Orthodontic tooth extrusion to regenerate missing papilla adjacent to maxillary anterior single implants: A 2- to 7-year retrospective study.

INTRODUCTION: Regeneration of the missing papilla adjacent to single implants in the esthetic zone has always been challenging, despite advances in vertical hard and soft tissue regeneration. Orthodontic tooth extrusion has been shown to effectively gain alveolar bone and gingival tissue. This retrospective study evaluated the effectiveness of orthodontic tooth extrusion on regenerating missing papilla between existing maxillary anterior single implant and its adjacent tooth. METHODS: Patients who underwent orthodontic tooth extrusion to regenerate missing papilla adjacent to a single implant in the esthetic zone were included in this study. The gingival phenotype, orthodontic extrusion movement, proximal bone level, dento-implant papilla level, facial gingival level, mucogingival junction level, and keratinized tissue width, of the extruded tooth were recorded at pre-orthodontic extrusion (T0 ), post-orthodontic extrusion and retention (T1 ), and latest follow-up (T2 ). RESULTS: A total of 17 maxillary single tooth had orthodontic tooth extrusion to regenerate missing papilla adjacent to 14 maxillary anterior single implants in 14 patients. After a mean follow-up time of 48.4 months, implant success rate was 100% (14/14), with none of the orthodontically extruded teeth being extracted. After a mean extrusion and retention period of 14.3 months, a mean orthodontic extrusion movement of 4.62 ± 0.78 mm was noted with a mean proximal bone level gain of 3.54 ± 0.61 mm (77.0% efficacy), dento-implant papilla level gain of 3.98 ± 0.81 mm (86.8% efficacy), and facial gingival tissue gain of 4.27 mm ± 0.55 mm (93.4% efficacy). A mean keratinized tissue width gain of 4.17 ± 0.49 mm with minimal mean mucogingival junction level change of 0.10 ± 0.30 mm were observed. The efficacy of orthodontic eruption movement on dento-implant papilla gain was less in the thin (80.5%) phenotype group when compared with that in the thick (91.5%) phenotype group. CONCLUSIONS: Within the confines of this study, orthodontic extrusion is an effective, noninvasive method in regenerating mid-term stable proximal bone and papilla adjacent to maxillary anterior single implants. CLINICAL SIGNIFICANCE: This retrospective study presents a mid-term result on orthodontic extrusion as a mean to regenerate dento-implant papilla defect. The extended retention period following orthodontic extrusion showed stable and efficacious proximal bone and papilla gain.

Implant interactions with orthodontics.

Many situations arise in which orthodontic therapy in conjunction with implant modalities is beneficial, relevant or necessary. These situations might entail orthodontic treatment preparatory to the placement of an implant, such as in the site preparation for implant placement. Traditionally, this has been somewhat well understood, but there are certain guidelines that must be adhered to as well as diagnostic steps that must be followed. Provision of adequate space for implant placement is of paramount importance, but there is also the consideration of tissue manipulation and remodeling which orthodontic therapy can achieve very predictably and orthodontists should be well versed in harnessing and employing this modality of site preparation. In this way, hopeless teeth that are slated for extraction can still be utilized by orthodontic extraction to augment tissues, both hard and soft, thereby facilitating site development. On the corollary, and representing a significant shift in treatment sequencing, there are many situations in which orthodontic mechanotherapy can be simplified, expedited, and facilitated by the placement of an implant and utilization as an integral part of the mechanotherapy. Implants have proven to provide excellent anchorage, and have resulted in a new class of anchorage known as "absolute anchorage". Implants can be harnessed as anchors both in a direct and indirect sense, depending upon the dictates of the case. Further, this has led to the development of orthodontic miniscrew systems and techniques, which can have added features such as flexibility in location and placement, as well as ease of use and removal. As orthodontic appliances evolve, the advent of aligner therapy has become mainstream and well accepted, and many of the aforementioned combined treatment modalities can and should be incorporated into this relatively new treatment modality as well.

Implants in orthodontics: the impact of new treatment modalities.

The specialty of orthodontics has felt the impact of implant dentistry, but not to the extent that the surgical and restorative specialties have, both of which have undergone dramatic transformation in the last 20 years. However, implant technology has begun to be embraced by the orthodontic community, and not merely for the purpose of tooth replacement. When implants are used for anchorage, orthodontic mechanotherapy is simplified and facilitated. In fact, treatment outcomes not considered possible by conventional means become quite feasible. Other advantages of the inclusion of implants in orthodontic appliance management include decreased treatment time (because en masse movements become possible) and elimination of compliance dependence. These factors all result in more predictable treatment outcomes. Various mechanisms by which implants can be used are available. All fall under the scheme of either "direct" or "indirect" anchorage. It is this author's firm contention that as these strategies become mainstream, many of today's conventional devices designed for anchor preservation will be rendered obsolete.

A case for absolute anchorage.

It would be an understatement to say that implant technology has changed the face of dentistry in the past 10 years or so. Both the surgical and restorative specialties have undergone dramatic transformation from treatment planning through all phases of rehabilitation. However, the same cannot necessarily be said for the specialty of orthodontics. Although it could be argued that implants have had an impact on the planning and setup of orthodontic cases (such as in congenitally missing teeth situations), the actual utilization of implants as an integral part of mechanotherapy has only begun to be realized. The ultimate extension of this application of using implants to enhance tooth movement would be to employ implants that are designed solely for the purpose of facilitating orthodontic therapy, with no intention to restore, but rather to explant such implants, after their purpose is fulfilled.

Implant-enhanced tooth movement: indirect absolute anchorage.

Four case reports demonstrate the effectiveness of indirect anchorage in orthodontics. These cases demonstrate the variety of situations in which absolute anchorage can be applied. A maxillary premolar extraction case illustrates the effectiveness of anterior retraction with this technique. A maxillary posterior protraction case shows the ease with which space closure can be achieved. Dual-arch capability is demonstrated through a four-premolar extraction case. Lastly, a case of severe dental mutilation devoid of any anchor units under conventional methods depicts how effectively distal driving can be accomplished. The technique involves the simple placement of a midpalatal endosseous implant that provides anchorage by indirect means to various teeth by virtue of a transpalatal arch soldered to its abutment. Once stabilized by such means, dramatic movements can be achieved in situations that would otherwise overtax anchor units and result in loss of anchorage. Teeth that would otherwise require stepwise and sequential movements can be mobilized en masse, greatly simplifying mechanotherapy and dramatically shortening treatment time. When no longer needed, the palatal implant is explanted and leaves no permanent deformation or defect after 2 or 3 weeks of healing.