Traumatic occlusal forces Flashcards
Define traumatic occlusal forces
• Traumatic occlusal force is defined as any occlusal force resulting in injury of the teeth and/or the periodontal attachment apparatus
Define the classification of traumatic occlusal forces on the periodontium
- Occlusal Trauma
A. Primary Occlusal Trauma
B. Secondary Occlusal Trauma
C. Orthodontic Forces
Define occlusal trauma
- Is a lesion (injury) to the periodontal attachment apparatus (periodontal ligament, cementum and adjacent bone).
- It is caused by traumatic occlusal forces
- It is a histological term however, a clinical diagnosis of occlusal trauma can be made through clinical observations
Define primary trauma.
What does it lead to?
Does it cause pocket formation or alter connective tissue attachment?
Does it cause periodontal attachment loss, non- carious cervical lesions or gingival recession?
Definition:
• Refers to occlusal excessive forces applied to a tooth or teeth with normal supporting structures
What it leads to:
• It results in adaptive mobility, not progressive
Does it cause pocket formation or alter connective tissue attachment?
• These changes do not alter connective tissue attachment or cause pocket formation
Does it cause non- carious cervical lesions or gingival recession?
• No evidence that traumatic occlusal forces lead to periodontal attachment loss, non‐carious cervical lesions, or gingival recessions
State causes/ examples of primary trauma (4)
- High restorations causing unhealthy, excessive occlusal forces on the healthy periodontium
- Prosthetic replacements creating excessive force on abutment teeth
- Drifting movement or extrusion of teeth into spaces created by missing teeth
- Orthodontic movement of teeth into functionally unacceptable positions
Describe acute trauma from occlusion in terms of:
• Definition
• Caused by
• Consequences
Definition:
• Is an abrupt change in occlusal force
• If force is dissipated, injury heals and symptoms subside
Caused by:
• Biting on a hard object
• Restorations or prosthetic appliances that interfere with or change direction of occlusal forces on teeth
Consequences:
• tooth pain
• sensitivity to percussion
• increased tooth mobility
Describe chronic trauma from occlusion in terms of:
• Definition
• Caused by
Definition:
• Develops from gradual changes in occlusion
• More common that acute trauma and has greater clinical significance
Caused by: • Tooth wear • Drifting movement • Extrusion of teeth • Combined with parafunctional habits such as bruxism and clenching
Define secondary occlusal trauma
- When normal or excessive occlusal forces are placed on teeth with already compromised periodontal attachment
- Inflammation causes bone loss, which impairs the adaptive capacity of tissues to withstand occlusal forces
- Existing periodontal destruction is present (harm is done to an already damaged system)
Describe the histological effects of secondary occlusal trauma
- Inflammation ⇨ Bone loss ⇨ ↓reduces periodontal attachment = ↑burden on the remaining tissues
- Apical migration of the JE = ↑pocket depths
Discuss the clinical signs that may indicate trauma from occlusion (12)
Clinically:
• Increased tooth mobility due to destruction of periodontal fibers and radiographically widened PDL space
• Adaptive tooth mobility/ Fremitus (premature occlusal content)
• Sensitivity of teeth to pressure and/or percussion
• Thermal sensitivity
• Discomfort/ pain when chewing
• Pathologic tooth migration (eg. extrusion)
• Wear facets or atypical incisal or occlusal wear
• Fractured teeth
• Open contacts - food impaction implications
• Neuromuscular disturbances (spasms)
• TMJ symptoms
Discuss the radiographic signs that may indicate trauma from occlusion by discussing:
Effect on the PDL space (2)
Type of interdental crestal bone loss
Effect on alveolar bone
Effect on tooth roots/ pulp (3)
Effect on the PDL space:
• Widened PDL stones
• Thickening of lamina dura
Type of interdental crestal bone loss:
• Vertical, rather than horizontal, destruction of interdental crests
Effect on alveolar bone:
• Radiolucency and condensation of alveolar bone
Effect on tooth root/ pulp:
• Root resorption
• Hypercementosis
• Pulp stones
Discuss the criterion used to determine traumatic occlusion
Consider:
Are all malocclusions injurious?
Is an aesthetically pleasing periodontium functionally acceptable?
Are all increased occlusal forces traumatic?
What are the differing consequences of traumatic occlusal forces on teeth with normal support and teeth with reduced support?
Are all malocclusions injurious?
• Malocclusion is NOT necessary to produce trauma . NOT all malocclusions are necessarily injurious to periodontium
Is an aesthetically pleasing periodontium functionally acceptable?
• Dentition may be anatomically and aesthetically acceptable but functionally injurious
Are all increased occlusal forces traumatic?
• Not if the periodontium can accommodate
• Remember: Adaptive capacity varies from person to person and in the same person at different times
What are the differing consequences of traumatic occlusal forces on teeth with normal support and teeth with reduced support?
• Teeth with normal support: Traumatic occlusal forces lead to adaptive mobility
• Teeth with reduced support: progressive mobility in teeth with reduced support, usually required splints
List the factors that influence the effect of occlusal forces
Magnitude (pressure) of forces
Direction of forces
Duration and frequency of pressure
Explain the effect of “magnitude (pressure) of forces” on the periodontium (specifically PDL and bone)
- PDL thickens
- Increase in number of PDL fibres
- Increased width of PDL fibers
- Increased density of surrounding alveolar bone
Explain the effect of the “direction of forces” on the periodontium
- Forces that occur along the long axis of the tooth are well tolerated by principal fibers
- Lateral and torque forces are more likely to injure periodontium
- Changing direction of occlusal forces causes reorientation of stresses and strains on periodontium
