Diagnostic Imaging End Session Flashcards
Number of canine cervical vertebrae
C1-C7
Number of canine thoracic vertebrae
T1-T13
Canine lumbar vertebrae
L1-L7
Canine sacral vertebrae
S1-S3
Caudal vertebrae number
Varies from 6-20
What is the atlas? What is the structure?
C1 -> no dorsal spinous process, large transverse processes commonly called wings
Articulation with skull forms atlanto-occipital joint allowing “yes” movement of head
What is the axis? What is its structure and function?
C2
Large dorsal spinous processes and partially overlaps C1
Dens projects along ventral vertebral canal onto floor of C1
C2 articulates with C1 to form atlantoaxial joint allowing “no” movement of head
Which cervical body is the shortest?
C3
Which cervical vertebrae has large TP’s that go ventrally?
C6
Which two intervertbral joint spaces are normally shorter?
C2/3
C7/T1
Which is the anticlinal vertebrae?
T11 -> the transitional segment of the thoracolumbar spine
Where do the ribs articulate with vertebrae?
Each pair of ribs articulates with the cranial aspect of the same numbered thoracic vertebra
Which vertebrae are sites for diaphragm attachments?
L3 and L4
The ventral margins are slightly irregular and less distinct
Which lumbar vertebra is the shortest?
L7
Structure of the sacral vertebrae
3 fused vertebrae without intervertbral spaces
What are haemal arches?
Small well defined Y shaped bony structures located ventrally to the first few caudal vertebrae
What is the intervertebral foramen?
Exit point for spinal nerves shaped like a horse head with nose pointing cranially
Where are intervertebral discs located?
Between every vertebral body except for C1-2 and in the sacrum
Where does the dorsal longitudinal ligament go?
Between vertebral bodies along the floor of vertebral canal from dens of C2 to the caudal vertebrae.
Thicker in cervical region and thinner in thoracolumbar
Where does ventral longitudinal ligament run?
Along ventral aspect of vertebrae attaching to each body from C2 to S1
Thickest in caudal thoracic and lumbar regions
Where does the spinal cord start and end?
Foramen magnum to around L6
What are the layers surround the spinal cord from central outwards?
Spinal cord -> Pia mater -> subarachnoid space -> arachnoid membrane -> subdural space -> Dura mater -> epidural space
Which space contains cerebrospinal fluid?
Subarachnoid space
What are the pedicles and lamina?
Pedicles form lateral boundaries of the vertebral canal joined dorsally by the lamina, which is a bony shelf forming the roof of the canal
Which centering points are needed for a view of the whole spine?
C2,C7,T4,T13,L3 and L7
What is needed for thickness above 10cm?
Centre, collimate and grid
Standard views of the cervical spine
Lateral and VD
Supplementary views of the cervical spine
Oblique lateral or VD -> LeVRtDO and RtVLeDO
Extended or flexed laterolateral
How many physis do vertebrae have?
Each has 2 but C2 also has a dens physis
Which 4 diseases have no radiographic signs even with contrast?
- Fibrocartilagenous thromboemboli
- Degenerative myelopathy
- Congenital cord malformations such a syringomyelia and hydromyelia
- Inflammatory diseases of the spinal cord
What is the site for contrast injection?
L5/L6 is preferred (the only one where needle goes through spinal cord, bevel cranial)
or high cervical (atlanto-occipital cisterna magna) - bevel caudal
What should be done before injecting contrast?
CSF sample in plain sterile and EDTA tube
What is the contrast and dose rate used?
Iohexal -> 240mg/ml or 300mg/ml
A non-ionic water soluble contrast
0.25ml/kg -> total volume depends on length of canal to be examined
Cervical myelogram process
- Point bevel caudally
- Afer csf collected inject entire dose into subarachnoid space of cisterna magna
- Remove needle
- Elevate head 2-4 minutes
- Take VD adn lat radiographs + obliques
What can occur after a myelogram?
