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Neurologic complications arising from overfilled root canals
Neurologic complications arising from overfilled root canals Report
of a case
An unusual case of neurologic complications following overfilling of the root canals of two mandibular premolars has been reported. Extraction of the teeth, followed by periapieal curettage, did not prove to be an effective treatment. The neuralgia was finally treated definitively by wide resection of the mental nerve.
T
he danger of overfilling root canals has always been recognized by endodontists, but their wish to carry out adequate treatment leads sometimes to problems arising from damaged dental nerves. Not many such eases have been published in the dental literature. Orlay reportetl two cases of overfilling-one of a maxillary premolar and one of a mandibular molar, both of which gave signs of trigeminal neuralgia with posttreatment numbness and paresthesia. Kramer’ reported an overfilled mandibular molar which produced similar complaints. In order to make a differential diagnosis, a diligent search must be made for the underlying cause. Various etiologic factors” are considered responsible for nerve injury: contusion, compression, elongation, and the severing of nerves by bone fractures. A simple etiologic factor such as an overfilled root will illustrate, in the case presented here, the complexity of the problem with which a dentist might be faced. CASE REPORT A 53.year-old married woman was directed in the lower left lip, chin, and teeth. *Lecturer, **Lecturer,
684
Oral Surgery Department. Oral Medicine Department.
to the dental
clinic
complaining
of acute pain
Volume Number
35 5
Neurologic
Fig. 2. Intraoral treatment and filling.
roentgenogram of mandibular Note overfillings.
Fig. 8. Extraoral persistent radiopaque
roentgenogram of mandibular premolar foreign material just below sockets.
problems
from overfilled
premolars
root canals
upon completion
area following
685
of endodontic
extractions.
Note
One year prior to admission, enclodontic treatment and filling had been performed on both lower left premolars (Fig. 1). Immediately afterward, she had complained of pain, paresthesia, and a feeling of “pins and needles. ” Over this period of time, the treatment consisted of renewal of the root canal fillings, medication with tranquilizers, sedatives, analgesics, and specific antineuralgic drugs (Tegretol), and, finally, extraction of the teeth. This treatemnt was without benefit to the patient. Clinical examination on admission revealed evidence of neuralgia of the left mental nerve. Roentgenograms of the mandibular region disclosed two radiopaque foreign bodies close to the mental foramen just below the sockets of the extracted teeth (Fig. 2). A diagnostic mental nerve block (lidocaine) completely relieved the symptoms of which the patient complained. In the belief that the foreign bodies might be the cause of the neuralgia, the area was explored. One of the foreign bodies was removed from the mental nerve sheath and the other was removed from the mental foramen. The mental foramen was widened in order to avoid postoperative pressure due to edema (Fig. 3). There was an immediate postoperative improvement, followed by a gradual return of the symptoms over a period of 3 weeks. Supportive mental block anesthesia with hyaluronidase was given in an attempt to avoid more drastic treatment. The very temporary periods of mild improvement led to a decision to inject alcohol by mental block. This treatment also was unsuccessful.
686
Shochuf
n77rl
Gn+ud;el
Oral Surg. May, 1973
Fig. .3. Roentgenogram of same area following surgical removal of foreign material from mandibular nerve sheath and mental forxmen. Mental foramen was widened in order to avoid postoperative pressure due to edema.
Reoperation and a neurectomy, removing 1 cm. of the mental nerve, provided the final solution to the neuralgia 5 months after the first intervention. Microscopic examination of the nerve specimen failed to divclose any pathologic condition. Follow-up over s period of 4 months revealed anesthesia over the left mental nerve distribution, as xell as of the left mandibular anterior teeth.
DISCUSSION
We believe that the initial complaint of hyperesthesia of the lower lip was due to permanent irritation of the left mental nerve by foreign material, removal of which did not free the patient of her symptoms. This is explained by the cicatricial changes produced and the local inflammation that can maintain the clinical picture of persistent neuralgia.” This statement brings us to a comparison of treatment by means of cutting the nerve in cases of essential neuralgia and in cases of traumatic neuralgia. Little is known about the causes or mechanisms of neuralgias. The use of Tegretol gives some support to patients with trigeminal neuralgia,” but sooner or later surgical treatment must be employed. In the case reported here, where the involved nerve is surrounded by bone, any slight edema can lead to neuritis. Another important notion is that every surgical treatment is subject to relapse, the more peripheral the nerves, more frequent is the relapse.5 The neurectomy in such cases as the one reported here must be as wide as possible in order to prevent nerve regeneration.‘j, 7 Various author+ a have reported success in experiments with different methods of preventing nerve regeneration, for example, alcohol injection, impregnation with silver nitrate, electrocoagulation, and obturation of the inferior dental nerve canal by gold foil, silver plug, or silicone rubber. Another possibility that should be kept in mind in differential diagnosis is that of traumatic neuroma. Swanson9 has stat,ed that “irritation produced by foreign bodies in contact with or lodged against a nerve” can cause a traumatic neuroma. This tumor can produce not only local pain but also pain extending to other regions innervated by the same nerve. Such a neuroma can form around any severed nerve. In our treatment with alcohol injection and resection of the
Volume Number
35 5
Neurologic
problenls
from
overfilled
root canals
687
nerve, we were taking this possibility into account. However, the histopathologic report did not confirm a diagnosis of traumatic neuroma. Reports have claimed that excision of the neuroma offers complete relief from symptoms.1° At the time of our first attempt to treat the neuralgia only by curettage of the foreign material, additional decompression of the mental nerve was performed. IVIerrillll has shown that decompression of an injured alveolar nerve facilitates nerve regeneration and the degree of myelination. Gardener and Miklos*” have stated that decompression is successful in the treatment of trigeminal neuralgia. The hyaluronidase injection given after removal of the foreign body did not lessen the compression and stretching action of the newly formed scar tissue, and thus did not ease the symptoms. Perhaps it should have been started earlier. In discussing this case, one has to take into consideration that the untoward reactions might have been produced not only by the pressure of the foreign material on the nerve but also by the irritating pharmacologic action of this foreign material. In a case described by White,13 removal of a medicated paper point from the mental foramen provided complete relief after months of burning sensation around the mandibular second premolar, irradiating to the lower lip. The possibility that the symptoms might be psychogenic in origin was also considered, but this seemed most unlikely as the patient appeared to be emotionally stable.14 SUMMARY
AND
CONCLUSIONS
An unusual case of neurologic complications following overfilling of the root canals of two mandibular premolars has been presented. The long course of the disease with only partial success of the treatment has been discussed. The most radical treatment, consisting of wide resection of the involved nerve, proved to be the treatment of choice for traumatic neuralgia. The psychologic aspect of the problem may play an important role during the period of treatment, although it was not accentuated in this case. The attitude of the treating team toward the patient helped to maintain the patient’s confidence, leading to complete elimination of symptoms. We believe that in similar cases it is still worthwhile to try a conservative approach at the beginning of treatment. REFERENCES
Two Accidents With N2, Br. Dent. J. 1. Orlay, H. G. : Overfilling in Root Canal Therapy; 120: 376 1966 Material in the Mandibular Canal, Quintessenz 17: 25-26, 1966. 2. Kramer, ‘T. : Root Filling 3. Champy, M. : Nerve Injury in Stomatology, Rev. Stomatol. 64: 193-206, 1963. of Trigeminal Neuralgia, Excerpta Medica Inter4. Rasmussen, P.: Tegretol in Treatment national Congress Series No. 110, Copenhagen, 1965, Geigy, pp. 23-28. 5. Delaire, Y.: Consideration of Neurectomy of Inferior Dental Nerve, Rev. Stomatol. 63: 945-959, 1962. 6. Thoma, K. M.: Oral Surgery, ed. 5, St. Louis, 1969, The C. V. Mosby Company, p. 770. 7. Cogan, M. I.: Evaluation of Silicone Rubber in Preventing Inferior Alveolar Nerve Regeneration, J. Oral Surg. 26: 95-101, 1968. 8. White, N. S., and Snyder, S. R.: An Unusual Case of Nerve Regeneration; Report of a Case, J. Oral Surg. 28: 453-454, 1970. 9. Swanson, H. H. : Traumatic Neuromas; a Review of the Literature, ORAL SURG. 14: 317-326, 1961.
688
Bhochnt
trnd
Gnrfudd
Oral Surg. May, 1973
10. Nelson, J. E’. : Central Amputation Neuroma of Mandible ; Report of a Case, J. Oral Surg. 22: 124-126, 1964. 11. Merrill, R. G. : Further Studies in Decompression for Inferior Alveolar Nerve Injury, J. Oral Surg. 24: 233-238, 1966. 12. Gardener, W. J., and Miklos, M. V.: Response of Trigeminal Neuralgia to Decompression of Sensory Root: Discussion of Cause of Trigeminal Neuralgia, J. A. M. A. 170: 17731776,
1959.
Report of a Case, OR~U, SURG. 25: 630-632, 13. White, E.: Paper Point in Mental Foramen; 1968. Diagnosis, 14. Seward, M. H. E.: Anaesthesia of the Lower Lip; n Problem in Differential Rr. Dent. J. 113: 423-426, 1962. Reprint reqzlests to : Dr. Simon Shochat School of Dental Medicine Hebrew University Jerusalem, Israel
of a case
An unusual case of neurologic complications following overfilling of the root canals of two mandibular premolars has been reported. Extraction of the teeth, followed by periapieal curettage, did not prove to be an effective treatment. The neuralgia was finally treated definitively by wide resection of the mental nerve.
