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Intraoral third molar transplants: report of three cases and long-term follow-up
Thaddeus G. Pantera, DDS Richard L. Pantera, MD, Lackawanna, NY
P re s e rv in g th e in terp ro x im a l s p a c e o f ex tra c te d firs t m olars in y o u n g adults ca n b e a cco m p lish ed in m a n y ways. T h e p r o c e d u r e d e s c r ib e d in this re p o rt u ses th e th ird m o la r as a re p la c e m e n t a n d h a s p r o v e d s u c c e s s fu l w h en all conditions a r e fa v o ra b le .
his report covers a span of 20 years; of 15 patients, three are de scribed in detail. Third molars were transplanted into the sockets of extracted first molars. The age of the patients at the time of the proce dure ranged from 14 to 22 years.
Methods The initial step was the radiographic evaluation of the teeth. The follow ing criteria were used in this evalua tion: — The crown of the first molar was decayed so that it was unrestorable. — Radiographic evidence of infec tion at the root of the first molar was not a contraindication to the procedure. However, the necessary 4 86 ■ JADA, V ol. 97, Septem ber 1978
antibiotics were prescribed. — Root canal procedures on the first molars were impossible be cause of the extent of damage to the crowns. Only the roots remained. — The third molars to be trans planted had to have more than a half of their root system formed at the time of the procedure. —Tissue or partial bony impaction of the third molars was not a con traindication for the procedure. — The size of the third molar was appropriate for the space of the ex tracted tooth either in its normal orientation or reversed 180°. If all these criteria were met, the procedure was performed.
Procedure The first molar was extracted. The socket was then curetted, and the third molar was removed. In this procedure, the root bud should not be unduly traumatized. Although the attempt was made to preserve the embryonic sac of the third molar, its preservation has not been essential to the survival of the transplant. Further preparation of the site for the transplant was dependent on the size of the third molar. The socket was enlarged as necessary; fre
quently, the interseptal bone was re moved. It was not necessary to main tain the original orientation of the third molar in its new position. The transplants were set into the sockets as far as possible to eliminate any occlusal contact. If there was contact, the alveolus was enlarged until the condition no longer existed. The final phase of the procedure was to stabilize the transplant with dental floss or sutures. A eugenol pack was placed and maintained for one to two weeks. The site of the transplant was checked every two to three days to ensure that the tooth was stable in the socket and that no signs of infection appeared. At that stage the tooth was understandably mobile, and care and cooperation on the part of the patient were required to safeguard the transplant. About two weeks after the proce dure, there was only minimal loose ness of the transplant and the packs could be removed. The patients were advised to continue chewing on the opposite side until full stability was achieved in approximately two months. The following cases demon strate the progression of root growth during a period of several months. No additional care or precautions were required after the initial stabili zation.
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Fig 1 ■ Preoperative view (case 1).
Fig 2 ■ Im mediate postoperative results (case 1).
Fig 3 ■ Postoperative results. A: six months; B: one year; C: two years; D: three years; E: seven years; F: 16 years (case 1).
Report of cases
C a se 1
Fig 4 ■ O cclusion and general appearance after 16 years (case 1).
A 17-year-old white girl had good general dental health. The maxillary right first molar was badly decayed and required extraction. The third molar in the same quadrant was sufficiently developed to meet the criteria for the transplant proce dure (Fig 1). The procedure was performed as de scribed. Figure 2 shows the immediate postoperative results; follow-up results are shown in Figure 3. Figure 4 shows the occlusion and general appearance of the transplant 16 years later. The tooth is in good occlusion with no complications.
A 19-year-old white woman had good general dental health. The maxillary left first molar had deteriorated. The preoperative condition is shown in Fig ure 5. The regular procedure was fol lowed, but the transplant was performed a few days after the extraction. Figure 6 shows the postoperative results; followup results are seen in Figure 7. Figure 8 shows the general appearance of the transplant and occlusion 15 years later; currently, no problems have devel oped.
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Fig 5 ■ Preoperative view (case 2).
ft ;4 tlM
Fig 7 ■ Postoperative results. A: eight months; B: two years; C: 4 Vi years; D: eight years (case 2). Fig 6 ■ Im m ediate postoperative results (case 2).
