Rapid orthodontic extrusion of crown root and cervical root fractured teeth Malmgren O, Malmgren B, Frykholm A. Rapid orthodontic extrusion of crown root and cervical root fractured teeth. Endod Dent Traumatol 1991; 7: 49-54. Abstract - This study concerns the relapse tendency and extent of root resorption in 33 extruded non-vital crown root fractured or cervical root fractured teeth in 32 patients 10-20 years old. They constitute all orthodontically extruded teeth at the Orthodontic or Pedodontic Departments, Eastman Institutet, Stockholm (1982-1987). A simple extrusion mechanism exerted a force of 60-70 p along the root axis of the tooth. An extrusion of 2-3 mm was obtained in most patients; the most extreme effect was 6 mm. In 16 patients the extrusion was achieved within 3 weeks, in 12 it lasted for 4—6 weeks and in 5, 7-9 weeks. The treatment was more complicated in the lower jaw. After the extrusion, a fibrotomy was done and in most patients also a gingival recontouring to create an optimal relation between the gingiva and the margin of the restoration. Periodically identical radiographs were taken immediately before and after the extrusion, after 3 months and after 1 year. A minor relapse, about 0.5 mm, was observed in 3 patients. Limited root resorption was found in 6 teeth and severe in only 1. The resorptions did not progress in the following 2 years of observation.
Prosthetic coronal restoration in a tooth with a complicated crown-root fracture or a cervical root fracture is unfavourable when the fracture line extends below the marginal bone level. Orthodontic extrusion to save such teeth was introduced by Heithersay 1973 (1) and further developed by Ingber 1974, 1976 (2, 3). Since then an increasing number of case presentations has been published, illustrating the rationale of this treatment (4-6). However, no prospective study elucidating the relapse tendency and the risk of root resorption has been published. The rapid extrusion involves stretching and readjustment of periodontal fibres, without marked bone remodelling due to the fast movement. It can thus be achieved without a coronal shift of marginal bone, thereby facilitating the coronal restoration because there is no need to reshape bone (5). Relapse may follow orthodontic extrusion, the primary reason being the stretched state of marginal periodontal fibres. Fibrotomy both before and immediately after the extrusion has been recommended to minimize the risk of relapse (7, 8). Rapid extrusion raises the question of damage to the root. Histoiogical studies
Olle Malmgren\ Barbro Mallngren^ Anders Frykholm^ Departments of 'Orthodontics, ^Pedodontics, 'Oral Radiology, Eastman Institute, Stockholm, Sweden
Key words: dental trauma; crown fracture; root fracture; crown-root fracture; orthodontic extrusion. 0. Malmgren, Department of Orthodontics, Eastmaninstitutet, Dalagatan 11, S-11324 Stockholm, Sweden. Accepted for publication June 26, 1990
of extruded human teeth indicate that root resorption is very rare (9, 10) but severe resorption of an extruded root has been reported by Artum and Aamdal (11). The aim of this study was to perform a prospective analysis of the relapse tendency and the risk of root resorption during orthodontic extrusion of nonvital teeth with crown-root or cervical root fractures. Material The study comprised all non-vital teeth with crownroot or cervical root fractures orthodontically extruded in 1982-87 at the Pedodontic or Orthodontic Department, Eastmaninstitutet, Stockholm. The treatment was given to 32 patients (10 girls, 22 boys) and included 28 upper and 3 lower incisors and 2 lower canines (one patient had 2 teeth extruded). The age of the patients ranged from 9.6 to 20.4 years, mean 14.0 years, at the time of the trauma that caused the fracture. In 24 patients an earlier trauma was registered at the age of 6.4 to 12.0 years.
fWalmgren et al.
Fig. 1. Frature types: A) Oblique (fracture below the marginal bone buccally); B) oblique (fracture below the marginal bone palatally); C) transverse; D) lateral.
mean 9.5 years. The interval between the first and the present trauma ranged from 0.7 to 5.8 years, mean 3.9 years. The different types of fracture (Types A to D) are illustrated in Fig. 1. The number of teeth of each type was: obhque fractures; oblique fractures; transverse fractures; lateral fractures;
Type Type Type Type
A: B: C: D:
12, 9, 5, 6.
