Evaluation of the Stomatognathic System in Patients with Hearing Impairment and Cochlear Implants-A Pilot Study

Background: Orofacial dysfunctions are a source of discontent and impair daily living activities. Patients with hearing impairments exhibit an elevated risk of stomatognathic system changes. Hence, this pilot study aims to evaluate changes in stomatognathic system functions in patients with hearing impairments and cochlear implants. Methods: During the examination, the Nordic Orofacial Test-Screening was used to assess orofacial functions. The range of motion within the temporomandibular joints was measured using a vernier caliper. A socio-medical study was conducted to collect data regarding the patients, the cochlear implant sides, and the methods of communication. Results: The statistical analysis showed a significant difference in the total NOT-S scores (p < 0.001) and examination scores (p < 0.001) between patients with hearing impairments and the control group. These significant differences of the total NOT-S score and examination score have large effect sizes (r > 0.5). In particular, significant differences were observed in the results of maximum mouth opening (p = 0.006) and right laterotrusion (p = 0.020). Differences were also observed in the answers regarding the method of communication and the examination score of the NOT-S questionnaire (p = 0.040). The 6A of the NOT-S significantly affected the examination score (p = 0.015) and the total NOT-S score (p = 0.037), while the result of section 6B only significantly affected the NOT-S examination score (p = 0.032). Conclusions: Patients with hearing impairments presented orofacial dysfunctions significantly more often than the control group. The side of cochlear implant implantation is important for stomatognathic system changes.