Seizures - most common sign of neurotoxicity
Higher chance after cervical injection than lumbar
Features of extradural lesions
Compression of spinal cord and subarachnoid space, spinal cord appears narrow on one radiograph and wide on orthogonal
Intervertebral disc protrusion or extrusion
Features of intradural extramedullary lesions
Located in subarachnoid space
lesion causes widened filling defect (golf Tee) + cord appears widened on orthogonal rad
caused by tumour in subarachnoid space
Features of intramedullary lesion
Occurs in spinal cord causing swelling of cord
What is CT good for?
Conditions at lumbosacral junction
Protruded discs without need for contrast
Developmental lesions and malformations
What is CT not so good for?
Does not show oedema, masses or malacia well in the spinal cord
What is MRI good for?
Soft tissue contrast
Disc degeneration before protrusion or extrusion occurs
Peripheral nerves
Spinal congenital abnormalities
Spina Bifida
Hemivertebrae
Block vertebrae
Transitional vertebrae
What is spina bifida and where does it occur?
Incomplete development of dorsal aspect of the vertebra due to developmental failure of lateral arches to fuse dorsally
Most common in thoracic and lumbar regions
Screw tail dog breeds mostly -> pug, bulldog
Spina bifida clinical signs
Often non, but can be ataxia, paresis, faecal and urinary incontinence, perineal analgesia and poor anal tone
Radiographic findings of spina bifida
Unfused spinous processes (radiolucent line), cleft SP, or lack of SP or lamina
What is spina bifida occulta?
No clinical signs
MRI used to differentiate from manifesta
What is spina bifida manifesta?
Sac containing neural tissue protrudes through bone defect
What is block vertebra?
Partial or complete of fusion of adjacent vertebrae from birth
Partial or absent intervertrbal disc space
Rarely causes signs - maybe increased risk of intervertebral disk protrusion at ends of block vertebra
What is hemivertebra?
Abnormal fusion of different parts of vertebrae
Screw tail breeds
May see wedge shape or butterfly anomaly
What is transitional vertebrae?
Vertebra has characteristics of adjacent ones
T13 may look like lumbar -> lumbarisation
L1 can also have thoracarisation
If C7 has ribs then it is thoracarisation
What breed is transitional vertebrae seen commonly?
German Shep
What is atlanto-axial subluxation and who does it occur in?
Miniature and toy breeds and young dogs
Hypoplasia OR Aplasia (lack) of the dens -> cord compression caused by abnormal rotation of C2 into vertebral canal
May see widening and malalignment of C1 and C2 on flexion or dorsal displacement of C2
What is cervical spondylomyelopathy and the two types?
Narrowing of vertebral canal leading to compression of spinal cord
2 types -> osseous and disc associated
What is osseous caudal cervical sponylomyelopathy?
Common in young large breeds
Changes to bones in neck during development lead to compression of spinal cord
What is disc associated caudal cervical sponylomyelopathy?
Seen in older large breed dogs - dobermans
Combination of changes to bones in neck and protrusion of one or more intervertebral discs leading to compression of spinal cord
Radiographic findings of cervical spondylomyelopathy (wobblers syndrome)
Malformed vertebrae
Coning or stenosis of canal
Dorsal tipping of vertebrae
Facet proliferation
What is wobblers syndrome?
Cervical spondylomyelopathy
Young large breeds
Ataxia, weakness, tetra paresis and paralysis
Deformity of ventral bodies, vertebral instability and malarticulation
C4-C7 most common
Wobblers syndrome myelography findings
Lesion dynamic -> compression worsens with hyperextension and improves with ventroflexion or traction
What is cauda equina syndrome called? What is it?
degenerative lumbosacral stenosis - can result from a variety of causes
LS malarticulation and instability
Reported in lots of breeds, particularly GSD (predisposed) and cats
Stenosis = abnormal narrowing
Clinical signs of cauda equina syndrome (degenerative lumbosacral stenosis)
Hindlimb weakness, paresis, incontinence issues
Tail movement affected
Causes of cauda equina syndrome
Hypertrophy of dorsal longitudinal ligament and/or annulus fibrosis
Disc protrusion/extrusion
Subluxation in LS joint (L7-S1)
Congenital stenosis of the vertebral canal
LS malalignment and instability
Spondylosis
Radiographic findings of cauda equina syndrome - what modes are best and which does not work?
