*Rand Herzallah

*Omar karadsheh

*22

Periodontics

Lecture No.

Date:

Doctor:

Done by:

Sheet Slides

Hand Out

University of JordanFaculty of Dentistry

Fourth year –2nd semester 2014-2015

Your name: Rand Herzallah Perio Sheet No 22 Date

Trauma from Occlusion

Occlusal adjustment is a part of the nonsurgical therapy.

This radiograph shows horizontal and vertical bone loss with a widening in the periodontal ligament space which is widened more coronally and combined with thickening of the lamina dura. These are the characteristic signs of what we call an occlusal trauma.

As we know that the function of the periodontal ligament includes:

1. Attachment of teeth to bone.

2. Transmission of occlusal forces to bone.

So the adaptive capacity of the periodontium to occlusal forces depends on: the magnitude, direction, duration and frequency of the force.

Magnitude: (how heavy is the force)

It's the most important part. When the magnitude of occlusal forces is increased; the periodontium respond normally as following:

I. The periodontium responds with a widening of the periodontal ligament space.

II. An increase in the number and width of periodontal ligament fibers.

III. An increase in the density of alveolar bone.

Direction:

Changing the direction of occlusal forces causes a re-orientation of the stresses and strains within the periodontium. If the force is coming from one direction there will be a compression side and a tension side, but if the forces are coming from more than one direction = jiggling forces that come from everywhere, the compression and tension sides will be everywhere. So how does the periodontal ligament adapt to these multi directional forces? That's what we're going to talk about up next.

Your name: Rand Herzallah Perio Sheet No 22 Date

The principal fibers of the periodontal ligament are arranged so that they best accommodate occlusal forces along the long axis of the tooth, these forces are the safest. But Lateral (horizontal) and torque (rotational) forces are more likely to injure the periodontium.

This is a tipping movement with pressure and tension on both sides.

While this is a bodily movement with pressure (bone resorption) on one side and tension (bone deposition) on the other.

Stress patterns around the roots changed by shifting the direction of occlusal forces (experimental model using photoelastic analysis). A, Buccal view of an ivorine molar subjected to an axial force with the long axis of the tooth. The shaded fringes indicate that the internal stresses are at the root apices.

B, Buccal view of an ivorine molar subjected to a mesial tilting force. The shaded fringes indicate that the internal stresses are along the mesial surface and at the apex of the mesial root.

Duration:

Constant pressure on the bone is more injurious than intermittent forces, but intermittent forces can also cause damage if happened more frequently.

Frequency:

The more frequent, the more injurious the force is to the periodontium.

Your name: Rand Herzallah Perio Sheet No 22 Date

Trauma from Occlusion; if the occlusal forces exceeded a certain threshold will cause an injury to the soft tissue. Here the trauma is referred to the periodontal tissue not to the teeth.

The Furcation àis the most susceptible area to excessive forces.

Excessive occlusal forces may also:

• disrupt function of masticatory musculature cause painful spasms,

• injure the temporomandibular joints,

• or produce excessive tooth wear.

Note that not every malocclusion can cause a trauma and not every well aligned teeth are functionally safe.

Types of occlusal Trauma:

Acute or chronic (depending on the onset)

Primary or secondary (depending on the cause)

Acute Occlusal trauma

Aetiology:

o Results from an abrupt occlusal impact such as that produced by biting on a hard object (e.g., olive pit).

o Restorations or prosthetic appliances that interfere with or alter the direction of occlusal forces on the teeth may also induce acute trauma.

Clinical signs:

o tooth pain,

o sensitivity to percussion,

o and increased tooth mobility.

Your name: Rand Herzallah Perio Sheet No 22 Date

Resolution:

1. Healing; If the force is dissipated by a shift in the position of the tooth or by the wearing away or correction of the restoration, then the injury heals, and the symptoms subside.

2. Sometimes Necrosis/ perio abscess occur instead which is very painful.

3. And sometimes it transforms into a chronic stage which is not really painful but widening of PDL at the expense of bone (vertical bone loss) appears on the radiograph.

Acute occlusal trauma can also produce cementum tears.

Chronic Occlusal Trauma

Is more common than the acute form and is of greater clinical significance. It most often develops from gradual changes in occlusion produced by tooth wear, drifting movement, and extrusion of teeth, combined with parafunctional habits such as bruxism and clenching.

• On Radiographs: The ligament is widened at the expense of the bone, which results in angular bone defects without periodontal pockets, and the tooth becomes loose.

• The most common sign that we see clinically: is tooth mobility.

Primary and Secondary Trauma from Occlusion

Your name: Rand Herzallah Perio Sheet No 22 Date

The first picture on the left shows heavy occlusal force (the large arrow) that is directed on a tooth with a healthy periodontium; it is called primary trauma from occlusion. But if a small force is applied on a tooth with a reduced capacity of its periodontium to withstand occlusal forces; this is known as secondary trauma from occlusion.