Fig 8 ■ Occlusion and general appearance (A, B, C) after 15 years (case 2).
Case 3 A 16-year-old white boy had an extensive infection at the site of the mandibular right first molar that necessitated its removal. The socket was curetted at the time of the transplant (Fig 9). The trans planted tooth was rotated 180° from the normal position but the procedure was otherwise the same. Figure 10 shows the postoperative con dition; no unusual difficulties developed. A ntibiotics were prescribed. Follow-up results are seen in Figure 11. Currently, the transplant is in good oc clusion. 488 ■ JADA, Vol. 97, Septem ber 1978
Fig 9 ■ Preoperative views (case 3}.
1 0 ■ Im m e d ia te
p o sto p e ra tiv e
re s u lts
(ca s e 3).
F ig 11 ■ P o sto p era tiv e re s u lts . A: o n e y ear; B : tw o y ea rs; C: th re e y e a rs (c a s e 3).
The procedure was performed on ten more patients. Currently, all trans planted teeth remain in good occlu sion and are free of any disease that is ascribable to the procedure. Differ ences between the maxillary and mandibular anatomy caused no addi tional problems. As a precautionary measure, maxillary packs were left in place for slightly longer periods. For more than 20 years, all transplants that met standards of the evaluation criteria have been functional but, as might be expected, the transplants are nonvital, with obliterated pulp chambers. Also, they are subject to normal decay and periodontal dis ease. In one 14-year-old boy, not in cluded in the case reports, the initial criteria were not met. Figure 12 shows that the root of the mandibular left third molar was not sufficiently developed at the time of the proce dure. Seven years after the transplant, signs of infection at the site of the transplant necessitated removal of the tooth (Fig 13). The source of the infection is unknown, and its rela tion to the procedure is not clear. A finding that is thought to be a conse quence of the procedure was present in the patient at the time of the extrac tion, that is, the transplant was ankylosed to the bone. This finding was present in spite of radiographic evi dence of a periodontal membrane. Because of this finding at the time of extraction and the rigidity of the transplants in all of the patients in the series, it is postulated that the ankylosis was a long-term outcome of the procedure. All of the foregoing cases involved transplantation within the dentition of the same patient. One case, in 1968, involved a transplant between two unrelated patients. The donor, an 11-year-old white girl, was under going removal of a maxillary left premolar for orthodontic reasons. The recipient, a 13-year-old white girl, had a badly decayed maxillary right premolar (Fig 14A). A peroxidase wash of the trans plant before implantation was the
F ig 1 2 ■ R o o t in 1 4 -y e a r-o ld bo y w a s n o t su ffi c ie n tly d ev elo p ed w h en tra n s p la n te d .
F ig 13 ■ P o sto p e ra tiv e re s u lts (sev e n y e a rs la ter) in 1 4 -y e a r-o ld b o y sh o w s ig n s o f in fe c tio n a n d d eca y .
only change in the procedure. The transplant currently remains func tional. Figures 14 B and C show the postoperative and follow-up results after three months. The tooth is still in place, but the patient refuses to have radiographs made.
Discussion This technique, when applied in strict adherence to the procedure de scribed here, has been shown to be an effective means of replacement of unrestorable teeth. The preservation of
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F ig 1 4 ■ T r a n s p la n t betw een tw o p atie n ts. A: p re o p e ra tiv e v iew ; B: im m ed ia te p o sto p e ra tiv e re su lts; C: re s u lts a fte r th re e m onths.
the function of the first molar in this strategic location for integrity of the dental arches is a goal that is often difficult to achieve. The ac complishment of this goal by use of an otherwise troublesome third molar is a rational, safe, and econom ical approach to this problem. In an age of improved dental health in which the loss of a single tooth in an otherwise healthy mouth is a fre quent occurrence, this technique stands out as a viable alternative to other modes of therapy. The prospect of transplants between people, with out evoking an immune response, also deserves further exploration.
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Dr. Thaddeus G. Pant era is in private, practice; his address is 1188 Ridge Rd, Lackawanna, NY 14218. Dr. Richard L.. Pantera is a lieutenant, US Navy. Ad dress requests for reprints to Dr. T. G. Pantera.