Dental Photography and the Medical Photographer

dental_photography

Dentistry is a branch of medicine concerned with the prevention and treatment of tooth and gum disorders. Dentistry is divided into several highly specialized areas; endodontics is a branch of dentistry concerned with the treatment and diagnosis of diseases which affect the pulp and roots of the teeth, orthodontics is concerned with the prevention and correction of abnormally aligned teeth and periodontics is concerned with the treatment of abnormal conditions of the gingivae (gums).

Dental photography has emerged as a specialized field within medical photography. Clinical photographs of the oral cavity and teeth are useful to practitioners of all dental specialities as well as to oral and plastic surgeons. External facial views and intra-oral views can be used to document and monitor a number of conditions including malformations of the oral cavity, dental disease, reconstructive surgery and corrective procedures to the teeth. As with all aspects of medical photography standardization is essential to produce consistent, high quality, repeatable images.

Anatomy of the Oral Cavity

It is important that the medical photographer has a good working knowledge of the anatomy and physiology of the oral cavity and teeth. This knowledge enables them to produce accurate, repeatable records of a dental patient’s condition or treatment. The medical photographer should have a good understanding of teeth notation and be aware of common dental terminology. This allows them to accurately locate and document a variety of anatomical structures and pathological conditions within the oral cavity.

Extra-Oral Photography

Most conditions of the face and mouth can be demonstrated by photographing anterior posterior (AP), oblique (45°) and lateral views. An AP and right and left lateral of the patient’s head and shoulders are generally all that are required for extra-oral views, although some consultants may also request oblique views. It is however important that both lateral views are taken to ensure any facial asymmetry shows clearly.

Extra-oral views can be taken with a standard camera and lens set-up using studio lighting. It is essential that the camera plane remains parallel to the anatomical plane and that the patient’s head remains straight when extra-oral views are photographed, otherwise distortion will occur. The photographer will also make sure that the orbito-helix line (outer canthus of the eye to the point on the junction of the helix of the ear to the head) is horizontal when photographing the AP and lateral views.
Figure-1

Intra-Oral Photography and ring flash/point source systems

Macro lenses are required when photographing intra-oral views as the teeth need to be photographed at high magnifications. Typical magnification ratios used for teeth are 1:1 and 1:2. Intra-oral views require maximum depth of field to ensure the entire dentition is sharply focused, therefore the highest aperture should be used.

The oral cavity cannot be lit sufficiently using standard studio lighting, for intra-oral views the source of illumination must be near to the lens axis and mounted at the front of the lens. There are two main methods of lighting the oral cavity, point source and ring flash. Point source is a short straight flash tube, it is called point source as its illumination is directional. The flash unit is mounted near the front of the lens on a flash bracket, this technique illuminates the oral cavity well but can cause shadowing.

Ring flashes have one or more curved flash tubes (the shape of a circle) built into the end of the lens. Ring flashes provide even, shadow-free illumination which is ideal for lighting the oral cavity. The only disadvantage to ring flashes is the distracting reflections which can occur on wet tooth enamel. These reflections can be reduced by asking the patient to swallow their excess saliva or by drying their teeth and gums on a piece of gauze before each photograph.
figure-2

Dental retractors and mirrors

Views of the dentition can only be achieved using dental retractors as it is necessary to retract the cheeks and lips from the field of view in order to obtain clear intra-oral pictures. Dental retractors are available in metal, wire and plastic and come in paediatric and adult sizes. Dental retractors (if used properly) should provide both vertical clearance as well as horizontal retraction of the lips.

Dental mirrors can be used alongside retractors, the mirrors are available in glass and plastic and also in paediatric and adult sizes. There are two main types of dental mirrors, occlusal mirrors are designed to fit inside the patient’s mouth. The occlusal mirror can be tilted until the reflection of either the upper or lower dentition is visible, the photographer can then photograph the reflected image of the maxillary or mandibular arch.

Buccal mirrors are used when photographing the buccal surfaces of the posterior teeth. Buccal mirrors are often double ended and the smaller side can be used to photograph the lingual surfaces of the posterior and anterior teeth.

