Replantation: An analysis of 29 teeth Fumihiko Gonda, DDS, Mamoru Nagase, DDS, PhD, Ruey-Bin Chen. DDS, PhD, Hideki Yakata, DDS, PhD, and Tamio Nakajima, DDS, PhD, Niigata, Japan FIRST DEPARTMENT NIIGATA
OF ORAL AND MAXILLOFACIAL
SURGERY,
SCHOOL OF DENTISTRY,
UNIVERSITY
The results of replantation of 29 teeth are described. Maxillary incisors constituted 85% of 27 permanent teeth. The period between avulsion and replantation ranged from within an hour to 88 days, but the actual extraoral period was within 5 hours in all but one case. Nineteen of the 27 permanent teeth were functioning for 7 months to 8 years and 7 months postoperatively. Root resorption was the cause of tooth loss in five cases. The incidence of root resorption seemed to increase with the increase of the extraoral period, but it was not affected by the period between avulsion and replantation, the condition of supporting tissues, the degree of root formation, and the type and period of splinting, indicating multiple factors involved in determining the prognosis of replanted teeth. In conclusion, every effort should be made to preserve avulsed teeth even in unfavorable conditions. (ORAL SURC ORAL MED ORAL PATHOL 1990;70:650-5)
R
eplantation has been widely accepted as an effective means of preserving avulsed teeth. They usually becomefirm and can endure function within a couple of months. The long-term fate of replanted teeth, however, is still unpredictable, inasmuch as they may undergo resorption and shed in several years. The time interval between avulsion and replantation, the condition during the extraoral period, the presenceor absenceof pulp and periodontal tissues, the type and period of splinting, and so forth have been claimed as the possible factors affecting the successrate of the procedure in experimental animals,le4 but accurate prediction of the fate of replanted teeth is not easy in clinical cases because a combination of these and many other factors may be involved. In this article the results of replantation of 29 teeth are described and factors influencing the prognosis of replantation are discussed. MATERIAL
AND METHODS
A total of 29 teeth that were replanted by members of our department after being avulsed in accidents or extracted accidentally or intentionally were included in this study. Replantation was done in a conventional manner in most cases. In a typical case in which a permanent tooth with completed root formation was 7/U/12657 650
replanted, the procedure included cleansing of the tooth surface in a physiologic saline solution containing an antibiotic, pulpectomy and root canal filling with gutta-percha, replacement into the alveolar socket, and splinting. The patients were usually given an antibiotic and placed on a soft diet for a given period after replantation. The replanted teeth were followed clinically and radiographically for 3 months to 8 years. RESULTS
Gender and age. The patients consisted of 8 males and 12 females. Their agesranged from 3 years to 44 years, but 16 of them were under 20 years of age. The mean age was 16 years. Type ofaccidents. Accidents during sports and play (seven cases), accidental falls (seven cases), and traffic accidents (five cases)were almost equally listed as the cause of tooth loss. Accidental extraction occurred on manipulation of a mouth gag during general anesthesiain one caseand from carelessmisdiagnosis in three cases. Replantation of a malpositioned tooth after intentional extraction was done for orthodontic reasons in one case. Type of affected teeth. Of 27 permanent teeth, 17 were maxillary central incisors and 7 were maxillary lateral incisors. Two deciduous teeth affected were also maxillary incisors and a canine. Three mandib-
Replantation
Volume 70 Number 5 Table
651
I. Period between avulsion and replantation No. of teeth (W)
Period (hr) o-1
5 (17) 12 (41)
l-3 3-12 12+
8 (28)
Total
Table II.
Extraoral period
Period (hr)
I
o-% E-2 2-5
No. of teeth (W) 16 (55) 3 (10) 9 (31)
5+ Total
Table Ill.
Type of splint Type
Surgical pack Acrylic splint Wire splint Orthodontic splint Total
Table IV.
