A case report of a removable denture using magnetic attachment andcircumferential clasp followed up for 9 years
M. Sone, D. Matsumoto, N. Koyama, F. Narumi, T. Matsukawa, S. Uchida, K. Takahashi, M. Takagi, Y.
Inoyama, D. Sakamoto, K. Okamoto, and S. Ohkawa
Division of Removable Prosthodontics, Department of Restorative and Biomaterials Sciences, Meikai
University School of Dentistry

Abstract
To reconstruct a harmonious craniofacial system, it is essential to maintain an appropriate occlusal
vertical dimension (OVD). This clinical report describes the prognosis of a magnetic attachment denturethat improved an immediate denture to maintain an appropriate OVD and the optimum mandibularposition. As a definitive prosthesis, a removable maxillary overlay denture was fabricated that included a
coping type of magnetic attachment, copings, and circumferential clasps.
Nine years after the denture setting, the definitive prosthesis has been used without serious problems,
and the magnetic attachment has no clinically significant loss of retention.

Introduction
To reconstruct a harmonious craniofacial system, it is essential to maintain an appropriate occlusal
vertical dimension(OVD). This clinical report describes the prognosis of a magnetic attachment denturethat improved an immediate denture to maintain an appropriate OVD and the optimum mandibularposition.

Clinical History
The patient, a 63-year-old female, complained of masticatory dysfunction. The patient had received amaxillary fixed bridge from tooth #3 to tooth #11 in 1989; however, the restoration failed, having amarginal discrepancy and damage by caries (Fig.1). We did not diagnose infraocclusion by analysis of theOVD. Finally, we suggested fabricating a removable maxillary overlay denture with a coping type ofmagnetic attachment as a definitive prosthesis by use of an immediate denture to maintain the optimum

Fig.1 Intraoral view at the initial examination

mandibular position, which the patient found acceptable.

Treatment Procedure
As the first therapy, the incompatible fixed bridge in a marginal portion was removed, and tooth #3 wasextracted. Then an immediate maxillary denture was set on a portion of the missing teeth. With theimmediate denture, the patient obtained an adequate occlusal relationship and maintained the optimum
mandibular position (Fig.2).

Fig.2 Intraoral view with immediate denture
As a definitive prosthesis, the reinforcement structure of the framework for preventing denture base
fracture was made to cover about three quarters of the circumference of the magnetic attachment, andprotrusion of the labial side was avoided (Fig.3). GIGAUSS C600® (GC, Japan), the magnetic attachment
in this case report, was applied to tooth #6. The keeper of the magnetic attachment and magnetic assembly
were fixed with adhesive resin cement (Multilink® Automix, Ivoclar Vivadent, Liechtenstein) (Fig.4).

Fig.3 Reinforcement structure of framework

Fig.4 Keeper of the magnetic attachment

A removable maxillary overlay denture was fabricated and included a coping type of magnetic attachment,

Fig.5 Removable maxillary overlay denturecircumferential clasps (wire type), and a horseshoe plate as the major connector. This denture wasfabricated with the existing occlusal height and the optimum mandibular position (Fig.5). Figure 6 is an
intraoral view of the definitive prosthesis.

Fig.6 Intraoral view with definitive prostheses

Outcome of Treatment
Presently, 9 years and 7 months have passed since the definitive prosthesis was set (Fig.7). Maintenance
was initially performed every month, but since the prognosis was good, it has been changed to every 3 to4 months after the first year. In addition to PMTC, maintenance included cleaning and cleaning guidanceby various cleaning tools such as Taft brushes, disinfection around the branch teeth by chlorhexidinehydrochloride, and the application of plaque dye in the oral cavity and denture every 6 months. At thattime, TBI was always performed for #6 (Fig.8). After about 8 years, there was no problem with #6, but
secondary caries was observed in #10. There may have been an effect that the maintenance interval became
a little longer due to the situation of COVID-19, but it is also possible that too much attention was focused
only on cleaning the coping type of magnetic attachment (#6) (Fig.9). In this case, many fulcrum lines
could be set because the front, back, left, and right of the abutment teeth could be arranged. In addition,molar abutment teeth with crown morphology have an excellent bracing function as compared to abutment
teeth with crown morphology in the form of the root surface, and it seems that the burden of the coping
type of magnetic attachment for #6 was reduced (Fig.10).

Fig. 7 Intraoral view with definitive
prosthesis at 9 years after treatment

Fig.8 MaintenanceFig.9 Intraoral view with definitive
prosthesis at 8 years after treatment

Fig.10 The fulcrum line

Conclusions
A magnetic attachment could be provided as a useful retentive appliance for alleviating patientcomplaints regarding aesthetics and function. It is difficult to maintain an ideal combination of aesthetics
and functionality because the design of a final prosthesis is complex. Therefore, continuous follow-up isnecessary with occlusal adjustment and relining of the denture base to prevent any reduction of the OVD.