CT or MRI best - myelogram wont show as subarachnoid space doesnt go far enough
Spondylosis and endplate sclerosis at the lumbosacral junction
Narrowing and wedging of the LS disk space
Ventral displacement of the sacrum relative to L7
Stenosis of the canal from proliferative changes on the facets or from congenital stenosis
2 types of intervertebral disc disease and what happens.
Hansen type 1 herniation -> chondrodystrophoid breeds. Chondroid metaplasia and disc degeneration. Degeneration and rupture of dorsal annulus, more acute and severe.
Hansen type 2 herniation -> Nonchondrodystrophoid breeds. Fibroid metaplasia and disc degeneration. No complete rupture of annulus - points up dorsally and puts pressure on cord without disc material breaking through. more gradual.
What is intervertebral disk degeneration?
Part of intervertebral disc disease -> Mineralised disk material in the disc space.
What is a parallax fault?
pseudonarrowing of disc spaces
As beam widens this occurs - if discs are same size they will look narrower on the periphery of the image. So we need series of rads
Radiographic findings of intervertebral disc protrusion
Narrowed or wedged IVD space
Decreased size of IV foramen
Increased opacity of IV foramen
Narrowed articular facet space
Endplate sclerosis and spondylosis
What is discospondylitis?
Infection of the intervertebral disk with extension to the regional vertebral bodies -> often not adjacent and may skip some so need lots of images
Haematogenous spread mostly, can be migrating foreign bodies
L7-S1 most common
What clinical signs would discospondylitis have?
fever, anorexia, pain, stiffness, spinal hyperesthesia, secondary cord compression may result in neurologic abnormalities
Depends on severity and location
Radiographic findings of discospondylitis
Endplate lysis, or bony sclerosis and proliferation of adjacent vertebrae endplates
Widening or collapse of disc space
Active with poorly defined margins
Potential for vertebral fusion with healing
Signs may persist for 3-9 weeks following clinical resolution
What can happen secondarily to discospondylitis?
Spondylosis deformans - osteophyte formation on the vertebral bodies
What is a Schmorl’s node?
Herniations of the intervertbral disc through the vertebral end-plate
Well marginated smooth radiolucency in the endplate
What is vertebral body spondylitis? What causes it?
An infection of the ventral vertebral bodies, generally a bacterial infection (e.g. with migrating grass awns) or parasitic migration as of Spirocerca lupi (africa)
Direct expansion from infected adjacent soft tissues, migrating foreign bodies, external wounds, neoplastic invasion from regional soft tissues
Radiographic findings of vertebral body spondylitis
Smooth, irregular or spiculated periosteal reaction (filling ventral concavity of vertebral body)
Possible retroperitoneal swelling or regional mass
DDx metastatic carcinoma
What is spondylosis deformans and what type is the worst?
Degenerative change related to instability - may be secondary to many things
Type 1-4 -> Diffuse idiopathic skeletal hyperostosis is the worst and seen in boxers. Ankylosing spondylosis
Usually older animals, rarely clinically significant (expect in wobbler and cauda equina syndrome)
Radiographic findings of spondylosis deformans
New solid bone proliferation formed between ventral ends of adjacent vertebral bodies
Varies from small incompletely bridging spurs to completely bridging bone over several vertebral bodies
What can spondylosis deformans occur from in cats?
Mucopolysaccharidosis and hypervitaminosis A
What is diffuse idiopathic skeletal hyperostosis
Ossifying condition with bony hyperostosis at tendon and ligamentous attachments along spine.
“flowing” mineralization and ossification (Type 4 spondylosis) along ventral and lateral aspects of 3 or more vertebrae
* IV disc space appears normal
What is spondyloarthropathy?
Most common in cervical and lumbar spinal area - Pain and reduced range of motion
Periarticular bone formation and subchondral bone sclerosis in chronic cases - may impinge on spinal cord/nerves due to narrowing of vertebral canal
What is ossifying pachymeningitis?
Dural ossification - dura mater ossifies and becomes mineralised and buldges dorsally
How are vetebral fractures classified?
