Showing posts with label Prosthetic Dentistry. Show all posts
Showing posts with label Prosthetic Dentistry. Show all posts

Thursday, October 17, 2013

The history of dentistry


A profession that is ignorant of its past experiences has lost a valuable asset because “it has missed its best guide to the future.” 
B.W. Weinberger Dentistry: An Illustrated History 
(Mosby, 1995)

Ancient  Dentistry
The Indus Valley Civilization has yielded evidence of dentistry being practised as far back as 7000 BC.
Earliest form of dentistry involved curing tooth related disorders with bow drills operated, perhaps, by skilled bead craftsmen.In what could be one of the earliest examples of dentistry.Scientists at the University of Missouri-Columbia in the United States have found tiny, perfectly rounded holes in teeth found in Mehrgarh in pre-historic Pakistan, which they suspect were drilled to repair tooth decay.Researcher Andrea Cucina, who first discovered the tiny holes, reveals that they didn't appear to be a funeral rite and the teeth were still in the jaw so they had not been drilled to make a necklace. He and his colleagues suspect the holes were a treatment for tooth decay and that plants or another substance had been inserted into the holes to prevent bacterial growth.

The earliest dental filling, made of beeswax, was discovered in Slovenia and dates from 6500 years ago.
The first and most enduring explanation for what causes tooth decay was the tooth worm, first noted by the Sumerians around 5000 BC. The hypothesis was that tooth decay was the result of a tooth worm boring into and decimating the teeth.The idea of the tooth worm has been found in the writings of the ancient Greek philosophers and poets, as well as those of the ancient Indian, Japanese, Egyptian, and Chinese cultures. It endured as late as the 1300s, when French surgeon Guy de Chauliac promoted it as the cause of tooth decay.
Examination of the remains of some ancient Egyptians and Greco-Romans reveals early attempts at dental prosthetics and surgery.Ancient Greek scholars Hippocrates and Aristotle wrote about dentistry, including the eruption pattern of teeth, treating decayed teeth and gum disease, extracting teeth with forceps, and using wires to stabilize loose teeth and fractured jaws. Some say the first use of dental appliances or bridges comes from the Etruscans from as early as 700 BC.


The ancient dentist
 The Egyptian,Hesi-Re was the earliest dentist whose name is known. He practiced in 3000 BC and was called “Chief of the Toothers.” Egyptian pharaohs were known to have suffered from periodontal disease. Radiographs of mummies confirm this fact.

Dental extractions
Historically, dental extractions have been used to treat a variety of illnesses. During the Middle Ages and throughout the 19th century, dentistry was not a profession in itself, and often dental procedures were performed by barbers or general physicians. Barbers usually limited their practice to extracting teeth which alleviated pain and associated chronic tooth infection.Before the 18th century, this often involved tying a string around the tooth; a drum might be played in the background to distract the patient, getting louder as the moment of extraction grew nearer. To advertise their services as ‘tooth-pullers’, many barber-surgeons hung rows of rotten teeth outside their shops.


The Armentariam
Dental Pelican

Dental Key


Instruments used for dental extractions date back several centuries. In the 14th century, Guy de Chauliac invented the dental pelican (resembling a pelican's beak) which was used to perform dental extractions up until the late 18th century. The pelican later gave way to the Dental Key which, in turn, was replaced by modern forceps in the 20th century.


The equipments
The first dental foot engine was built by John Greenwood in 1790 . It was made from an adapted foot-powered spinning wheel.
John Greenwood

1790 was a big year for dentistry, as this was also the year the first specialized dental chairwas invented. It was made from a wooden Windsor chair with a headrest attached.In 1871, George F. Green invented the first electrical dental engine and in 1957, John Borden invented the first high speed electric hand drill.





The father of modern dentistry
By 17th-century French physician Pierre Fauchard (1678 – 1761) started dentistry as it is known today, and he has been named "the father of modern dentistry".He is tremendously recognized for his book, Le chirurgiendentiste, "The Surgeon Dentist" 1728, where he described the basic oral anatomy and function, signs and symptoms of oral pathology, operative methods for removing decay and restoring teeth, periodontal disease, orthodontics, replacement of missing teeth, and tooth transplantation. His book is said to be the first complete scientific description of dentistry. Among many of his developments were the extensive use of dental prosthesis, the introduction of dental fillings as a treatment for dental caries and the statement that sugar derivative acids such as tartaric acid are responsible for dental decay.