No. of teeth (W) 2 (7) 4 (14)
11 (38)
Period of splinting
Period (wk) o-4 4-8
8-12
No. of teeth (W) 4 (14)
11 (38) 9 (31)
12+
Total
ular teeth included two lateral incisors and a first premolar. Period between avulsion and replantation. Including 5 teeth that were replanted within 30 minutes after avulsion, 17 teeth were replanted within 3 hours and 24 teeth within 6 hours. In two cases,6 days and 86 days, respectively, had passedbefore replantation, which was delayed becauseof other injuries requiring earlier treatment. Fortunately, the affected tooth had been kept in the alveolar bone after being wedged into it in both cases (Table I). Extraoralperiod. When defined as the period teeth were kept out of the mouth, the extraoral period varied from within 30 minutes to more than 5 hours, but it did not exceed 30 minutes in 16 cases (Table II). Condition of the alveolar bone. At the time of replantation, fractures of the surrounding alveolar bone
Fig. 1. A, Intraoral view 2 weeks after replantation of accidentally extracted upper left canine. B, Intraoral view 2 years after replantation. C, Dental radiograph immediately after replantation.D, Dental radiograph 2 years after replantation.
were noted grossly or radiographically in 14 cases, whereas in the 15 other casesthe alveolar bone was healthy except for the presenceof wounds caused by tooth loss. The labial alveolar bone had undergone extensive resorption in the case in which the affected tooth was replanted in a newly formed socket 86 days after avulsion. Preparation of a socket was done in another case in which a malpositioned maxillary lateral incisor was replanted for orthodontic reasons. In four cases,damage of the alveolar bone was such that
652
Gonda et al.
A . .
( bme
ORAL SLRC ORAL
,MED ORAL PATHOI. November 1990
fract
. . . . . . A i dental ca;
Fig. 3. Dental radiographs 15 months after replantation with no evidence of root resorption of upper right (left figure) and left (right figure) lateral incisors, which had been completely out of sockets for about 5 hours.
Fig.
2. Fate of replanted teeth.
favorable results could not be expected from the beginning. Degree of root formation and endodontic treatment. Root formation had beencompleted in 20 teeth.
Two of these teeth and four of the nine other teeth with incomplete root apices were replanted without endodontic treatment. Despite narrowing of the pulpal chamber, the results of electric pulp testing turned from negative to positive in 12 months to 15 months postoperatively in the latter four cases.A left maxillary canine that was partially erupted at the time of accidental extraction and replantation continued normal processof eruption that was accompanied by an evident apex formation (Fig. 1). A maxillary lateral incisor and a first premolar with completed root apiceswere replanted without endodontic treatment, but root canal fillings had to be done postoperatively because the pulp underwent necrosis. An apicoectomy was done extraorally before replantation of a maxillary central incisor that had already been root filled. Type of splints and period of splinting. In earlier cases,wire splints and acrylic splints were most often used, but more recently they were replaced by orthodontic splints (Table III). In two casesof accidental extraction surgical packs and gingival sutures were sufficient to keep the teeth in place. The period of splinting ranged from 5 days to 11 months with a
mean of 11 weeks.In approximately half of the cases, it was lessthan 8 weeks (Table IV). Maxillary central incisors that were replanted 12 hours after avulsion were fixed for 1I months with orthodontic splints because of extensive loss of the alveolar bone on the labial aspect. When these incisors were excluded, the mean period of splinting was 8 weeks. Fate of replanted teeth. The fate of the 27 replanted permanent teeth is shown in Fig. 2. The patient who underwent replantation of deciduous incisors was lost from the follow-up shortly after the procedure, but the primary healing was uneventful in all cases and 19 teeth were functioning from 7 months to 6 years 7 months postoperatively. During the observation period, 5 teeth were extracted 15 months to 8 years postoperatively because of mobility resulting from root resorption, but in the three other cases,extensive loss of the alveolar bone, dental caries, and fracture of the crown were the causesof tooth loss. Radiographically, root resorption was not observed in 11 teeth and five of them showedno evidenceof root resorption for 3 years 6 months to 7 years 6 months postoperatively. Twelve teeth showed inflammatory resorption and four teeth replacement resorption. Both types of root resorption took place within a year after replantation in all 16 cases.In terms of the period between avulsion and replantation, only one of five teeth that were replanted within an hour after avulsion showed root resorption. On the other hand, root resorption was noted in 14 of 18 teeth replanted 1 to 12 hours after avulsion. Interestingly, three of four teeth in which more than 12 hours had passed before replantation did not show any type of resorption (Table V). The actual extraoral period was less than 30 minutes in these cases, since the teeth had
Replantation
Volume 70 Number 5
653
Root resorption in terms of period between avulsion and replantation
Table V.
Type of resorption Period (hr)
o-1 l-3 3-12 12+
Table VI.
Incidence of resorption (%)
Injlammatory
l/5 (20) 9/10 (90) 518 (63) 114 (25)
Replacement
0 9 3 0
1 0 2 1
Root resorption in terms of extraoral period Type of resorption
Period (hr) 0-%
!h-2 2-5 5-k
Table VII.
