[Edit]Etiology and treatment
Teeth are constantly subject to both horizontal and vertical occlusal forces. With the center of rotation of the tooth acting as a fulcrum, the surface of bone adjacent to the pressured side of the tooth will undergo resorption and disappear, while the surface of bone adjacent to the tensioned side of the tooth will undergo apposition and increase in volume.[11]
In both primary and secondary occlusal trauma, tooth mobility might develop over time, with it occurring earlier and being more prevalent in secondary occlusal trauma. To treat mobility due to occlusal trauma, whether it be primary or secondary, the affected teeth are splinted together and to the adjacent teeth so as to eliminate their mobility.
In primary occlusal trauma, the etiology, or cause, of the mobility was the excessive force being applied to a tooth with a normal attachment apparatus, otherwise known as a periodontally-uninvolved tooth. The approach should be to eliminate the etiology of the pain and mobility by determining the causes and removing them; the mobile tooth or teeth will soon cease exhibiting mobility. This could involve removing a high spot on a recently restored tooth, or even a high spot on a non-recently restored tooth that perhaps moved into hyperocclusion. It could also involved altering ones parafunctional habits, such as refraining from chewing on pens or biting one's fingernails. For a bruxer, treatment of the patient's primary occlusal trauma could involve selective grinding of certain interarch tooth contacts or perhaps employing a nightguard to protect the teeth from the greater than normal occlusal forces of the patient's parafunctional habit. For someone who is missing enough teeth in non-strategic positions so that the remaining teeth are forced to endure a greater per square inch occlusal force, treatment might include restoration with either a removable prosthesis or implant-supported crown or bridge.
In secondary occlusal trauma, simply removing the "high spots" or selective grinding of the teeth will not eliminate the problem, because the teeth are already periodontally involved. After splinting the teeth to eliminate the mobility, the etiology of the mobility (in other words, the loss of clinical attachment and bone) must be managed; this is achieved through surgical periodontal procedures such as soft tissue and bone grafts, as well as restoration of edentulous areas. As with primary occlusal trauma, treatment may include either a removable prosthesis or implant-supported crown or bridge.
[edit] [edit]Histologic features associated with occlusal trauma
Microscopically, there will be a number of features that accompany occlusal trauma[6]:
Hemorrhage
Necrosis
Widening of the periodontal ligament, or PDL (also serves as a very common radiographic feature)
Bone resorption
Cementum loss and tears
It was concluded that widening of the periodontal ligament was a "functional adaptation to changes in functional requirements".[7]
[edit]Clinical signs and symptoms associated with occlusal trauma
Clinically, there are a number of physiologic results that serve as evidence of occlusal trauma[8]:
Tooth mobility
Fremitus
Tooth migration
Pain
Wear facets
[edit]Primary vs. secondary occlusal trauma
There are two types of occlusal trauma, primary and secondary.
[edit]Primary occlusal trauma
Primary occlusal trauma occurs when greater than normal occlusal forces are placed on teeth, as in the case of parafunctional habits, such as bruxism or various chewing or biting habits, including but not limited to those involving fingernails and pencils or pens.
The associated excessive forces can be grouped into three categories. Excesses of[9]:
Duration
Frequency and
Magnitude
Primary occlusal trauma will occur when there is a normal periodontal attachment apparatus and, thus, no periodontal disease.[10]
[edit]Secondary occlusal trauma
An example of secondary occlusal trauma. This X-ray film displays two lone-standing mandibular teeth, #21 and #22, or the lower left first premolar and canine. As the remnants of a once full complement of 16 lower teeth, these two teeth have been alone in opposing the forces associated with mastication for some time, as can be evidenced by the widened PDL surrounding the premolar Because this trauma is occurring on teeth that have 30-50% bone loss, this would be classified assecondary oclcusal trauma.
