|Year : 2015 | Volume
| Issue : 2 | Page : 39-44
Magnification in dental practice: How useful is it?
Savita Abdulpur Mallikarjun1, Pheiroijam Romibala Devi2, Archana R Naik1, Superna Tiwari3
1 Department of Periodontics, Dayananda Sagar College of Dental Sciences, Bengaluru, India
2 Consultant Periodontist, Imphal West, Manipur, India
3 Department of Periodontics, Sri Sai College of Dental Surgery, Vikarabad, Telangana, India
|Date of Web Publication||16-Jul-2015|
Dr. Archana R Naik
Department of Periodontics, Dayananda Sagar College of Dental Sciences, Bangalore - 560 078, Karnataka
Source of Support: None, Conflict of Interest: None
Microsurgery, this terminology itself is self-explanatory, where a surgical procedure is performed making use of the magnification obtained by an operating microscope. The instruments like a microscope which provides the magnification is made use of, in the fields of medicine since decades. Now the use of such magnification systems is a very popular practice in dentistry as well. Before adopting visual magnification systems such as microscopes and successfully applying it in the dental procedures, it is mandatory to understand the principles and the physics of such instruments. Microsurgery in dentistry has more advantages in terms of efficiency, improved ergonomics, minimally invasiveness and less fatigue. This review paper, highlights about the various magnification systems, its principles and the application of microsurgery in various fields of dentistry.
Keywords: Application, magnification, review
|How to cite this article:|
Mallikarjun SA, Devi PR, Naik AR, Tiwari S. Magnification in dental practice: How useful is it?. J Health Res Rev 2015;2:39-44
|How to cite this URL:|
Mallikarjun SA, Devi PR, Naik AR, Tiwari S. Magnification in dental practice: How useful is it?. J Health Res Rev [serial online] 2015 [cited 2018 Dec 18];2:39-44. Available from: http://www.jhrr.org/text.asp?2015/2/2/39/160903
| Introduction|| |
In clinical dentistry, the human skill and manual dexterity are of extreme importance. The surgical precision can be even achieved manually provided with visual acuteness, but this could be enhanced multiple times making use of good magnifying devices. Usage of microscopic magnifying devices has revolutionized the dental practice. This is indeed an evolution from the conventional methods of macrodentistry to a high precision microdentistry. Almost all spheres of precision dentistry have adopted these microscopic devices.
There are several major advantages in microsurgical techniques while compared with conventional macrosurgical procedures. The new method offers advanced results in connection with passive wound closure and also significant reduction in tissue trauma, which results in rapid healing. This was not previously possible in traditional macrosurgical techniques.
The determination of potential areas for the usage of magnification and/or the tangible use of magnification devices in clinical practice of dentistry is not explored much. The reports and literature in this regard are relatively few. However, such devices are used extensively in connection with operative techniques , and there are numerous reports available in this regard.
This article sheds light on several existing magnification systems, its principles, and its numerous applications in microsurgery in different fields of dentistry.
| History and Terminology|| |
The use of magnification for microsurgical procedures is not a new concept. The first magnifying devices to assist surgery were introduced to the field of medicine during late 1800s. Nevertheless, the first surgical microscope OPMI 1 was introduced in 1950. This instrument, which was invented and commercially marketed by Carl Zeiss Company, had a coaxial lighting system and an option for stereoscopic view. However, this instrument failed to gain acceptance by the medical fraternity because of its poor configuration and too-long focal length. The first microscope for dentistry was introduced by Apotheker and Jako in 1978.  In endodontics, microsurgery has been practiced since 1986.  In 1992, the microsurgery was also introduced to the specialty of periodontics.
To comprehend the said topic in a better way, it is essential to understand the various terminologies of microsurgery and also the physics of magnification.
This refers to a surgical medical procedure performed under magnification by a microscope. 
This is a phenomenon of visually amplifying and availing an enlarged, exaggerated, intensified view of an object or an image or a model.
The surgical operating microscopes unlike loupes offer several different options of magnification within the same instrument. Such instruments used by the dentists for microsurgery has six steps of magnification (2.5x, 4.0x, 6.7x, 10x, 16x, and 24x).
This is the distance between the plane of the eye of the operator and the surface subjected for the surgical treatment. The determination of this working distance is done by the linear measurement of the distance between the objective front lens of the microscope and surgical site. A fairly longer working distance facilitates the operator to perform comfortably with the help of the magnified vision.
Depth of field
This is the range within the appropriate working distance, where the operator has the ability to maintain visual accuracy.
Width of field
This is also often referred as "field of view." This represents the width and height of the area the operator sees while using the magnification device.