Incidence of resorption (%)
Injlammatory
9116 (56) 213 (67) 517 (71) O/l (0)
Replacement
5 2 5 0
4 0 0 0
Root resorption in terms of root formation and endodontic treatment Type of resorption Incidence of resorption
Root formation Complete Incomplete Endodontic treatment Root-filled No filling
(W)
Injlammatory
Replacement
lo/18 (55) 619 (67)
7 5
3 1
15/23 (52) 114 (25)
12 0
3 1
been kept in the sockets even after avulsion. Of 16 teeth in which the extraoral period was less than 30 minutes, 9 teeth (56%) showed root resorption. In the groups with 30 minutes to 2 hours and 2 to 5 hours of the extraoral period, the incidences of root resorption increased to 66% and 71% of the population, respectively (Table VI). Root resorption was not observedin four teeth in which the extraoral period exceeded30 minutes (Fig. 3). Root resorption was seenin 8 of 14 teeth with healthy supporting tissuesand 8 of 13 teeth with fractures of the alveolar bone. Thus the incidences of root resorption did not differ in the two groups. The degree of root formation did not affect root resorption, but it was seen more frequently in root-filled teeth than in those without root fillings (Table VII). All the root-filled teeth with incomplete root formation showed evidence of root resorption. Root resorption was seen in 6 of 11 teeth fixed with wire splints and in 8 of 12 teeth splinted with orthodontic appliances. In the three groups with the period of splinting from 4 weeksto more than 12 weeks,
the incidences of root resorption were in the range of 55% to 73% (Table VIII). Two accidentally extracted teeth showed no root resorption despite simple splinting with surgical packs for less than a week. DISCUSSION
Most replanted teeth are lost after a certain period becauseof root resorption. Thus root resorption is the major factor to determine the fate of replanted teeth. In our series,five of the eight extracted teeth were lost becauseof root resorption that was detected within 6 months after replantation in most casesand in no case was it noted after 1 year of replantation. Analogous findings are reported by Andreasen and [email protected] A number of clinical factors have been associated with this phenomenon, but the effect of removal of the periodontal membrane was not included in this study becausein no case was the periodontal membrane scraped off from the root surface. Mahajan and Sidhu6 reported that the removal of the periodontal membrane raised the successrate of tooth
654
Gonda et al.
Table VIII.
ORALSURG ORALMED ORALPATHOL November 1990
Root resorption in terms of type of splints and period of splinting Type of resorption Incidence
Type of splints Surgical pack Acrylic splint Wire splint Orthodontic splint Period of splinting (wk) o-4 4-8 8-12 12+
of resorption
o/2
(0)
(96 j
InJammatory
Replacement
0
0
2/2 (100) 6/11 (55) 8/12 (67)
0 5 7
2 1 1
o/2
0
0
6 5 I
2 0 2
(0)
8/11 (73) 519 (55) 315 (60)
replantation. Andreasen and Kristerson4 however, found that the removal of the periodontal membrane led to the development of ankylosis resulting from replacement resorption. The importance of the periodontal membrane has been indicated in intentional replantation and transplantation73 8 The condition during the extraoral period was also deleted from the analysis becausethe information was not available in all cases. The period from avulsion to replantation and the condition under which teeth were kept during this period were the most critical factors affecting the prognosis of human tooth replantation.5 According to Andreasen and Hj@ting-Hansen5 the time between avulsion and replantation was defined as the extraoral period, but in this study, it was modified to mean the period teeth were actually out of the mouth, because there were casesin which the actual extraoral period was much shorter than the period between avulsion and replantation since avulsed teeth had been kept in their socketsuntil replantation. The incidence of root resorption was higher in the groups in which more than an hour had passed before replantation. Since the incidence also increased with the increase of the extraoral period and both periods were closely related in most cases,the results might have been due to the damage to the periodontal membrane during the extraoral period. Andreasen and Hjeting-Hansen5 stated that the successrate of tooth replantation decreased significantly when the extraoral period exceeded 90 minutes. It should be remembered, however, that although 12 hours or more had passedbefore replantation, three of the four teeth showed no evidence of root resorption. Two of these had been wedged into the alveolar bone. Obviously, cells in the periodontal membrane remained viable. The actual extraoral period was less than 15 minutes in both cases.Thus, even long after avulsion, chancesstill re-