Secondary occlusal trauma occurs when normal occlusal forces are placed on teeth with compromised periodontal attachment, thus contributing harm to an already damaged system. As stated, secondary occlusal trauma occurs when there is a compromised periodontal attachment and, thus, a pre-existing periodontal condition.[10]
[edit]Etiology and treatment
Teeth are constantly subject to both horizontal and vertical occlusal forces. With the center of rotation of the tooth acting as a fulcrum, the surface of bone adjacent to the pressured side of the tooth will undergo resorption and disappear, while the surface of bone adjacent to the tensioned side of the tooth will undergo apposition and increase in volume.[11]
In both primary and secondary occlusal trauma, tooth mobility might develop over time, with it occurring earlier and being more prevalent in secondary occlusal trauma. To treat mobility due to occlusal trauma, whether it be primary or secondary, the affected teeth are splinted together and to the adjacent teeth so as to eliminate their mobility.
In primary occlusal trauma, the etiology, or cause, of the mobility was the excessive force being applied to a tooth with a normal attachment apparatus, otherwise known as a periodontally-uninvolved tooth. The approach should be to eliminate the etiology of the pain and mobility by determining the causes and removing them; the mobile tooth or teeth will soon cease exhibiting mobility. This could involve removing a high spot on a recently restored tooth, or even a high spot on a non-recently restored tooth that perhaps moved into hyperocclusion. It could also involved altering ones parafunctional habits, such as refraining from chewing on pens or biting one's fingernails. For a bruxer, treatment of the patient's primary occlusal trauma could involve selective grinding of certain interarch tooth contacts or perhaps employing a nightguard to protect the teeth from the greater than normal occlusal forces of the patient's parafunctional habit. For someone who is missing enough teeth in non-strategic positions so that the remaining teeth are forced to endure a greater per square inch occlusal force, treatment might include restoration with either a removable prosthesis or implant-supported crown or bridge.
In secondary occlusal trauma, simply removing the "high spots" or selective grinding of the teeth will not eliminate the problem, because the teeth are already periodontally involved. After splinting the teeth to eliminate the mobility, the etiology of the mobility (in other words, the loss of clinical attachment and bone) must be managed; this is achieved through surgical periodontal procedures such as soft tissue and bone grafts, as well as restoration of edentulous areas. As with primary occlusal trauma, treatment may include either a removable prosthesis or implant-supported crown or bridge.
[edit]
Malocclusion
From Wikipedia, the free encyclopedia
"Deep bite" redirects here. For the village, see Deep Bight, Newfoundland and Labrador.
Malocclusion |
|
Classification and external resources |
|
ICD-10 |
K07.4 |
ICD-9 |
524.4 |
MeSH |
D008310 |
A malocclusion is a misalignment of teeth or incorrect relation between the teeth of the two dental arches. The term was coined byEdward Angle, the "father of modern orthodontics",[1] as a derivative of occlusion, which refers to the manner in which opposing teeth meet.
Contents [hide]
|
[edit]Presentation
Most people have some degree of malocclusion, although it is not usually serious enough to require treatment. Those who have more severe malocclusions may require orthodonticand sometimes surgical treatment (orthognathic surgery) to correct the problem. Correction of malocclusion may reduce risk of tooth decay and help relieve excessive pressure on the temporomandibular joint. Orthodontic treatment is also used to align for aesthetic reasons.
Malocclusions may be coupled with skeletal disharmony of the face, where the relations between the upper and lower jaws are not appropriate. Such skeletal disharmonies often distort sufferer's face shape, severely affect aesthetics of the face and may be coupled with mastication or speech problems. In these cases the dental problem is, most of the time, derived from the skeletal disharmony.[citation needed] Most skeletal malocclusions can only be treated by orthognathic surgery.
[edit]Classification
Malocclusions can be divided mainly into three types, depending on the sagittal relations of teeth and jaws, by Angle's classification method. However, there are also other conditions e.g. crowding of teeth, not directly fitting into this classification.
Many authors have tried to classify or modify Angle's classification. This has resulted in many subtypes.