In one tooth the fracture did not fit any ofthe types. At the time ofthe injury 16 teeth had a permanent and 8 a temporary rootfilling and 9 teeth were vital. Clinical methods The temporarily root-filled teeth were given permanent fillings before the extrusion. In these cases the crown was left in situ during the endodontic procedure. In six ofthe vital teeth there were sufficient coronal remnants for the adaptation of a rubber dam and a permanent root filling. Three teeth were filled temporarily with calcium hydroxide before the extrusion; in these teeth a button could be bonded to remnants ofthe enamel for the extrusion. After the extrusion an adequate permanent root filling was performed using gutta-percha and lateral condensation technique. The typical treatment sequence is illustrated in Figs. 2 and 3. An anchorage for the extrusion was 50
arranged in different ways. In nine teeth a cast core with a separate temporary crown was used; a hole was made in the cervical part of the core and also through the temporary crown; a steel ligature was threaded through the hole and used to fasten the spring to the tooth. Fig. 2(D, E). In 11 ofthe teeth a button could be bonded to enamel remnants of the tooth crown. In 13 teeth a screw post was cemented in the root canal. Fig. 3(1). A spring of Elgiloy wire (type blue, 0.016 x 0.016 inches) was used for the extrusion. The wire was fitted to brackets bonded to three of the neighbouring teeth, creating a force directed along the root axis of the tooth to be extruded. Fig. 3B. Before ligation the wire was heat treated and generated a force of about 60 to 70 p. In two patients, who already had an orthodontic fixed appliance, an elastic ligature to the archwire created the extrusion force. After the extrusion a fibrotomy and in most cases a gingivectomy was performed. Fig. 3F. Retention was achieved by bonding the extruded tooth to the neighbouring teeth in 22 cases (Fig. 3G) and in 11 cases the extrusion mechanism was made passive during the retention period. An extrusion of 2-3 mm was obtained in most patients; the most extreme effect was 6 mm. Fig. 4. In 16 patients the extrusion was achieved within 3 weeks; in 12 patients the treatment lasted for 4-6 weeks and in 5 patients 7-9 weeks. In one of the latter patients two lower incisors were extruded and in another a lower canine.
Rapid erthodontic tooth extrusion
Fig. 2. Treatment sequence I. A, B) Radiographs at the time of trauma, note the fracture line; the crown left in situ during endodontic procedure; C) radiograph taken 4 years after the extrusion, showing limited resorption; D) a cast core with a hole cervically; E) a temporary crown cemented to the cast core, with a hole and a ligature through the hole; F) permanent crown.
Follow-up
The periodontal conditions around the extruded roots were evaluated one year after treatment by probing the pocket depths. In an attempt to obtain periodically identical radiographic exposures of the extruded teeth a device for stereo comparison designed by one of us (A.F.) was used. The device has been described and used in an earlier study (12). In short, an acrylic splint was prepared for each patient. The sphnt was firmly connected to the filmholder and the x-ray source. The filmholder was adjusted parallel to the long axis ofthe tooth to be extruded, and the x-ray
beam was aligned perpendicular to the tooth. Two films, making a stereopair, were exposed on each occasion. The roentgen stereopairs were used for the evaluation of the extent of root resorption. Radiographs were taken with the device immediately before and after the extrusion, after 3 months and after 1 year. Further follow-up radiographs were taken in some cases with routine methods. The periodically obtained radiographs were studied with a tracing method on one of the films in the stereo pairs. The outlines ofthe tooth which had been extruded and neighbouring teeth were traced on the first film of the series and the tracing was superimposed on the neighbouring teeth on the follow-up 51
Malmgren et al.
Fig. 3. Treatment sequence II. A) The patient's own tooth used as a temporary crown, cemented with a screw post in the root canal; B) a heat-treated spring of Elgiloy wire (0.016x0.016 inches) with a force of about 60 to 70 p was used for the extrusion; C) after one week the root had been extruded 1.5 mm; D) the crown was shortened to enable further extrusion; E) after the second week the root had been extruded another 1.5 mm. The root was now available for preparation; F) a fibrotomy is made immediately before the retention period; G) the tooth bonded to the neighbouring teeth; H) permanent crown; I) radiograph before extrusion; J) radiograph after two weeks of extrusion; K) radiograph 2 years after extrusion: no signs of resorption.
films. The change in position of the extruded tooth was measured with a scale under a magnifying glass ( X 5) to the nearest tenth of a millimetre. Each measurement was made twice and the mean value was used. The method involved an error of 0.1 mm (12). The risk of root resorption during the extrusion was evaluated on the stereopair of radiographs taken before and one year after treatment. Resorption was classified as no resorption. Figs. 3(K), 4(C), limited resorption. Fig. 2(C), and severe resorption. Fig.