When dental mirrors are placed into the mouth misting can occur which can obscure the reflected image, this problem can be minimised by placing the mirror in a jar of warm water prior to use. It also helps if the patient breathes through their nose and not through their mouth during the procedure.

Medical photographers should be familiar with dental retractors and mirrors and have experience using them on themselves before they attempt to photograph any patients. This is important as retractors and mirrors can be uncomfortable or painful, particularly if the patient has limited jaw movement or mouth lesions. With experience the photographer can take intra-oral photographs quickly and with a minimum of discomfort to the patient. Where mirrors have been used the finished photographs will be a mirror image of the patient’s actual teeth so the photographer must manually reverse the image in photo editing software.

Health and safety issues

Medical photographers have a responsibility to their patients and other healthcare workers to ensure that their camera and dental equipment is sterile and safe to use. They must adhere to infection prevention policies rigorously when performing dental photography. Hands should be washed before and after patient contact and gloves should be worn to prevent the transfer of organisms from patient to photographer or vice versa.

Saliva and blood are both carriers of potentially infectious micro-organisms which can be transferred from the mouth onto dental mirrors and retractors. It is therefore essential that dental retractors and mirrors are sterilized after use to ensure no cross-contamination takes place. After the clinical photographs have been taken the used retractors and mirrors should be placed in a secure container and sent to a sterile services department to be cleaned. If this is not possible the equipment must be thoroughly sterilized in the medical illustration department before it can be reused.

 


Bibliography

Vetter, J.P (Ed.). 1992. Biomedical Photography. Focal Press.
Wander, P., Gordon, P.1987. Dental Photography. The British Dental Association.
Cardew, P.N., Lunnon, R.J., Tredinnick, W.D., Turnbull, P.M. (Eds.). (3rd Edition)
.1975. The Study Guide of the London School of Medical Photography. The London School of Medical Photography Limited.
Hansell, P (Ed.).1979. A Guide to Medical Photography. MPT Press Limited.
Tortora, G.J., Grabowski, S.R. 2003. (10th Edition) Principles of Anatomy & Physiology. John Wiley & Sons, Inc.
Delly, J.G (Ed.). (1st Edition) .1976. Biomedical photography- a Kodak seminar in print. Eastman Kodak Company.
Aldred. M.J., Bagg. J., Hartles. F.R. 1990. Colour teaching aids in oral pathology. JAMM. 13:1 9-11.
Merin. L.M., Mills. R.A. 1995. Intraoral and intranasal photography using a retinal fundus camera. JAMM. 18:1 23-25.
Hyland. G.J. 1986. Photographic planning for maxillary mandibular osteotomies. JAMM. 9:1 10-11.
Damani, N. N. (2nd Edition).2003. Manual of Infection Control Procedures. Greenwich Medical Media Limited.
McCulloch, J. (Ed.).2000. Infection Control: Science, Management and Practice. Whurr Publishers.
Meers, P., McPherson, M., Sedgwick, J. (Eds.) (2nd Edition).1997. Infection Control in Health Care. Stanley Thornes (Publishers) Limited.
Wilson, J. (2nd Edition).2001. Infection Control in Clinical Practice. Harcourt Publishers Limited.

The role of the medical photographer in an operating theatre environment

“Photography in the operating theatre is only a small part of a wide field, but it demands not only solidly based technical competence but also the full commitment of the photographer and good co-operation with the surgical personnel” 1

Surgical photography has emerged as a specialized field within medical photography. Clinical photographs taken in operating theatres provide surgeons with precise visual records of surgical procedures and new surgical techniques.

Surgical images are useful for a number of reasons, they can be used for teaching purposes, for publication and for documentary evidence in the patient’s case notes.

Surgical images usually consist of a series of close-up views of an incision site taken at different stages of the procedure. A medical photographer will endeavour to document each stage from the same viewpoint and at the same magnification. This will ensure that the each photograph in the sequence is taken at the same scale. A knowledge and understanding of anatomy and pathology is also needed to help the photographer locate and record the correct features in the incision site.

Surgical photographic techniques

Surgical photography can be more technical than other aspects of clinical photography and specialized lenses and lighting equipment are often required. Close-up views are frequently requested, so a macro lens is essential, this will enable the photographer to record minute features in great detail.

Specialized lighting equipment is also needed when photographing deep into the body as conventional camera flashes are unable to evenly illuminate cavities. In this situation the source of illumination must be near to the lens axis and mounted at the front of the lens. There are two main methods for lighting cavities, point source and ring flash. Point source and ring flash systems provide an even illumination which is ideal for lighting deep body cavities.

Directional theatre lights are very bright and can affect the exposure of the image, they can also create un-wanted colour casts on the final photograph. The photographer will ask for the theatre lights to be turned off each time a photograph is taken to minimise these problems.

The photographer will also ask the surgeon to staunch the blood flow from vessels and mop up any excess blood prior to a photograph being taken. If this blood is not removed it may obscure the underlying anatomy and create distracting reflections on the final image.

Metal retractors and clamps are used by the surgeon to gain access to the incision site. These instruments can also create distracting reflections, sometimes it is not possible for them to be removed for the photograph. In this situation the photographer will ask the surgeon to tilt the instruments as this can often minimise the reflections.

A medical photographer will, wherever possible avoid photographing an untidy surgical field as it can appear distracting on the final image. Unnecessary surgical instruments and used swabs should be removed from the field of view. The replacement of bloody and wet drapes is also preferred.

Consent

“Patients have a fundamental legal and ethical right to determine what happens to their own bodies. Valid consent to treatment is therefore absolutely central in all forms of healthcare, from providing personal care to undertaking major surgery. Seeking consent is also a matter of common courtesy between healthcare professionals and patients.” 2

Clinical photographs can only be taken if the patient has given their consent. The patient can only give informed consent if they are fully aware of the reason for the photographs and know what the photographs will be used for.

Photographs which are taken for the patient’s case notes cannot be used for publication or research purposes unless specific written consent is given by the patient. Photographic images may be used within the clinical setting for teaching purposes without specific consent if there is no possibility of the patient being recognised.

Specific written consent must always be sought if the photographs are to be used for publication. The patient should be informed that they can view the images that have been taken before deciding whether to give consent for the photographs to be published. The patient must receive information on the possible future uses of the photographs and be made aware that it may not be possible to withdraw their consent once the images are in the public domain. If the patient then decides they are not happy for the images to be used for publication the images must be destroyed.

The patient is usually unconscious when surgical photographs are requested. The photographer may take the photographs in the operating theatre without the patient’s consent but must seek written consent as soon as the patient is conscious. If the patient then refuses consent, the surgical images must be destroyed.

Sterile and non-sterile areas

Operating theatres contain sterile areas and special infection control protocols must be observed before entering. Theatres are subject to meticulous daily cleaning regimes, they must be kept clean at all times and have a working ventilation system to keep the theatre dust free. Decontamination and aseptic procedures must be strictly adhered to.

The theatre floor should be cleaned thoroughly on a daily basis and floors and surfaces should be damp-dusted between operations to remove any spillages of blood or body fluids. To reduce airborne contamination the movement of people in and out of the theatre should be kept to a minimum and the theatre door should be kept closed where possible to ensure the efficiency of the ventilation system.

All healthcare workers must change out of their uniforms and put on clean, un-contaminated clothes before entering an operating theatre. This clothing protects the patient and healthcare workers from potential infection from pathological micro-organisms.

There are two main types of theatre clothing (sterile and non-sterile). Sterile gowns should be worn by the surgeons and the scrub nurses as they have direct contact with the sterile field, i.e. the draped patient and the instrument table. The sterile long sleeved gowns are designed to resist wetting, tearing and bacterial penetration. Surgeons and scrub nurses must also observe strict hand washing procedures and wear sterile gloves.

Healthcare workers (including medical photographers) don’t have direct contact with the surgical field and can wear non-sterile clothing which usually consists of trousers and a short sleeved top.

Non-sterile clothing is usually made of a poly-cotton material, it is not as effective as sterile gowns and, if soiled, can allow bacteria and body fluids to penetrate the weave. If non-sterile clothing does get contaminated with body fluids it is advisable to remove it and put on a clean outfit as soon as possible. When the procedure is complete all theatre clothing should be removed and placed in a specified dirty linen bin.

