Vallecular Bolus Aggregation During Swallowing of Solid Food Boluses for Subject Rehabilitated With Mandibular Implant Retained Overdentures. A Crossover Study

Healthy edentulous subjects seeking prosthetic treatment at the prosthodontics department, Faculty of Dentistry, Mansoura University will be eligible for this study. The inclusion criteria will be: age >60 year; Class I maxilla-mandibular relation; available inter-arch space; and adequate bone quality and quality in the mandibular anterior alveolar ridge (inter-foraminal area). Subjects with physical or cognitive limitations, neurodegenerative disorders that could influence their swallowing function, parafunctional habits, smokers, signs or symptoms of temporomandibular disorders, osteoporosis, uncontrolled systemic diseases, previously undergone radiotherapy or laryngeal surgery will be excluded from the study.

Sample size estimation is based on a previous study evaluated the oral and pharyngeal phases of swallowing by videofluroscopy and found significant differences between groups. We determined that 16 participants will be required for the detection of significant differences with effect size of 0.78, 90% power, and 5% error probability. Ethical agreement will be taken from ethical committee of the faculty of dentistry and written consent will be gotten from all the participants after illustrating in detail the whole research protocol.

Prosthetic and surgical procedures:

For each patient, new conventional complete denture will be constructed with optimal denture extension and lingualized balanced occlusal scheme. The new prosthesis will be inserted intraorally and adjusted for occlusal interferences. Subsequently, two dental implants will be placed in the canines region according to guided surgery protocol and two-stage approach. After osseointegration, locator attachments will be screwed to the dental implants to convert the conventional mandibular denture to mandibular implant retained overdenture. The mandibular implant overdentutre will be inserted and occlusal adjustment will be done and follow up visits will be scheduled.

II- Evaluation method: