International Journal of Engineering Research & Technology (IJERT) ISSN: 2278-0181 Vol. 2 Issue 8, August - 2013 Magnification Tools: Surgical Operating Microscope And Magnifying Loupe In Dental Practice 1. Dr. Ranjana Mohan, Professor and Head, Dept of Periodontology, Teerthanker Mahaveer Dental College and Research centre, Delhi Road, Moradabad, U.P., INDIA 2. Dr. Mohan Gundappa, Principal, Professor and Head, Dept of Endodontics, Teerthanker Mahaveer Dental College and Research centre, Delhi Road, Moradabad, U.P., INDIA IJERTIJERT IJERTV2IS80029 www.ijert.org 14 International Journal of Engineering Research & Technology (IJERT) ISSN: 2278-0181 Vol. 2 Issue 8, August - 2013 1876- magnification was introduced to Abstract: dentistry.3 Magnification is an apparent increase in size Nylen, 1922 – first performed eye surgery 4,5 especially by the use of lenses. under a microscope. History of the Magnification dates back to 1694 when Barraquer, 1950s- began using microscope 6 Anton van Leewenhook constructed first compound for corneal surgery. lens microscope. Optical magnification has Jacobsen & Suarez, 1960 – obtained 100% broadened the horizions of dentistry in general, and patency in suturing 1 mm diameter blood 7 Periodontology, Restorative dentistry and vessels for anastomosis Endodontics in particular. Various magnification 1960s – microsurgery was standard in many systems used in dentistry include Dental Loupes & specialities such as neurology & 8,9 Surgical Operating Microscope. Magnification tools opthamology. are utilized in routine dental practice for diagnosis, 1970s &1980s - First articles about using a esthetically demanding prosthetic restorations, microscope in Odontology Dentistry were 10-13 routine endodontic procedures, non- surgical published . periodontal procedures, periodontal plastic Apotheker & Jako, 1978 – first introduced microsurgeries, implant dentistry etc for better the microscope to dentistry. visualization, improved treatment quality and ideal 1986 – microsurgery has been practiced in 14 treatment ergonomics enhancing motor skills to endodontics. improve surgical ability by maintaining the right 1990s - systematic use of surgical posture. Minimally invasive dental procedures with microscopes started and was applied by the ease and precision are possible today with the use of different odontological dentistry 15 16 magnification in dental practice. specialities , such as Periodontal Surgery. Carr, 1992- published an article outlining Key words: Magnification, Dental Loupes, Surgical the use of a surgical microscope during 14 Microscope, periodontal microsurgery. endodontic procedures . Shanelec & Tibbetts, 1993 – Presented a Introduction continuing education course on periodontal microsurgery at the annual meeting of the 16 Visualisation of fine details is enhanced by increasing American Academy of Periodontology. the image size of the object. Image size can be IJERT 1994—The first microscopes were increased by getting closer to the objects or byIJERT routinely used for restorative dentistry.17 magnification. Magnification increases the focal 1999—The American Association of length in order to see small objects accurately, which Endodontists required all endodontic in turn increases the working distance between the graduate students to be microscope eye and the object allowing, extra-ocular muscles to proficient.17 remain more relaxed and a dentist to maintain normal 2002—The Academy of Microscope posture. Enhanced Dentistry is formed.17 In dental practice, the tissues to manipulate are 2005—Several dental schools integrate usually very fine resulting in a situation in which the microscopes into undergraduate natural visual capacity reaches its limits. Therefore, programs.17 the clinical procedure may be performed successfully with the use of magnification improving precision and, hence, the quality of work1. Principles of magnification Historical background Two basic types of magnification systems are commonly used: 1. Loupes References to magnification date back to 2,800 years, 2. Surgical microscope when simple glass meniscus lenses were described in Egypt. 