The Importance of Interdisciplinary Treatment in an Esthetically Challenging Case

Often providing a first impression about someone, a person's smile can be a personal trademark that both serves as a means of communication and is indicative of the individual's self-confidence. A smile plays an integral role in psychological-social well-being and emotional health.^1-5 Therefore, many people wish to modify their smiles, and this presents dentists with a number of considerations when planning patient care. Should the treatment be conservative or invasive? Are there physical and/or emotional limitations to achieving the desired goals? What treatment options are available? What will the length of time and cost be to complete the treatment? Oftentimes a treatment can become quite complex, and to accommodate such cases an interdisciplinary approach from the outset may be needed to provide patients the best, most efficient care.

In the clinical case presented, poor planning and execution had led to inferior orthodontic treatment, which needed to be salvaged. A new esthetic-prosthetic management plan was put into effect to achieve a successful result from the standpoint of both oral health and an esthetically pleasing smile. This case is representative of many others like it that require careful consideration for the cosmetic challenges of treating anterior teeth, and for how treatment modalities and outcomes can vary depending on the all-important surrounding frame: the gingivae.

A 7-year-old patient presented to the orthodontist in 2002 with a congenitally missing maxillary left central incisor (Figure 1). The patient underwent orthodontic treatment for 6 years that resulted in an unacceptable smile and compromised state for future restorative/prosthetic outcome, as the right central incisor had been moved into the patient's midline (Figure 2 and Figure 3). Additionally, the patient's improper course of treatment and unsatisfactory progress also resulted in lost time during growth as well as the expenditure of considerable finances. Because of the complexity of the case, other dental disciplines should have been included in the treatment planning and care from the outset but were not.

The orthodontist then referred the patient to the prosthodontist (the author, SR) for a consultation to determine how an esthetic outcome could be achieved. The prosthodontist thus saw the patient for the first time when the patient was 13 years old. The prosthodontist attempted to rectify the improper course of treatment while working with the orthodontist; however, it eventually became apparent to the prosthodontist that a new interdisciplinary team would be needed. Despite the prosthodontist's guidance, poor orthodontic mechanics and improper anchorage execution had led to excessive buccal flaring (Figure 4). Although temporary, overarch expansion during the orthodontic treatment had created an unacceptable cosmetic situation for the now 14-year-old boy, with an extreme edentulous space having been created in the area of the left central incisor. This mistake on behalf of the orthodontist consequently led to psychological-social concerns for the patient such as shyness, introversion, and being uncomfortable smiling.

To address the situation, with the congenitally missing tooth being the maxillary left central incisor and the orthodontically moved adjacent teeth now being in improper positions, the prosthodontist deemed it necessary to extract the maxillary left first premolar to create the necessary space for the upper left central incisor future implant and crown. A short-term esthetic solution was implemented by bonding a denture tooth using an orthodontic wire on the palatal surface of the right central incisor. This procedure slightly improved the cosmetic concern (excessive diastema) and served as a helpful guide for the original orthodontist by providing the correct width needed to close the large existing space (Figure 5). In this instance, an extreme concave buccal contour on the maxillary right central incisor was diagnosed (Figure 5), and it was determined that the final restoration of this tooth would be conservatively addressed with either direct bonding or a porcelain veneer.

Space closure for the missing central incisor and improved esthetics were achieved, but the anterior teeth had an undesirable and unacceptable buccal flaring (Figure 6).

At this point the prosthodontist made referrals to a new orthodontist and a periodontist in anticipation of achieving a satisfactory outcome. The prosthodontist presented the patient and parent with a new treatment plan. The plan, developed by the newly formed interdisciplinary team, was predicated on repositioning the patient's teeth into their proper locations and allowing for the replacement of the missing left central incisor with an implant and implant-supported crown. This, the team determined, would lead to an esthetic, healthy, and long-lasting result.

