Developmental Problems Affecting the Palate

Question 1

How is the primary palate formed?

Answer 1

The primary palate is formed by fusion of the incisive bone at the rostral aspect
of the hard palate. During normal development, the incisive bone fuses caudally
with the palatal processes of the maxilla, at the palatine fissures (at the maxillary suture lines). Failure of this fusion causes either unilateral or bilateral primary clefts, often associated with cleft lips.

Question 2

When is surgical repair of a cleft palate usually attempted?

Answer 2

Surgical repair of cleft palates and cleft lips are challenging procedures and is
usually postponed until the puppies are 3 to 4 months old. In general, the cleft
becomes wider over time so postponing it for too long could make the surgical
repair even more challenging. There are some indications that animals that have
cleft palates prepared early, might have impaired growth of the palate and often
appear to have narrower upper jaws.

Question 3

The secondary palate is formed by?

Answer 3

The secondary palate is formed by fusion of the palatine processes of the maxilla and palatal bones with the vomer at the midline. The nasal septum from the
nasal aspect also fuses to this fusion line.

Question 4

How is the secondary palate formed?

Answer 4

The secondary palate is formed by the fusion of the palatal processes of the
maxillary bones, in the central midline of the palate. These horizontal processes
fuses dorsally with the vomer and the nasal septum in the midline, at the nasal
aspect. Clefts in the hard palate could extend caudally and can result in clefts
in the soft palate.

Question 5

What is the aetiology of clefts?

Answer 5

Specific causes of abnormal or lack of fusion of the palatine fissures have not
been specifically identified but is thought to be affected by genetic and environmental factors, teratogens and mechanical factors.

Question 6

What are strategic extractions and how can they help repair cleft palates?

Answer 6

Surgery to close these defects might require the extraction of teeth to provide
tissue for this procedure and the main aim is to eliminate communication between the oral and nasal cavities which is a consequence of the cleft.

Question 7

What is the Von Langenbeck Technique?

Answer 7

In this technique two full thickness flaps are created by making an incision along
the edge of the cleft and a second along the palatal aspect of the maxillary dental arch. Preservation of the major palatine artery during elevation of these mucoperiosteal flaps is crucial. Both of these flaps are moved towards the midline
and sutured to cover the midline defect.

Question 8

What is Two-Flap Palatoplasty?

Answer 8

The technique is similar to von Langenbeck except that the two flaps are severed at
the rostral aspect (creating two unique pedicle flaps) by extending the incision
along the premolars to the maxillary incisor arcades.

Question 9

What is the V-Y Push Back Procedure?

Answer 9

In this modification of the tooth flap technique the flaps are closed in a V to Y
configuration.

Question 10

What is the overlapping flap procedure?

Answer 10

In this procedure a single flap is created with an incision through the soft tissue
of the palate, onto the palatal bone, along one side of the maxillary premolars.
This flap is rotated (the palatal mucosa facing the nasal cavity) and sutured to
the debrided edge of the cleft on the contralateral side. Preservation of the palatal artery remains crucially important. Many surgeons consider this the best
technique because of the fact that the suture line is away from the midline and
is supported by palatal bone.

Question 11

Where can grafts for palate repairs be taken from?

Answer 11

Grafts can be created using cartilage harvested from the pinna.

Question 12

How are obturators used in cleft palate repair?

Answer 12

Obturators can be manufactured from silicone impression material and can be
used either as temporary or permanent closure of persistent palatal defects.

Question 13

What is soft palate hypoplasia?

Answer 13

This rare condition creates problems with closure of the nasopharynx during
swallowing and allows food to cause chronic rhinitis. Repair of this defect is
possible with the use of mucosa and other tissue from the lateral pharyngeal
wall.

Question 14

Discuss overlong soft palates?

Answer 14

his abnormality forms one of the many encountered in Brachycephalic Obstructive Airway Syndrome. (BOAS). In these patients the soft palate extends far
more caudally than its normal position and partly occludes the rima glottis. In
dogs with normal palatal anatomy, the caudal margin of the soft palate extends
to just rostral to the base of the epiglottis.
Shortening of the soft palate (staphylectomy) is used to address this one aspect
of the BOAS syndrome. After resecting the excess tissue from the caudal aspect
of the over long soft palate, the nasal and oral mucosal layers are sutured together. Atraumatic technique is crucial to reduce post-operative swelling.
Over shortening will create complications similar to that of soft palate hypoplasia with food entering the nasal cavity and causing chronic rhinitis.