T
he danger of overfilling root canals has always been recognized by endodontists, but their wish to carry out adequate treatment leads sometimes to problems arising from damaged dental nerves. Not many such eases have been published in the dental literature. Orlay reportetl two cases of overfilling-one of a maxillary premolar and one of a mandibular molar, both of which gave signs of trigeminal neuralgia with posttreatment numbness and paresthesia. Kramer’ reported an overfilled mandibular molar which produced similar complaints. In order to make a differential diagnosis, a diligent search must be made for the underlying cause. Various etiologic factors” are considered responsible for nerve injury: contusion, compression, elongation, and the severing of nerves by bone fractures. A simple etiologic factor such as an overfilled root will illustrate, in the case presented here, the complexity of the problem with which a dentist might be faced. CASE REPORT A 53.year-old married woman was directed in the lower left lip, chin, and teeth. *Lecturer, **Lecturer,
684
Oral Surgery Department. Oral Medicine Department.
to the dental
clinic
complaining
of acute pain
Volume Number
35 5
Neurologic
Fig. 2. Intraoral treatment and filling.
roentgenogram of mandibular Note overfillings.
Fig. 8. Extraoral persistent radiopaque
roentgenogram of mandibular premolar foreign material just below sockets.
problems
from overfilled
premolars
root canals
upon completion
area following
685
of endodontic
extractions.
Note
One year prior to admission, enclodontic treatment and filling had been performed on both lower left premolars (Fig. 1). Immediately afterward, she had complained of pain, paresthesia, and a feeling of “pins and needles. ” Over this period of time, the treatment consisted of renewal of the root canal fillings, medication with tranquilizers, sedatives, analgesics, and specific antineuralgic drugs (Tegretol), and, finally, extraction of the teeth. This treatemnt was without benefit to the patient. Clinical examination on admission revealed evidence of neuralgia of the left mental nerve. Roentgenograms of the mandibular region disclosed two radiopaque foreign bodies close to the mental foramen just below the sockets of the extracted teeth (Fig. 2). A diagnostic mental nerve block (lidocaine) completely relieved the symptoms of which the patient complained. In the belief that the foreign bodies might be the cause of the neuralgia, the area was explored. One of the foreign bodies was removed from the mental nerve sheath and the other was removed from the mental foramen. The mental foramen was widened in order to avoid postoperative pressure due to edema (Fig. 3). There was an immediate postoperative improvement, followed by a gradual return of the symptoms over a period of 3 weeks. Supportive mental block anesthesia with hyaluronidase was given in an attempt to avoid more drastic treatment. The very temporary periods of mild improvement led to a decision to inject alcohol by mental block. This treatment also was unsuccessful.
686
Shochuf
n77rl
Gn+ud;el
Oral Surg. May, 1973
Fig. .3. Roentgenogram of same area following surgical removal of foreign material from mandibular nerve sheath and mental forxmen. Mental foramen was widened in order to avoid postoperative pressure due to edema.
Reoperation and a neurectomy, removing 1 cm. of the mental nerve, provided the final solution to the neuralgia 5 months after the first intervention. Microscopic examination of the nerve specimen failed to divclose any pathologic condition. Follow-up over s period of 4 months revealed anesthesia over the left mental nerve distribution, as xell as of the left mandibular anterior teeth.
