Histopathology of Periapical Disease

Question 1

Causes of inflammatory PA disease

Answer 1

Trauma - physical, high fillings, bruxism, malocclusion. chemical leakage
Infection - caries

Question 2

Symptomatic (acute) PAP - features

Answer 2

Confined to PA space
Greater proprioception - localised pain
Slight widening of PDL space
Elevated tooth due to vasodilation and oedema

Question 3

Progression of symptomatic PAP

Answer 3

Acute periapical abscess
Anaerobic bacteria present within periapical space
Minute radiographic changes

Question 4

Progression of symptomatic PAP (2) and routes of infection

Answer 4

Acute alveolar abscess 
Further spread of bacteria via pus 
Via route of least resistance - PDL
Bone --> sinus infection
Antrum entry --> spread into sinuses - into IO region 
Soft tissues --> cellulitis 
Bone --> osteomyelitis

Question 5

Asymptomatic (chronic) PAP

Answer 5

AKA periapical granuloma
Clinically sound
Significant radiographic changes
Mass of inflamed fibrous connective tissue replacing lost bone

Question 6

Histology of periapical granuloma

Answer 6

Fibrous capsule filled with vascular connective tissue
Lymphocytes, macrophages and plasma cells. Neutrophils if inflamed
Scattered remnants of epithelium (RofM)
Bone resorption

Question 7

Progression of A(C)PAP granuloma

Answer 7

Radicular cyst
Epithelium proliferates and then breaks down after reaching growth capacity - becomes necrotic
Fluid accumulates and forms cyst
Cholesterol also accumulates

Question 8

Types of inflammatory radicular cyst

Answer 8

Apical - at root apex
Lateral - at side of tooth
Residual - persists after extraction of affected tooth

Question 9

Reactive/neoplastic conditions

Answer 9

Osteosclerosis - changes in bone structure

Question 10

Rarefying Osteitis

Answer 10

• acute
• loss of bone
• inflammatory widening of PA space

Question 11

Focal sclerosing osteitis

Answer 11

• ill defined radiopacity - suggesting bone growth
• osteoblasts have laid down more bone to ‘confine’ infection
• bone has become sclerotic

Question 12

Hypercementosis and potential causes

Answer 12

• more common in older its
• reactive changes due to loss of fx (partially erupted/unerupted/overgrowth)
• inflammation due to PD
• Paget’s disease - abnormal bony turnover
• Idiopathic - unexplained
• cementum can become fused with tooth - ankyloses

Question 13

Cemento-Osseous dysplasia

Answer 13

• reactive lesions

- several radiopacities around roots and edentulous areas

Question 14

Florid cemento-osseous dysplasia

Answer 14

• masses of fused bone

- calcified bodies which become larger

Question 15

Neoplastic condition - cementoblastoma

Answer 15

• 10-40 y/o
• benign neoplasm
• radiopaque lesion attached to root
• usually Md Molar
• resembles osteoblastoma
• sheets of osteoid and cementum