main that an avulsed tooth can be replanted with a favorable result when it is kept in a condition to minimize the damage to the periodontal membrane. No root resorption wasobservedin three of the eight casesin which the extraoral period exceeded2 hours. In one case, the tooth had been kept dry, whereas in another case,there was a fracture of the alveolar bone. Therefore there was no favorable condition for good results to be expected in these cases.In the analysis of Andreasen and Hj@rting-Hansen,5 some teeth showed no root resorption despite a long extraoral period. Sonnenberg and coworkers9 also reported a casein which two maxillary incisors that had beenout of the mouth for 16 hours were functioning for 2 years without significant root resorption. A relatively high percentage of root resorption in the group with less than 30 minutes of the extraoral period might be because, including four cases with relatively severe damage of the alveolar bone, alveolar fractures were combined in more than two thirds of the cases. According to Andreasen and Hjqting-Hansen5 the presenceof alveolar fractures led to an early development of root resorption in all cases.In our series, there was no difference in the incidences of root resorption in the groups with and without alveolar fractures, but root resorption was observedin all cases with moderate to severedamage of the alveolar bone. Therefore it seemsto depend on the type and degree of alveolar bone damage. Endodontic treatment is ususally done when an avulsed tooth has a completed root apex. The incidence of replacement resorption, however, increased after endodontic treatment in an animal study.2 The results of tooth replantation were also unaffected by postponing endodontic treatment in human replanted teeth.5 Andreasen and Hj$rting-Hansen5 therefore recommendedreplantation wit&out endodontic treatment to minimize the extraoral period. In our casesa
Replantation
Volume 70 Number 5
better result was obtained in the group without endodontic treatment, but this may partly be due to the fact that three of the four teeth were replanted immediately after being extracted accidentally and the patients were 10 years of age or younger. The degree of root formation did not influence the incidence of root resorption. Kristerson and Andreasen’Ofound that the incidence of inflammatory resorption was slightly higher in teeth with incomplete apical foramen, whereas no difference was noted in replacement resorption in terms of root development. Andreasen3 indicated that rigid splinting might exert an unfavorable effect on replanted teeth because replacement resorption was observed more often in splinted teeth than in nonsplinted teeth after extraoral preservation for 18 minutes. The type and length of splinting, however, did not influence the degree or severity of root resorption in clinical cases.6In our cases, neither of them seemedto affect the result. A number of clinical factors have been shown to be associated with root resorption and fate of replanted teeth. A definite conclusion was not obtained in this study becausethe size of the sampleswas too small for the analysis of each factor. It should be noted, however, that despite unfavorable conditions for replantation, some teeth showed no evidence of root resorption after replantation, whereas other teeth remained in function for more than 5 years even in the presence of root resorption, indicating that the prognosis of each individual tooth is not always predictable before replantation. Thus an attempt should be made to preserveavulsed teeth with whatever method is available
655
to an operator becausethe failure of the procedure is minimal. REFERENCES
1. Andreasen JO. Effect of extra-alveolar period and storage media upon periodontal and pulpal healing after replantation of mature permanent incisors in monkeys. Int J Oral Surg 1981;10:43-53. 2. Andreasen JO. The effect of pulp extirpation or root canal treatment on periodontal healing after replantation of permanent incisors in monkeys. J Endod 1981;7:245-52. 3. Andreasen JO. The effect of splinting upon periodontal healing after replantation of permanent incisors in monkeys. Acta Ondontol Stand 1975;33:313-23. 4. Andreasen JO, Kristerson L. The effect of limited drying or removal of the periodontal ligament. Periodontal healing after replantation of matured permanent incisors in monkeys. Acta Ondontol Stand 1981;39:1-13. 5. Andreasen JO. Hjorting-Hansen E. Replantation of teeth. I. Radiographic and clinical study of 110 human teeth replanted after accidental loss. Acta Odontol Stand 1966;24:263-86. 6. Mahajan SK, Sidhu SS. Periodontal ligament, extraoral period, and use of fluorides in replantation of teeth. Indian J Med Res 1982;75:441-5. 7. Grossman LI. Intentional replantation of tooth. J Am Dent Assoc 1966;72:1111-8. 8. Pogre MA. Evaluation of over 400 autogenous tooth transplantations. J Oral Maxillofac Surg 1987;45:205-11. 9. Sonnenberg EM, Wepman BJ, Wong RT, Viglianti AC. Treatment of a long-term avulsion. J Pedod 1979;4:155-64. 10. Kristerson L, Andreasen JO. Influence of root development on periodontal and pulpal healing after replantation of incisors in monkeys. Int J Oral Surg 1984;13:313-23. Reprint requests to: Dr. Fumihiko Gonda First Department of Oral and Maxillofacial Surgery School of Dentistry, Niigata University 2-5274, Gakkocho Niigata City 951, Japan
