Interdisciplinary rehabilitation for mutilated dentition with mini-implants, autotransplants, and a dental implant

A patient with mutilated dentition was treated to an acceptable result with the help of mini-implants for anchorage, autotransplantation of 2 teeth, one dental implant, and multiple prostheses. The major problems for this mutilated dentition were multiple missing teeth, bite collapse with posterior crossbites, deepbite with a canted gummy smile, and severe skeletal discrepancy of maxillary protrusion and mandibular retrusion. Mini-implant anchorage was applied to retract and intrude the maxillary arch to reduce the protrusion and rotate the mandible counterclockwise to improve the chin projection. Two autotransplantations, one dental implant, and multiple prostheses were used to accomplish a satisfactory full mouth rehabilitation with an interdisciplinary approach, including orthodontics, periodontics, endodontics, prosthodontics, and implantology. The understanding of biological principles, improvement in surgical protocol makes it possible to preserve the periodontal ligament (PDL) cells with atraumatic extraction after loosening the donor with orthodontic force and reduce the extraoral time with the 3-dimensional print-out replica segmented from cone-beam computed tomography for trying fitness. Soft wire splinting to gain initial stabilization and root canal treatment to avoid endotoxin further reduce the risk of root resorption, loss of attachment, and ankylosis. Autotransplantation could be considered as a part of full mouth rehabilitation. Orthodontic space management is also an important procedure to confirm the site of dental implant installation in the interdisciplinary collaboration.

Graphical abstract

Highlights

  • Interdisciplinary treatment was needed for a patient with mutilated dentitions.

  • Mini-implant anchorage was required for full mouth rehabilitation.

  • Autotransplantation was a viable treatment option for this patient.

A mutilated dentition is one of the most difficult malocclusions to treat. Lack of posterior support and appropriate anchorage units, loss of vertical dimension, ill-fitting prostheses, endodontic involvement, and compromised periodontal condition can all contribute to the mutilated dentitions. The treatment for mutilated dentitions needs not only comprehensive orthodontic treatment but also considerable support from various specialties of dentistry. In addition to thorough communication, a comprehensive treatment plan is an important key to overall success. The orthodontist is the one who might be responsible for the treatment plan and coordination. The orthodontist needs to be aware of all the disciplines regarding various specialties in dentistry to manage the treatment sequences, support the treatment progress and monitor the treatment quality to assure the final success.

Moreover, many patients with mutilated dentitions require an atypical treatment plan involving various designs of implant prostheses or even autotransplantations. The applications of temporary skeletal anchorage devices (TSADs) are important in the treatment of mutilated dentitions, especially for the intrusion of the elongated teeth and asymmetrical force system. Nowadays, the dental implant is the gold standard for the restoration of missing teeth. However, orthodontic space closure is an important consideration during full mouth rehabilitation of a mutilated dentition, and tooth autotransplantation could be considered an alternative to a dental implant if appropriately indicated. A severe skeletal Class II malocclusion with multiple missing posterior teeth is reported to demonstrate the applications of mini-implant anchorage, dental implant restoration, and autotransplantations in full mouth rehabilitation. Although orthognathic surgery might be the treatment of choice, this patient declined the surgical approach and asked for a minimal number of implant prostheses due to financial considerations. This patient was treated with skeletal anchorage to reduce protrusion and correct a gummy smile. The use of 2 autotransplants successfully reduced the number of implant prostheses to only one.

Diagnosis and etiology

This 35-year-old woman asked for orthodontic treatment with the chief complaints of protrusion and multiple missing teeth. Facial photographs showed asymmetry, with the right side larger than the left. An asymmetrical gummy smile with uneven gingival line was evident because of canted occlusal plane. The lateral view showed a convex facial profile because of maxillary protrusion and mandibular retrusion ( Fig 1 ). Intraorally, deep overbite (6 mm) and severe overjet (6 mm) were noted. The maxillary dental midline was shifted to the left by 2 mm, and the mandibular dental midline was further shifted to the left by 2 mm. The maxillary left first molar, mandibular right first and second molars, and mandibular left first premolar and first molar were all missing. The maxillary left wisdom tooth was missing, and the mandibular left wisdom tooth was mesioangular impacted. The maxillary right buccal segment was vertically elongated because of the lack of opposing teeth. Posterior buccal crossbites were evident at the premolar areas bilaterally. Molar relationships were not defined because of multiple missing posterior teeth, but canine Class II relationships were noted on both sides ( Figs 2 and 3 ). The panoramic radiograph showed multiple missing teeth, as previously mentioned. Maxillary right central and lateral incisors and maxillary left lateral incisors were endodontically treated and restored with ill-fitted prostheses. Moderate periodontitis was noted, especially more severe around the edentulous areas. The left temporomandibular joint (TMJ) showed dystrophic morphology on the panoramic radiograph compared with the right TMJ, which might be the cause of mandibular deviation to the left. No TMJ symptoms and signs were noted. Cephalometric radiograph revealed a skeletal Class II relationship (ANB, 12°). Mandibular plane angle showed a severe hyperdivergent craniofacial pattern (SN-MP, 44.4°). Dental compensations for skeletal Class II were evident (U1-SN, 97.3°; L1-MP, 102.7°) ( Fig 4 ; Table II ).