Dorsal, middle and ventral compartment
What makes up the middle compartment?
dorsal longitudinal ligament, dorsal aspect of the annulus
fibrosus of the IVD, dorsal part of the vertebral bod
What makes up the dorsal compartment?
Articular processes, laminae, pedicles, spinous processes, and supporting soft-tissue structures
What makes up the ventral compartment?
Rest of the vertebral body, lateral and ventral annulus fibrosus, nucleus pulposus, ventral longitudinal ligament.
When is a vertebral fracture considered unstable?
If 2 out of 3 compartments are damaged
What is a spinal arachnoid diverticulum? Where does it occur?
Localised enlargment of the subarachnoid space - free comms between the CSF and abnormal cavity
Mostly at C1-C5 and T3-L3, puts pressure on spinal cord
Signs of spinal arachnoid diverticulum and who it affects
Ataxia
Hypermetria
UMN faecal and urinary incont.
No appreciable spinal hyperesthesia
Male dogs over-represented, likely congenital
4-14 months of age
Primary bone tumours affecting the spine
Osteosarcoma
Chondrosarcoma
Aggressive lysis and proliferation
Monostotic
Metastatic and multicentric tumours affecting the spine
Urogenital tumours and carcinomas
Multiple myeloma - punched out look
Variable aggressive lysis and proliferation
categories of neural canal to evaluate soft tissue in myelography
Extradural sign
Intradural/extramedullary sign
Intramedullary sign
Extradural sign
Displaces subarachnoid space away from lesion causing attenuation and displacement of contrast columns within the subarachnoid space
Spinal cord displaced
Kinked hose
Intradural/extramedullary sign
Lesions located in subarachnoid space that attenuate contrast medium proximally and produce golf tee sign at each end of lesion
Intramedullary sign
Cord swelling with usually symmetrical displacement of the dura and meninges
Attenuation of contrast in SA space in stretched around the swollen spinal cord
Visible from any angle and not projection dependent
Hoof prep for horses
Shoe on for LM view
Shoe removal essential for most except in cases of laminitis
Clean and trim hoof and sole - prevent air artifacts
For upright views (D65PrPaDO) pack sulci with substance same opacity of the horn
Standard projections of the hoof
LM
DPa
D65Pr-PaDiO (upright pedal, upright navicular)
PaPr-PaDiO
What is the correct position of the navicular?
Superimposed over the distal aspect of P2 but not over the coffin joint
What is the upright navicular view?
DPr-PaDiO
Heel elevated and taken 90 degrees to dorsal hoof aspect through to the heel
What is the skyline navicular view?
PaPr-PaDiO
Can do 55-65 degrees or 35-45 degrees to the horizontal plane
2 oblique views of the hoof
D 45degreeL PaMO
D 45degreeM PaLO
Proximal and middle phalanges (Pastern region) views
LM
DPa
DLPaMO
DMPaLO
each includes distal and proximal interphalangeal joints + distal half of proximal phalanx
Oblique views of the pastern
DPr-PaDiO
D45LPaMO
D45MPaLO
Standard and oblique views of the fetlock (metacarpo/metatarso-phalangeal joint)
LM
DPa
DLPaMO
DMPaLO
Flexed LM
How to take a DP of the fetlock (considering sesamoids)
D10Pr-PaDO
Shoot from above (10 degrees) down towards plate to get proximal sesamoids out of joint space
Anne happy to call this DP as well
Standard views of the carpus of horse
LM
DPa
DLPaMO
DMPaLO
Flexed LM
DPrDDiO (skyline)
Which carpal bone is bigger in horses, radial or ulnar?
Radial = medial
Standard projections of the elbow in horses
ML
CrCd
Standard projections of the shoulder in horses
ML
CrMCdLO
Standard projections of the tarsus in horses
LM
DPl
Obliques = DLPlMO, DMPlLO
Additional views of tarsus in horses
Flexed LM
CdPrPlDiO
DPrPlDiO
Standard projections of Stifle in horses
LM
CdCr (actually Cd15degreePrCrDiO)
Flexed LM
Cd60degreeL-CrMO
Additional stifle projections
CrPrCrDiO (patella skyline)
CLCdMO
When is osteophytes visible?
