- Email: [email protected]
Response to letter from Professor Valmaseda-Castellon
Vol. 116 No. 5 November 2013
LETTERS TO THE EDITOR Risk of lingual nerve damage: lingual split vs ostectomy with burs To the Editor: I read with great interest the article entitled “Lingual split versus surgical bur technique in the extraction of impacted mandibular third molars: a systematic review,” written by Dr. Ben Steel.1 It addresses an interesting subject: whether or not extraction of lower third molars using a chisel is better than using a bur, which is the most popular method nowadays (I dare say the gold standard). This systematic review of randomized clinical trials seems insufficient to answer the question, due to the scarcity of analyzed reports, the methodological concerns (for instance, some randomized controlled trials have an insufficient power to detect differences in infrequent complications such as lingual nerve injuries) and the heterogeneity of outcomes. But in my opinion, it risks giving the wrong message. The main concerns with the lingual split technique, from my point of view, are two: the confort of the patient and the risk of lingual nerve injury. The first issue is patient’s confort, the use of chisels being perceived by many conscious patients as very uncomfortable. Indeed, in 2 out of 4 included studies the extractions were performed under general anesthesia. It should be taken into account that third molar extraction is usually safely performed under local anesthesia, with or without sedation, and general anesthesia is usually more costly and less safe. On the other hand, the selected randomized clinical trials have small sample sizes to detect differences in lingual nerve injury (taking into account that the risk of this complication is low). Besides, some reports suggest that manipulation of the lingual flap (either using a lingual approach or a vestibular approach and lingual flap retraction) is responsible for the occurrence of lingual nerve injuries.2-4 Not raising the lingual flap at all seems to be the best way to avoid lingual nerve injury. In conclusion, there is, as the author honestly state, a weak evidence that both techniques have similar neurological sequelae. But current evidence supports the use of a buccal approach, without unnecessary manipulation of the lingual flap to “protect” the lingual nerve. Yours, Eduard Valmaseda-Castellón, DDS, PhD Professor of Oral Surgery, Faculty of Dentistry
658
University of Barcelona, UB IDIBELL Institute Oral and Maxillofacial Surgery, Feixa Llarga sn Campus de Bellvitge Facultat d’Odontologia 08005 L’Hospitalet de Llobregat Barcelona, Spain REFERENCES 1. Steel B. Lingual split versus surgical bur technique in the extraction of impacted mandibular third molars: a systematic review. Oral Surg Oral Med Oral Pathol Oral Radiol. 2012;114: 294-302. 2. Pichler JW, Beirne OR. Lingual flap retraction and prevention of lingual nerve damage associated with third molar surgery: a systematic review of the literature. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2001;91:395-401. 3. Valmaseda-Castellón E, Berini-Aytés L, Gay-Escoda C. Lingual nerve damage after third lower molar surgical extraction. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2000;90:567573. 4. Queral-Godoy E, Figueiredo R, Valmaseda-Castellón E, BeriniAytés L, Gay-Escoda C. Frequency and evolution of lingual nerve lesions following lower third molar extraction. J Oral Maxillofac Surg. 2006;64:402-407.
