandibular block analgesia Hospital, University of Copenhagen, Denmark S. Hillerup, R. Jensen: Nerve injury caused by mandibular block analgesia. Int. J. Oral Maxillofac. Surg. 2006; 35: 437–443. # 2005 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved. Abstract. Fifty-four injection injuries in 52 patients were caused by mandibular block analgesia affecting the lingual nerve (n = 42) and/or the inferior alveolar nerve (n = 12). All patients were examined with a standardized test of neurosensory functions. The perception of the following stimuli was assessed: feather light touch, pinprick, sharp/dull discrimination, warm, cold, point location, brush stroke direction, 2-point discrimination and pain perception. Gustation was tested for recognition of sweet, salt, sour and bitter. Mandibular block analgesia causes lingual nerve injury more frequently than inferior alveolar nerve injury. All grades of loss of neurosensory and gustatory functions were found, and a range of persisting neurogenic malfunctions was reported. Subjective complaints and neurosensory function tests indicate that lingual nerve lesions are more incapacitating than inferior alveolar nerve lesions. Unlike most mechanical injuries after surgery, injection injuries were not followed by a course of spontaneous improvement of neurosensory and/or gustatory Key words: nerve injury; injection; neurotoxi- function. This may indicate neurotoxicity as a central aetiological factor. Fifty-four city; Articaine 4%. percent of the nerve injuries were associated with Articaine 4%, and a substantial increase in the number of injection injuries followed its introduction to the Danish Accepted for publication 20 October 2005 market. Available online 15 December 2005 Mandibular block analgesia is normally a of 0.15–0.54%7,12 whereas permanent Direct physical fascicular damage may be safe and rewarding method of pain control injury caused by injection of local analge- caused by a penetrating injection needle, for interventions in dental and oral and sics is much less frequent, 0.0001– or by a damaged injection needle on maxillofacial surgery practice. Nerve 0.01%6,7,16 depending on mode of data retraction after bone contact7,12,21. Intra- injury caused by injection of local analge- collection, type of sample, etc. (Table 1). neural bleeding may exert pressure, and sics is considered as rare. Yet, a minor Subjective symptoms may be manifold subsequent constrictive scarring may fraction of patients do experience the and include impaired sensory function obstruct nerve conduction. Finally, HAAS 6 undesired side effects of a temporary or such as anaesthesia or hypaesthesia, and &LENNON suggested that local anaes- permanent impairment of neurosensory neurosensory disturbances of various thetic formulations may have the potential function after mandibular block analgesia kinds as paraesthesia, dysaesthesia, etc. for neurotoxicity, in particular Articaine with currently used local analgesics. Esti- Also, the gustatory function may be 4% and Prilocaine 3–4%. Experimentally, mates indicate a prevalence of temporarily affected in case of lingual nerve injury15. neurotoxicity has been demonstrated to impaired lingual and inferior alveolar Various views have been expressed to induce loss of conductivity and structural nerve function ranging in the order of size explain the mechanism of nerve injury. changes after intrafascicular microinjec- 0901-5027/050437 + 07 $30.00/0 # 2005 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved. 438 Hillerup and Jensen Table 1. Reports on nerve injury caused by inferior alveolar and lingual nerve block analgesia Author Temporary injury Permanent injury Study design, comment 12 KRAFFT &HICKEL <6 months, 0.15% >12 months, 0.008% Prospective study, N = 12.104 pts. interview 6 6 HAAS &LENNON ? 0.00013% Retrospective study, N > 1.1 Â 10 pts. ‘reported cases’ 7 HARN &DURHAM 0.54% >12 months, 0.01% Questionnaire study, N = 2.735 pts.; conservative dentistry and oral surgery pts. tion of local analgesic solutions of con- Neurosensory evaluation—interview and crimination), thermal stimuli (0 and centrations used in current clinical prac- clinical examination 45 8C) and stereotactic stimuli (point loca- tice3. tion and brush stroke direction)8,10,17,18. The aims of the present study were to All patients were interviewed and exam- Patients with injury to the LN were exam- ined according to a standardized test of ined for the presence of a traumatic neu- 10,17,18 Clarify the magnitude of sensory neurosensory functions by the same roma. An unpleasant, irradiating sensation impairment and the character of signs observer (S.H.) to clarify the subjective in the injured side of the tongue induced and symptoms in patients suffering sen- and objective neurosensory status of the by digital pressure to the region of sus- sory dysfunction after mandibular block injured nerve. A standardized record form pected injury at the medial aspect of the analgesia. was used. The terms applied to neurosen- mandibular ramus was interpreted as Follow and describe the level of func- sory and gustatory function and dysfunc- caused by a traumatic neuroma. tion/dysfunction over time. tion are listed and explained in Appendix The sensory function of each stimulus 23 Describe possible differences related to A according to SUNDERLAND . was evaluated with the unaffected side as type of analgesic agent. The patients were urged to describe control and scored according to the ratings their neurosensory deficit in plain words listed in Table 2. The sum of 7 semi- to be recorded in terms of anaesthesia, quantitative ratings for each patient Patients and methods hypaesthesia, normaesthesia or hyper- (feather light touch, pinprick, point/dull During the years 1997–2004 the first aesthesia with reference to the healthy discrimination, warm, cold, point location author (S.H.) examined 56 consecutive side. The patients rated their sense of and brush stroke direction, each ranging patients with injection injury to oral subjective sensory perception according from 0 to 3) constitutes the ‘sum score’, branches of the trigeminal nerve. Patients to the scores listed and explained in thus ranging from 0 to 218. were referred from all parts of the country Table 2. Patients seen less than 12 months after of Denmark housing a population of 5.5 Neurogenic signs and symptoms were the injury were offered 1 or more re- million inhabitants. Referrals were recorded as paraesthesia, dysaesthesia, examinations up till 12 months post injury, obtained from colleagues and the Danish including allodynia23. In case of injury to at least. Eighteen LN patients and 4 IAN Dental Association’s Patient Insurance the LN the patients were questioned about patients accepted follow-up examinations. Scheme covering all dental practitioners. their gustatory ability that might be rated as Nerve injuries causing symptoms beyond Criterion for inclusion: Nerve injury normal, missing (ageusia), deficient (hypo- 12 months after injury were considered caused by unilateral administration of geusia) or distorted (dysgeusia)4. permanent. inferior mandibular nerve block for con- The clinical examination included tests servative dental procedures (including one of pain perception (blink reflex or protec- Gustatory evaluation simple dental extraction). Inclusion of tive reaction on pinching with a tissue new patients terminated June 2004. forceps), 2-point discrimination thresh- The patients’ gustatory function was Criteria for exclusion: Neurological olds and tests of tactile stimuli (feather tested by topical application of sweet (sac- disease, known alcoholism, endodontic light touch, pinprick and point dull dis- charine 5%), salt (sodium chloride 5%), procedures that might affect inferior alveolar nerve (IAN) conduction, implant 8,10 surgery and oral and maxillofacial sur- Table 2. Applied rating scales of neurosensory and gustatory function gery. Likewise, injury to nerves other than Score the lingual nerve (LN) and the inferior Ratings of neurosensory function—pinprick, point/dull discrimination, alveolar nerve (IAN) were excluded warm, cold, point location and brush stroke direction (n = 4). No perception of stimulus 0 Records including date of injury, gen- Perception of touch or temperature without ability to discriminate 1 eric type and volume of local analgesic quality