Modified Willet appliance: A case report

Introduction

The willet appliance, that guides the young’s permanent first molar into place, is one of the most beneficial techniques that pediatric dentists can employ when a primary second molar is prematurely lost. Gerber pioneered the distal shoe space maintainer, which Croll further improved. Its indications and contraindications were thoroughly explored by Hicks, who favored the production of a cast gold device, however the clinically acceptable appliances were the ones which were soldered to stainless steel crowns or bands. Brill described chairside manufacturing of a distal shoe space maintainer to be supplied immediately after extraction, which had a high success rate if the patient co-operated.1

There are various conditions that make the willet appliance ineffective. Abutments to anchor a cemented device may be missing if numerous teeth are removed. Poor oral hygiene or an inadequate level of patient and parent’s involvement significantly diminishes the likelihood of a satisfactory clinical outcome. Certain medical diseases, including blood disorders, immunodeficiency, congenital heart defects, rheumatic fever, hyperglycemia, and systemic debilitation, may exclude its use.

In cases where distal shoe appliance usage is contraindicated, there are two treatment options

Carroll and Jones described three examples in which a removable or fixed pressure gadget was employed to guide the erupting permanent molar.3 The goal of this case report is to discuss the clinical care of severe caries on mandibular primary molars with a modified Willet appliance.

Case Report

A 5-year old male patient reported to department of Pediatric and Preventive dentistry with a chief complaint of pain in the left lower back tooth region. Clinical examination revealed deep occlusal caries w.r.t 75, 84 and deep proximal caries w.r.t 74 (Figure 1). Intraoral periapical radiograph showed furcal radiolucency and external root resorption w.r.t 75 and complete root resorption and bone resorption is seen w.r.t 74 (Figure 2). The mandibular first molar on the right side in IOPA showed furcal radiolucency and root resorption. Coronal radiolucency approximating enamel, dentin and pulp was also evident. Cervical caries was seen in mandibular right primary canine on right side is filled with type 2 restorative glass ionomer cement. The young permanent tooth showed Stage 7 of development according to Nolla’s classification. So, then it was decided to extract the 74,75 and 84 followed by modified willet appliance was indicated. Therefore, has planned for distal shoe appliance on left side and on right side Mayne’s space maintainer was planned. It was planned to connect both sides with single wire from lingually.

The entire procedure was well explained to the patient and his parents, and consent was taken before starting treatment. On his next visit, banding was done on 85, 73 and alginate impression was taken. The band was stabilized with acrylic, and cast was poured with dental stone. In the same visit, extraction of 84 was done, and analgesic and antibiotic were prescribed.

To make the appliance a cut was made on the cast on left side for distal shoe and calculated radiographically. The wire component was adapted with a 19-gauze wire followed by soldering, finishing and polishing of appliance with a stone bur (Figure 3). On 2^nd visit after extraction of 74,75 the intra-alveolar projection of the appliance was placed in the socket to touch and guide the vertical eruption path of the unerupted permanent first molar on left side of the mandibular arch and appliance was adjusted. Intraoral periapical radiographs were taken to check the projection of appliance and cementation of appliance was done with type -1GIC (Figure 4, Figure 5).

Figure 1

Preoperative intraoral photograph

Figure 2

IOPA w.r.t 74,75

Figure 3

Wire banding on cast

Figure 4

Intraoral photograph of modified Willet appliance

Figure 5

IOPA shows extension of Willet appliance w.r.t. 36

Discussion

Premature exfoliation of primary second molars has always been difficult for paediatric dentist and premature exfoliation of many primary molars becomes significantly more challenging. If Malocclusion can result if no suitable preventive precautions are taken. Following clinical and radiographic examination, space maintainers are advised to prevent such occlusal discrepancies.4

In some clinical situations, like as this one with primary molar loss, the standard space maintainer must be changed to match the patient's demands. Some adaptations, such as Croll's use of prefabricated lingual arch wire embedded in acrylic and Gegenheimer's use of an acrylic pressure ridge, but the principal downsides of these alterations were poor retention and patient compliance.5

Long-term clinical trials are needed to determine the efficacy of this device. The current report demonstrated that this personalised distal shoe appliance was stable and acceptable to the patient.

Conclusion

It may be inferred that by providing broad contact and limiting lingual or buccal deviation during eruption, this design can endure the force of eruption. This design may be an alternate treatment with advantages over the standard design for mandibular second molar early loss.

Source of Funding

None.

Conflict of Interest

None.