It is usual practice for the sterile drapes and gowns to be green and the non-sterile clothing to be a different colour. This makes the sterile field easier to identify, and therefore easier to avoid.

As close-up views of the surgical procedure are often requested, the photographer must stand next to the sterile field. The photographer must ensure they don’t touch or rub against any sterile areas, for example the instrument table, surgeons, scrub nurses or patient. If the photographer does touch a sterile area they must tell the surgeon immediately and the drapes, clothing or instruments can be replaced.

Safe working practices

The most important thing a medical photographer should do before and after photographing each patient is wash their hands. This is necessary as it prevents the hands from becoming contaminated with micro-organisms. If the hands were not washed cross-contamination could occur. This is especially important when photographing a surgical procedure in an operating theatre environment.

The use of protective clothing such as a surgical mask, theatre clogs and hair net is also essential to avoid contaminating the theatre or incision site. Outside shoes should never be worn in an operating theatre as they harbour bacteria and could contaminate the floor. The hospital should supply non-slip, anti-static theatre clogs which can be washed after use. Hair nets should also be worn to prevent loose hair and skin from falling on the incision site or sterile areas.

Medical photographers should wear masks when photographing patients in operating theatres, or when they are in close contact with patients undergoing any form of surgical procedure. This is necessary as masks trap any organisms exhaled by the photographer. A fresh mask should be worn for each procedure and masks should be replaced when they become damp, as damp masks no longer deflect organisms. At the end of the procedure the mask should be removed and placed in a yellow clinical waste bin.

The photographer’s camera bag should be left outside the theatre and the photographer should only bring in the camera equipment which is needed. It is imperative that the photographer decontaminates this camera equipment with alcohol wipes before entering the theatre. If the photographer doesn’t disinfect their equipment they could inadvertently introduce micro-organisms into the incision site.

The photographer should display their identity badge clearly so that the other theatre staff know who they are and will not ask them to perform tasks they are not trained to do, for example help transfer the patient from the bed to the operating table.

The photographer should always let the surgeon know when they are about to take a photograph and should never deploy the flash without warning. If they do they might distract the surgeon at a critical point in the procedure. The photographer should also make sure they are not in the way and should only step up to the table when a photograph is being taken. This will prevent the surgeons and scrub nurses from bumping into the photographer and contaminating their sterile clothing.

X-rays and lasers

Portable x-ray machines are often used in operating theatres as they are a useful diagnostic tool. An image is produced on photographic film by passing electromagnetic radiation through parts of the body. Dense structures such as bone absorb the x-rays and appear as lighter regions on the developed film.

Precautions should be taken to protect theatre staff from the damaging effects of occupational exposure to x-rays as radiation has the potential to cause mutations in the germ cells that may then be passed on to future generations. Pregnant theatre staff should avoid all exposure to x-rays as the radiation can also cause foetal abnormalities. Theatre staff can limit their exposure by wearing special protective clothing such as a lead apron.

Lead aprons are very effective at absorbing diagnostic x-rays to the parts of the body shielded by the apron. The aprons contain lead and often other metals such as tin, tungsten, antimony and barium. These metals are mixed with synthetic rubber or polyvinyl chloride (PVC). Sheets of the metal impregnated rubber/PVC are placed between sheets of nylon fabric which has been coated with urethane. This material is then cut into a pattern and sewn together to form the protective apron.

When an x-ray is taken the number of people present in the theatre should be limited to those performing the procedure, all other theatre staff, including medical photographers should leave the theatre. If the photographer needs to be present for any reason a lead apron must be worn.

Laser surgery is also performed in operating theatres. A laser is a device which absorbs electromagnetic energy and re-radiates it as a highly focused beam of single wavelength radiation. The wavelength of the beam determines its colour and different wavelengths have distinct effects on the body.

Carbon dioxide and infra-red lasers have a long wavelength which is easily absorbed by water in the cells. Long wavelengths are very effective at cutting through tissue. Argon lasers have a shorter wavelength which is not readily absorbed by water. Argon lasers are used in ophthalmic surgery to shine through the liquid in the eyeball and treat the retina.