C : there is no gingival recession but the bone height is reduced and the periodontal ligament support is reduced too; so this is a secondary trauma from occlusion.

In conclusion:

• Trauma from occlusion may be caused by alterations in occlusal forces, a reduced capacity of the periodontium to withstand occlusal forces, or both.

• When trauma from occlusion is the result of alterations in occlusal forces, it is called primary trauma from occlusion.

When it results from the reduced ability of the tissues to resist the occlusal forces, it is known as secondary trauma from occlusion

Primary Occlusal Trauma

• Occurs when alterations in occlusal forces causes periodontal injury around teeth with a previously healthy periodontium (no previous bone loss or AL)

Examples:

o Insertion of a “high filling”

o Insertion of a prosthetic replacement that creates excessive forces on abutment and antagonistic teeth

o The drifting movement or extrusion of the teeth into spaces created by unreplaced missing teeth

o The orthodontic movement of teeth into functionally unacceptable positions

Bone loss/resorption that is caused by primary occlusal trauma is reversible; because Changes produced by primary trauma do not alter the level of connective tissue

Your name: Rand Herzallah Perio Sheet No 22 Date

attachment and do not initiate pocket formation. This is probably because the supracrestal gingival fibers are not affected and therefore prevent the apical migration of the junctional epithelium (the supracrestal gingival fibers and the junctional epithelium are intact with no inflammation or periodontitis).

But if there was periodontitis the bone loss will be irreversible.

Two mandibular premolars with normal periodontal tissues (a) are exposed to jiggling forces (b) as illustrated by the two arrows. The combined tension and pressure zones (encircled areas) are characterized by signs of acute inflammation including collagen resorption, bone resorption, and cementum resorption. => This is a primary occlusal trauma.

As a result of bone resorption the periodontal ligament space gradually increases in size on both sides of the teeth as well as in the periapical region.

(c)When the effect of the force applied has been compensated for by the increased width of the periodontal ligament space, the ligament tissue shows no sign of inflammation. The supra-alveolar connective tissue is not affected by the jiggling forces and there is no apical downgrowth of the dentogingival epithelium. (d) After occlusal adjustment the width of the periodontal ligament becomes normalized and the teeth are stabilized.

So it is reversible as long as it's not caused by a periodontal disease or by bacteria.

Secondary Occlusal Trauma

Occurs when occlusal forces cause damage in teeth with reduced periodontium (attachment loss present).

Caused by reduced adaptive capacity due to:

1) bone and attachment loss

2) systemic diseases can also affect adaptive capacity of supporting tissues.

Your name: Rand Herzallah Perio Sheet No 22 Date

(a) Two mandibular premolars are surrounded by a healthy periodontium (no inflammation and the supracrestal gingival fibers are normal) with reduced height.

(b) If such premolars are subjected to traumatizing forces of the jiggling type a series of alterations occurs in the periodontal ligament tissue and the supporting tissue.

(c) These alterations result in a widened periodontal ligament space and in an increased tooth mobility but do not lead to further loss of connective tissue attachment. (d) After occlusal adjustment (removing the jiggling forces) the width of the periodontal ligament is normalized and the teeth are stabilized. So here the bone resorption that

is caused by the occlusal trauma is reversible.

In this picture there is an inflammation, a pocket and the supragingival fibers are not intact. Also there is vertical and horizontal bone loss.

(a) Illustration of a tooth where subgingival plaque has mediated the development of an infiltrated soft tissue (shadowed area) and an infrabony pocket. (b) When trauma from occlusion of the jiggling type is inflicted (arrows) on the crown of this tooth, the associated pathologic alterations occur within a zone of the periodontium which is also occupied by the inflammatory cell infiltrate (shadowed area). In this situation the increasing tooth mobility may also be associated with an enhanced loss of connective tissue attachment and further downgrowth of dentogingival epithelium; compare arrows in

(c) and(d). Occlusal adjustment will result in a narrowing of the periodontal ligament, less tooth mobility, but no improvement of the attachment level (d)

In conclusion: if there is already a periodontal disease and the supragingival fibers are not intact, the occlusal trauma can propagate/exaggerate the attachment loss. But do the occlusal forces actually initiate the attachment loss? No, only exaggerating it.

green

Red

Your name: Rand Herzallah Perio Sheet No 22 Date

Clinical signs of Occlusal Trauma:

1) Mobility (most common sign); although this tooth mobility is greater than the so-called normal mobility, it cannot be considered pathologic, because it is an adaptation and not a disease process. If it

does become progressively worse, it can then be considered pathologic.

