The 23rd International Conference on Magnetic Applications in Dentistry (Feb. 26 to Mar 15, 2024)
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A case rehabilitated using overdentures with magnetic attachments for apartially edentulous patient with severe periodontal disease
Shintaro Suzuki, Junichiro Wada, Noriyuki Wakabayashi
Department of Advanced Prosthodontics, Graduate School of Medical and Dental Sciences, Tokyo
Medical and Dental University (TMDU)

Abstract
The patient was a 71-year-old partially edentulous patient suffering from masticatory disturbance caused bya reduction of occlusal contacts in posterior regions and severe tooth mobility with severe periodontitis.
Treatment dentures were delivered to maintain oral functions and initial periodontal therapy was performed,
followed by rehabilitation with maxillary overdenture and mandibular clasp-retained removable partial
denture placement as the definitive prosthodontic treatment. By application of magnetic attachments
incorporated in an overdenture, the disarranged occlusal plane was corrected and denture stability wasachieved. Based on the oral health impact profile (OHIP-14) assessment, the oral health-related quality oflife (OHRQoL) of the patient was improved with the prosthodontic treatment.

Introduction
There are several factors that make a prosthodontic treatment clinically difficult as follows: abnormal bone
resorption after tooth extraction with severe periodontitis; flabby tissue with combination syndrome 1); anddifficulty in acquiring overdenture stability with severe displacements of remaining teeth. For the cases withthose factors, an application of magnetic attachment would help to stabilize overdenture while saving
remaining teeth and protecting residual ridge. In this case, magnetic attachments were incorporated into anoverdenture to reconstruct a partially edentulous dental arch with severe periodontal disease, and the patient’s
satisfaction was obtained.

Clinical history
The patient was a 71-year-old male without any systemic health problems who claimed difficulty in eating
due to a reduction of occlusal contacts in posterior regions. Over the past 20 years, posterior teeth had been
lost and the patient had undergone dental therapy. For several months, he had realized the remaining teeth
mobility. Figure 1 reveals the intraoral views and Figure 2 reveals a panoramic radiograph at the first visit(8th July 2020), while the periodontal assessment is shown in Figure 3. The remaining teeth were #11, #12,#13, #16, #17, #22, #23, and #25 in maxillary and #31, #32, #33, #34, #41, #42, and #43 in mandibular(Eichner classification B4 and Miyachi classification Area B). #25 revealed severe caries without a toothcrown. Based on the Miller index of tooth mobility, a fixed bridge restoring #14 and #15 with abutment teethof #13, #16, and #17 showed a mobility of Grade I as well as #11, #12, #13, #22, #23, #25, #31, #32, #33,
#41, #42, and #43. Meanwhile, #44 revealed a mobility of Grade II. Additionally, the alveolar bone resorption
was severe, resulting in a diagnosis of severe periodontitis. Especially in #16 and #17, the attachment loss

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The 23rd International Conference on Magnetic Applications in Dentistry (Feb. 26 to Mar 15, 2024)
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reached the root apex, while reaching at half or two-thirds of the root length in #22, #23, #25, and #44. The
occlusal plane was disarranged with the extruded remaining teeth (#11, #12, and #22). The disease typeclassification of the Japan Prosthodontic Society was level II 2). Based on the lower facial height and freeway
space, the occlusal vertical dimension (OVD) was diagnosed to be clinically acceptable. The overall
diagnosis was masticatory disturbance caused by a reduction of occlusal contacts in posterior regions andsevere tooth mobility with severe periodontitis.

Fig.1 Intraoral views at first visit[Web Presentation] PS3-3-2

The 23rd International Conference on Magnetic Applications in Dentistry (Feb. 26 to Mar 15, 2024)
http://jsmad.jp/international/23/Fig.2 Panoramic radiograph at first visit

Fig.3 Periodontal assessment at first visit

Treatment procedure
Within the remaining teeth, #16, #17, #22, #23, #25, and #44 were diagnosed to be hopeless and planned
to be extracted before the treatment denture delivery. Soon after the extractions of those teeth, periodontal
treatment was begun and the treatment dentures were placed (Fig.4). The abutment teeth of the maxillarydenture were #11 and #13, while those of the mandibular denture were #34 and #43. For each abutment tooth,the retainer consisted of a wrought wire clasp assembly without any rest. The OVD with the treatment denture
placement was defined based on the original dimension.
Reassessment after initial periodontal therapy (July 2021) revealed that the pocket probing depth of allremaining teeth in the mandibular was less than 3mm, while deep pocket and increased mobility of Grade I
remained in the maxillary remaining teeth (#11, #12, and #13) (Fig.5). Based on the periodontal reassessment,#11, #12, and #13 were judged to be too weakened to use as abutment teeth of clasp-retained removablepartial denture (RPD). Therefore, the definitive dentures are designed as follows: an overdenture
incorporating magnetic attachments in #11, #12, and #13 for the maxillary; and a clasp-retained RPD for the[Web Presentation] PS3-3-3

The 23rd International Conference on Magnetic Applications in Dentistry (Feb. 26 to Mar 15, 2024)
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To apply magnetic attachments, #11, #12, and #13 were endodontically treated and cut their crowns,
followed by modification of the maxillary treatment denture to be an overdenture type with additional
artificial teeth. After acquiring the denture stability, #13 was judged not to be accepted for a magnetic
attachment abutment tooth due to its severe attachment loss and shortened root length. Therefore, only #11
and #12 were converted to abutment teeth of magnetic attachments (MAGFIT M400, AICHI STEELCORPORATION, Aichi, Japan), whereas #13 was covered with a composite resin (ESTELITE UNIVERSALFLOW, Tokuyama Dental Corporation, Tokyo, Japan) and used just as a resin coping. The magnetic
attachments were fixed to #11 and #12 with an adhesive resin cement (Super-Bond, Sun Medical Co., Ltd.,
Shiga, Japan).