This is the degree where the eyes of the operator are declined to view the area being treated. Declination angles range from 15 degrees to 44 degrees [Figure 1]. 
| Principles of Microsurgery|| |
Periodontal microsurgery is a kind of fine-tuning of the rudimentary periodontal surgical techniques. This is conceived through the enhancement in visual sharpness gained by using the surgical microscope.
The three important principles of the microsurgery
- Improvement in the motor skills of the operator and thus the enhancement in the surgical ability
- The passive wound closure will be emphasized with exact primary positioning (opposite to each other) of the wound edges, which is then accomplished by microsuturing
- Minimal tissue trauma, which is accomplished through smaller incisions and reduced surgical field.
In the course of microsurgical procedures the manifestation of the physiological tremors are common and natural. This will result in undesirable hand and finger movements. In order to reduce and minimize such mild tremors, the microsurgeon must possess anunperturbed state of mind. He should have a comfortable body posture, stable grip, and position while handling the instruments. Above all the attitude of the surgeon plays a vital role.
To sustain the accurate and precise motor regulatory expertise during the procedure, good patience and the focused mental condition of the microsurgeon are the important factors. 
| Armamentarium used in Microsurgery|| |
Even though there is vast variety of microsurgical equipment consoles, specifically designed for periodontal therapy, these could be broadly classified into following subgroups:
- Micro scissors
- Micro needle holders
- Micro forceps
- Tying forceps
- Micro scalpel
- Others (suture materials and needles).
All the instruments used in microsurgery are downscaled and miniaturized for surgical use hence minimizing trauma to the tissues. The gauges of the sutures used in microsurgery range from 7-0 to 10-0. These sutures may be of monofilament or of braided poly filament. While compared with normal sutures, these are less stiff with more flexibility offering more comfort to the patients. Usually these sutures are made up of polypropylene compounds. The advanced suture material polyhexafluoropropylene has excellent tissue properties. 
| Types of Microsurgical Devices|| |
The modern day dentist has numerous magnification systems to choose from. These magnifying systems range from simple loupes to compound prism telescopic loupes and vast variety of surgical microscopes. Each magnification system has its own advantages and also its own limitations. Fundamentally these loupes are made up of two monocular microscopes with lenses positioned side by side and angled in such a way to focus on a single object.
The various types of loupes are: ,
- Simple loupes
- Compound loupes
- Galilean loupes
- Prism loupes.
Devices of each category may differ widely in construction of the lens and design.
Simple loupes consist of a pair of single, positive, side-by-side meniscus lenses. Each lens has two refracting surfaces. The first refraction occurs when light enters the lens, and the other refraction happens when the light leaves. The magnification of simple loupes can be increased only by enhancing the lens diameter or increasing the lens thickness. The size and weight are the limitations of these devices, so they do not have any practical applications in dentistry.
Compound loupes have an array of convergent multiple lenses. There are air spaces in between these lenses which gives an additional refracting power, magnification, working distance, and depth of field. Such loupes can be easily adjusted as per the clinical requirements by lengthening or shortening the distance between the lenses. Compound lenses can be achromatic, and this feature is to be given importance while selecting a dental loupe. These achromatic lenses are efficient in producing a color perfect image.
These loupes are cheap and are simple to operate while compared to other compound loupes. These loupes consist of only 2 or 3 lenses which make them light in weight and also inexpensive. Their only disadvantages are limited magnification (2.5- or 3.5-fold) and a blurry peripheral border of the visual field. 
Prism loupes (or wide-field loupes)
As their name itself suggest, these loupes consist prisms which are used to refract light rays. These loups have prism fixed at the top, i.e., they are called as rooftop or Schmidt prisms. These prisms are used to lengthen the light path through a series of switchback mirrors positioned between lenses. This system hence provides better magnification, wider depths of field. This also ensures the users to have long working distances and if compared with other loops they have larger fields of view. So these loupes are optically most advanced type of magnification instrument in the market at present. The ranges of magnification of these loupes are around 1.5x to 6x. Generally the dentists use magnification loupes of range 2.5 to 3.5. However, periodontists prefer magnification of 3.5 to 4.5-fold. In case of surgeries done on delicate tissues requires loupes that magnify 5.5 to 6.5-fold.
| Surgical Microscope|| |
The surgical microscopes provide much greater magnification, higher optical performance when matched with normal dental loupes. Surgical microscopes specially designed for dentistry makes use of Galilean optics. They have binocular eyepieces joined by counteracting prisms to create the parallel optical axis. Galilean optics allows the users to experience a stereoscopic vision without eye convergence or any strain to the eyes. Depth of focus and field of view features are at the optimum level in surgical microscopes [Figure 2]. 
