Dental implants in the management of nonsyndromal oligodontia

The orthodontic implant site-switching technique: a preliminary study in dogs

BACKGROUND

To evaluate the quantity and quality of bone in the newly formed edentulous area produced by the orthodontic implant site-switching technique.

METHODS

The bilateral maxillary first premolars of five beagle dogs were extracted and bone defects were created. The right and left sides of the maxilla were randomly divided into control and experimental sides. On the experimental side, the maxillary second premolar was mesially moved into the position of the missing first premolar. On the control side, the second maxillary premolar was extracted. Six months later, the beagles were euthanized. Microcomputer tomography was used to analyze bone microstructure parameters, alveolar bone height and alveolar bone width of the regenerated bone. Histological analysis was performed by staining tissue sections with toluidine blue.

RESULTS

Median BV/TV values in the experimental group (81.78%) were significantly larger than those in the control group (35.67%; p = 0.04). Median Tb.Sp values in the experimental group (0.14 mm) were significantly lower than those in the control group (0.54 mm; p = 0.04). Median Tb.Th values in the experimental group (0.48 mm) were significantly higher than those in the control group (0.21 mm; p = 0.04). Median Tb.Pf values in the experimental group (0.65/mm) were significantly lower than those in the control group (3.15/mm; p = 0.04). There was no significant difference in the trabecular number (Tb.N) between the two groups (p = 0.23). The median alveolar bone height values in the experimental group (-0.81 mm) were significantly higher than those in the control group (-2.11 mm; p = 0.04) at a distance 5 mm from the mesial CEJ of the third premolar. The median alveolar bone height values in the experimental group (0.45 mm) were significantly higher than those in the control group (-1.70 mm; p = 0.04) at a distance 6 mm from the mesial CEJ of the third premolar. There was no significant difference in alveolar bone width when compared between the two groups (p > 0.05).

CONCLUSIONS

The newly formed edentulous area created by orthodontic treatment had more compact and thicker trabeculae than the extraction socket. Furthermore, the newly formed edentulous area had a greater alveolar bone height available for the placement of implants.

Oral Rehabilitation of Hypodontia Patients Using an Endosseous Dental Implant: Functional and Aesthetic Results

Hypodontia often leads to limited bone availability of the alveolar ridges. Oral rehabilitation of severe hypodontia patients is challenging. In this retrospective study, we evaluated the functional and aesthetic results after dental implants in hypodontia patients, corroborated by Albrektsson implant success criteria. Over a period of 15 years (2000–2015), a total of 43 patients were diagnosed with hypodontia and 165 dental implants were inserted. Six patients who received 10 implants were lost in the follow-up. We examined 155 implants in 37 patients between December 2015 and May 2017. Besides family history, patients evaluated the general satisfaction, functionality, and aesthetics of the implants. Study subjects were between 17 and 44 years old (mean ± SD: 21.4 ± 5.6). Hypodontia patients were missing one to five teeth (n = 28), whereas patients diagnosed with oligodontia (≥6 missing teeth, n = 9). In this study, 24 patients (64.9%) with hypodontia had a positive family history; the remaining 13 patients had no family member with hypodontia. The final follow-up time ranged between 5 and 189 months after implant placement. Orthodontic treatment was performed in 32 patients (86%) before implant placement. Rehabilitation resulted in 62% of the cases being treated with 1–2 implants and 38% treated with 3–15 implants. However, out of 155 inserted dental implants, 18 implants failed to meet Albrektsson criteria, under which two implants were removed. Only autografts were used for bone augmentation with 97 implants. More than two-thirds of the patients showed high general satisfaction and masticatory function (69.4%) as well as phonetic ability (80.6%). The aesthetic outcome was rated as excellent by 17 patients (47.2%). The findings emphasize the importance of interdisciplinary treatment of hypodontia, leading to a satisfactory, functional, and long-term fixed prosthodontics using dental implants.