OF ORAL AND MAXILLOFACIAL
SURGERY,
SCHOOL OF DENTISTRY,
UNIVERSITY
The results of replantation of 29 teeth are described. Maxillary incisors constituted 85% of 27 permanent teeth. The period between avulsion and replantation ranged from within an hour to 88 days, but the actual extraoral period was within 5 hours in all but one case. Nineteen of the 27 permanent teeth were functioning for 7 months to 8 years and 7 months postoperatively. Root resorption was the cause of tooth loss in five cases. The incidence of root resorption seemed to increase with the increase of the extraoral period, but it was not affected by the period between avulsion and replantation, the condition of supporting tissues, the degree of root formation, and the type and period of splinting, indicating multiple factors involved in determining the prognosis of replanted teeth. In conclusion, every effort should be made to preserve avulsed teeth even in unfavorable conditions. (ORAL SURC ORAL MED ORAL PATHOL 1990;70:650-5)
R
eplantation has been widely accepted as an effective means of preserving avulsed teeth. They usually becomefirm and can endure function within a couple of months. The long-term fate of replanted teeth, however, is still unpredictable, inasmuch as they may undergo resorption and shed in several years. The time interval between avulsion and replantation, the condition during the extraoral period, the presenceor absenceof pulp and periodontal tissues, the type and period of splinting, and so forth have been claimed as the possible factors affecting the successrate of the procedure in experimental animals,le4 but accurate prediction of the fate of replanted teeth is not easy in clinical cases because a combination of these and many other factors may be involved. In this article the results of replantation of 29 teeth are described and factors influencing the prognosis of replantation are discussed. MATERIAL
AND METHODS
A total of 29 teeth that were replanted by members of our department after being avulsed in accidents or extracted accidentally or intentionally were included in this study. Replantation was done in a conventional manner in most cases. In a typical case in which a permanent tooth with completed root formation was 7/U/12657 650
replanted, the procedure included cleansing of the tooth surface in a physiologic saline solution containing an antibiotic, pulpectomy and root canal filling with gutta-percha, replacement into the alveolar socket, and splinting. The patients were usually given an antibiotic and placed on a soft diet for a given period after replantation. The replanted teeth were followed clinically and radiographically for 3 months to 8 years. RESULTS
Gender and age. The patients consisted of 8 males and 12 females. Their agesranged from 3 years to 44 years, but 16 of them were under 20 years of age. The mean age was 16 years. Type ofaccidents. Accidents during sports and play (seven cases), accidental falls (seven cases), and traffic accidents (five cases)were almost equally listed as the cause of tooth loss. Accidental extraction occurred on manipulation of a mouth gag during general anesthesiain one caseand from carelessmisdiagnosis in three cases. Replantation of a malpositioned tooth after intentional extraction was done for orthodontic reasons in one case. Type of affected teeth. Of 27 permanent teeth, 17 were maxillary central incisors and 7 were maxillary lateral incisors. Two deciduous teeth affected were also maxillary incisors and a canine. Three mandib-
Replantation
Volume 70 Number 5 Table
651
I. Period between avulsion and replantation No. of teeth (W)
Period (hr) o-1
5 (17) 12 (41)
l-3 3-12 12+
8 (28)
Total
Table II.
Extraoral period
Period (hr)
I
o-% E-2 2-5
No. of teeth (W) 16 (55) 3 (10) 9 (31)
5+ Total
Table Ill.
Type of splint Type
Surgical pack Acrylic splint Wire splint Orthodontic splint Total
Table IV.
No. of teeth (W) 2 (7) 4 (14)
11 (38)
Period of splinting
Period (wk) o-4 4-8
8-12
No. of teeth (W) 4 (14)
11 (38) 9 (31)
12+
Total
ular teeth included two lateral incisors and a first premolar. Period between avulsion and replantation. Including 5 teeth that were replanted within 30 minutes after avulsion, 17 teeth were replanted within 3 hours and 24 teeth within 6 hours. In two cases,6 days and 86 days, respectively, had passedbefore replantation, which was delayed becauseof other injuries requiring earlier treatment. Fortunately, the affected tooth had been kept in the alveolar bone after being wedged into it in both cases (Table I). Extraoralperiod. When defined as the period teeth were kept out of the mouth, the extraoral period varied from within 30 minutes to more than 5 hours, but it did not exceed 30 minutes in 16 cases (Table II). Condition of the alveolar bone. At the time of replantation, fractures of the surrounding alveolar bone
Fig. 1. A, Intraoral view 2 weeks after replantation of accidentally extracted upper left canine. B, Intraoral view 2 years after replantation. C, Dental radiograph immediately after replantation.D, Dental radiograph 2 years after replantation.