6(C).
Results In all extruded teeth a normal gingival pocket depth was found one year after treatment. A minor relapse, about 0.5 mm, was observed in three patients during the follow-up period. In one patient complete relapse occurred during the retention period due to a loosened temporary crown. This patient refused retreatment. Only a few teeth showed signs of root resorption one year after extrusion. Fig. 5. In six teeth a limited
Rapid orthodontic tooth oxtrusion Extrusion in
No of teeth
4,00-
0,00 Orthodontic extrusion of 33 teeth
Ho
Limited
Severe
Degree of root resorption
Fig, 5, Degree of root resorption evaluated 1 year after treatment.
Fig, 4, A) Extrusion of 33 teeth in mm evaluated 1 year after treatment: each bar represents one tooth; in one tooth there was a complete relapse due to a loosened temporary crown; B, C) extrusion of 6 mm obtained in one patient: no signs of resorption.
resorption on the apical part of the root was observed at the follow-up one year after treatment. An example is presented in Fig. 2(B, C); this tooth was extruded 3 mm. Only one tooth developed a severe resorption, Fig. 6. Discussion The cause of most of the severe cervical fractures was repeated trauma. Many of the teeth had been treated endodontically at an immature stage and the dentinal walls were thin. For a tooth with a complicated crown-root or cervical root fracture, two types of pertinent therapy are available: orthodontic extrusion and surgical extrusion (12 15). In teeth with thin dentinal walls orthodontic extrusion would seem to be more gentle. In the present study an extrusion of about 3 mm was obtained in most patients in 3 to 6 weeks by a rather simple orthodontic method. In a few patients the roots were extruded further and over a longer period. The treatment tended to be more complicated in the lower jaw, due to the difficulty of constructing an extrusion mechanism that does not interfere with occlusion.
The extrusion generally lead to a coronal shift of the marginal gingiva. It has been shown that this shift includes a proliferation of the gingival tissue and is not related to coronal displacement (3), most probably due to the rapid extrusion. In two case reports Weissman (9) has found that gingival fibrotomy immediately before the extrusion allows the tooth to extrude without bringing the gingiva with it. Porterio et al. (10) recommend repeated fibrotomies during treatment. In the present study, fibrotomy after the extrusion, often together with a gingival recontouring, was sufficient for an optimal relation between the gingiva and the margin of the restoration. In view of the different reports, however, further studies are needed to determine the optimal timing of fibrotomy. The minimal relapse tendency in this material might be a consequence ofthe fibrotomy. Only three teeth showed a minor relapse in the follow-up period. In 22 cases, retention was achieved by bonding the extruded tooth to the neighbouring teeth. This is generally known to provide poor retention in traumatized incisors, but in these patients the neighbouring teeth were well functioning and the bonding could be performed under controlled conditions. In three of the teeth a minor relapse was observed. A prolonged retention period with a bonded-wire retainer on the lingual aspect ofthe incisors in these cases might have been a favourable alternative. Only one tooth developed a severe root resorption. This may have arisen from a traumatic occlusion in connection with the prosthetic restoration after the extrusion. The resorption did not progress during the following two years of observation. There was no correlation between the degree of extrusion and root resorption. Gonciusions 1. A risk of relapse is always present after orthodontic extrusion of fractured teeth. To avoid relapse, fibrotomy should be performed before the reten53
Malmgren et ai.
Fig. 6. Treatment sequence III. A) Before treatment; B) immediately after extrusion; C) 1 year after extrusion: severe resorption; D) 3 years and 8 months after the extrusion: no progression of the resorption.
tion period, which should last for at least 3-4 weeks. 2. Root resorption as a consequence of rapid orthodontic extrusion is rare. 3. Rapid orthodontic extrusion is simple and safe.
8. 9. 10. 11.
Roferences 1.
2. 3. 4. 5. 6. 7.