Women in dentistry
Women in pre-20th century seems to play an unknown role in dentistry. In an early copper engraving by Lucas Van Leyden, a traveling dentist can be seen along with a woman acting as his assistant.  In 1852, AmaliaAssur became the first female dentist in Sweden. She was given special permission from the Royal Board of Health to practice independently as a dentist, despite the fact that the profession was not legally opened to women in Sweden until 1861. 

Emeline Roberts Jones became the first woman to practice dentistry in the United States in 1855.  She married the dentist Daniel Jones when she was a teenager, and became his assistant in 1855 and later on put up her own practice. Rosalie Fougelberg in 1866 became the first woman in Sweden to officially practice dentistry when profession was legally opened to females in 1861.
Dental schools throughout the world did not accept female students. Women such as Lucy B. Hobbs-Taylor and Nellie E. Pooler broke those barriers. In 1866 Lucy Hobbs Taylor became the first woman to graduate from a dental college which was the Ohio Dental College.

Dental education
Dr. John M. Harris started the world's first dental school in Bainbridge, Ohio, and influenced establishing dentistry as a health profession. It opened on 21 stFebruary 1828, and today is a dental museum. The first dental college, Baltimore College of Dental Surgery, opened in Baltimore, Maryland, USA in 1840.Chapin Harris and Horace Hayden founded the Baltimore College of Dental Surgery, the first school dedicated solely to dentistry. The college merged with the University of Maryland School of Dentistry in 1923, which still exists today.


History of the tooth brush
A recent researches reveals that the earliest use of toothbrushes may have occurred in India and Africa. It was discovered that a bristle toothbrush had been used there as early as 1600 BC. The first bristle toothbrush found was in China during the Tang Dynasty (619–907) and used hog bristle. In 1223, Japanese Zen master DōgenKigen recorded on Shōbōgenzō that he saw monks in China clean their teeth with brushes made of horse-tail hairs attached to an ox-bone handle. The bristle toothbrush spread to Europe, brought back from China to Europe by travellers. It was adopted in Europe during the 17th century. Many mass-produced toothbrushes, made with horse or boar bristle, were imported to England from China until the mid-20th century.The first patent for a toothbrush was by H. N. Wadsworth in 1857 in the United States, but mass production in the United States only started in 1885. During the 1900s, celluloid handles gradually replaced bone handles in toothbrushes. Natural animal bristles were also replaced by synthetic fibers, usually nylon, by DuPont in 1938. The first nylon bristle toothbrush, made with nylon yarn, went on sale on February 24, 1938. The first electric toothbrush, the Broxodent, was invented in Switzerland in 1954.

The first publication on dentistry

The first book focused solely on dentistry was the "ArtzneyBuchlein" in 1530 and the first dental textbook written in English was called "Operator for the Teeth" by Charles Allen in 1685.
 

Monday, August 26, 2013

MEDICAL EMERGENCIES IN THE DENTAL PRACTICE



1. INTRODUCTION

Fortunately, medical emergencies in the dental office are a rare occurrence.  Unfortunately, this rarity prevents us from becoming comfortable with management of problems, and worse still, may lead to complacency.  In light of their uncommon occurrence, it is useful to revisit the subject, sometimes from a different perspective.  The perspective taken for today's discussion is a relatively broad one, allowing for a  "from first principles " approach to the prevention of preparation for, recognition of and action involved in the management of medical emergencies.


2. DEFINITION

A medical emergency is a stress induced, relatively sudden, acute, uncontrolled failure of physiologic adaptation capability (or decompensation in the face of stress ).


A. Stress induced:  This implies that there is usually a more or less recognizable cause or identifiable stress that is driving the system toward failure.  This could be the presence of an allergen, anxiety, drugs or foreign object in the airway that stresses the system maximally and beyond in such a manner that the system is no longer able to cope.

B.Relatively  sudden:  While some emergencies occur rapidly, many take time to evolve.  An identifiable, gradual chain of events often conspire to lead a patient to the point where they are maximally stressed and failure occurs as the last link in the chain.  Prevention centres on breaking the chain of events prior to reaching failure.

C. Acute: The central theme of all emergencies is that they are acute occurrences happening right now.  From this perspective they require immediate recognition and attention.

D.Uncontrolled failure: Emergencies rarely display intrinsic control by the patient.  Clearly, the patient’s system has lost the ability to respond to the stress and extrinsic help must be brought in.  The key to management of emergencies is the resumption of control by the clinician.

E.Decompensation: Loss of compensation implies that compensation was happening in the first place.  In the normal healthy subject, this ability to compensate for stress or strategic reserve is maximal and much has to happen before the system is no longer able to adapt to rising levels of stress.  In the medically compromised patient, some of this reserve has been lost as a function of the underlying illness and decompensation or failure occurs earlier and in the face of lower levels of stress.


F. Examples:

                 An excellent model for medical emergency is the coronary stress test.  In this example, the stress is the treadmill, specifically related to its slope and its rate.  As the slope and rate of the treadmill increases, the stress to the heart and the demand for coronary perfusion of the myocardium increases.

                While the angina attack or the MI that the patient experiences while having the test is a relatively sudden event, the steps leading to the acute event took place over a well defined interval and occurred in a clearly laid out pattern.

Although the progression to the angina attack or the MI may have been drawn out, the event itself is acute and must be recognized and dealt with immediately by the stress lab technician.  If  the patient has gone on to having an MI during the stress test, the extent of the damage is essentially uncontrolled unless the technician intervenes, stops the test and begins supportive management immediately.

                The stress test is designed to assess the patient's coronary reserve. "Failing" a stress test means the patient's reserve was minimal in the first place and that decompensation or failure is likely to occur very early in the process of applying stress to the system.

What is a medical emergency?

A medical emergency can be described as any situation in which a patient becomes ill, may become unconscious and ultimately their life may be at risk due to a failure of an effective oxygenated circulation to the brain and vital organs. There are certain specific emergencies that are the most commonly encountered in General Dental Practice and all DCPs should be familiar with their presentation and management, these are shown in table 1.

Table 1 :Specific Medical Emergencies

·         Choking
·         Asthma
·         Anaphylaxis
·         Hyperventilation
·         Respiratory arrest
·         Angina
·         Myocardial infarction
·         Seizures
·         Faints/syncope
·         Cerebro-vascular accident (stroke)
·         Cardiac arrest

3. THE CORNERSTONES OF EMERGENCY MANAGEMENT

Viewed from this perspective, the management of emergencies can be thought of as occurring in four domains.  Each domain is interdependent with the other domains and requires support form the other three.

Prevention:   The most successful way to manage an emergency is to prevent it form happening in the first place.  This is based on:

                a) An assessment of relative risk: This is the ‘product’ of medical compromise multiplied by the complexity of the procedure.  The more ill the patient and the more invasive the procedure, the greater the likelihood of an emergency.  Careful medical assessment is the key to determining where the patient is sitting on the compensation curve, and therefore, their medical risk.

                b)  Risk reduction and hazard avoidance:  Having recognized increased risk (as a function of  illness and procedural complexity), prevention revolves around risk reduction (medical tune up in order to ensure optimal control of medical compromise) and hazard avoidance (reduce anxiety, avoid allergens, avoid drug interactions, reduced pain, shorter procedures, avoid aspiration, refer, etc.).

B.             Preparation:

                a) Medical assessment: Careful medical assessment not only allows for identification of risk and thus avoidance, it should also give the practitioner an indication of the type of medical emergency that the patient may have,  for example:  bronchospasm in the asthmatic.  Having this information readily at hand when dealing with an emerging problem will save on considerable guesswork and allow the practitioner to zero in on the most likely diagnosis.

                b) Emergency kit: An important aspect of preparation for emergencies is the purchase and careful maintenance of an emergency kit.  This should include key drugs and equipment needed to manage emergencies.  A key example of this is to ensure that there are syringes and needles for the delivery of emergency drugs when needed.  A further point to stress is the need to monitor expiration dates and the condition of equipment such as airways or          masks.  The following is a short list of recommend drugs and equipment:

1.   Oxygen                                                                                           6 1/min by mask
2.   Epinephrine (alpha and beta agonist)                               0.5 to 1 ml of 1:1,000 IM
3.   Nitroglycerine (vasodilator)                                                  0.3 mg sublingual to 3 doses (if no
  response…assume MI and call 911)
                               
4.   salbutamol (Ventolin) (bronchodilator)                           2 puffs by inhalation                      
5.   diphenhydramine (Benedryl) (antihistamine)               50 mg IM or PO
6.   Sucrose                                                                                            soda PO
7.   Glucagon                                                                                         1 mg IM
8.   ASA                                                                                                    325 mg PO
9.   Lorazepam                                                                                      1 mg SL
10. Oxygen bottle with regulator and gas tubing
11. An assortment of adult and paediatric airways and face masks
12. Ball valve bag for ventilation (Ambubag)
13. Various syringes and needles for delivery of emergency drugs
14. Tape
15. Flashlight
16. Tonsil suction tip
17. File cards with emergency protocols and drug dosage information
                 
                c) Clear guidelines: During the middle of a medical emergency is no time to be figuring out what to do next.  This has been recognized by the American Heart Association in their guidelines for CPR and ACLS (Advanced  Cardiac Life Support). These guidelines, once learned, allow the rescuer to follow standard protocols for the management of cardiac emergencies.  They are based on sound judgement and scientific study and most importantly, are detailed IN ADVANCE.  Similar thinking for the management of other emergencies is equally reasonable.  Taking the time, in advance, to think through an emergency situation, outlining it on a file card, familiarizing all staff, in advance, and then placing the card in the emergency kit will tremendously simplify problem management.

                d) Practice:  The AHA again recognizes the importance of rehearsal for the management              of emergencies. Annual mock emergencies not only keeps the staff sharp but it is also an excellent opportunity to recheck the emergency kit and restock stale dated medications.

                e) Vigilance:  Watching and listening for potentially emergent situations whether they be in the operatory, the other operatory or the waiting room will help to prevent problems before they occur and to act on emerging problems early in their progression.  This requires constant vigilance and observation for the patterns of  " problems waiting to happen".


Recognition:  Early recognition and intervention is essential to the successful management of emergencies once they have happened.  The comment,  " the right thing was done too late "  may be the epitaph for the unsuccessful emergency intervention.

                a) Monitoring: Monitoring of patients takes many forms. The most extreme is intensive ICU  or OR monitoring that involves EKG, pulse oximetry, blood pressure and so on.  In the normal dental office, these items are usually unnecessary and unfamiliar.  What is done is moment to moment monitoring through assessment of colour, respiratory rate and distress pattern, level of consciousness and observation of overt signs of  distress. Dentists are particularly good at this sort of monitoring because we are constantly watching for signs of discomfort or inadequate anaesthesia that may complicate our procedure.  The most useful practical technique is the comparison of patient's state of mind as we progress through treatment.  How often have you asked a patient  " are you OK", after observing some subtle  mood or postural change in the patient?  This type of monitoring is crucial for the detection of problems early in their progression.

                b) Context: The importance of an accurate and up-to-date medical history cannot be overstressed.  If a patient is decompensating, it is usually a function of a lack of strategic reserve in a given system and it is usually obvious from the medical history.  A patient with a history of six heart attacks in the past is likely having another one if he collapses in your waiting room.  This allows for early diagnosis and appropriate management.
               
                c) Assessment of severity: Determining the severity of a problem is a function of the interplay of a complex series of observations and then the performance of mental arithmetic in order to extrapolate ahead and try to predict just how bad things might get and how soon they might get there.  If a patient was fine two minutes ago and is now swelling visibly and wheezing audibly following the administration of a local anaesthetic, its a good bet that he going to continue getting worse in a hurry.  This determination of how severe things are (and how severe they are going to get) directs management in terms of the intensity of response.  The above noted patient needs epinephrine right now and an ambulance ride as soon as possible if he hopes to survive the day.  On the other hand a simple episode of syncope from which the patient recovers quickly may only require repositioning and reassurance before resuming the treatment.  Measurable parameters like heart rate, blood pressure and respiratory rate are much more objective guides to the ongoing status of the patient and as such will be very helpful in determining whether a patient is worsening or improving.

                d) Diagnosis and differential diagnosis: In some cases, the diagnosis will be obvious.  Examples of this are epileptic convulsions or airway obstruction following loss of a crown down the patients's throat.  In these cases, the obvious diagnosis leads to early appropriate management. In other situations, the diagnosis of the emergency situation may be obscure.  An unconscious patient lying on the floor of your waiting room may have fainted, overdosed on drugs, hypoglycaemic, dead, having a heart attack or simply be asleep.  Having a working differential diagnosis will direct the early steps in managing this situation to supporting the basic ABC's  and to determining the exact nature of the problem.  Quick review of the medical history is often helpful at this point.           In other circumstances, the results of early intervention may be diagnostic if  applied appropriately.  An excellent example of this is the patient with chest pain.  If the nitroglyercine does not clear up the problem after three dosages, then a call to the ambulance and a trip to the local emergency room is indicated to rule out an MI.

Action:   Action may be indicated even before an emergency situation is clearly diagnosed.  Supportive measures such as airway maintenance will buy valuable time for the clear determination of the problem and definitive intervention.
               
                1.  Stop the procedure and manage the emergency.

                2.  ABC's of emergency management:  airway, breathing and circulation

                3.  911....... Get help as soon as the situation appears serious

                4.  On the basis of diagnosis:
                                                a)  Maneuvers, eg. Trendellenberg position, Heimlich maneuver
                                                b)  Drugs......see emergency kit and protocol card
                                                c)  Follow up........911 (ambulance), emergency room or physician

How do you “manage” an emergency?

The ability to effectively manage a medical emergency is dependent on three things which are all inter-related:-

  • Theoretical knowledge.
  •  Practical skills
  •  Team work

Theoretical knowledge

This includes an understanding of the basic physiology of the vital organs and systems of the body, together with detailed knowledge of the causes, effects and treatment of the more common emergencies.  There are several textbooks available which are useful sources of reference and a list of useful websites is provided at the end of this article.

Practical skills

There are specific skills that are required to effectively assess and treat a patient who is feeling unwell, or who has collapsed.  It is not always immediately obvious what the cause of the problem is, but this does not preclude effective management.  A systematic assessment of the patient is essential, and the universally accepted method is the ABCDE approach.  The only way to acquire practical skills is simulation training which allows for constant repetition of the skill until the individual develops the appropriate level of competence.  The knowledge and skills are briefly described below:-


A=Airway

A person must have an open airway to allow oxygen to enter the lungs, so the first step in effective management is to assess the patency of the upper airway-the patency is obvious if the patient is talking ,however ,if the patient is unconscious. are there any obvious obstructions e.g. fluid, vomit, or the tongue?

A=Airway
A person must have an open airway to allow oxygen to enter the lungs, so the first step in effective management is to assess the patency of the upper airway-the patency is obvious if the patient is talking ,however ,if the patient is unconscious. are there any obvious obstructions e.g. fluid, vomit, or the tongue?

Airway skills
Know the location of the emergency suction and how to use it.
Deal effectively with choking-back blows; abdominal thrust.
Ability to place an unconscious patient into the “recovery position”
Jaw thrust             
Head tilt chin lift
Insertion of oro-pharyngeal airways
Insertion of naso-pharyngeal airways

B=Breathing
If the airway is open then a person must be breathing effectively to draw inspired oxygen into the lungs.  Noisy breathing is indicative of an obstruction, and the type of noise produced will indicate the possible cause e.g. bronchospasm producing an expiratory wheeze in asthma and anaphylaxis. Administration of oxygen is essential, and if a person is not breathing then ventilations need to be supplied.

