The unique concept of Four-Handed Dentistry was developed beginning in the early 1960's by dental researchers at the University Of Alabama School Of Dentistry in Birmingham, Alabama. The research found existing dental equipment did not meet the criteria or allow the true concept and techniques to be properly implemented. In spite of the exhaustive, cutting-edge R&D, existing dental manufacturers ignored and were unwilling to review the findings and ultimately invest in the design of equipment to accommodate the concept. Health Science Products, Inc. (HSP) rose to the occasion and has been producing the unique patented systems that meet and exceed the criteria ever since.Health Science Products, Inc. was founded in 1969 and charged itself with the responsibility of designing and manufacturing dental equipment to meet and exceed the criteria defined in the research. The Dentassist Unit, with its transthoracic delivery position, met all the criteria for Four-Handed Dentistry and allowed the dentist to increase productivity and reduce stress and fatigue. The quality of its components and the simplicity of its design have kept a vast majority of the original units functioning at peak performance and allow our dental clients to maintain the productivity levels the unit was designed to achieve.