> 3wks
How long does it take for incomplete or fissure fractures to be visible?
Up to 2 weeks
Reasons for both general and localised bone destruction
General -> Pregnancy, metabolic
Localised -> disuse atrophy
Reasons for focal new bone formation
Osteophytes, periarticular osteophutes, enthesophytes
Reasons for periosteal or endosteal new bone
Inflammation from fractures, trauma, infection, tumour, abnormal stress at soft tissue attachment
Reasons for sclerosis
Stress - subchondral stress in DJD
Attempt to wall off infection - osteomyelitis
Support weak area - osseous cysts
8 equine MS diseases
Fractures
Infection - abscess, osteomyelitis, septic arthritis
DJD - osteophytes, enthesophytes
OCD
Stress related bone injury
Laminitis
Navicular disease
Angular limb deformities
What can be used to detect non-radiographic fractures?
Nuclear scintigraphy
Amount and quality of callus depends on:
Stability
infection
age of horse - metabolic status
site of fracture
Which bones heal by fibrous union in the horse?
Proximal and distal sesamoids
Accessory carpal
Navicular
P3
Healing time of fractures in horses
6-12wks
When is delayed union?
fracture line at >6 months
When is nonunion?
> 12 months
rare in horses
Fractures of the fetlock
Distal MC (MT) condylar fractures
TBs, SBs, QHs
may need multiple oblique views
stress related
Proximal sesamoid fracture types
I. Apex fracture
II. Midbody fracture
III. Base fracture
IV. Abaxial fracture
V. Axial fracture
VI. Comminuted fracture
Forelimb and medial sesamoid more commonly affected
Fractures of distal phalanx types
I. Abaxial without joint involvement
II. Abaxial with joint
III. Axial/saggital and perisaggital fracture
IV. Fractures of extensor process (hyperextension injuries)
V. Multifragment (comminuted)
VI. Solar margin fractures
These heal by fibrous healing not callus formation
Common fracture of carpal bone
Slab fracture of third carpal -> do a flexed LM to see if it reduces itself
Radiocarpal also common
Be careful -> ulna has normal ossification centre so can see radiolucent circle
What are fractures of MC II and IV associated with?
Often suspensory desmitis or external trauma
Where is MC III normally affected by a fracture?
Middle of the dorsal surface - stress fracture
Can also get thickened dorsal cortex due to young racehorses trained hard on hard surfaces
Where is the most common location for a fracture in the tarsus?
Lateral malleolus
Also see medial malleolus, trochlear ridges, calcaneous
Distal tarsals -> Young horses dorsal disaplacement and collapse
Firth classification of infection of bone
Type P - begins in physis - extneds to epiphysis and metaphysis
Type E - begins in epiphysis
Type S - begins in synovium
Type T - Distal tibial physis and or tarsocrural joint
Type C - localised to carpal bone
What is the pedal osteitis complex a result of?
Trauma or inflammation in adjacent soft tissue
or aseptic: Flat footed, thin sole, worked on hard surfaces
lysis of margins of distal phalanx, can get pathological fractures and gas accumulation
What is infectious pedal osteitis usually a result of?
Common in adult horses at a single site as a result of penetrating wound
What can be a sequelum to foot abscess?
Septic pedal osteitis - abscess causes pressure and demineralisation of pedal bone - can go into pedal bone and cause septic arthritis
Will have irregular margins with this, whereas a kerotoma would have sharp edges
What does osteomyelitis in distal phalanx, skull and navicular bone cause?
Destruction with little to no evidence of new bone formation - this is different to usual osteomyelitis presentation
Usually osteomyelitis is infection of bone with varying degrees of lysis and new bone formation - can have periosteal new bone formation and if it continues, a sequestrum and involucrum
3 types of DJD in horses
Arthritis -> inflammation of joint - synovial distension, soft tissue or joint involved
Osteoarthritis -> bone involved with inflammatory soft tissue component
Osteoarthrosis - bone involved with no inflammatory soft tissue component
Explain tarsal DJD
Low motion joints can cause pain, ankylosis:
1. Distal intertarsal + tarsometatarsal most common
2. Proximal intertarsal less common
High motion joint - tarsocrural joint:
1. significant, long term lameness and pain. If this gets OA then it is serious
Most common joints for OCD
Stifle
Tarsi
Fetlocks
Others -> elbow, cervical spine, proximal humerus
What are osseous cyst like lesions?