Breathing skills
Location of emergency oxygen and how to attach this to the relevant face mask.
Assembly and use of a pocket mask
Assembly and use of a bag-valve mask
Ability to deliver effective ventilations.
Ability to assess respiration for:-
  • Rate
  • Depth
  • Noise
  • Use of accessory muscles
  • Bilateral chest expansion 
C=Circulation

  • An effective circulation is essential to ensure an adequate supply of oxygenated blood reaches all vital organs.  In a medical emergency this can become compromised and therefore needs to be monitored, and in a cardiac arrest external chest compressions need to be supplied.
Circulation skills

  • Ability to measure central and peripheral pulses for rate, regularity, volume.
  • Ability to measure blood pressure
  • Measure and understand the significance of capillary refill time
  • Ability to perform effective cardiac compressions at a rate of 100 per minute
  • Safe use of an automated external defibrillator if the practice has one.
 
D=Disability

  • This is an assessment of the effect the emergency is having on the patient’s brain and nervous system.  The two things that are essential for the brain to function effectively are an adequate supply of oxygen and glucose, if these are not supplied then the patient’s level of consciousness will be affected.  The method of assessment of conscious level is the AVPU scale, a further useful test is the response of the pupils of the eye to light.  Blood glucose level can be measured using a suitable monitor.
Disability skills

  • Use the AVPU response scale to assess consciousness ( Alert; responding to Voice; responding to Pain; Unresponsive)
  • Assess pupil reaction and understand the significance
  • Ability to use a blood glucose monitor. 
E=Exposure

  • This assessment is a physical examination of the patient which will be limited in a dental surgery setting.  The main things to be considered are rashes/ flushing, any signs of swelling around the mouth and face, and prevention of heat loss. 
Exposure skills

  • Record any flushing or rashes
  • Know the location of blankets within the practice

The use of this systematic assessment will provide essential information about the nature of the emergency and which body systems are being affected, it is not always necessary to have a specific diagnosis to provide effective treatment to compensate for the problem.  This assessment is carried out each time something changes e.g. the patient becomes unconscious, and each time an intervention is done e.g. the respiration rate was 30 per minute but after oxygen was supplied it reduced to 20 per minute-this is reassuring that the intervention carried out was effective.  It is good practice to write down the assessment results each time it is carried out and this will provide valuable documentation for the paramedics on transfer.

Emergency Drugs
All dental practices carry an emergency drugs kit and all team members should know the location and content of this kit.  The presentation of emergency drugs varies quite considerably and therefore practice may be required to actually prepare the appropriate drug for administration e.g. how to assemble a syringe.  It is good practice for all team members to train to do this, using preparations that are out of date, to avoid confusion and delay if drug administration is required.  A summary of the emergency drugs and their use is given in table 2.

Emergency drug skills
Know the location of the emergency drug box
Know the type of drug and dose required for which emergency
Understand the different methods of drug delivery (inhalational ,oral; transmucosal; intra-muscular and intra-venous)
Practice assembling the drug ready for administration
Practice intra-muscular  administration using a simulator.


Paramedic Transfer

The last responsibility the dental team has is to transfer the patient safely into the care of the paramedics.  It is good practice to ensure that all the information required is provided as written documentation for ease of reference.  The acronym SAMPLE or MAPLES provides a useful “aide –memoir” to ensure all the appropriate details are included.

Paramedic Handover-essential information

Symptoms
Allergies
Medications
Past Medical History
Last oral intake
Events prior to the incident

3. Team work

All members of the dental team should undertake regular scenario training within the dental practice.  This will help to increase the confidence and competence of each individual team member with their individual roles and responsibilities.  Each time a scenario is conducted the team members should alternate roles so all aspects of the management of the emergency are rehearsed.  All scenarios should end with a practised “paramedic handover” including provision of all documentation.  Attendance at lectures and external courses can be very beneficial but are no substitute for regular “in house” training.

Team roles and responsibilities

Who acts as the team leader and directs the team?
Who is responsible for locating and preparing the emergency equipment and drugs?
Who is keeping a note of the time and recording the results of the assessments?
Who contacts the paramedics and waits by the entrance to lead them to the emergency?
Who is responsible for collating and photocopying the necessary documentation?


For each of the following sample emergencies, consider the affected system, the pathophysiology of the emergency and add detail with respect to the mechanisms of action, dosages and routes of the emergency drugs.

E.            Sample Emergencies:


Medical Problems which may alter dental treatments
Medical Problems which may alter dental treatments

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