A tooth can be divided into two parts,one of which is clinically visible called to be the crown and the part that is not visible clinically is called the root of the tooth.As in dentistry the part above the cervical line is termed to be the crown and the part below the cervical line is called the root of the tooth.
The word "peri - apical infection " means spread of infection around the root apex of the tooth.
Causes of the spread of infection -
There may be different causes of the spread of infection,it can be due to the periodontal diseases,infection spread from some other part of the jaw/tooth or it can be due to caries.
Secondary causes can be trauma,unhealed fractures,fractured enamel/crown/root. In simple words it can be caused by micro-organisms,getting access into the deeper tissue/bone,colonizing to which the body's immune system reacts to prevent the further spread of the infection.
Symptoms -
Most commonly severe pain ,localized and radiating outwards,halitosis,difficulty in mastication due to onset of pain,the pain is relieved upon medication,difficulty in hot and cold,others.Most of cases the cause is clinically visible or is revealed in an radio-graph.
Case Study -
Here is a patient ,34/M,with an history of severe pain in the lower left back region of his mouth.presently he has no sensation of pain in the region and had visited the clinic for a regular check up.upon diagnosis , it was found that the patient had root stump 37 and 47 .The radio-graph revealed resorbed roots and a controlled Peri-apical infection around 37 which was the sole cause of the recurrence of pain and inflammation in the lower left pack region of his mouth.37 and 47 was later extracted under antibiotic coverage.
Below - 3 contrast radio-graphs are given for better understanding .From the radio-graph it is also evident of the wear facets on 36 ;loss of inter-proximal bone and the erupted 38 -which can be considered to be the reason for the initiation of caries in the 37,due to its path of eruption mesially , pushing towards the 37 - Similar case is also reported for 48.