54
Combined endodontic-orthodontic treatment of transverse root fractures in the region ofthe alveolar crest. Oral Surg Oral Med Oral Pathol 1973; 36: 404-15. INGBER J S . Forced eruption: Part I. A method of treating isolated one and two wall infrabony osseous defects - rationale and case report. J Periodontol 1974; 45: 199-206. INGBER JS. Forced eruption: Part II. A method of treating nonrestorable teeth - periodontal and restorative considerations. J Periodontol 1976; 47: 203-16. SIMON J H S . Root extrusion. Rationale and technique. Dent Clin North Am 1984; 28: 909-21. GoLDSON L, MALMGREN O . Orthodontic treatment of traumatized teeth. In: ANDREASEN J, ed. Traumatic injuries ofthe teeth. Copenhagen: Munksgaard, 1981. BENENATI F W , SIMON JHS. Orthodontic root extrusion: its rationale and uses. Gen Dent 1986; 34: 285-9. REITAN K . Clinical and histological observations on tooth movements during and after orthodontic treatment. Am J Orthod 1967; 55.- 72145. HEITHERSAY G S .
12. 13.
REITAN K . Initial tissue behavior during apical root resorption. Angle Orthod 1974; 44: 68-86. PERSON M , SERNEKE D. Ortodontisk framdragning av tand med cervikal rotfraktur for att mojliggora kronersattning. Tandldkartidningen 1977; 22: 1263-9. WEISSMAN J. Orthodontic extrusion of endodontically treated anterior teeth. Can Dent As,soc J 1983; 11: 21-4. PONTORIERO R , CELENZA F, RICCI G, CARNEVALE G . Rapid extrusion with fiber resection: a combined orthodontic periodontic treatment modality. Int J Period Rest Dent 1987; 5: 31-43. MALMGREN B, CVEK M , LUNDBERG M , FRYKHOLM A. Surgical treatment of ankylosed and infrapositioned reimplanted incisors in adolescents. Scand J Dent Res 1984; 92: 391-9. TEGSJO U , VALERIUS-OLSSON H , OLGART K . Intra-alveolar transplantation of teeth with cervical root fractures. Swed Dent J 1978; 2: 73-82.
14. TEGSJO U , VALERIUS-OLSSON H , FRYKHOLM A, OLGART K .
Clinical evaluation of intra-alveolar transplantation of teeth with cervical root fractures. Swed Dent J 1987; //.- 235-50. 15. KAHNBERG K - E . Intra-alveolar transplantation of teeth with crown-root fractures. J Oral Maxillofac Surg 1985; 43: 38-42. 16. KAHNBERG K - E . Surgical extrusion of root-fractured teeth - a follow-up study of two surgical methods. Endod Dent Traumatol 1988; 4: 85-9. 17. ARTUN J, AAMDAL H M A A . Severe root resorption of fractured maxillary lateral incisor following endodontic treatment and orthodontic extrusion. Endod Dent Traumatol 1987: 3: 263-7.
Prosthetic coronal restoration in a tooth with a complicated crown-root fracture or a cervical root fracture is unfavourable when the fracture line extends below the marginal bone level. Orthodontic extrusion to save such teeth was introduced by Heithersay 1973 (1) and further developed by Ingber 1974, 1976 (2, 3). Since then an increasing number of case presentations has been published, illustrating the rationale of this treatment (4-6). However, no prospective study elucidating the relapse tendency and the risk of root resorption has been published. The rapid extrusion involves stretching and readjustment of periodontal fibres, without marked bone remodelling due to the fast movement. It can thus be achieved without a coronal shift of marginal bone, thereby facilitating the coronal restoration because there is no need to reshape bone (5). Relapse may follow orthodontic extrusion, the primary reason being the stretched state of marginal periodontal fibres. Fibrotomy both before and immediately after the extrusion has been recommended to minimize the risk of relapse (7, 8). Rapid extrusion raises the question of damage to the root. Histoiogical studies
Olle Malmgren\ Barbro Mallngren^ Anders Frykholm^ Departments of 'Orthodontics, ^Pedodontics, 'Oral Radiology, Eastman Institute, Stockholm, Sweden
Key words: dental trauma; crown fracture; root fracture; crown-root fracture; orthodontic extrusion. 0. Malmgren, Department of Orthodontics, Eastmaninstitutet, Dalagatan 11, S-11324 Stockholm, Sweden. Accepted for publication June 26, 1990
of extruded human teeth indicate that root resorption is very rare (9, 10) but severe resorption of an extruded root has been reported by Artum and Aamdal (11). The aim of this study was to perform a prospective analysis of the relapse tendency and the risk of root resorption during orthodontic extrusion of nonvital teeth with crown-root or cervical root fractures. Material The study comprised all non-vital teeth with crownroot or cervical root fractures orthodontically extruded in 1982-87 at the Pedodontic or Orthodontic Department, Eastmaninstitutet, Stockholm. The treatment was given to 32 patients (10 girls, 22 boys) and included 28 upper and 3 lower incisors and 2 lower canines (one patient had 2 teeth extruded). The age of the patients ranged from 9.6 to 20.4 years, mean 14.0 years, at the time of the trauma that caused the fracture. In 24 patients an earlier trauma was registered at the age of 6.4 to 12.0 years.