The advantages of surgical microscopes are that the focusing or the changes in magnification can be done real time. When a dentist is carrying out a clinical procedure, he can adjust the magnifications easily to the appropriate value. Along with this magnification changing feature, this microscope has another advantage: An illuminator which sends a light beam through the objective lens so that the line of illumination is in par with the viewer's line of vision. Consequently, the surgical spot will be lightened and the surgeon avails a shadow-free clear vision. 
The surgical microscopes consist of a magnification changer, objective lenses, a lighting unit to illuminate the field of vision, binocular tubes, and eyepieces. The microscope could be fixed on the floor or even it could be mounted to the wall or ceiling. 
Microscopes with higher magnification are always in demand. The higher magnification makes the job easier for the microsurgeon. The control over micromotor muscles and joints like fingers and wrists are of utmost importance in microsurgical procedures. To achieve this control, gross motor joints such as elbow and shoulder should be in stable position with micro surgeon's chair. Shanelec and Tibbets  have reported that the microsurgeon operating without the aid of magnification, made movements that were measuring up to 1 to 2 mm in real time. When a 20x magnification was used, movements were astonishingly refined to an insignificant 10 to 20 microns (10-20/1000 of an mm) in real time. The noteworthy observation is that the precision achieved in the surgical procedure is not related to the hands or the fingers, but it is more directly related to eyes, i.e., the vision.
[Table 1] shows several magnification systems and their resolution in millimeters.
The powerful magnifications that are more than 16x, or in some instances as high as 32x or 40x, are commonly used for diagnostic purposes. Using such microscopes very minute details could be examined. Intra-surgical examinations and some type of "difficult-to-detect" findings are located using such microscopes. However, such degree of highest magnification has also some drawbacks. The depth of field in the area of focus will be extremely reduced causing considerable tiredness to the eyes of the viewer.
| Advantages of Surgical Microscope|| |
- Tissue trauma will be reduced
- Mobility of surgeon is less and controlled
- Anxiety of patients are reduced
- Atraumatic tissue management
- Accuracy achieved in primary wound closure
- Increased diagnostic skills
- Minimally invasive
- Improved cosmetic outcomes
- Improvement in surgical quality
- Increased effectiveness of root debridement results in greater predictability of regeneration procedures and cosmetic procedures
- Improved documentation, e.g., video, slide, digital imagery, etc. 
| Disadvantages of Surgical Microscope|| |
- Specialized education and training required- e.g. High degree of surgical techniques and understanding of optics essential
- Prolonged adjustment period
- Prolonged pre surgical preparations
- Expensive to patients
- Limited surgical access. 
The common errors in the use of surgical microscope are
- Using extremely high magnification will sometimes be troublesome
- Inadequate task sharing between the surgeon and the assistant
- Lack of practice.
Generally the practice of using higher magnification results in some inconvenience because the field of vision will be too small and the depth of field will also be reduced. Subsequently when significant movement is involved in the surgical process, then the higher magnification causes problems and the operative procedure becomes complex and difficult. In such circumstances comparatively low magnifications like 4X to 7X is more ideal. While dissecting a small area, for example 'papilla preservation technique', the higher magnifications to the tune of 10X to 15X suits well. 
In any surgery, at least two people are involved; one the surgeon who carries out the whole operational procedure and the other, an assistant who helps the surgeon with some elementary tasks. Nevertheless when a process of surgical intervention is underway, continuous and uninterrupted workflow should be assured. So to achieve such smooth work flow, a second assistant who can assist the surgeon by arranging and organizing the instruments swiftly is desirable.
| Application of Microsurgery in Dentistry|| |
Almost all surgical microscopes used in dentistry possess stereoscopic vision and are equipped with coaxial lighting system. The magnification and clarity of vision they offer makes them ideal and convenient gadgets to be incorporated in various complex and sophisticated clinical procedures associated with dentistry. The microscope's ability to magnify the image depends mostly on the quality of the optics and the focal distance of the lens. The shorter this is, the greater the magnification achieved.
Usually the dentist undergoes traumatic spasms of spinal column due to prolonged stagnant body postures. Adopting a surgical microscope will be beneficial to the dentist to work for an extended period with correct body position, with increased physical comfort and less lassitude. 
Endodontists were the first among dentistry professionals to discover the applications of the surgical microscopes in their everyday practice, both in conventional and also in surgical endodontistry.  Microscopes are used in different clinical situations, in order of most to least frequent-removing broken instruments from the canals, preparing the retrograde obturation cavity, permeabilising of calcified channels and locating the pulpal chamber canals. 
