Autotransplantation of a mature premolar in adults can be a treatment of choice for tooth replacement when combined with well-planned orthodontic treatment. This case report describes the successful treatment of a 39-year-old patient with severe crowding and a hopelessly fractured tooth on the maxillary left side. Maxillary dental crowding was relieved by extraction of a premolar on the right side, and this extracted tooth was autotransplanted to replace the fractured tooth. A mandibular incisor was extracted to correct anterior crossbite. The total treatment period was 20 months. The treatment results showed a good long-term prognosis after transplantation of a mature premolar with normal surrounding alveolar bone level for over 6 years of follow-up. Occlusion and periodontal health were excellent in the long term.
Highlights
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An adult patient had a fractured premolar and severe crowding.
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Treatment included autotransplantation of a premolar to the fracture site.
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This plan relieved crowding, restored function, and improved esthetics.
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Interdisciplinary consultations with the oral surgeon and endodontist were critical.
Middle-aged or older adult patients, whose proportion is increasing, , are more concerned about saving teeth. It has been reported that orthodontic treatment can be chosen for saving an already missing or hopeless tooth. Successful replacement of missing molars by third molars, replacement of an ankylosed incisor with tooth autotransplantation, and the space closure at a tooth-missing site with orthodontic treatment are examples of saving a tooth with orthodontic treatment.
In an adult patient with a hopeless tooth, the additional extraction of a healthy tooth for orthodontic purposes may have some limitations because patients are usually reluctant to have another tooth extracted. A tooth hopelessly fractured because of severe caries may be managed by various approaches such as a prosthetic implant, orthodontic treatment, or autotransplantation. If the extraction of permanent tooth is considered to relieve crowding or to correct skeletal or dental discrepancies for orthodontic reasons, autotransplantation of the available extracted tooth to the tooth-missing area would be beneficial for saving more teeth and restoring function and esthetics, only if the donor and the recipient match nicely. Therefore, the selection of a suitable case is important.
Autotransplantation has advantages over dental implants, such as maintenance of the periodontal ligament (PDL) and the alveolar bone. In a review of single-crown restorations using implants, a 5-year survival of 94.5% was reported. The survival rate of an autotransplanted tooth was reported to be fairly high, ranging from 75.3% to 91%. The success rate was 79% during a 17-41 year follow-up and was even reported to be 100% for the premolar cases. In a well-coordinated interdisciplinary approach, the success rate of autotransplantation is predictable enough to be presented as an option for replacing a tooth.
This case report is about the treatment of a mild Class III patient, with a fractured premolar on the maxillary left side and crowding in the maxillary right side, by autotransplantation of the right premolar to the fractured site.
Diagnosis and etiology
The patient was a 39-year-old man referred from the Department of Oral and Maxillofacial surgery, Seoul St Mary’s Hospital, The Catholic University of Korea, Seoul, South Korea for treatment of a fractured tooth and crowding. The pretreatment intraoral photographs showed mild Class III malocclusion with edge-to-edge bite, severe crowding on the maxillary right side, and a fractured first premolar on the maxillary left side. The shapes of the incisal edges of the anterior teeth were not smooth because of chipping and attrition ( Fig 1 ). Facial photographs showed a straight profile with a slightly insufficient incisor. The maxillary dental midline was deviated 1.0 mm to the right, and the mandibular dental midline was deviated 2.0 mm to the left side. However, no noticeable facial asymmetry was observed ( Figs 1 and 2 ).
The panoramic radiograph showed the retained root of the fractured maxillary first premolar and chronic periodontitis with caries on molars. Also, he had a horizontally impacted mandibular right third molar ( Fig 3 , A ). The lateral cephalometric analysis showed a mild Class III skeletal pattern with a slight hyperdivergent profile. Slight retroclination of the maxillary incisors and the mandibular incisors (U1 to SN, 103.0°; U1 to FH, 112.5°; IMPA, 93.0°) was observed ( Fig 3 , B ; Table ).
| Variable | Norm | Pretreatment | Posttreatment |
|---|---|---|---|
| Skeletal | |||
| SNA (°) | 82.0 | 82.0 | 82.0 |
| SNB (°) | 80.0 | 80.5 | 80.5 |
| ANB (°) | 2.0 | 1.5 | 1.5 |
| Wits appraisal (mm) | −2.0 | −4.0 | −3.0 |
| APDI (°) | 81.0 | 88.0 | 88.0 |
| FMA (°) | 24.0 | 25.5 | 26.0 |
| SN-GoGn (°) | 34.0 | 39.0 | 39.0 |
| Facial height ratio (posterior facial height/anterior facial height) | 66.0 | 62.5 | 62.5 |
| Dental | |||
| U1 to FH (°) | 116.0 | 112.5 | 116.5 |
| U1 to SN (°) | 106.0 | 103.0 | 108.0 |
| IMPA (°) | 94.0 | 93.0 | 88.0 |
| 1-NA (°) | 24.0 | 21.0 | 25.5 |
| 1-NA (mm) | 8.0 | 5.5 | 7.5 |
| 1-NB (°) | 27.0 | 31.0 | 25.0 |
| 1-NB (mm) | 8.0 | 8.5 | 7.0 |
| Soft tissues | |||
| Maxillary lip to E-line (mm) | −1.0 | −1.0 | −1.0 |
| Mandibular lip to E-line (mm) | 1.0 | 1.5 | 1.5 |
On the basis of these findings, the patient was diagnosed as having Class III malocclusion with crowding and a fractured maxillary left first premolar.
Treatment objectives
The treatment objectives for this patient were: (1) manage the problem of the fractured tooth by autotransplantation; (2) relieve the crowding and align the arches; (3) correct the overbite and overjet by labial movement of the maxillary incisors and lingual movement of the mandibular incisors; and (4) improve esthetics and establish a functional occlusion with proper overjet.
Treatment alternatives
Under normal circumstances, extraction of the 4 first premolars, including the fractured premolar, would be considered first to relieve crowding and to improve the Class III molar relationship. The second alternative would be extraction of 2 maxillary first premolars and 1 mandibular incisor for camouflage treatment of Class III malocclusion. The third option would be extraction of the maxillary right premolar and space closure at the fracture site on the left side. However, because of the fractured tooth on the maxillary left side and crowding at the maxillary right side, and the quite stable posterior occlusion on the left side, an alternative treatment option was presented to the patient: extract the maxillary right second premolar and replace the fractured tooth by transplanting this extracted tooth ( Fig 4 , A ). The maxillary second premolar was chosen as the donor after consultation with the Department of Conservative Dentistry because the maxillary right first premolar was 2-rooted, and the second premolar was single-rooted. In addition, the mandibular right incisor was to be extracted to correct the edge-to-edge bite. Owing to this asymmetric extraction, the diagnostic set-up demonstrated end-on Class II dental relationship on the right side, and Class I dental relationship on the left side ( Fig 4 , B ). The patient chose this option because of the less number of teeth to be extracted and a possibly shorter treatment time.