DISCUSSION
We believe that the initial complaint of hyperesthesia of the lower lip was due to permanent irritation of the left mental nerve by foreign material, removal of which did not free the patient of her symptoms. This is explained by the cicatricial changes produced and the local inflammation that can maintain the clinical picture of persistent neuralgia.” This statement brings us to a comparison of treatment by means of cutting the nerve in cases of essential neuralgia and in cases of traumatic neuralgia. Little is known about the causes or mechanisms of neuralgias. The use of Tegretol gives some support to patients with trigeminal neuralgia,” but sooner or later surgical treatment must be employed. In the case reported here, where the involved nerve is surrounded by bone, any slight edema can lead to neuritis. Another important notion is that every surgical treatment is subject to relapse, the more peripheral the nerves, more frequent is the relapse.5 The neurectomy in such cases as the one reported here must be as wide as possible in order to prevent nerve regeneration.‘j, 7 Various author+ a have reported success in experiments with different methods of preventing nerve regeneration, for example, alcohol injection, impregnation with silver nitrate, electrocoagulation, and obturation of the inferior dental nerve canal by gold foil, silver plug, or silicone rubber. Another possibility that should be kept in mind in differential diagnosis is that of traumatic neuroma. Swanson9 has stat,ed that “irritation produced by foreign bodies in contact with or lodged against a nerve” can cause a traumatic neuroma. This tumor can produce not only local pain but also pain extending to other regions innervated by the same nerve. Such a neuroma can form around any severed nerve. In our treatment with alcohol injection and resection of the
Volume Number
35 5
Neurologic
problenls
from
overfilled
root canals
687
nerve, we were taking this possibility into account. However, the histopathologic report did not confirm a diagnosis of traumatic neuroma. Reports have claimed that excision of the neuroma offers complete relief from symptoms.1° At the time of our first attempt to treat the neuralgia only by curettage of the foreign material, additional decompression of the mental nerve was performed. IVIerrillll has shown that decompression of an injured alveolar nerve facilitates nerve regeneration and the degree of myelination. Gardener and Miklos*” have stated that decompression is successful in the treatment of trigeminal neuralgia. The hyaluronidase injection given after removal of the foreign body did not lessen the compression and stretching action of the newly formed scar tissue, and thus did not ease the symptoms. Perhaps it should have been started earlier. In discussing this case, one has to take into consideration that the untoward reactions might have been produced not only by the pressure of the foreign material on the nerve but also by the irritating pharmacologic action of this foreign material. In a case described by White,13 removal of a medicated paper point from the mental foramen provided complete relief after months of burning sensation around the mandibular second premolar, irradiating to the lower lip. The possibility that the symptoms might be psychogenic in origin was also considered, but this seemed most unlikely as the patient appeared to be emotionally stable.14 SUMMARY
AND
CONCLUSIONS
An unusual case of neurologic complications following overfilling of the root canals of two mandibular premolars has been presented. The long course of the disease with only partial success of the treatment has been discussed. The most radical treatment, consisting of wide resection of the involved nerve, proved to be the treatment of choice for traumatic neuralgia. The psychologic aspect of the problem may play an important role during the period of treatment, although it was not accentuated in this case. The attitude of the treating team toward the patient helped to maintain the patient’s confidence, leading to complete elimination of symptoms. We believe that in similar cases it is still worthwhile to try a conservative approach at the beginning of treatment. REFERENCES
Two Accidents With N2, Br. Dent. J. 1. Orlay, H. G. : Overfilling in Root Canal Therapy; 120: 376 1966 Material in the Mandibular Canal, Quintessenz 17: 25-26, 1966. 2. Kramer, ‘T. : Root Filling 3. Champy, M. : Nerve Injury in Stomatology, Rev. Stomatol. 64: 193-206, 1963. of Trigeminal Neuralgia, Excerpta Medica Inter4. Rasmussen, P.: Tegretol in Treatment national Congress Series No. 110, Copenhagen, 1965, Geigy, pp. 23-28. 5. Delaire, Y.: Consideration of Neurectomy of Inferior Dental Nerve, Rev. Stomatol. 63: 945-959, 1962. 6. Thoma, K. M.: Oral Surgery, ed. 5, St. Louis, 1969, The C. V. Mosby Company, p. 770. 7. Cogan, M. I.: Evaluation of Silicone Rubber in Preventing Inferior Alveolar Nerve Regeneration, J. Oral Surg. 26: 95-101, 1968. 8. White, N. S., and Snyder, S. R.: An Unusual Case of Nerve Regeneration; Report of a Case, J. Oral Surg. 28: 453-454, 1970. 9. Swanson, H. H. : Traumatic Neuromas; a Review of the Literature, ORAL SURG. 14: 317-326, 1961.
688
Bhochnt
trnd
Gnrfudd
Oral Surg. May, 1973
10. Nelson, J. E’. : Central Amputation Neuroma of Mandible ; Report of a Case, J. Oral Surg. 22: 124-126, 1964. 11. Merrill, R. G. : Further Studies in Decompression for Inferior Alveolar Nerve Injury, J. Oral Surg. 24: 233-238, 1966. 12. Gardener, W. J., and Miklos, M. V.: Response of Trigeminal Neuralgia to Decompression of Sensory Root: Discussion of Cause of Trigeminal Neuralgia, J. A. M. A. 170: 17731776,
1959.
Report of a Case, OR~U, SURG. 25: 630-632, 13. White, E.: Paper Point in Mental Foramen; 1968. Diagnosis, 14. Seward, M. H. E.: Anaesthesia of the Lower Lip; n Problem in Differential Rr. Dent. J. 113: 423-426, 1962. Reprint reqzlests to : Dr. Simon Shochat School of Dental Medicine Hebrew University Jerusalem, Israel