Solitary circular lucent areas in a bone with possible sclerotic margin
True bone cysts, part of DOD syndrome, traumatic in origin and cause vascular abnormalities at weight bearing surfaces - usually in fast growing horses
Some resolve spontaneously, some migrate as bone grows
Lameness if near articular surface
Locations for osseous cyst like lesions
Stifle -> medial femoral condyle
Elbow
Hock
Carpus
Fetlock
P3
Usually in fast growing horses
Most common OCD lesion location in stifle
Lateral trochlea ridge of femur
Usually bilateral
Less commonly patella articular surface or medial trochlea ridge
Most common OCD lesion in tarsus
Distal intermediate ridge tibia (DIRT)
Need to radiograph both sides as often bilateral
DDx for P3 osseous cyst like lesions
Epidermoid cyst
Keratoma
Infectious osteitis
Progressive changes of laminitis
Dorsal hoof wall thickens
Alignment of P3 unchanged
Thin sole
Soft tissue buldge at coronary band
Rotation of P3 - separates from wall, can penetrate sole
Gas between dermal and epidermal laminae - gas coming from coronary is worst prognosis, and gas via vacuum in the middle of the toe is the best prognosis
Chronic changes of laminitis
Ski tipped remodeling of dorso-distal P3
Pedal osteitis changes
P3 sinks and causes ridge above coronary band - all of laminae gone for this to happen
Chronic as soon as p3 moves relative to the hoof wall
5 radiographic measurements for laminitis
Coronary extensor distance
Horn lamellar distance
Sole depth
Digital breakover
Palmar angle
Radiographic changes in navicular disease
Distal border - increased size + number of synovial invaginations
Cyst like lucencies
Enthesophytes - collateral ligaments (proximal border) + impar ligament (distal border)
Sclerosis
Flexor surface erosions - flattened saggital ridge + thinned flexor surface
Causes of angular limb deformities
Congenital and perinatal factors: Premature birth, twins, placentitis, perinatal soft tissue trauma, flaccid soft tissues around joints
Developmental factors: unbalanced nutrition, excess exercise, trauma to physis
How are angular limb deformities diagnosed?
Determine site and cuase for deviation
Lines down centre of long bones, determine pivot point (varus or valgus)
Distal radial metaphysis, physis, epiphysis or cuboidal bones may be site of deviation
Mildly affected foals recover spontaneously
What needs to be determined/differentiated in angular limb deformities?
If it is incomplete ossification of carpal bones - rest and bandage/cast
Or due to distal radius epiphyseal uneven growth - surgery
Lax ligaments - controlled exercise
What is physitis?
Invovles distal extremities of radius, tibia, third metacarpal or metatarsal and proximal P1
Flaring at level of growth plate giving boxy appearance to joint
What is villonodular synovitis?
Synovial pad hyperplasia
Swelling dorsal of joint
Bone erosion at dorsoproximal joint capsule
Periarticular enthesophytes
Supracondylar lysis
Why do accessory carpal verticle fractures occur?
Hyperextension of metacarpus putting accessory under tensile stress
Where do umbilical infections end up?
Distal metaphysis of long bones - blood flow slows and bacteria can lodge
Which intercondylar eminence is larger?
medial
What is proximal sesamoiditis?
usually not septic - if heat and lysis, pyrexia present then it is
Seen as increased size of vascular channels into sesamoid bone
Can be avulsion fractures from pull of suspensory and lysis
Common location of DOD in fetlock (metacarpo-phalangeal joint)
Dorsoproximal P1
Or palmar process of P1 - could be fracture or OCD lesion
What is osteomyelitis?
