Multidisciplinary approach of congenitally missing upper laterals: A case study.

In an orthodontic patient, missing teeth will require restoration or reshaping of an adjacent tooth, after the orthodontic treatment. Furthermore, each type of restoration may require slightly different tooth position. Therefore, it is mandatory for the team to establish a treatment plan. The orthodontist should join hands with the restorative dentist and consult before the treatment plan. However, some adult orthodontic patients may have several missing permanent teeth. If teeth have been absent for several years, the remaining teeth may have been drifted. In such situation, it may be necessary to position the teeth in unusual place. These patients may require a combination of orthodontic and restorative dentistry to rehabilitate their occlusion. In these patients, it may be difficult for the orthodontist to visualize or foresee the final result as she/he may not be aware of restorative requirements or the eventual restoration plans and vice versa for the restorative dentist also.

Most commonly, the missing permanent teeth next to third molars and second premolars are the maxillary laterals. Treatment planning for patients with missing maxillary lateral incisors traditionally includes either space closure[1] or space reopening and insertion of implants.[23] Some common objections to orthodontic space closure are that the treatment outcome may not look “natural,” that the functional occlusion is compromised, and that retention of the treatment result is difficult, although it may appear preferable esthetically and functionally to create space for replacement of the missing lateral incisor with a single-tooth implant[45] or resin-bonded bridge,[6] and while high survival rates for implant-supported porcelain crowns can be expected.

Case Report

A girl, aged 18 years 5 months, came to my practice with the request of having teeth fixed for upper front spacing. She was physically healthy with no history of dental trauma. She had a slightly convex profile. She had a pleasing smile and lip competence. The intraoral examination showed half-cusp Class II molar relationships and spacing in upper arch with crowding of 3.5 mm in the mandibular arch. Her maxillary dental midline was displaced 2 mm to the right of the facial midline and mandibular dental midline coincided with the body midline. Overbite was 50% with a moderate curve of Spee of 3 mm [Figures 1–9].

Figure 1

Pretreatment-extraoral frontal

Figure 9

Midtreatment-intraoral

Pretreatment-extraoral profile

Pretreatment-intraoral frontal

Pretreatment-intraoral left

Pretreatment-intraoral occlusal lower

Pretreatment-intraoral occlusal upper

Pre treatment intraoral X-ray

Pretreatment-intraoral right

The panoramic radiograph showed normal root and tooth development, with the missing maxillary lateral incisors. Cephalometric assessment showed Class II (Wits, 2 mm; ANB, 4.5°; SN-GoGn, 32°) with normally inclined incisors [Table 1, Figures 10 and 11].

Table 1

Cephalometric analysis

Figure 10

Pretreatment-lateral cephalogarm

Figure 11

Pretreatment orthopantomogram

Treatment objectives

Ideally, the treatment objectives would include full resolution of the replacement of the missing teeth. However, achievement of this objective might subject the restoration and orthodontics. Class I molar and canine relationships, ideal overjet and overbite, and an esthetic smile with minimal change in the profile were desired.

Treatment progress

We started the case on size 022 ROTH Preadjusted Edgewise Appliance (PEA), and did initial leveling and aligning of the upper and lower arches. After leveling, we planned to open space for the missing teeth, followed by more radiographs to confirm the position of the canine and central incisors roots. The width for the root implant of the lateral incisor space was adequate. The roots of the central incisors and canines were made parallel. Sequential arch wire changes progressing to rigid stainless steel wires were achieved in both arches. Open-coil spring was used to open up the space for the laterals. After space for implants were consolidated, tapered root implants were placed by osteotomy in the lateral areas. Check X-rays confirmed their positions. The metal-fused ceramic crowns were placed on their respective implant abutments. Lower lingual retainer was given.

Discussion

A common orthodontic restorative situation involves a patient who has congenitally missing one or two lateral incisors. If the patient has one maxillary lateral incisor missing, the contralateral incisor would determine the amount of space for the implant and crown. However, in some patients, the existing lateral may be peg shaped. In other situations, both lateral incisors missing are congenitally absent and the amount of space is determined by two factors[3] “esthetics and occlusion”. An esthetic relationship exists between the size of the maxillary central and lateral incisors. The size relationship has been called as the “Golden proportion”.[4] Ideally, maxillary lateral incisor should be about two-third the width of the central incisor.[5] Since most central incisors are about 9 mm wide, the width of the lateral incisor space should not be less than 6 mm. Today, the narrowest implant is about 3.2 mm in diameter. If the edentulous space is 6 mm wide, then 1.4 mm would exist between the implant and adjacent roots. In this case, the important things are implant site development and timing of implant placement, which are vital for the success, and had been achieved [Figures 12–22].

Figure 12

Posttreatment-extraoral profile

Figure 22

Posttreatment-lateral cephalogarm

Posttreatment-extraoral frontal

Posttreatment-extraoral smile

Posttreatment-intraoral left

Posttreatment-intraoral occlusal upper

Posttreatment-intraoral occlusal lower

Posttreatment-intraoral right

Posttreatment-intraoral frontal

Posttreatment-intraoral X-rays

Posttreatment-orthopantomogarm

Treatment results

The restoration was fully achieved with ideal Class I molar and canine relationships. Ideal overjet and overbite was achieved with adequate canine disclusion and protrusive guidance.