Using an operating microscope along with appropriate microsurgical techniques benefits the dentist to identify and manage the complex system of canals in a safe manner. This also makes the things easier for a dentist in resolving some complex clinical issues which was previously not possible without the help of magnification devices. 
The magnification devices like surgical prism loupes or the surgical microscopes have brought sweeping changes in periodontal surgery. The better magnified view of the surgery spot has made the surgery less intrusive and minimally invasive. The final appearance of the operated area after the microsurgical process is simply superior while compared with the end result of the traditional means of operation. This is due to negligibly small incisions which lead to rapid healing with considerably less post-operative pain.  The incisions and flap reflections are accurate in nature. The surgeon's capability to generate a clean and smooth root surface is improved by magnification. It also permits butt joint-approximation of the flap, which is mandatory for the healing and regeneration. The principles of microsurgery can be applied effectively in various wide-ranging surgical periodontal procedures including resective procedures, combined resective/periodontal microsurgery, and regenerative procedures, extractions and ridge preservation procedures, sinus augmentation and repairs, biopsy, and larger soft tissue grafting. Andrade et al. in their recent study compared the macro and microsurgical techniques for root coverage using coronally advanced flap along with enamel matrix derivative. They found an increase in root coverage in test (microsurgical) group compared to control group along with statistical increase of width and thickness of keratinized tissue. 
The idea of minimal invasiveness could be achieved by using microsurgical instruments with the aid of magnification which help the surgeon to make very small cuts just enough to expose and gain access to the operating spot. 
The microsurgical tools can also be used in tooth preparation and final restoration of the tooth in fixed prosthodontics.  In this regard some interesting observations are made by Leiknius and Geissberger.  The study carried out by them shows positive results. The dental students using devices like low-magnification telescopic loupes made very less errors in preparation design and laboratory processing. The errors by these students were reduced to half while compared with another set of control group students who were not using magnification devices. The study also showed that the microscopes are extremely useful during the try-in and seating appointments.
The magnification devices proved to be beneficial even to laboratory technicians who could trim the stone dies with utmost precision and improve the quality of prosthesis with the aid of microscopes.
The clinical and operational advantages of microsurgery are exceptionally helpful in oral and maxillofacial surgery. A clearer and magnified view is particularly important in all surgical procedures for treating impacted teeth, and in particular for mucogingival surgical procedures to increase the width of attached gingiva by harvesting soft tissue grafts. The injuries and lesions to the sensitive nerves of the mouth area are surgically treated in a better way using microscopes.  During lower molar and premolar level oral surgical treatment, or during the surgery of third molars, if appropriate care is not taken about the lingual flap, then the lingual nerve and the lower dental nerves are prone to injury. This could be well avoided by adopting microsurgery assisted by high end magnification.
Optically enhanced vision through proper degree of magnification is of utmost importance in orthodontic practice. The orthodontists are now using a magnification eyewear along with smaller bracket systems, lingual appliances, self-ligating system, s and ceramics. The standard of patient care will be well improved if superior magnification devices with better ergonomics are put in place.  Recently the use of new technique in orthodontic microsurgery piezosurgical bone cuts and monocortical tooth dislocation showed good dental repositioning in a shorter time with a decrease in treatment time by 65-70%. 
The specialized branch of implant dentistry is an emergent segment with ample space for improvisation. The microscopic magnification systems can be suitably incorporated in all levels of implant treatment. The age of painful and traumatic tooth loss, never-ending replacement of a continuously deteriorating anterior tooth, etc., will be taken over by the new age microsurgical procedures assisted with cutting edge magnification instruments. 
| Conclusion|| |
The history of dentistry tells us numerous amazing stories about how this science advanced and how time and again the technological progresses facilitated the evolution of treatment procedures. Achievement of excellence is the choice but a retrospective sight gives us the glimpses of technological milestones realized and a journey of science unfolds. Likewise, this is yet now another juncture where dentistry takes a huge turn. The Microsurgical procedures coupled with Microscopic Magnification offers an absolute clinical accuracy. The use of surgical microscopes have brought revolutionary transformation and opened up abundant avenues in front of the new age dentist. The principal necessities of gentle tissue management, perfect approximation, scrupulous hemostasis, and marginal tissue damage are the assurances of the microsurgical approach. Hence the role of microsurgery aided by magnification in dentistry is really vital. Conversely, when integrating the new technology, the lack of skill, training and practice can lead to physiological tremors resulting in inaccurate incisions, improper suturing etc. All these will end up with failure of the procedure which is very much technique sensitive.
Thus to conclude, microsurgery is a treatment philosophy whose clinical horizons will continue to improve with operator experience and the willingness to employ previously unused basic optical magnification and ergonomic technique and technology.
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[Figure 1], [Figure 2]