Laser surgery can be hazardous for theatre staff. If the light from a laser is transmitted directly or reflected into the eye it could burn the retina causing a permanent blind spot. If the beam of light hits the head of the optic nerve it could cause partial or total blindness. Infra-red lasers can be more hazardous to theatre staff as the beam of light cannot be seen by the naked eye.

Theatre staff must wear well fitting eye protection for all laser procedures. The type of goggles required depends on the wavelength of the laser. The glass in the goggles consists of alternate layers of two different optical materials (Bragg mirrors). Each optical layer reflects a certain wavelength. This stops the harmful wavelengths from entering the eye and damaging it.

Modern laser safety goggles are labelled with the wavelengths that the goggles protect from and the strength of the goggles. This information should correspond exactly with the information on the laser. It is vital that the correct goggles are worn, if the wrong ones are selected they will offer no protection from the laser beam.

Conclusion

Medical photographers have a responsibility to the patient and other healthcare workers to ensure that they wear the correct protective clothing. The photographer must also have a working knowledge of sterile and non-sterile areas within the theatre. If the photographer is not aware of the correct protocols they could put themselves, the patient and surgical staff at risk. It is therefore essential that medical photographers rigorously adhere to theatre protocols when photographing surgical procedures.

 


References

  1. Hansell, P., (Ed.) 1979. A Guide to Medical Photography. MPT Press Limited.
  2. South Manchester University Hospital NHS Trust. 2006. Consent to examination or treatment policy. SMUHT.

A Brief History of Medical Illustration in Clinical Dermatology

Today medical photography is universally accepted as the best way to document and monitor dermatological conditions. Standardised full-body mole mapping views provide a baseline against which to evaluate changes in a patient’s presentation.

This is achieved by taking a series of establishing views which divide the body into sections, close-ups of moles or lesions identified by the dermatologist are then photographed at a higher magnification with a mm scale. The resulting images are then numbered and organised so that they can be easily viewed in a follow-up clinic or by patients self-monitoring at home.

UK based medical photographers adhere to the Institute of Medical Illustrator’s national guidelines on mole mapping photography; this ensures that views are standardised and consistent in all medical illustration departments.


IMI standard positions for mole mapping 1

mole_mapping_standard_positions

The first book to explore skin conditions was Girolamo Mercuriali’s De Morbis Cutaneis (the diseases of the skin), originally published in 1572. It was followed by Daniel Turner’s De Morbis Cutaneis, published in 1714. These publications led to dermatology being recognised as a medical speciality in its own right.

Robert Willan (1757-1812) was an early pioneer in this new field of dermatology. He identified eight classifications of disease: papulae, sqamae, exanthemata, bullae, pustulae, vesiculae, tubercula and maculae. In 1808 he published On Cutaneous Diseases, it was the first book to contain hand drawn dermatological illustrations. Thomas Bateman (1778-1821) finished compiling the categories of disease after Willan’s death and A Practical Synopsis of Cutaneous Diseases According To The Arrangement Of Dr Willan was published in 1813. 2


Porrigo favosa (disease of the scalp) affecting the face.

by Bateman and Willan 3

310

Impetigo figurata pustules on hand.
by Bateman 4

64

Willan understood the importance of medical illustrations as an aid to teaching the clinical attributes of skin diseases. He recorded the appearances of individual categories of lesions in great detail. The illustrations proved very popular and all future dermatological skin atlases and publications have included illustrations or clinical photographs. 5

The earliest known medical photograph is a calotype of a woman with a large goitre taken in 1847 by Scottish photographers Robert Adamson (1821-1848) and David Octavius Hill (1802-1870). They opened the first photographic studio in Scotland and predominately photographed studio portraits as well as landscapes and urban scenes. It has been suggested that the medical photograph was a one-off taken for a doctor they had photographed who had an interest in goitres. 6


Woman with goitre
by Hill and Adamson 7

earliest_goitre_photo_1847_hill_and_adamson

The first dedicated photographic atlas of dermatological disease was published in 1865 by Alexander John Balmanno Squire (1836-1908). Squire was chief of surgery and medicine for the British Hospital for Diseases of the Skin in London. He produced a three part series called Photographs (coloured from life) of the Diseases of the Skin. The atlas included 12 hand coloured albumin prints. 8