3,16,18 1) Optical principles of loupes Anton van Leeuwenhook, 1694 – Loupes are the most common magnification system constructed first compound lens used in dentistry. These are fundamentally two 2 microscope . monocular microscopes, with side by-side lenses, IJERTV2IS80029 www.ijert.org 15 International Journal of Engineering Research & Technology (IJERT) ISSN: 2278-0181 Vol. 2 Issue 8, August - 2013 angled to focus an object. The magnified image that confined to a range determined by the is formed has stereoscopic properties that are created loupe's characteristics1. The proper depth of by the use of convergent lens systems. field allows the practitioner to avoid too Loupes are further classified as: much leaning and any overextension while (1) Single-lens magnifiers (clip-on, flip-up, jeweller's practicing22. With any brand of loupe the glasses) and depth of field decreases as the magnification (2) Multi-lens telescopic loupes. increases. (1) Single-lens magnifiers (Fig.1) produce the described diopter magnification that simply adjust the 2. Convergence angle - is the pivotal angle working distance to a set length. As diopters increase, aligning the two oculars, such that they are the working distances decrease. A set working pointing at the identical distance and angle. distance creates difficulty in maintaining focus and, At a defined working distance, the therefore, may cause neck and back strain from poor convergence angle varies with interpupillary posture19,20,21. distance. A preset convergence angle as well as preset interpupillary distance is more user (2)Telescopic loupes (compound or prism friendly, since they should not be changed loupes) (Fig.2) - compound loupes use multiple once correctly positioned. Whereas an lenses with intervening air spaces which allow an adjustable interpupillary distance allows the adjustment of magnification, working distance, and loupe to be used by more than one person.25 depth of the field without excessive increase in size 4. Field of view (Width of field) - is the linear or weight. size or angular extent of an object when 1 Prism loupes are the most optically advanced type of viewed through the telescopic system or, loupe magnification, offering improved ergonomic represents the width and height of the area posture as well as significant advancements in optical the practitioner sees while using the performance3.They contain Pechan or Schmidt prisms magnification device. The higher the magnification, the smaller the width of that lengthen the light path through a series of mirror 22 reflections within the loupes field. Optical features of loupes (Fig.3) 5. Interpupillary distance - depends on the position of the eyes of each individual and is 1. Working distance - is measured from the a key adjustment that allows long-term, eye lens location to the object in vision1, or is IJERTroutine use of loupes. The ideal setting, as the distance between the plane of the eye andIJERT with binoculars, is to create a single image the surface being treated.22 Working distance with a slightly oval-shaped viewing area. 1 with slightly bended arms usually ranges from 30 to 45 cm. At this distance, postural 6. Viewing angle ergonomics are greatly improved and eye The viewing angle is the angular position of strain reduced due to lessened eye the optics allowing for comfortable working. convergence. 23,24 The shallower the angle, the greater the need to tilt the neck to view the object being One way to measure it is to ask the clinician worked at. Therefore, loupes for dental to adjust the second hand on their watch clinicians should have a greater angulation while holding their arm at midline or heart than loupes designed for industrial workers. level. It is important that clinician remember The ocular structure of the Designs for their own working positions, and not match Vision loupe is small and lightweight and is those prescribed. The correct working physically secured to the lens of the glasses. should never allow for overextension of the 22 The viewing angle is customized for each neck, chin, or shoulders. operator and then locked into position by 1. Working range (depth of field) is the range building the magnifier into the lens. The within which the object remains in focus1 or, ocular structures of Dimension Three loupes within which one is able to maintain visual are front frame- mounted. These systems accuracy at the appropriate working offer pivotal angle adjustments that can distance.22 Normally, eye position and body easily be altered and locked into position posture vary constantly. Wearing loupes based on the wearer’s comfortable working posture.25 changes this geometry, as the body posture and position of the extraocular muscles are IJERTV2IS80029 www.ijert.org 16 International Journal of Engineering Research & Technology (IJERT) ISSN: 2278-0181 Vol. 2 Issue 8, August - 2013 7) Illumination accommodation & refractive error. The eyepieces magnify the interim image generated in the binocular Collateral lighting systems may be helpful tubes. Eyepiece selection not only determines the for higher magnification in the range of 4X magnification, but also the size of the field of view and more. Loupes with a large field of view corresponding to the loupe spectacles. will have better illumination and brighter images than those with narrower fields of II. Binocular tubes The precise adjustment