Tooth Trauma Flashcards
Discuss Papillary Squamous Cell Carcinoma (PSCC)?
Papillary Squamous Cell Carcinoma, a malignant tumour, is often, but not exclusively, seen in young dogs. This condition might be associated with transformation of oral papillomas. There are no reports of distal metastases but the tumours are locally invasive.
Two forms of the tumour have been identified:
* The exophytic form is characterised by the formation of a mass that
vaguely resembles a benign papilloma.
* The intra-osseous form, the lesion is a cyst-like structure in the bone of
the jaw. The cyst lining consists of neoplastic epithelium that form papilloma like structures.
Complete excision with clear margins is usually curative.
Discuss Mandibular Periostitis Ossificans – MPO?
This rare condition affects young, large breed dogs. It usually presents as a unilateral, non-painful swelling at the ventral margin of the mandible at the erupting permanent mandibular first molar tooth. The aetiology is considered to be
associated with inflammation of the dental follicle or pericoronitis.
Radiographic confirmation relies on the pathognomonic double layering of the
mandibular cortex and biopsies confirm a reactive inflammatory process with
new bone formation with a core of necrotic bone and granulation tissue.
Discuss Craniomandibular Osteopathy – CMO?
This condition is often colloquially referred to as “Lion Jaw” or “Westie Jaw”. It
is characterised by a non-neoplastic, self-limiting condition affecting dogs between 3 to 8 months of age. Osseous proliferation occurs at the ramus and body
of the mandibles, the tympanic bulla, the temporomandibular joint, as well as of
the parietal and occipital bones. Symptoms include pain on the opening of the
mouth, salivating, intermittent pyrexia and the inability to open the mouth fully.
The condition affects West Highland White terriers, Cairn terriers and Scottish
terriers but can also affect other breeds. It is associated with an autosomal
dominant, mono genetic mutation. Genetic testing is available to identify carriers
and one study found that 36% of WHWT carried the mutation.
Histopathology of affected cases shows proliferative bone at both periosteal and
endosteal surfaces. There could also be evidence of bone lysis and remodelling
associated with inflammatory change, and signs of fibrosis.
Even though the condition is self-limiting, pain relief, anti-inflammatory treatment and nutritional support might be required. As a consequence of the deposition of abnormal bone, the function of especially the temporomandibular joint
can be affected
What is Calvarial Hyperostosis?
his condition appears to be similar to cranial mandibular osteopathy but affects the bones associated with the frontal sinus. A new description of Idiopathic Canine Juvenile Cranial Hyperostosis is proposed with the assumption
that this condition and CMO are manifestations of the same condition.
What is Hypertropic Osteopathy?
Patients affected by Marie’s disease show signs of metastatic thoracic hyperplasia and may also show signs of diffuse proliferation periosteal bone. This
condition occasionally affects the mandibles and could resemble CMO (Craniomandibular Osteopathy)
Radiographic Signs of Loss of Pulp Vitality are?
Periapical radiolucency at the discoloured tooth, confirms periapical periodontitis.
The size of the pulp canal, when compared to a normal contralateral tooth,
would be larger in a tooth with a non-vital pulp. This phenomenon occurs because dentine production will cease as soon as the pulp becomes devitalised.
Continued dentine production in an unaffected tooth will therefore cause the
difference in the dimensions of the root canal and pulp chamber in affected
teeth. It should be clear differences in root canal dimensions would occur more
rapidly in immature teeth where dentine production occurs more rapidly.
It is important to keep in mind that if pulp vitality cannot be established during
initial radiographic investigation, that it is possible that it is not because the
pulp is unaffected but only because the radiographic change (in bone cementum
and dentine) associated with injury, is just so slight that changes remain undetectable.
What are Enamel fractures?
Injuries that result in the fracture of enamel only,
are described as enamel fractures. Full thickness
enamel fractures would be painful because of exposure the innervated dentine.
What is Enamel infraction?
These thin superficial concentric fracture lines,
parallel to the gingival margin, probably only extend through enamel. It rarely requires treatment
but indicates that the patient might be using high
force when loading its canine teeth.
How should Uncomplicated Crown fractures be described?
Enamel-dentine
Fractures
What are the best treatments for uncomplicated crown fractures?
One option in the treatment of near exposure of the pulp would be sealing of
the exposed dentine after radiography to confirm the absence of signs of pulp
necrosis. This should only be considered if the owner commits to radiographic
follow-up of teeth affected in this way. Alternatively, it might be better for the
patient to accept that it is possible/likely that the pulp was affected and therefore consider either extraction or root canal treatment.
How should Complicated crown fractures really be described?
Alternative descriptions of crown fractures with pulp exposure would be enamel-dentine-pulp fractures.
How can root fractures be treated?
Root fractures that occur in the apical third of
the root could heal without further intervention.
Coronal root fractures associated with mobility
can be splinted to support healing or are good
candidates for for extraction
Discuss intrinsic staining of teeth?
The other potential causes of discoloured teeth will be discussed later but intrinsic staining as a consequence of pulpal haemorrhage, is an important cause
of discoloured teeth. Other than trauma, haemorrhage within the pulp could be
caused by other causes of pulpitis.
Haemoglobin and its breakdown products from within the injured pulp, diffuse
into the dental tubules and would eventually cause visible discolouration of the
crown. The colour changes observed in affected teeth are the same as those
that occur after bruising elsewhere.
An early publication established that more than 90% of intrinsically stained canine teeth in dogs have a non-vital pulp. The best advice therefore of intrinsically stained teeth would be at least radiography to attempt to establish pulp
vitality. With confirmed pulp necrosis, either extraction or endodontic treatment
should be considered
What is extrusion and how should it/can it be treated?
This describes the partial displacement of
the tooth from its socket in an injury that
is characterised by total or partial separation of the periodontal ligament attachment.
The alveolus is intact and distinguishes
this from lateral luxation. In many extrusion cases, the intrusion component of
this displacement could be more pronounced than the extrusive element.
Treatment comprises of gentle flushing of
the alveolus, ideally with lactated Ringer’s solution, to remove all contamination.
The tooth is replaced in the alveolus and all soft tissue lacerations sutured. This
tooth should be splinted in this position for at least 2 to 3 weeks and radiographic to monitor pulp vitality is crucially important. Without the owner’s commitment to follow-up and potential further intervention if the pulp vitality is
compromised, this replacement of the tooth should not be considered.
The prognosis varies significantly according to the maturity of the tooth.
What is tooth intrusion?
In these injuries the tooth is displaced into
the alveolus and is usually associated with a
fracture of the alveolus. Especially maxillary
teeth could be completely intruded into the
nasal cavity, accompanied by epistaxis.
Teeth not that dramatically affected would
have the normal cemento-enamel junction
displaced apically. Radiography is essential
to evaluate this displacement.