Anatomical evaluation of adjacent teeth and hard and soft tissue should be considered at early stages of therapy, in the authors' opinion, because this can alter the sequence of treatment for the replacement of missing teeth. In this case, as can be seen in Figure 4, it was clinically evident that the missing tooth was associated with a deficient alveolar ridge, and bone grafting would be required for the placement of an implant and to improve esthetics. As treatment progressed, it was important to look beyond the orthodontic progress and the space closure (Figure 7 and Figure 8) and consider the implant position for the replacement of the missing tooth.

Flaring of the anterior teeth became a concern in that after a total of now 8 years of orthodontic treatment the buccal bone was extremely thin. Although bone grafting was considered for the involved teeth, there was concern regarding correction of the narrow ridge on the edentulous area. With the aid of a cephalometric radiograph, the new interdisciplinary team had to consider whether the buccal inclination of the anterior teeth was an acceptable or correct position for both the short and long term, especially because an implant was to be placed.

While the temporary esthetic result achieved with the bonded tooth in the position of the left central incisor was an improvement, excessive buccal flaring of the maxillary anterior teeth was a concern with regard to longevity, as was a compromised implant placement with regard to proper position/angulation. The second orthodontist from the new team was consulted for a second opinion to determine if an even better esthetic outcome could be achieved. With the newly created interdisciplinary team, the prosthodontist and new orthodontist were in agreement with the new treatment plan, which included retraction of the upper and lower incisors, occlusal considerations for long-term function of an implant and crown, and a second round of orthodontic treatment. Thus, the plan was implemented.

Implants are known to absorb vertical loading forces significantly better than lateral forces.⁶ Consequently, when considering the placement of an implant to replace an anterior tooth, anterior guidance, excursive movements, and their loading forces must be taken into account. Without a second phase of orthodontic treatment, the implant would have been placed in relation to teeth that were improperly positioned, resulting in off-axial loading and esthetic compromise. Although the second phase of orthodontics was limited due to the fact that the patient had already concluded much of his growth and treatment time was, therefore, not fully sufficient, the treatment result nonetheless was highly effective, as a proper space was created for the future implant and tooth restoration, anterior teeth protrusion was reduced, and a proper, healthy occlusion was established. This second course of orthodontic treatment was completed in 16 months. Final orthodontic and debond images revealed a noticeable reduction of incisor protrusion and proper mesial-distal distance from the teeth adjacent to the future implant (Figure 9 through Figure 12).⁷

In patients with severe dental bimaxillary protrusion, several treatment options may be possible depending on facial profile, space requirements, and cephalometric findings. Extracting teeth (such as four bicuspids) may lead to the creation of excessive space and flattening of the facial profile during retraction. In addition, consideration must be given such that airway space is not encroached upon during significant retraction.⁸ An acceptable alternative to extractions may be the placement of mini-implants or mini-plates in the posterior of the mandible and maxilla to distalize the upper and lower dentitions.⁹ The ultimate result is judged not only by the esthetic outcome and proper function but also by a long-lasting healthy outcome and a proper tissue biotype to protect the implant and restoration.

Upon completion of the orthodontic treatment, occlusion and esthetic tooth alignment were evaluated. To assess the space allocation on the missing tooth, a radiograph was taken to ensure that the future implant would have adequate mesial-distal space and not be in close proximity to adjacent roots (Figure 12).

Furthermore, a final cephalometric radiograph was taken to evaluate the patient's profile and proclination of the anterior teeth (Figure 13). Several parameters must be established before fixed orthodontic appliances are removed. It has been suggested that at least 1.5 mm to 2 mm of interproximal bone be maintained between teeth and implants.^10,11 The diameter of the future implant used for the tooth being replaced has an impact on not only the biomechanical and esthetic functions but also the proximity to adjacent teeth and the preservation of healthy buccal and lingual bone. The restorative contact point and its relationship to the underlying proximal bone helps to determine the presence or absence of a papilla.¹² In implant therapy, formation of biologic width is consistent with varying degrees of bone remodeling.¹³ This relates to the presence or absence of the proximal periodontium of the adjacent tooth.¹⁴