Question 15

What is Tight lip Syndrome?

Answer 15

This is a condition that affects Shar-pei and some members of the Mastiff family. The lower lip is positioned very close to the mandibular incisors and occasionally rolls over the incisive edge of these teeth. This situation is associated
with the lack of a rostral labial vestibule in this area.
This confirmation causes a lingual displacement and crowding of the mandibular
incisor teeth. One technique to treat this condition in very young patients is the
incision of the mucocutaneous attachment of the lip to the gingiva, at the mucogingival junction. Owners are instructed to manipulate this area to prevent the
mucosal from reattaching to the same site.
The preferred approach is to create an incision along the inside of the lower lip
and then to suture the ventral margin of the margin of mucogingival flap to the
periosteum, to create a deeper vestibule.

Question 16

What is Feline Juvenile Hyperplastic Gingivitis?

Answer 16

This inflammatory process affects cats (it is rare in dogs) at, or soon after eruption of the permanent dentition. The exact cause is unclear, but a genetic predisposition is suspected based the fact that some breeds for example Maine
Coon, Persian, Abyssinian and Siamese cats are overrepresented.
It is important during investigation and treatment of this condition, to confirm
that gingivitis is not a sign of early onset periodontitis. Periodontal probing and
radiography is therefore critical.
Gingivectomy and gingivoplasty to remove the proliferative gingival margin, can
be successful if no other signs of periodontitis have been detected. Extreme
care should be taken to prevent complete removal of the very narrow band of
gingiva at the affected sites, as exposure of alveolar mucosa to the plaque on
the crowns of teeth could cause inflammation and ulceration. Full mouth extraction in these young cats should not be considered until all other possible
treatment options have been carefully explored.
Effective dental home care is even more important in these patients as they
might be prone to developing other forms of mucositis later in life. Close monitoring for any signs of persistent gingivitis or stomatitis, and early intervention in
these cases is advisable.

Question 17

What is feline juvenile periodontitis?

Answer 17

his form of aggressive early onset periodontitis might be associated with hyperplastic gingivitis described above. These patients develop periodontitis with periodontal pockets, furcation exposure and gingival recession (and all other signs
of periodontitis) and the associated teeth are often also affected by inflammatory resorption.
Extraction of all the affected teeth and often extraction of all the premolar and
molar teeth is indicated. Meticulous home care is even more important to prevent recurrence in remaining teeth.

Question 18

Discuss Papillomatosis – Papillomavirus - PV?

Answer 18

These distinctive, cauliflower-like growths occur on the mucocutaneous junction, and the oral mucosa of animals affected by papilloma virus. Severely affected animals could have difficulty eating. In general, the lesions spontaneously
regress after about three months once the immune system has created protective antibodies. Surgical debulking of large growths interfering with mastication
can be considered as an interim measure

Question 19

Discuss Papillary Squamous Cell Carcinoma (PSCC)?

Answer 19

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.

Question 20

Discuss Mandibular Periostitis Ossificans – MPO?

Answer 20

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.

Question 21

Discuss Craniomandibular Osteopathy – CMO?

Answer 21

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

Question 22

What is Calvarial Hyperostosis?

Answer 22

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.

Question 23

What is Hypertropic Osteopathy?

Answer 23

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)

Question 24

Radiographic Signs of Loss of Pulp Vitality are?

Answer 24

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.

Question 25

What are Enamel fractures?

Answer 25

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.

Question 26

What is Enamel infraction?

Answer 26

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.

Question 27

How should Uncomplicated Crown fractures be described?

Answer 27

Enamel-dentine
Fractures

Question 28

What are the best treatments for uncomplicated crown fractures?

Answer 28

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.

Question 29

How should Complicated crown fractures really be described?

Answer 29

Alternative descriptions of crown fractures with pulp exposure would be enamel-dentine-pulp fractures.

Question 30

How can root fractures be treated?

Answer 30

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