Fig.4 Intraoral views with treatment denture placement[Web Presentation] PS3-3-4

The 23rd International Conference on Magnetic Applications in Dentistry (Feb. 26 to Mar 15, 2024)
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Fig.5 Periodontal reassessment after initial periodontal therapy
The OVD for the definitive dentures was set to be the same as that with the treatment dentures placement,
while the occlusal position was set to coincide with the tapping point. After the maxillomandibular
relationship record, the first try-in of wax dentures was performed only with artificial teeth, followed by thedesigning of internal and external finish lines as well as the outline of the frameworks. Then, the second tryin of wax dentures with both artificial teeth and frameworks was performed to confirm the aesthetics, thefitting of frameworks, and the validity of the maxillomandibular relationship. After the above-mentionedprocedures, the definitive dentures were finalized and delivered (Fig.6). Regarding the framework design ofthe maxillary definitive denture, the metallic housing covering the occlusal and palatal surfaces of #11, #12,
and #13 was designed to strength the denture structure. Meanwhile, the buccal surfaces of those teeth werecovered with denture base resin materials to make it easy to put spillways for incorporating magnets into thedenture using the acrylic resin material (UNIFAST Ⅱ, GC Corporation, Tokyo, Japan) (Fig.7A-C). A bilateralbalanced occlusion was used to help stabilize the dentures. After the confirmation of denture settling (twoweeks after denture delivery), the magnets coated by an adhesive resin cement (Super-Bond, Sun MedicalCo., Ltd., Shiga, Japan) were incorporated into the maxillary denture (Fig.7D).

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The 23rd International Conference on Magnetic Applications in Dentistry (Feb. 26 to Mar 15, 2024)
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Fig.6 Intraoral views with definitive denture placement

Fig.7 Images of the housing structure in the maxillary definitive denture. A: overall image; B and C: themagnified image of the inner and outer surfaces before magnet placement (arrows reveal spillways); and D:
the magnified image of the inner surface after magnet placement.

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The 23rd International Conference on Magnetic Applications in Dentistry (Feb. 26 to Mar 15, 2024)
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Outcome of treatment
Using the short version of the oral health impact profile (OHIP-14) 3), the oral health-related quality of life(OHRQoL) was assessed both before and after the prosthodontic treatment. The assessment before thetreatment revealed an OHIP-14 score of 33 including especially high scores in “physical pain”, “socialdisability”, and “handicap”. On the other hand, the score after the treatment was 12 including especially lowscores in “handicap”, indicating that the prosthodontic treatment with the magnetic attachments was
successful based on the subjective assessment of the patient. To date, periodontal and prosthodontic
maintenance has been conducted every two months.

Discussion
In this case, the periodontal assessment at the first visit revealed a deep pocket depth and hypermobility ineach remaining tooth in the maxillary. Meanwhile, magnetic attachments were applied for #11 and #12
instead of tooth extraction because those teeth had strategic values to be maintained from the prosthodontic
viewpoint. Thanks to the magnetic attachments, preferred outcomes have been obtained to date. However,the long-term prognosis of overdenture treatment would depend on several factors, such as the age of patients,habits, occlusal force, and the condition of periodontal tissues of the remaining teeth. To achieve long-term
success, in addition to the patient's oral hygiene, clinical follow-up focusing on the occlusal position stability
and the artificial teeth wear is necessary to prevent excessive occlusal stress on the anterior region 4).

Conclusion
In this case, a partially edentulous dental arch with severe periodontitis and hypermobility of remaining
teeth was rehabilitated using maxillary overdenture and mandibular clasp-retained RPD. By application ofmagnetic attachments incorporated in an overdenture, the disarranged occlusal plane was corrected anddenture stability was achieved. Based on the OHIP-14 assessment, the OHRQoL of the patient was improved
with the prosthodontic treatment.

Acknowledgment
All the authors of this study would like to thank the patient who willingly consented to publish ourtreatment for him including his clinical history.

Conflict of interest statement
None.

Reference1.

E. Kelly: Changes caused by a mandibular removable partial denture opposing a maxillary complete
denture, J Prosthet Dent, 27(2), 140-50, 1972.

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2.

M. Hideshima, T, Ichikawa, Y. Tomotake, N. Yasuda, H. Sato, M. Hattori, T. Oyama: The judgement oftreatment difficulty for partially and completely edentulous dental arch: The significance andapplication of the disease type classification -Approach for the definition of the clinical-path and diseasetype classification by the Japan Prosthodontic Society-, Shikai Tembo, 105, 825-833, 2005.

3.

K. Ikebe, T. Hazeyama, K. Enoki, S. Murai, T. Okada, R. Kagawa, K. Matsuda, Y. Maeda: Comparisonof GOHAI and OHIP-14 measures in relation to objective values of oral function in elderly Japanese,Community Dent Oral Epidemiol, 40(5), 406-14, 2012.

4.

Y. Ogino, Y. Ayukawa: Anterior Hyperfunction by Mandibular Anterior Teeth: A Narrative Review,Healthcare (Basel), 11(22), 2967, 2023.

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