What is biomechanics?
It’s the interaction between the biological environment and the mechanical device that is fixed or removable prosthesis is called as biomechanics.
• They are 2 types of forces that is horizontal and vertical.
• The forces are directed in the vertical direction to the long axis of the tooth. Forces transferred by vertical direction are during mastication, clenching and swallowing.
• The forces transferred by the vertical direction is much more than the horizontal direction.
• The forces transferred by horizontal direction are mainly by the tongue and by perioral musculature.
• The factors for edentulism are trauma, patient’s oral hygiene, ageing , attitude of the patient , diet and financial status.
• If the forces are directed obliquely then the bone remodelling takes place and bone deposition will occur.
• In natural dentition , masticatory forces will be transferred through the periodontal ligament to the bone. The arrangement fibres in periodontal ligament also plays a major role.
• The periodontal ligament acts like a cushion and distributes the masticatory forces.
• The tooth is supported by the periodonium. Hard tissues supporting are cementum and bone and soft tissues are PDL and lamina propria of gingiva covered by the epithelium.
• The load taken up by the natural dentition is 20 kg and that in complete denture wearers is 8 kg.
• The major difference between the natural dentition is the compressibility of PDL and in the complete denture patient the oral mucous membrane has less compressibility to deliver forces.
• Normal mastication – 30 sec. Act of deglutution – 18 sec.
• We swallow about 500 times in a day and masticate about 17 minutes approximately in a day.
Reference :- deepak nallaswamy