were noted grossly or radiographically in 14 cases, whereas in the 15 other casesthe alveolar bone was healthy except for the presenceof wounds caused by tooth loss. The labial alveolar bone had undergone extensive resorption in the case in which the affected tooth was replanted in a newly formed socket 86 days after avulsion. Preparation of a socket was done in another case in which a malpositioned maxillary lateral incisor was replanted for orthodontic reasons. In four cases,damage of the alveolar bone was such that
652
Gonda et al.
A . .
( bme
ORAL SLRC ORAL
,MED ORAL PATHOI. November 1990
fract
. . . . . . A i dental ca;
Fig. 3. Dental radiographs 15 months after replantation with no evidence of root resorption of upper right (left figure) and left (right figure) lateral incisors, which had been completely out of sockets for about 5 hours.
Fig.
2. Fate of replanted teeth.
favorable results could not be expected from the beginning. Degree of root formation and endodontic treatment. Root formation had beencompleted in 20 teeth.
Two of these teeth and four of the nine other teeth with incomplete root apices were replanted without endodontic treatment. Despite narrowing of the pulpal chamber, the results of electric pulp testing turned from negative to positive in 12 months to 15 months postoperatively in the latter four cases.A left maxillary canine that was partially erupted at the time of accidental extraction and replantation continued normal processof eruption that was accompanied by an evident apex formation (Fig. 1). A maxillary lateral incisor and a first premolar with completed root apiceswere replanted without endodontic treatment, but root canal fillings had to be done postoperatively because the pulp underwent necrosis. An apicoectomy was done extraorally before replantation of a maxillary central incisor that had already been root filled. Type of splints and period of splinting. In earlier cases,wire splints and acrylic splints were most often used, but more recently they were replaced by orthodontic splints (Table III). In two casesof accidental extraction surgical packs and gingival sutures were sufficient to keep the teeth in place. The period of splinting ranged from 5 days to 11 months with a
mean of 11 weeks.In approximately half of the cases, it was lessthan 8 weeks (Table IV). Maxillary central incisors that were replanted 12 hours after avulsion were fixed for 1I months with orthodontic splints because of extensive loss of the alveolar bone on the labial aspect. When these incisors were excluded, the mean period of splinting was 8 weeks. Fate of replanted teeth. The fate of the 27 replanted permanent teeth is shown in Fig. 2. The patient who underwent replantation of deciduous incisors was lost from the follow-up shortly after the procedure, but the primary healing was uneventful in all cases and 19 teeth were functioning from 7 months to 6 years 7 months postoperatively. During the observation period, 5 teeth were extracted 15 months to 8 years postoperatively because of mobility resulting from root resorption, but in the three other cases,extensive loss of the alveolar bone, dental caries, and fracture of the crown were the causesof tooth loss. Radiographically, root resorption was not observed in 11 teeth and five of them showedno evidenceof root resorption for 3 years 6 months to 7 years 6 months postoperatively. Twelve teeth showed inflammatory resorption and four teeth replacement resorption. Both types of root resorption took place within a year after replantation in all 16 cases.In terms of the period between avulsion and replantation, only one of five teeth that were replanted within an hour after avulsion showed root resorption. On the other hand, root resorption was noted in 14 of 18 teeth replanted 1 to 12 hours after avulsion. Interestingly, three of four teeth in which more than 12 hours had passed before replantation did not show any type of resorption (Table V). The actual extraoral period was less than 30 minutes in these cases, since the teeth had
Replantation
Volume 70 Number 5
653
Root resorption in terms of period between avulsion and replantation
Table V.
Type of resorption Period (hr)
o-1 l-3 3-12 12+
Table VI.
Incidence of resorption (%)
Injlammatory
l/5 (20) 9/10 (90) 518 (63) 114 (25)
Replacement
0 9 3 0
1 0 2 1
Root resorption in terms of extraoral period Type of resorption
Period (hr) 0-%
!h-2 2-5 5-k
Table VII.
Incidence of resorption (%)
Injlammatory
9116 (56) 213 (67) 517 (71) O/l (0)
Replacement
5 2 5 0
4 0 0 0
Root resorption in terms of root formation and endodontic treatment Type of resorption Incidence of resorption
Root formation Complete Incomplete Endodontic treatment Root-filled No filling
(W)
Injlammatory
Replacement
lo/18 (55) 619 (67)
7 5
3 1
15/23 (52) 114 (25)
12 0
3 1
been kept in the sockets even after avulsion. Of 16 teeth in which the extraoral period was less than 30 minutes, 9 teeth (56%) showed root resorption. In the groups with 30 minutes to 2 hours and 2 to 5 hours of the extraoral period, the incidences of root resorption increased to 66% and 71% of the population, respectively (Table VI). Root resorption was not observedin four teeth in which the extraoral period exceeded30 minutes (Fig. 3). Root resorption was seenin 8 of 14 teeth with healthy supporting tissuesand 8 of 13 teeth with fractures of the alveolar bone. Thus the incidences of root resorption did not differ in the two groups. The degree of root formation did not affect root resorption, but it was seen more frequently in root-filled teeth than in those without root fillings (Table VII). All the root-filled teeth with incomplete root formation showed evidence of root resorption. Root resorption was seen in 6 of 11 teeth fixed with wire splints and in 8 of 12 teeth splinted with orthodontic appliances. In the three groups with the period of splinting from 4 weeksto more than 12 weeks,
the incidences of root resorption were in the range of 55% to 73% (Table VIII). Two accidentally extracted teeth showed no root resorption despite simple splinting with surgical packs for less than a week. DISCUSSION
Most replanted teeth are lost after a certain period becauseof root resorption. Thus root resorption is the major factor to determine the fate of replanted teeth. In our series,five of the eight extracted teeth were lost becauseof root resorption that was detected within 6 months after replantation in most casesand in no case was it noted after 1 year of replantation. Analogous findings are reported by Andreasen and [email protected] A number of clinical factors have been associated with this phenomenon, but the effect of removal of the periodontal membrane was not included in this study becausein no case was the periodontal membrane scraped off from the root surface. Mahajan and Sidhu6 reported that the removal of the periodontal membrane raised the successrate of tooth
654
Gonda et al.
Table VIII.
ORALSURG ORALMED ORALPATHOL November 1990
Root resorption in terms of type of splints and period of splinting Type of resorption Incidence
Type of splints Surgical pack Acrylic splint Wire splint Orthodontic splint Period of splinting (wk) o-4 4-8 8-12 12+
of resorption
o/2
(0)
(96 j
InJammatory
Replacement
0
0
2/2 (100) 6/11 (55) 8/12 (67)
0 5 7
2 1 1
o/2
0
0
6 5 I
2 0 2
(0)
8/11 (73) 519 (55) 315 (60)
replantation. Andreasen and Kristerson4 however, found that the removal of the periodontal membrane led to the development of ankylosis resulting from replacement resorption. The importance of the periodontal membrane has been indicated in intentional replantation and transplantation73 8 The condition during the extraoral period was also deleted from the analysis becausethe information was not available in all cases. The period from avulsion to replantation and the condition under which teeth were kept during this period were the most critical factors affecting the prognosis of human tooth replantation.5 According to Andreasen and Hj@ting-Hansen5 the time between avulsion and replantation was defined as the extraoral period, but in this study, it was modified to mean the period teeth were actually out of the mouth, because there were casesin which the actual extraoral period was much shorter than the period between avulsion and replantation since avulsed teeth had been kept in their socketsuntil replantation. The incidence of root resorption was higher in the groups in which more than an hour had passed before replantation. Since the incidence also increased with the increase of the extraoral period and both periods were closely related in most cases,the results might have been due to the damage to the periodontal membrane during the extraoral period. Andreasen and Hjeting-Hansen5 stated that the successrate of tooth replantation decreased significantly when the extraoral period exceeded 90 minutes. It should be remembered, however, that although 12 hours or more had passedbefore replantation, three of the four teeth showed no evidence of root resorption. Two of these had been wedged into the alveolar bone. Obviously, cells in the periodontal membrane remained viable. The actual extraoral period was less than 15 minutes in both cases.Thus, even long after avulsion, chancesstill re-