Fig 1
Pretreatment facial photographs.

Fig 2
Pretreatment intraoral photographs.

Fig 3
Pretreatment study models.

Fig 4
Pretreatment panoramic x-ray and cephalogram.

Table I
Comparisons of treatment options
Option Premolar extraction Wisdom tooth removal Implant restoration Treatment modality
No. Position No. Position No. Position
1 3 UR4, UL4, LR4 3 UR8, LL8, LR8 4 UL6, LL6, LR6, LR7 Four-premolar extraction
Orthognathic surgery required
2 2 UR4, UL4 3 UR8, LL8, LR8 5 UL6, LL4, LL6, LR6, LR7 Maxillary single arch extraction
Symmetrical space closure
3 1 UR5 2 UR8, LL8 4 UL7, LL4, LL6, LR6 Asymmetrical space closure
Partial closure of LL6
4 1 UR5 2 UR8, LL8 1 LL4 Asymmetrical space closure
Partial closure of LL6
Autotransplantation-UR5 to LL6, LL8 to LR6

The patient stated that most of her missing teeth were extracted due to large decays at least 5 years ago. She was aware of her uneven gingival line since adolescence, but she was not aware of her facial asymmetry. No dental or facial trauma was recalled by the patient. Genetics might be a possible etiology of her skeletal discrepancies, both on sagittal and transverse aspects. As for the mutilated dentition, that was largely the patient’s responsibility because of inadequate dental care.

The diagnosis of this present patient was severe skeletal Class II malocclusion, high mandibular plane angle with skeletal asymmetry, and Class II dental relationships complicated by multiple missing posterior teeth.

Treatment alternatives

Because of the severe skeletal discrepancies in both sagittal and transverse dimensions, the treatment plan of choice for the patient was orthodontic treatment combined with orthognathic surgery, which was presented as the primary option ( Table I ).

The first option was surgical orthodontics. With one first premolar missing already, 3 other first premolars were planned for extraction. All 3 third molars were also planned for removal. Then, 4 implant prostheses were planned to restore all the missing molars. A 2-jaw surgery including maxillary LeFort I impaction and sagittal split mandibular advancement was indicated to finish at Class I skeletal and dental relationships. However, the patient did not accept the surgical plan.

Therefore, 3 nonsurgical options were proposed.

The second option was Class II camouflage treatment by single arch extractions of maxillary first premolars, removal of all 3 third molars, and restoration of the missing molars by implant prostheses. This treatment plan required 5 dental implants to restore the occlusion with Class II molar relationships. However, the patient could not afford the cost of this treatment option.

The third option was the partial closure of the edentulous areas to reduce the number of implant prostheses ( Fig 5 ), and extraction of the maxillary right and mandibular left third molars and maxillary right second premolar; space closure of the maxillary left first molar and mandibular right second molar, and implant prostheses for the remaining spaces. The number of implants could be decreased to 4. The implant distal to maxillary left second molar could be reevaluated after space closure according to the occlusal contacts between maxillary left and mandibular second molars. Only 1 implant could be avoided by the substitution of the mandibular right second molar by the wisdom tooth. In terms of financial considerations, it did not improve much.

Fig 5
Treatment option 3, edentulous areas were closed or partially closed to reduce the number of the required implant prostheses. In addition to the third molars, only the maxillary right second premolar was planned to extract for protrusion reduction. However, the number of implants only decreased by 1 from 5 to 4. Although the maxillary left second molar replaced the maxillary left first molar after space closure, an implant might be indicated distal to the maxillary left second molar.