http://dx.doi.org/10.1016/j.oooo.2013.04.022
Response to letter from Professor Valmaseda-Castellon In reply: I would like to thank Professor ValmasedaCastellon for his interest in my paper and appreciate his comments. I agree that this systematic review is insufficient to fully answer the question of whether a chisel or surgical bur is better in the extraction of impacted mandibular third molars. My quality analysis of the small number of included RCTs showed small patient cohorts with heterogeneous results. This leads to only weak conclusions being possible. These weak conclusions mean that the nonrandomized observational studies I mentioned in the discussion section assume more importance. Taken in combination with the review, a broader view of the current evidence would be obtained. Therefore this review only forms a small piece of the jigsaw, as many factors, such as the raising of a lingual flap as the Professor mentions, could exert an influence on outcomes. The aim with this paper was to consider only randomized studies and thus hopefully present a combined analysis based on only the most rigorous and reliable type of study, which has not to my knowledge
OOOO Volume 116, Number 5
LETTERS TO THE EDITOR
659
been done previously on this matter. Unfortunately, as with many systematic reviews, the included RCTs proved to be of low quality and prevented a definitive answer being reached as to which technique is best. I am sure that clinicians working in this field would recognize the lack of high quality evidence available to compare these 2 techniques as shown by this review. This serves to illustrate the need for good quality clinical studies such that these questions can be more reliably answered. Kind regards, Ben Steel, BDS, MFDS, RCSEd Hull York Medical School Hertford Building University of Hull HULL, HU6 7RX United Kingdom
http://dx.doi.org/10.1016/j.oooo.2013.04.023
Under-recognized: inflammatory trigeminal neuropathy To the Editor: We recently reported a case of an inflammatory inferior alveolar neuropathy occurring after an ipsilateral inferior alveolar block and amalgam restoration of a patient’s lower right second molar tooth.1 Analogous to inflammatory brachial plexopathy (neuralgic amyotrophy, ParsonageeTurner syndrome),2,3 inflammatory trigeminal neuropathy (ITN) is an important yet underrecognized differential diagnosis for postprocedural neurological symptoms in the dental setting. We recently recognized another case of ITN following dental surgery indicating that the prevalence of ITN is likely to be greater than previously recognized and highlighting the importance of practitioner awareness of this condition. A 36-year-old woman, previously well apart from a history of postnatal depression, underwent extraction of third molar teeth (18, 38, 48) under general anesthetic with no intra-operative complications. She awoke postoperatively with a feeling of numbness involving the left lower lip and left side of tongue, which did not resolve. On day 3 she began to experience a “searing” burning sensation in the same distribution, associated with allodynia and exacerbated by movement of the jaw and tongue. Dental review on day 5 noted trismus (15 mm opening), as well as the development of numbness and allodynia of the anterior two-thirds of the left side of tongue. Her symptoms of discomfort became increasingly severe, and around day 14 the dysesthesia and allodynia spread further to involve
the left upper palate. Symptoms persisted and at dental review approximately 3 weeks postoperatively she was commenced on prednisolone (Solone; Valeant Pharmaceuticals Australasia Pty Ltd, Rhodes, NSW, Australia) 10 mg daily. Magnetic resonance imaging (MRI) of the mandible performed at 4 weeks showed a small localized hematoma (maximum dimensions 14 4 7 mm) adjacent to the left mandibular foramen. There was no evidence of temporomandibular joint arthropathy or effusion on computed tomography or MRI. When symptoms failed to improve she was referred to an orofacial pain specialist who increased prednisolone to 30 mg daily and commenced pregabalin (Lyrica; Pfizer Australia Pty Ltd, West Ryde, NSW, Australia), low dose nocturnal amitriptyline (Endep, Alphapharm Pty Ltd, Millers Point, NSW, Australia), and duloxetine (Cymbalta; Eli Lilly Australia Pty Ltd, West Ryde, NSW, Australia). Partial improvement in symptoms was achieved, however she was subsequently referred to a neurologist for further evaluation and management. No further abnormalities were identified on neurological examination. In this patient, the evolving neurological symptoms are the key to recognizing the diagnosis as ITN rather than iatrogenic injury.1 In inflammatory neuropathies, neuropathic pain and patchy sensorimotor changes evolve in the days-weeks after the procedure. The neurological distribution of these