main that an avulsed tooth can be replanted with a favorable result when it is kept in a condition to minimize the damage to the periodontal membrane. No root resorption wasobservedin three of the eight casesin which the extraoral period exceeded2 hours. In one case, the tooth had been kept dry, whereas in another case,there was a fracture of the alveolar bone. Therefore there was no favorable condition for good results to be expected in these cases.In the analysis of Andreasen and Hj@rting-Hansen,5 some teeth showed no root resorption despite a long extraoral period. Sonnenberg and coworkers9 also reported a casein which two maxillary incisors that had beenout of the mouth for 16 hours were functioning for 2 years without significant root resorption. A relatively high percentage of root resorption in the group with less than 30 minutes of the extraoral period might be because, including four cases with relatively severe damage of the alveolar bone, alveolar fractures were combined in more than two thirds of the cases. According to Andreasen and Hjqting-Hansen5 the presenceof alveolar fractures led to an early development of root resorption in all cases.In our series, there was no difference in the incidences of root resorption in the groups with and without alveolar fractures, but root resorption was observedin all cases with moderate to severedamage of the alveolar bone. Therefore it seemsto depend on the type and degree of alveolar bone damage. Endodontic treatment is ususally done when an avulsed tooth has a completed root apex. The incidence of replacement resorption, however, increased after endodontic treatment in an animal study.2 The results of tooth replantation were also unaffected by postponing endodontic treatment in human replanted teeth.5 Andreasen and Hj$rting-Hansen5 therefore recommendedreplantation wit&out endodontic treatment to minimize the extraoral period. In our casesa
Replantation
Volume 70 Number 5
better result was obtained in the group without endodontic treatment, but this may partly be due to the fact that three of the four teeth were replanted immediately after being extracted accidentally and the patients were 10 years of age or younger. The degree of root formation did not influence the incidence of root resorption. Kristerson and Andreasen’Ofound that the incidence of inflammatory resorption was slightly higher in teeth with incomplete apical foramen, whereas no difference was noted in replacement resorption in terms of root development. Andreasen3 indicated that rigid splinting might exert an unfavorable effect on replanted teeth because replacement resorption was observed more often in splinted teeth than in nonsplinted teeth after extraoral preservation for 18 minutes. The type and length of splinting, however, did not influence the degree or severity of root resorption in clinical cases.6In our cases, neither of them seemedto affect the result. A number of clinical factors have been shown to be associated with root resorption and fate of replanted teeth. A definite conclusion was not obtained in this study becausethe size of the sampleswas too small for the analysis of each factor. It should be noted, however, that despite unfavorable conditions for replantation, some teeth showed no evidence of root resorption after replantation, whereas other teeth remained in function for more than 5 years even in the presence of root resorption, indicating that the prognosis of each individual tooth is not always predictable before replantation. Thus an attempt should be made to preserveavulsed teeth with whatever method is available
655
to an operator becausethe failure of the procedure is minimal. REFERENCES
1. Andreasen JO. Effect of extra-alveolar period and storage media upon periodontal and pulpal healing after replantation of mature permanent incisors in monkeys. Int J Oral Surg 1981;10:43-53. 2. Andreasen JO. The effect of pulp extirpation or root canal treatment on periodontal healing after replantation of permanent incisors in monkeys. J Endod 1981;7:245-52. 3. Andreasen JO. The effect of splinting upon periodontal healing after replantation of permanent incisors in monkeys. Acta Ondontol Stand 1975;33:313-23. 4. Andreasen JO, Kristerson L. The effect of limited drying or removal of the periodontal ligament. Periodontal healing after replantation of matured permanent incisors in monkeys. Acta Ondontol Stand 1981;39:1-13. 5. Andreasen JO. Hjorting-Hansen E. Replantation of teeth. I. Radiographic and clinical study of 110 human teeth replanted after accidental loss. Acta Odontol Stand 1966;24:263-86. 6. Mahajan SK, Sidhu SS. Periodontal ligament, extraoral period, and use of fluorides in replantation of teeth. Indian J Med Res 1982;75:441-5. 7. Grossman LI. Intentional replantation of tooth. J Am Dent Assoc 1966;72:1111-8. 8. Pogre MA. Evaluation of over 400 autogenous tooth transplantations. J Oral Maxillofac Surg 1987;45:205-11. 9. Sonnenberg EM, Wepman BJ, Wong RT, Viglianti AC. Treatment of a long-term avulsion. J Pedod 1979;4:155-64. 10. Kristerson L, Andreasen JO. Influence of root development on periodontal and pulpal healing after replantation of incisors in monkeys. Int J Oral Surg 1984;13:313-23. Reprint requests to: Dr. Fumihiko Gonda First Department of Oral and Maxillofacial Surgery School of Dentistry, Niigata University 2-5274, Gakkocho Niigata City 951, Japan