fWalmgren et al.
Fig. 1. Frature types: A) Oblique (fracture below the marginal bone buccally); B) oblique (fracture below the marginal bone palatally); C) transverse; D) lateral.
mean 9.5 years. The interval between the first and the present trauma ranged from 0.7 to 5.8 years, mean 3.9 years. The different types of fracture (Types A to D) are illustrated in Fig. 1. The number of teeth of each type was: obhque fractures; oblique fractures; transverse fractures; lateral fractures;
Type Type Type Type
A: B: C: D:
12, 9, 5, 6.
In one tooth the fracture did not fit any ofthe types. At the time ofthe injury 16 teeth had a permanent and 8 a temporary rootfilling and 9 teeth were vital. Clinical methods The temporarily root-filled teeth were given permanent fillings before the extrusion. In these cases the crown was left in situ during the endodontic procedure. In six ofthe vital teeth there were sufficient coronal remnants for the adaptation of a rubber dam and a permanent root filling. Three teeth were filled temporarily with calcium hydroxide before the extrusion; in these teeth a button could be bonded to remnants ofthe enamel for the extrusion. After the extrusion an adequate permanent root filling was performed using gutta-percha and lateral condensation technique. The typical treatment sequence is illustrated in Figs. 2 and 3. An anchorage for the extrusion was 50
arranged in different ways. In nine teeth a cast core with a separate temporary crown was used; a hole was made in the cervical part of the core and also through the temporary crown; a steel ligature was threaded through the hole and used to fasten the spring to the tooth. Fig. 2(D, E). In 11 ofthe teeth a button could be bonded to enamel remnants of the tooth crown. In 13 teeth a screw post was cemented in the root canal. Fig. 3(1). A spring of Elgiloy wire (type blue, 0.016 x 0.016 inches) was used for the extrusion. The wire was fitted to brackets bonded to three of the neighbouring teeth, creating a force directed along the root axis of the tooth to be extruded. Fig. 3B. Before ligation the wire was heat treated and generated a force of about 60 to 70 p. In two patients, who already had an orthodontic fixed appliance, an elastic ligature to the archwire created the extrusion force. After the extrusion a fibrotomy and in most cases a gingivectomy was performed. Fig. 3F. Retention was achieved by bonding the extruded tooth to the neighbouring teeth in 22 cases (Fig. 3G) and in 11 cases the extrusion mechanism was made passive during the retention period. An extrusion of 2-3 mm was obtained in most patients; the most extreme effect was 6 mm. Fig. 4. In 16 patients the extrusion was achieved within 3 weeks; in 12 patients the treatment lasted for 4-6 weeks and in 5 patients 7-9 weeks. In one of the latter patients two lower incisors were extruded and in another a lower canine.
Rapid erthodontic tooth extrusion
Fig. 2. Treatment sequence I. A, B) Radiographs at the time of trauma, note the fracture line; the crown left in situ during endodontic procedure; C) radiograph taken 4 years after the extrusion, showing limited resorption; D) a cast core with a hole cervically; E) a temporary crown cemented to the cast core, with a hole and a ligature through the hole; F) permanent crown.