So mobility is an important sign but you can't use it as the only clinical sign of the occlusal trauma, because lots of things could cause mobility not only the occlusal trauma.

2) Pain on chewing or percussion

3) Fremitus: is the movement of a tooth or teeth during function or closure. Tested by putting our finger on the upper or lower teeth and ask the patient to close his mouth or to do a chewing movement if you noticed that teeth slightly move then it is fremitus cause normally teeth don't move during function or closure.

4) Occlusal prematurities/discrepancies

5) Wear facets & abfractions in the presence of other clinical indicators

6) Tooth migration

7) Chipped or fractured tooth (teeth)

8) Thermal sensitivity

Radiographic signs of OT:

• Increased width of PDL space (funnel-shaped coronally).

• Thickening of lamina dura.

• Vertical or angular bone loss.

• Radiolucency in furcation areas.

This is an example on the radiolucency that happens in the furcation area.

Red arrow => widening of the PDL space

White arrow => thickening of the lamina dura

Green arrow => vertical bone loss

Your name: Rand Herzallah Perio Sheet No 22 Date

Effects of Insufficient Occlusal Force:

When there's a tooth with no opposing, this also not a good thing.

• Insufficient occlusal force may also be injurious to the supporting periodontal tissues.

• Insufficient stimulation causes thinning of the periodontal ligament, atrophy of the fibers, osteoporosis of the alveolar bone, and a reduction in bone height.

• Hypofunction can result from an open-bite relationship, an absence of functional antagonists, or unilateral chewing habits that neglect one side of the mouth.

Reversibility of Traumatic Lesions:

Trauma from occlusion is reversible. When the impact of the artificially created force is relieved, the tissues undergo repair. The presence of inflammation in the periodontium as a result of plaque accumulation may impair the reversibility of traumatic lesions.

Effects of Excessive Occlusal Forces on Dental Pulp:

The effects of excessive occlusal forces on the dental pulp have not been established. Some clinicians report the disappearance of pulpal symptoms after the correction of excessive occlusal forces. Pulpal reactions have been noted in animals subjected to increased occlusal forces, but these did not occur when the forces were minimal and occurred over short periods.

Influence of Trauma from Occlusion on the Progression of Marginal Periodontitis:

• Plaque à affects gingiva and progress into periodontal pockets.

• Occlusal trauma à only PDL & Bone because gingival blood supply is not affected by excessive forces.

• “Trauma from occlusion does not cause pockets or gingivitis” and that it also does not increase gingival fluid flow.

When would you do an occlusal correction?

If a patient came to you with periodontitis, bone loss, inflammation and a tooth with occlusal trauma. What do you do?

Your name: Rand Herzallah Perio Sheet No 22 Date

1) A periodontal treatment to get rid of the inflammation, because regeneration doesn't occur with the presence of inflammation.

2) Then do an occlusal adjustment to relive the occlusal trauma, by:

Using the bur removing any high areas

Or reducing any parafuntional habits

Or extraction of a misplaced tooth

Or a full mouth rehabilitation

Pathologic Tooth Migration:

Pathologic migration refers to tooth displacement that results when the balance among the factors that maintain physiologic tooth position is disturbed by periodontal disease.

Caused by:

a) The forces that affect the tooth; the equilibrium of forces of the tongue, cheeks, lips, occlusal forces, denture or parafunctional habits is not favorable.

b) Reduce tissue support (ex: bone support).

c) Loss of the occlusal support; when the lower posterior teeth are lost, extrusion of the maxillary molars will occur and the Maxillary incisors are pushed labially. The lower premolars will drift distally and retroclination of the lower anterior teeth will occur.

Mobility:

Aetiology:

1. Advanced bone loss (periodontal disease),

2. Inflammation of the periodontal ligament of periodontal or periapical origin,

3. Some systemic causes (e.g., pregnancy),

4. The destruction of surrounding alveolar bone, such as occurs with osteomyelitis or jaw tumours,

5. Overloading of teeth and occlusal trauma,

6. Increased Immediately following periodontal surgery.

Your name: Rand Herzallah Perio Sheet No 22 Date

7. Root resorption

8. Root fractures

Management:

From a therapeutic point of view it is important to assess not only the degree of increased tooth mobility but also the cause of the observed hypermobility.

Management aims to reducing mobility, achieve health, function and comfort. This can be done by a combination of the followings:

• removal of causative factors (scaling and root planing, RCT, Occlusal adjustments).

• Extraction (Grade III mobility with severe bone loss)

• Splinting (Grade I-II on multiple adjacent teeth only when causing discomfort or dysfunction to the patient). Types of splints:

1) Etch-retained composite splints with or without:

• Glass fiber

• SS wire

• Metal mesh

2)Extracoronal restorations (bridges)

3)Maryland type adhesive cast bridges

4)Removable PD (rare)

Good Luck