The fourth option was based on option 3, with autotransplantations added to reduce the number of dental implants ( Fig 6 ). Autotransplantation of the maxillary right second premolar to the mandibular left first molar space, and the mandibular left wisdom tooth to mandibular right first molar space, reducing the number of dental implants to 1 or 2, which greatly reduced the cost as the fee of autotransplantation procedure might be around one-fourth of the cost of a dental implant.

Fig 6
Treatment option 4, autotransplantations of maxillary right second premolar to mandibular left first molar space and mandibular left wisdom tooth to mandibular right first molar space, were further applied to treatment option 3. The number of implants could be decreased to 2 or 1. The need for the implant at the maxillary left second molar could be reevaluated after space closure because of the atypical occlusal scheme on the left side with 2 premolars on the maxillary and 3 premolars on the mandibular arch.

Option 1 might be the ideal treatment option. However, the patient declined the surgical approach. Option 2 was a typical camouflage treatment for Class II malocclusion with maxillary single arch extraction. The extractions of 2 maxillary first premolars and 3 third molars were acceptable to this patient. The problem was the cost of 5 dental implants, which was far beyond her budget. Option 3 tried to reduce the number of implants by space closure of UL6, LR7, and part of LL6. Aside from the removal of 2 third molars (UR8 and LL8), only UR5 was planned for extraction. Asymmetrical space closure of UR5 and UL6 in the maxillary arch and LR7 and partial closure of LL6 may lead to midline deviation. Four dental implants were still required in treatment option 3. The patient still could not afford the cost of the implant prostheses.

After thorough discussion and communication, option 4 was accepted to reduce the number of dental implants with 2 autotransplants. The need for an implant at the maxillary left second molar was to be reevaluated after the establishment of a stable occlusion. If the occlusal contacts were good enough, then the number of the required implant could be one at the position of mandibular left first premolar. Of course, the cost and risks for the failure of autotransplantation were thoroughly discussed.

Treatment objectives

Full mouth rehabilitation was the ultimate goal of this orthodontic treatment. Maximal retraction of maxillary and mandibular incisors was indicated for profile reduction. Maxillary anterior intrusion would be essential for the correction of a gummy smile. Active vertical control by intruding maxillary posteriors may lead to counterclockwise rotation of the mandible, which would be beneficial to the profile improvement. Transverse coordination between both arches was also important to correct the posterior crossbites. Dental implants, autotransplants, and prostheses were required to rebuild the occlusion. Spaces would be either closed, replaced with autotransplants, or restored with prostheses.

Treatment progress

A modified Alexander prescription was used. The slot sizes of the anterior teeth (canine to canine) were 0.018-in, whereas the slot sizes of the posterior teeth were 0.022-in. After the removal of the maxillary right third molar and periodontal phase I treatment, the maxillary arch was bonded, and 2 maxillary posterior miniscrews (A1-P, 2.0 × 10 mm, Bioray Biotech Corporation, Taipei, Taiwan) were installed buccally at infrazygomatic crest to retract the maxillary canines on 0.016-in nickel-titanium (NiTi) archwire. The donor premolar, UR5, was bonded with wire engagement to make it slightly mobile for a less traumatic extraction. A 0.016 × 0.022-in improved super-elastic NiTi alloy wire (ISW, L&H Titan, Tomy International, Tokyo, Japan) was the initial archwire after mandibular arch bonding.

A palatal miniscrew (A1-P, 2.0 × 10 mm) was inserted after 2 months of treatment. Intrusive forces for the elongated maxillary right first molar were applied from buccal and palatal miniscrews simultaneously, which were also helpful to correct the canted occlusal plane ( Fig 7 ). Autotransplantation of maxillary right second premolar to mandibular left first molar was performed after 5 months into treatment ( Fig 7 , B ). After the flap was reflected, an artificially drilled socket at the recipient site was made, and the autotransplant was loosely fitted into the socket. Selective occlusal reduction was performed to avoid occlusal trauma. A bracket was bonded to the autotransplant to receive the mandibular archwire, which was a 0.016 × 0.022-in improved super-elastic NiTi alloy wire developed by Tokyo Medical and Dental University. The recipient site was covered with a periodontal dressing after suturing (Coe-Pak, GC, America, Ill). Antibiotics (Amoxicillin, 250 gm, TID) and analgesics (Acetaminophen, 500 gm, QID) were prescribed for 3 days. Root canal treatment was performed 2 weeks after surgery.

Dec 24, 2021 | Posted by in Orthodontics | Comments Off on Interdisciplinary rehabilitation for mutilated dentition with mini-implants, autotransplants, and a dental implant
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