symptoms is often a further clue to the correct diagnosis: symptoms extend beyond the area supplied by the “iatrogenically injured” nerve. In this case, although imaging showed a localized hematoma at the left mandibular foramen, branches of both the maxillary and mandibular nerves were affected and therefore the hematoma alone could not account for the symptoms. Furthermore, if symptoms were due to hematoma or injury at the time of local anesthetic injection, they would be expected to be maximal at onset and improving over the ensuing weeks rather than worsening.4 Our approach to treatment, based upon experience with inflammatory brachial plexopathy and recognition that ITN is most likely an immune-mediated condition, is early intervention with high-dose prednisolone (e.g., 1 mg/kg orally and reducing over 7-10 days according to pain response). As the initial pain is inflammatory, a reduction in the inflammatory response may be very effective in ameliorating the pain. If sensory nerve injury has occurred then medications for treating neuropathic pain such as gabapentin (Neurontin, Pfizer Australia Pty Ltd, West Ryde, NSW, Australia), pregabalin, and amitriptyline may be helpful, with more potent analgesics (e.g., opioids) occasionally required. Early recognition and treatment of ITN is the key to management. Effective and timely multimodal analgesic therapy may prevent the transition from acute to chronic pain with its associated morbidity.5 In addition, early
LETTERS TO THE EDITOR Risk of lingual nerve damage: lingual split vs ostectomy with burs To the Editor: I read with great interest the article entitled “Lingual split versus surgical bur technique in the extraction of impacted mandibular third molars: a systematic review,” written by Dr. Ben Steel.1 It addresses an interesting subject: whether or not extraction of lower third molars using a chisel is better than using a bur, which is the most popular method nowadays (I dare say the gold standard). This systematic review of randomized clinical trials seems insufficient to answer the question, due to the scarcity of analyzed reports, the methodological concerns (for instance, some randomized controlled trials have an insufficient power to detect differences in infrequent complications such as lingual nerve injuries) and the heterogeneity of outcomes. But in my opinion, it risks giving the wrong message. The main concerns with the lingual split technique, from my point of view, are two: the confort of the patient and the risk of lingual nerve injury. The first issue is patient’s confort, the use of chisels being perceived by many conscious patients as very uncomfortable. Indeed, in 2 out of 4 included studies the extractions were performed under general anesthesia. It should be taken into account that third molar extraction is usually safely performed under local anesthesia, with or without sedation, and general anesthesia is usually more costly and less safe. On the other hand, the selected randomized clinical trials have small sample sizes to detect differences in lingual nerve injury (taking into account that the risk of this complication is low). Besides, some reports suggest that manipulation of the lingual flap (either using a lingual approach or a vestibular approach and lingual flap retraction) is responsible for the occurrence of lingual nerve injuries.2-4 Not raising the lingual flap at all seems to be the best way to avoid lingual nerve injury. In conclusion, there is, as the author honestly state, a weak evidence that both techniques have similar neurological sequelae. But current evidence supports the use of a buccal approach, without unnecessary manipulation of the lingual flap to “protect” the lingual nerve. Yours, Eduard Valmaseda-Castellón, DDS, PhD Professor of Oral Surgery, Faculty of Dentistry
658
University of Barcelona, UB IDIBELL Institute Oral and Maxillofacial Surgery, Feixa Llarga sn Campus de Bellvitge Facultat d’Odontologia 08005 L’Hospitalet de Llobregat Barcelona, Spain REFERENCES 1. Steel B. Lingual split versus surgical bur technique in the extraction of impacted mandibular third molars: a systematic review. Oral Surg Oral Med Oral Pathol Oral Radiol. 2012;114: 294-302. 2. Pichler JW, Beirne OR. Lingual flap retraction and prevention of lingual nerve damage associated with third molar surgery: a systematic review of the literature. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2001;91:395-401. 3. Valmaseda-Castellón E, Berini-Aytés L, Gay-Escoda C. Lingual nerve damage after third lower molar surgical extraction. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2000;90:567573. 4. Queral-Godoy E, Figueiredo R, Valmaseda-Castellón E, BeriniAytés L, Gay-Escoda C. Frequency and evolution of lingual nerve lesions following lower third molar extraction. J Oral Maxillofac Surg. 2006;64:402-407.