Facial osseous integrity is required for not only osseointegration but also the stability and health of soft tissues. A deficiency in this area will lead to recession.^15,16 When teeth are congenitally missing, typically there is a ridge of inadequate thickness to receive an implant unless a staged or simultaneous bone grafting procedure is performed. Numerous techniques have been proposed to reconstruct the localized alveolar ridge to facilitate implant placement.^17-19 Regardless of the mode of regeneration, adequate bone thickness must be achieved for a sustainable, healthy, and esthetic outcome.

Additionally, a CBCT scan is paramount for proper 3-dimensional implant planning to determine the optimal bone grafting protocol and location for the implant and its proximity to adjacent teeth, and to evaluate the quantity and quality of the surrounding osseous foundation (Figure 14). Also, the surgeon should know at this point if the final restoration will be cemented or screw-retained, and any concerns should be addressed to avoid potential miscommunications regarding the final implant position and design for the final restoration. In this case the knife-edge ridge (Figure 4) was also corrected to provide a proper foundation for the implant (Figure 15). Due to an extreme deficient buccal concave contour on the maxillary right central incisor, the final contour of this tooth also had to be considered, as the adjacent edentulous area would need a bone graft to correct the edentulous knife-edge ridge, and the implant size and position and final crown contour would have to be evaluated (Figure 15 and Figure 16).

When replacing an anterior tooth with an implant-supported restoration, as in this case, it is important to develop hard and soft tissue using a provisional restoration to facilitate an ideal emergence profile and optimal esthetics (Figure 17). The tissue should be allowed to mature so the laboratory technician can fabricate the final crown to accurately represent the clinical situation (Figure 18 and Figure 19). The ultimate goal is to provide patients a healthy, stable, functional, and highly esthetic result with which they can be well pleased (Figure 20 through Figure 22).

Framing an implant-supported restoration with healthy hard and soft tissue for long-term stability is critical. With a thick, resilient periodontal biotype, a restorative/prosthetic solution is often achievable. When the tissue has experienced recession and/or the surrounding biotype of the tooth/teeth is friable, a more collaborative, and in many instances a surgical, approach may be indicated. When the case involves congenitally missing teeth, as seen in this case, the edentulous ridge may present with various challenges for which osseous and soft-tissue reconstructions are required to create a proper foundation, and, if possible and desired, dental implants may be warranted. Often, adequate tissue dimensions can be created by combining surgical augmentation(s) with provisional restorative therapy.

As this case demonstrated, complex diagnoses require the assembly and cooperation of an interdisciplinary team. Although treatment may be administered over a long period of time and may not necessitate that every dental specialist be involved in every step of the process, it is essential that the treatment team follow the patient's progress together. In this case, the recognition of failure to achieve an ideal outcome with the first phase of orthodontic treatment demanded a mid-treatment revision. By following this framework clinicians can help ensure that a successful outcome is achieved and the patient is happy with the results.

Sergio Rubinstein, DDS
Private Practice limited to Prosthodontics, Cosmetic Dentistry, and Implant Dentistry, Skokie, Illinois

Barry P. Levin, DMD
Clinical Associate Professor, Department of Graduate Periodontology, University of Pennsylvania School of Dental Medicine, Philadelphia, Pennsylvania; Private Practice limited to Periodontics and Implant Dentistry, Jenkintown, Pennsylvania; Diplomate, American Board of Periodontology

Elizabeth R. Michalczyk, DMD, PhD
Resident, Georgia School of Orthodontics, Atlanta, Georgia

Yan Razdolsky, DDS
Private Practice limited to Orthodontics, Buffalo Grove, Illinois; Diplomate, American Board of Orthodontics

Toshiyuki Fujiki, RDT
Laboratory Technician, Skokie, Illinois