Follow-up
The periodontal conditions around the extruded roots were evaluated one year after treatment by probing the pocket depths. In an attempt to obtain periodically identical radiographic exposures of the extruded teeth a device for stereo comparison designed by one of us (A.F.) was used. The device has been described and used in an earlier study (12). In short, an acrylic splint was prepared for each patient. The sphnt was firmly connected to the filmholder and the x-ray source. The filmholder was adjusted parallel to the long axis ofthe tooth to be extruded, and the x-ray
beam was aligned perpendicular to the tooth. Two films, making a stereopair, were exposed on each occasion. The roentgen stereopairs were used for the evaluation of the extent of root resorption. Radiographs were taken with the device immediately before and after the extrusion, after 3 months and after 1 year. Further follow-up radiographs were taken in some cases with routine methods. The periodically obtained radiographs were studied with a tracing method on one of the films in the stereo pairs. The outlines ofthe tooth which had been extruded and neighbouring teeth were traced on the first film of the series and the tracing was superimposed on the neighbouring teeth on the follow-up 51
Malmgren et al.
Fig. 3. Treatment sequence II. A) The patient's own tooth used as a temporary crown, cemented with a screw post in the root canal; B) a heat-treated spring of Elgiloy wire (0.016x0.016 inches) with a force of about 60 to 70 p was used for the extrusion; C) after one week the root had been extruded 1.5 mm; D) the crown was shortened to enable further extrusion; E) after the second week the root had been extruded another 1.5 mm. The root was now available for preparation; F) a fibrotomy is made immediately before the retention period; G) the tooth bonded to the neighbouring teeth; H) permanent crown; I) radiograph before extrusion; J) radiograph after two weeks of extrusion; K) radiograph 2 years after extrusion: no signs of resorption.
films. The change in position of the extruded tooth was measured with a scale under a magnifying glass ( X 5) to the nearest tenth of a millimetre. Each measurement was made twice and the mean value was used. The method involved an error of 0.1 mm (12). The risk of root resorption during the extrusion was evaluated on the stereopair of radiographs taken before and one year after treatment. Resorption was classified as no resorption. Figs. 3(K), 4(C), limited resorption. Fig. 2(C), and severe resorption. Fig.
6(C).
Results In all extruded teeth a normal gingival pocket depth was found one year after treatment. A minor relapse, about 0.5 mm, was observed in three patients during the follow-up period. In one patient complete relapse occurred during the retention period due to a loosened temporary crown. This patient refused retreatment. Only a few teeth showed signs of root resorption one year after extrusion. Fig. 5. In six teeth a limited
Rapid orthodontic tooth oxtrusion Extrusion in
No of teeth
4,00-
0,00 Orthodontic extrusion of 33 teeth
Ho
Limited
Severe
Degree of root resorption
Fig, 5, Degree of root resorption evaluated 1 year after treatment.
Fig, 4, A) Extrusion of 33 teeth in mm evaluated 1 year after treatment: each bar represents one tooth; in one tooth there was a complete relapse due to a loosened temporary crown; B, C) extrusion of 6 mm obtained in one patient: no signs of resorption.
resorption on the apical part of the root was observed at the follow-up one year after treatment. An example is presented in Fig. 2(B, C); this tooth was extruded 3 mm. Only one tooth developed a severe resorption, Fig. 6. Discussion The cause of most of the severe cervical fractures was repeated trauma. Many of the teeth had been treated endodontically at an immature stage and the dentinal walls were thin. For a tooth with a complicated crown-root or cervical root fracture, two types of pertinent therapy are available: orthodontic extrusion and surgical extrusion (12 15). In teeth with thin dentinal walls orthodontic extrusion would seem to be more gentle. In the present study an extrusion of about 3 mm was obtained in most patients in 3 to 6 weeks by a rather simple orthodontic method. In a few patients the roots were extruded further and over a longer period. The treatment tended to be more complicated in the lower jaw, due to the difficulty of constructing an extrusion mechanism that does not interfere with occlusion.