http://dx.doi.org/10.1016/j.oooo.2013.04.022
Response to letter from Professor Valmaseda-Castellon In reply: I would like to thank Professor ValmasedaCastellon for his interest in my paper and appreciate his comments. I agree that this systematic review is insufficient to fully answer the question of whether a chisel or surgical bur is better in the extraction of impacted mandibular third molars. My quality analysis of the small number of included RCTs showed small patient cohorts with heterogeneous results. This leads to only weak conclusions being possible. These weak conclusions mean that the nonrandomized observational studies I mentioned in the discussion section assume more importance. Taken in combination with the review, a broader view of the current evidence would be obtained. Therefore this review only forms a small piece of the jigsaw, as many factors, such as the raising of a lingual flap as the Professor mentions, could exert an influence on outcomes. The aim with this paper was to consider only randomized studies and thus hopefully present a combined analysis based on only the most rigorous and reliable type of study, which has not to my knowledge
OOOO Volume 116, Number 5
LETTERS TO THE EDITOR
659
been done previously on this matter. Unfortunately, as with many systematic reviews, the included RCTs proved to be of low quality and prevented a definitive answer being reached as to which technique is best. I am sure that clinicians working in this field would recognize the lack of high quality evidence available to compare these 2 techniques as shown by this review. This serves to illustrate the need for good quality clinical studies such that these questions can be more reliably answered. Kind regards, Ben Steel, BDS, MFDS, RCSEd Hull York Medical School Hertford Building University of Hull HULL, HU6 7RX United Kingdom
http://dx.doi.org/10.1016/j.oooo.2013.04.023
Under-recognized: inflammatory trigeminal neuropathy To the Editor: We recently reported a case of an inflammatory inferior alveolar neuropathy occurring after an ipsilateral inferior alveolar block and amalgam restoration of a patient’s lower right second molar tooth.1 Analogous to inflammatory brachial plexopathy (neuralgic amyotrophy, ParsonageeTurner syndrome),2,3 inflammatory trigeminal neuropathy (ITN) is an important yet underrecognized differential diagnosis for postprocedural neurological symptoms in the dental setting. We recently recognized another case of ITN following dental surgery indicating that the prevalence of ITN is likely to be greater than previously recognized and highlighting the importance of practitioner awareness of this condition. A 36-year-old woman, previously well apart from a history of postnatal depression, underwent extraction of third molar teeth (18, 38, 48) under general anesthetic with no intra-operative complications. She awoke postoperatively with a feeling of numbness involving the left lower lip and left side of tongue, which did not resolve. On day 3 she began to experience a “searing” burning sensation in the same distribution, associated with allodynia and exacerbated by movement of the jaw and tongue. Dental review on day 5 noted trismus (15 mm opening), as well as the development of numbness and allodynia of the anterior two-thirds of the left side of tongue. Her symptoms of discomfort became increasingly severe, and around day 14 the dysesthesia and allodynia spread further to involve
the left upper palate. Symptoms persisted and at dental review approximately 3 weeks postoperatively she was commenced on prednisolone (Solone; Valeant Pharmaceuticals Australasia Pty Ltd, Rhodes, NSW, Australia) 10 mg daily. Magnetic resonance imaging (MRI) of the mandible performed at 4 weeks showed a small localized hematoma (maximum dimensions 14 4 7 mm) adjacent to the left mandibular foramen. There was no evidence of temporomandibular joint arthropathy or effusion on computed tomography or MRI. When symptoms failed to improve she was referred to an orofacial pain specialist who increased prednisolone to 30 mg daily and commenced pregabalin (Lyrica; Pfizer Australia Pty Ltd, West Ryde, NSW, Australia), low dose nocturnal amitriptyline (Endep, Alphapharm Pty Ltd, Millers Point, NSW, Australia), and duloxetine (Cymbalta; Eli Lilly Australia Pty Ltd, West Ryde, NSW, Australia). Partial improvement in symptoms was achieved, however she was subsequently referred to a neurologist for further evaluation and management. No further abnormalities were identified on neurological examination. In this patient, the evolving neurological symptoms are the key to recognizing the diagnosis as ITN rather than iatrogenic injury.1 In inflammatory neuropathies, neuropathic pain and patchy sensorimotor changes evolve in the days-weeks after the procedure. The neurological distribution of these symptoms is often a further clue to the correct diagnosis: symptoms extend beyond the area supplied by the “iatrogenically injured” nerve. In this case, although imaging showed a localized hematoma at the left mandibular foramen, branches of both the maxillary and mandibular nerves were affected and therefore the hematoma alone could not account for the symptoms. Furthermore, if symptoms were due to hematoma or injury at the time of local anesthetic injection, they would be expected to be maximal at onset and improving over the ensuing weeks rather than worsening.4 Our approach to treatment, based upon experience with inflammatory brachial plexopathy and recognition that ITN is most likely an immune-mediated condition, is early intervention with high-dose prednisolone (e.g., 1 mg/kg orally and reducing over 7-10 days according to pain response). As the initial pain is inflammatory, a reduction in the inflammatory response may be very effective in ameliorating the pain. If sensory nerve injury has occurred then medications for treating neuropathic pain such as gabapentin (Neurontin, Pfizer Australia Pty Ltd, West Ryde, NSW, Australia), pregabalin, and amitriptyline may be helpful, with more potent analgesics (e.g., opioids) occasionally required. Early recognition and treatment of ITN is the key to management. Effective and timely multimodal analgesic therapy may prevent the transition from acute to chronic pain with its associated morbidity.5 In addition, early