Loss of Fine Motor Dexterity and Reduced Oral Hygiene 15 Years After Diagnosis of Multifocal Motor Neuropathy with Screw-Retained Implant-Supported Rehabilitation: Literature Review and Case Report

Purpose: Multifocal motor neuropathy (MMN) is a rare immune-mediated neuropathy causing progressive, asymmetric weakness without sensory loss. Long-term administration of intravenous (IVIg) or subcutaneous (SCIg) immunoglobulins is the primary therapeutic approach. Despite this, therapy failure can result in a decline in strength, particularly in the hands, impacting daily activities. This review and case report presents the current literature on this complex dental and medical topic and explores the novel use of dental implants for full-mouth rehabilitation in MMN patients undergoing long-term IVIg therapy.
Materials and Methods: A patient with MMN underwent 15 years of long-term treatment with intravenous immunoglobulin (IVIg), starting with an initial dose of 0.4 g/kg for 5 days every 4 months in 2008. The maintenance dosage of 0.2 g/kg as a single dose every 3 months was established as a long-term therapy. In 2017, the patient received a maxillary and mandibular complete-arch implant-supported prosthesis.
Results: MMN showed no progression until the IVIg interval was extended to every 4 months in 2022. Significant deterioration in dental health resulted from a loss of right-hand dexterity, which affected toothbrush use and interproximal brushing, resulting in poor oral hygiene. Dental hygiene and dental health, which were not optimal anyway, were considerably worsened by the loss of dexterity in the right hand, which impaired the use of the toothbrush and the cleaning of the interdental spaces.
Conclusion: Dental implants are a well-established treatment for edentulous patients, but their success in those with MMN requires careful consideration of oral health practices. Effective maintenance protocols and optimised prosthetic designs are crucial for long-term implant therapy success in MMN patients. Peri-implant diseases pose risks influenced by various factors. In the case of MMN and its neurological considerations, implications for dental implant provision warrant further exploration, considering clinical symptoms, therapy, and potential progression. Keywords: case report, mouth rehabilitation, multifocal motor neuropathy, oral health, peri-implantitis, review