Missing Laterals

A Common Esthetic Challenge for Every Dentist

Introduction

Missing maxillary lateral incisors is a somewhat commonly occurring dental anomaly throughout all dental practices. The literature states that maxillary lateral incisor agenesis occurs in 0.8 to 2% of the population.1,2,3 When considering the cosmetic ramifications of these situations, it is obvious that all dentists consider these cases to be both challenging and complex. Typically, these patients are younger and have reached the point in life that they are searching for permanent solutions for these missing teeth. In addition, these patients often have high cosmetic expectations and require results that simulate natural teeth in feel, function, and looks. All of these criteria add to the complexities of the procedures required to replace missing maxillary lateral incisors in a naturally pleasing manner. Replacing missing lateral incisors can also be esthetically challenging due to the anatomy and tissue architecture, but when planned well and handled properly, the final results can be amazingly similar to those of natural teeth.

It is very common for a patient to present wearing a removable partial denture that replaces these missing teeth. Their desire is to find a more permanent or fixed solution for these edentulous spaces. There are several treatment options for cases like this: Bonded Maryland bridges, traditional full coverage FPD bridge work, and dental implants are the three primary fixed options. Each option has its own pluses and minuses, but dental implants are typically the best option when handled properly.4,5 Some of the reasons implants could be considered a superior option overall are conservation of enamel on adjacent teeth, bio-mimetic restorations, bone preservations, and superior cosmetic results.6 This case illustrates, and discusses, many of the criteria associated with the delivery of beautiful implants and porcelain crowns in the maxillary lateral incisors positions.

Fig. 1 – Pre-op, full facial. Note crowding and lack of M-D spacing on 7 and 10.

Figs 2, 3 – PA’s 7 and 10. Three month post-operative. Complete osseous and gingival healing, implants ready for final restorations with EMax /porcelain layered crowns.

Case Presentation

The patient was a 29 year old female with congenitally missing maxillary lateral incisors (Fig. 1). Her main concern is to replace teeth 7 and 10, but in a way that looks very natural. Obviously, the missing teeth were a major esthetic challenge, but additionally, the maxillary and mandibular crowding added another facet to the overall plan.

The treatment plan presented was to address both upper and lower arch crowding in conjunction with creating correct spacing for 7 and 10 in preparation for implant placements and restorations. It was also planned that the implants would be placed while she was still in full ortho and this would help temporize the missing teeth during the osseointegration phase. By choosing this route, the patient would not have to wear a removable prosthesis at any time during the treatment.

Full upper and lower conventional orthodontic treatment was started with the initial goals being to correct the lower crowding and to create proper spacing for implants in the 7 and 10 positions. By using plastic denture teeth, teeth 7 and 10 were replaced with ovate pontics attached to the arch wire by ortho brackets.

These provisionals were removable and shaped in a way to begin creating the proper future gingival architecture for the implant restorations. At 6 month intervals throughout the entire ortho treatment, the spacing on 7-10 was evaluated and adjusted accordingly. The initial implant surgery and placements were planned for when the teeth were positioned in the correct alignment and the retention phase started.

Because there was adequate B-L bone volume in both sites, there was no need for pre-operative ridge grafting. At this time, the ortho treatment would be complete in 6 more months and the brackets removed. By planning the treatment phases accordingly, the implants could be restored immediately after the brackets were removed, thus avoiding the need of a removable temporary prosthesis to replace 7 and 10.

When the spacing and root angulations on 7 and 10 were deemed correct, the patient presented for the surgical placement of the implants. The maxillary arch wire, along with the ovate pontics, was removed before the surgery and then immediately replaced after the implant placements. 2 OsteoReady 3.75 X 11.5 mm implants were placed in the 7 and 10 spots with great care taken to assure precise angulations and depths. It is noted that the implants were placed so the the platforms were 3 mm apical to the adjacent CEJ’s. This was purposefully done so that proper emergence profile and contact lengths could be created later to ensure excellent cosmetic results. Transmucosal PEEK healing caps were placed and the arch wire replaced along with the pontics.

The patient would continued to wear the brackets and arch wires during the next 6 month osseointegration stage. At the end of 6 months, the ortho brackets were removed and the patient sent directly back to her dentist for immediate restorations on 7 and 10. The PEEK healing caps were removed and zirconia abutments placed on the implants 7 and 10. Both abutments were torqued down to 35NcM and both implants were found to be stable and completely integrated. Provisional crowns were made for 7 and 10 and the patient was to wear them for 3 months to allow for proper gingival healing and contouring. (Fig 2-5).

After 3 months, the gingival presentation was satisfactory and master impressions made for individual EMax/porcelain layered crowns, shade Vita A1 with A2 gingival 2 mm (Megan Burke, C.D.T., Louvre Dental Lab, Agoura Hills, CA.) The patient returned 2 weeks later for the cementation appointment. After try in and patient approval, the crowns were cemented with a very thin reline layer of Rely X (3M ESPE) cement with great care taken to not extrude any cement apically onto the implant surface. Post-op X-rays were taken to ensure no cement was retained on the abutments or on the implant surfaces.

Conclusion

Replacing missing teeth in the maxillary esthetic zone is challenging for even the most advanced cosmetic/implant dentists. Missing maxillary lateral incisors and their limited spacings have their own specific issues and problems. These complex cosmetic cases require purposeful and completely focused treatment planning to create natural results and patient satisfaction. By adhering to proper cosmetic and implant protocols, dentists can create bio-mimetic results that give patients natural results that and possibly a lifetime of beautiful smiles.

Figs 4, 5 – Post op 3 months, provisional crowns teeth 7 and 10 with completed gingival healing. Note proper gingival heights, margins, and esthetic embrasures developed by utilizing correct gingival contours of the provisional restorations and proper healing times

Fig 6. – Final restorations EMax /porcelain layered crowns 7 and 10 cemented with RelyX (3M-ESPE).