Squire wrote in his introduction:

“The great difficulty hitherto experienced in producing illustrations adequately portraying the various diseases of the skin, induced me to try if greater accuracy and more lifelike representations might not be obtained by means of photographs of the disease coloured from life by one of the best artists… soon became evident that excellent results were to be obtained by this means and that they might be rendered more widely available by publication”


Hand coloured albumin print
by Squire 9

squire_sqamae_clip

Squires’ publication was well received and photography became the accepted medium to document dermatological conditions. Over the next century medical photography developed into a distinct profession and photographic views were standardised. Clothing and jewellery were removed from frame and plain backgrounds were utilized. More importantly photographers began to respect a patient’s anonymity by only photographing the diseased area of the body and ensuring informed patient consent had been obtained.

 


References

  1. IMI National Guidelines – Mole Mapping Photography (www.imi.org.uk). Accessed November 19th 2016.
  2. Royal College of Physicians – Robert Willan and the History of Dermatology. (http://www.rcplondon.ac.uk/news/robert-willan-and-history-dermatology). Accessed November 19th 2016.
  3. Delineations of Cutaneous Diseases. (https://prettypotache.wordpress.com/2013/11/19/thomas-bateman-and-robert-willan/) Accessed November 19th 2016.
  4. Delineations of Cutaneous Diseases. (https://prettypotache.wordpress.com/2013/11/19/thomas-bateman-and-robert-willan/) Accessed November 19th 2016.
  5. A. Bernard Ackerman, M.D., Helmut Kerl, M.D., Jorge Sánchez, M.D., A Clinical Atlas of 101 Common Skin Diseases with Histopathic Correlation. Ardor Scribendi; 2000.
  6. McFall KJ. A critical Account of the history of medical photography in the United Kingdom: IMI Fellowship submission. (http://www.migroup.co.uk/wp-content/uploads/2013/05/A-critical-account-of-the-history-of-medical-photography-in-the-UK.pdf) Accessed November 20th 2016.
  7. McFall KJ. A critical Account of the history of medical photography in the United Kingdom: IMI Fellowship submission. (http://www.migroup.co.uk/wp-content/uploads/2013/05/A-critical-account-of-the-history-of-medical-photography-in-the-UK.pdf) Accessed November 20th 2016.
  8. Art and Medicine – Photographs (coloured from life) of the diseases of the skin. (http://www.artandmedicine.com/biblio/authors/Squire.html). Accessed November 20th 2016.
  9. Art and Medicine – Photographs (coloured from life) of the diseases of the skin. (http://www.artandmedicine.com/biblio/authors/Squire.html). Accessed November 20th 2016.

So what does a medical photographer do?

This is a question I am often asked by family and friends and it’s a difficult one to answer. It is also partly why I decided to write this blog, to give people a glimpse into the weird and wonderful world of a medical photographer.

The photography bit is easy, everybody knows what a photographer does but as soon as you go into any specifics you come up against two main problems:

1. The details can be quite gruesome and gory and can easily distress those with a weak constitution or low ‘gore’ threshold.

2. We are bound by privacy and confidentiality laws not to disclose any personal information about the patients we photograph.

So what does a medical photographer do? Well we pretty much photograph everything and anything in a hospital. Our main role is recording and documenting injuries and diseases in clinics, on wards and in operating theatres. The images are also used for teaching medical staff. We also undertake PR, location and staff portraiture in and around the hospital.

Our images are requested by doctors, consultants, child protection services, the police and solicitors to name but a few, the images can also be used as evidence in court.

Everyday is different we don’t know where we will be from one request to the next. I might get sent to burns theatre to photograph a serious burn injury then get called back to the photographic studio to record a series of intra-oral dental views. Then be asked to take photographs of a stillborn baby as a memento for the bereaved parents.

So as you can see medical photography is a pretty unique profession, yes you experience harrowing and distressing sights on a daily basis and see people at their most vulnerable. However it is a truly interesting, worthwhile and rewarding job and I wouldn’t change it for the world!