Medical Emergencies does not usually occur in dental practice but are not uncommon,the incidence is low but a DENTIST needs to be in control of that situation
so it is essential for a DENTIST to have the following goals listed below while dealing with a child pateint 
image source : https://www.google.com/search?q=medical+emergencies+in+pediatric+patient+in+dental+practice&hl=en-GB&source=android-browser&source=lnms&tbm=isch&sa=X&ved=0ahUKEwi4vb7Iv7rbAhVHXn0KHSnlDk8Q_AUIBigB&biw=360&bih=514#imgrc=roGKNA9HvRiX6M:
- The dentist should be able to recognize the particular medical emergency
2.should be able to tackle and manage smoothly the emergency relatively
3.should respond to the emergency very well and should have knowledge about the medications needed during emergency
COMMONLY OCCURING MEDICAL EMERGENCIES IN CHILD PATEINT
1.Anaphylaxis
2.Drug overdosage ,commonly occurs due to local anesthesia administration
3.Seizures
4.Hypoglycemic Attack
5.Acute Asthmatic attack
6.Syncope
MANAGEMENT
The best rule is that during emergency stop all the dental procedures and as widely accepted and followed the pattern of P,A,B,C,D
P:POSITION it implies the position of a child pateint on the dental chair when there is medical emergency
A:AIRWAY should maintain a proper airway
B:BREATHING there should be proper assesment whether the breathing is proper
C:CIRCULATION there should be proper evaluation that the blood supply is adequate or not
D:DEFNITIVE as depending on the emergency there should be definite treatment
POSITION(P)
Mainly there are three important positions when there is an medical emergency
1.SUPINE POSITION
It is position where the legs of the pateint are to be elevated slightly so as to bring head and heart at the same level ensuring adequate supply to the brain when there is loss of consciousness
image source: textbook of pedodontics 2nd edition by SHOBHA TANDON
2.TRENDELENBURG POSITION
this position is same as above mentioned supine position the difference is only the head is below the level of heart this position is used when there foreign body obstructs the airway of child pateint by keeping head below downwards helps to retrieve it .
3.SEMIERECT POSITION
Generally this position makes beathing easier used when there occurs the emergency like attack of asthma.
AIRWAY(A)
The only thing that ensures that oxygen is reaching the lungs is the proper airway as during this the tongue falls back thereby blocks the airway ,it can be opened by using HEAD TILT CHIN LIFT POSITION
IMAGE SOURCE:TEXTBOOK OF PEDODONTICS 2ND EDITION BY SHOBHA TANDON
BREATHING(B)
if the breathing is not adequate that means oxygenated blood in circulation os not sufficient ,it is assessed by LOOK LISTEN FEEL TECHNIQUE
the rise and fall of the chest should be observed and breath sounds should be listened and observed if there is no such sign then oxygen should be administered immidiately 
IMAGE SOURCE:TEXTBOOK 9F PEDODONTICS 2ND EDITION BY SHOBHA TANDON
CIRCULATION(C)
Proper circulation shows that the heart is beating and various critical organs indicates that the brain is also being supplied with oxygenated blood
it is assessed by palpating a large artery e.g the carotid artery which is located and felt between the Adams apple and sternocleidomastoid muscle
if pulse is not felt there then the heart should b restarted by compressing externally by putting the child on the hard surface 
IMAGE SOURCE :TEXTBOOK OF PEDODONTICS 2ND EDITION BY SHOBHA TANDON
DEFNITIVE THERAPY (D)
This involves the administration of emergency drugs ,
so in dental emergency management P,A,B,C should be done if not gets managed then u should go for D