Interdisciplinary Approach to Treat Patients With Tooth Agenesis: A Case Report

INTRODUCTION

Tooth agenesis is a type of dental anomaly in which individuals are missing teeth due to developmental failure as a result of genetic or environmental factors. With approximately one fourth of the population missing ≥1 third molar, tooth agenesis is considered a common dental anomaly. However, the severity of tooth agenesis can range from a missing single tooth to multiple teeth. When suffering from severe tooth agenesis, the patient's health and social relationships are often affected.

CASE PRESENTATION

The patient in this report congenitally lost 11 teeth and suffered from compromised esthetics and impaired chewing function. In such a severe tooth agenesis case, interdisciplinary treatments involving orthodontics, periodontics, and prosthodontics were engaged to reconstruct the ideal biology, function, and esthetics for the patient. With an interdisciplinary approach, the periodontist played an important role in the rehabilitation of the edentulous regions with implants in combination with various hard and soft tissue augmentation procedures. In addition, the patient with severe tooth agenesis presented with additional dental anomalies. The periodontist, therefore, had to collaborate with other specialists to provide early detection and intervention to avoid future complications, such as the management of infraoccluded ankylosed deciduous molars and aberrant frenum. The patient at the end of treatment had a good occlusion with improved function and esthetics.

CONCLUSION

This case report describes the interdisciplinary treatment approach used and points out the role of periodontists in the treatment of a patient with severe tooth agenesis.

Adjunctive Orthodontic Applications in Dental Implantology

Implant placement is often necessitated for replacement of teeth with pathologically damaged alveolar bone due to periodontitis or traumatic injury. Surgical augmentation of resorbed bone has many limitations, including lower efficacy of vertical augmentation than horizontal augmentation, as well as morbidity associated with grafting procedure. Orthodontic therapy has been proposed as a useful method for augmenting the resorbed alveolar bone and reforming aesthetically appealing gingival margin, prior to implant placement. This narrative review summarizes the available evidence for the application of orthodontic strategies that can be used as adjunct in selected cases to augment bone volume for the future implant site and maintain space for the prosthetic parts of the implant. These are (1) orthodontic extrusion of compromised teeth to generate vertical bone volume and enhance gingival architecture, (2) tooth preservation and postponing orthodontic space opening to maintain bone volume in future implant site, (3) orthodontic implant site switching to eliminate the deficient bone volume or risky implant sites, and (4) the provision of a rigid fixed-bonded retainer to maintain the implant site. Although there are no randomized controlled clinical trials to evaluate the efficacy of orthodontic therapy for implant site development, clinical case reports and experience document the efficacy of orthodontic therapy for this application.

Orthodontic Considerations in Restorative Management of Hypodontia Patients With Endosseous Implants

The use of implant-supported restorations in patients with hypodontia remains challenging and requires a multistage treatment that begins in late mixed dentition and continues into late adolescence. The aim of this article is to review the role of orthodontics in endosseous implant rehabilitation of patients with hypodontia. The MEDLINE, Web of Science, Scopus, Cochrane databases, and necessary scientific textbooks were searched for relevant studies and reviews, and as far as possible, they were only included if they had been cited at least once in the literature. Dental implants are susceptible to overloading as the periodontal ligament is absent and the proprioceptive nerve endings are either lacking or very limited. Patients with hypodontia may present with skeletal features such as short and retrognathic maxilla, prognathic mandible, and shorter lower anterior facial height, and they sometimes need orthognathic correction as part of their overall treatment. Dental problems vary and include bimaxillary retroclination of incisors, spacing, centerline discrepancies, microdontia, hypoplastic enamels, ankylosis of the retained primary teeth, overeruptions, and volume deficiencies of alveolar ridges. The challenges mentioned, as well as bone volume deficiencies, compromise the successful placement of implants. Orthodontic strategies and techniques, such as uprighting mechanics, extrusion/intrusion, delayed space opening, and orthodontic implant site-switching, can be used to create, preserve, or augment the implant site. After orthodontic site development, the final planned position of the teeth should be maintained with a rigid bonded retainer; overlooking this stage may compromise the implant site and require orthodontic retreatment.