The extrusion generally lead to a coronal shift of the marginal gingiva. It has been shown that this shift includes a proliferation of the gingival tissue and is not related to coronal displacement (3), most probably due to the rapid extrusion. In two case reports Weissman (9) has found that gingival fibrotomy immediately before the extrusion allows the tooth to extrude without bringing the gingiva with it. Porterio et al. (10) recommend repeated fibrotomies during treatment. In the present study, fibrotomy after the extrusion, often together with a gingival recontouring, was sufficient for an optimal relation between the gingiva and the margin of the restoration. In view of the different reports, however, further studies are needed to determine the optimal timing of fibrotomy. The minimal relapse tendency in this material might be a consequence ofthe fibrotomy. Only three teeth showed a minor relapse in the follow-up period. In 22 cases, retention was achieved by bonding the extruded tooth to the neighbouring teeth. This is generally known to provide poor retention in traumatized incisors, but in these patients the neighbouring teeth were well functioning and the bonding could be performed under controlled conditions. In three of the teeth a minor relapse was observed. A prolonged retention period with a bonded-wire retainer on the lingual aspect ofthe incisors in these cases might have been a favourable alternative. Only one tooth developed a severe root resorption. This may have arisen from a traumatic occlusion in connection with the prosthetic restoration after the extrusion. The resorption did not progress during the following two years of observation. There was no correlation between the degree of extrusion and root resorption. Gonciusions 1. A risk of relapse is always present after orthodontic extrusion of fractured teeth. To avoid relapse, fibrotomy should be performed before the reten53
Malmgren et ai.
Fig. 6. Treatment sequence III. A) Before treatment; B) immediately after extrusion; C) 1 year after extrusion: severe resorption; D) 3 years and 8 months after the extrusion: no progression of the resorption.
tion period, which should last for at least 3-4 weeks. 2. Root resorption as a consequence of rapid orthodontic extrusion is rare. 3. Rapid orthodontic extrusion is simple and safe.
8. 9. 10. 11.
Roferences 1.
2. 3. 4. 5. 6. 7.
54
Combined endodontic-orthodontic treatment of transverse root fractures in the region ofthe alveolar crest. Oral Surg Oral Med Oral Pathol 1973; 36: 404-15. INGBER J S . Forced eruption: Part I. A method of treating isolated one and two wall infrabony osseous defects - rationale and case report. J Periodontol 1974; 45: 199-206. INGBER JS. Forced eruption: Part II. A method of treating nonrestorable teeth - periodontal and restorative considerations. J Periodontol 1976; 47: 203-16. SIMON J H S . Root extrusion. Rationale and technique. Dent Clin North Am 1984; 28: 909-21. GoLDSON L, MALMGREN O . Orthodontic treatment of traumatized teeth. In: ANDREASEN J, ed. Traumatic injuries ofthe teeth. Copenhagen: Munksgaard, 1981. BENENATI F W , SIMON JHS. Orthodontic root extrusion: its rationale and uses. Gen Dent 1986; 34: 285-9. REITAN K . Clinical and histological observations on tooth movements during and after orthodontic treatment. Am J Orthod 1967; 55.- 72145. HEITHERSAY G S .
12. 13.
REITAN K . Initial tissue behavior during apical root resorption. Angle Orthod 1974; 44: 68-86. PERSON M , SERNEKE D. Ortodontisk framdragning av tand med cervikal rotfraktur for att mojliggora kronersattning. Tandldkartidningen 1977; 22: 1263-9. WEISSMAN J. Orthodontic extrusion of endodontically treated anterior teeth. Can Dent As,soc J 1983; 11: 21-4. PONTORIERO R , CELENZA F, RICCI G, CARNEVALE G . Rapid extrusion with fiber resection: a combined orthodontic periodontic treatment modality. Int J Period Rest Dent 1987; 5: 31-43. MALMGREN B, CVEK M , LUNDBERG M , FRYKHOLM A. Surgical treatment of ankylosed and infrapositioned reimplanted incisors in adolescents. Scand J Dent Res 1984; 92: 391-9. TEGSJO U , VALERIUS-OLSSON H , OLGART K . Intra-alveolar transplantation of teeth with cervical root fractures. Swed Dent J 1978; 2: 73-82.
14. TEGSJO U , VALERIUS-OLSSON H , FRYKHOLM A, OLGART K .
Clinical evaluation of intra-alveolar transplantation of teeth with cervical root fractures. Swed Dent J 1987; //.- 235-50. 15. KAHNBERG K - E . Intra-alveolar transplantation of teeth with crown-root fractures. J Oral Maxillofac Surg 1985; 43: 38-42. 16. KAHNBERG K - E . Surgical extrusion of root-fractured teeth - a follow-up study of two surgical methods. Endod Dent Traumatol 1988; 4: 85-9. 17. ARTUN J, AAMDAL H M A A . Severe root resorption of fractured maxillary lateral incisor following endodontic treatment and orthodontic extrusion. Endod Dent Traumatol 1987: 3: 263-7.