[edit]Angle's classification method
Class I with severe crowding andlabially erupted canines
Class II molar relationship
Edward Angle, who is considered the father of modern orthodontics, was the first to classify malocclusion. He based his classifications on the relative position of the maxillary first molar.[2] According to Angle, the mesiobuccal cusp of the upper first molar should align with thebuccal groove of the mandibular first molar. The teeth should all fit on a line of occlusion which is a smooth curve through the central fossae and cingulum of the upper canines, and through the buccal cusp and incisal edges of the mandible. Any variations from this resulted in malocclusion types. It is also possible to have different classes of malocclusion on left and right sides.
Class I: Neutrocclusion Here the molar relationship of the occlusion is normal or as described for the maxillary first molar, but the other teeth have problems like spacing, crowding, over or under eruption, etc.
Class II: Distocclusion (retrognathism, overjet) In this situation, the upper molars are placed not in the mesiobuccal groove but anteriorly to it. Usually the mesiobuccal cusp rests in between the first mandibular molars and second premolars. There are two subtypes:
Class II Division 1: The molar relationships are like that of Class II and the anterior teeth are protruded.
Class II Division 2: The molar relationships are class II but the central are retroclined and the lateral teeth are seen overlapping the centrals.
Class III: Mesiocclusion (prognathism, negative overjet) In this case the upper molars are placed not in the mesiobuccal groove but posteriorly to it. The mesiobuccal cusp of the maxillary first molar lies posteriorly to the mesiobuccal groove of the mandibular first molar. Usually seen as when the lower front teeth are more prominent than the upper front teeth. In this case the patient very often has a large mandible or a short maxillary bone.
[edit]Crowding of teeth
Crowding of teeth is where there is insufficient room for the normal complement of adult teeth.
[edit]Cause
Extra teeth, lost teeth, impacted teeth, or abnormally shaped teeth have been cited as causes of malocclusion. Ill-fitting dental fillings, crowns, appliances, retainers, or braces as well as misalignment of jaw fractures after a severe injury are other causes. Tumors of the mouth and jaw childhood habits such as thumb sucking, tongue thrusting, pacifier use beyond age 3, and prolonged use of a bottle have also been identified as causes.[3]
A 2011 paper suggested that "the changes in human skulls are more likely driven by the decreasing bite forces required to chew the processed foods eaten once humans switch to growing different types of cereals, milking and herding animals about 10,000 years ago."[4]
[edit]Treatment
Crowding of the teeth is treated with orthodontics, often with tooth extraction, dental braces, followed by growth modification in children or jaw surgery (orthognathic surgery) in adults. Surgery may be required on rare occasions. This may include surgical reshaping to lengthen or shorten the jaw (orthognathic surgery). Wires, plates, or screws may be used to secure the jaw bone, in a manner similar to the surgical stabilization of jaw fractures. Very few people have proper teeth alignment. However, most problems are very minor and do not require treatment.[3]
[edit]Other conditions
Open bite treatment after eight months of braces
Other kinds of malocclusions are due to vertical discrepancies. Long faces may lead to open bite, while short faces can be coupled to adeep bite. However, there are many other more common causes for open bites (such as tongue thrusting and thumb sucking), and likewise for deep bites.
Malocclusions can also be secondary to transverse skeletal discrepancy or to a skeletal asymmetry.
[edit]Etiology
Oral habits and pressure on teeth or the maxilla and mandible are etiological factors in malocclusion.[5][6]
In the active skeletal growth[7] mouthbreathing, finger sucking, thumb sucking, pacifier sucking, onychophagia (nail biting), dermatophagia, pen biting, pencil biting, abnormalposture, deglutition disorders and other habits greatly influence the development of the face and dental arches.[8][9][10][11][12]
Pacifier sucking habits are also correlated with otitis media.[13][14]
Dental caries, periapical inflammation and tooth loss in the deciduous teeth alter the correct permanent teeth eruptions.