Infection in bone with cortex and medulla - pedal bone does not have this
sequestrum and involucrum formation
Can go to patella - from abscess
Signs of DJD
Osteophytes
Enthesophytes
Sclerosis or lysis
Soft tissue swelling
Narrowing/widening joint space
Where are the malleolus (x2) located?
Lateral and medial distal tibia
Indications for dental conditions
Facial / mandibular focal swelling or draining sinus tract
Dysphagia, nasal discharge, quidding
Chronic weight loss, bitting problems, head shaking
Views of the cranium
VD, Lateral
Oblique
Views for the frontal and maxillary sinuses + maxilla
VD
Lateral
RtDLeVO, LeDRtVO
Intraoral oblique views for the incisors/canines
Ro60 degree DCdVO (maxillary)
Ro60VCdDO (mandibular)
DV
Views for the upper far cheek teeth
L30D-LVO or LL
Views for lower near cheek teeth
L40D-LVO
Lateral (incisors/canines)
Views for upper near cheek teeth
L30V-LDO
Views for lower far cheek teeth
L45V-LDO
Open mouth lateral oblique view
L15D-LVO
L15V-LDO
What is an offset DV?
DV with mandible moved to one side and then the other
How can we locate affected tooth?
Use a wire marker into draining tract to locate affected tooth with radiographs
Positive contrast - water soluble iodine injected into tract
“fistulogram”
What is sinusography?
Positive Contrast into sinus
What is the clinical crown and reserve crown?
Crown visible in the mouth and the unerupted portion
What is the apical area?
The portion of the reserve crown where the roots develop
What is the cranial and caudal part of the tooth called?
Mesial surface and distal surface
What is the slim area between adjoining teeth?
Interproximal space
What is the vestibular and lingual surfaces?
Surfaces facing the lips - vestibular AKA labial/buccal
Surfaces facing the tongue - lingual
quadrant 1,2,3,4
1 -> right maxilla
2 -> left maxilla
3 -> left mandible
4 -> right mandible
Triadan numbers
first digit is the quadrant, 2 and 3 are the tooth
Incisors are 01-03
Canine 04
Premolars 05-08
Molars 09-11
Eruption of permanent incisors
i1: 2.5, make contact at 3
i2: 3.5, make contact at 4
i3: 4.5, make contact at 5
eruption of canine
5 years
Permanent premolars eruptions
pm1: 6 months (wolf tooth)
PM2: 2.5 years
PM3: 3 years
PM4: 4 years
Deciduous incisors eruption time
6 days
6 weeks
6 months
Molars eruption
M1: 9-12 months
M2: 2 years
M3: 3.5-4 years
What is an eruption cyst?
A normal radiolucency around the apex from large pulp cavity as dentine has not filled in yet
in young horses
Which tooth does not continually erupy?
PM1 wolf tooth
Changes to tooth as horse ages
Tooth becomes more opaque (more dentin)
Roots become longer
Pulp cavity narrower
Root apex narrower
Tooth gets shorter
What is attrition and abrasion?
Attrition -> natural wear (aging)
Abrasion -> unnatural wear
What are signs of periapical/apical infection?
Loss of lamina dura detail
Lysis of periapical bone
Bone sclerosis
Apex destruction
Widening of pulp cavity
Sinusitis
Fractures of the maxilla/manidible classifications
Incisival
Diastema
Equine odontoclastic tooth resorption and hypercementosis
Painful disorder of incisor and canine teeth
Variably causes periodontitis
Resorptive or proliferative changes of the calcified dental tissues
What is the calvarium?
The top part of the skull
3 conditions of the calvarium
Fractures (frontal bone, non-displaced basisphenoid fracture)
Neoplasia
Temporal teratoma with dentigerous cyst (ectopic tooth in temporal part of skull)
3 conditions of paranasal sinuses
Sinusitis - from dental pathology
Neoplasia
Ethmoid haematoma
Cysts
3 conditions of the mandible
Fractures - displaced mandibular diastema fracture, horizontal/vertical ramus
Neoplasia
Teeth
Where are ethmoid haematomas found?
Rostral to ethmoidal labyrinth in nasal passage
In maxillary sinus
In frontal sinus
Often have narrowing/obliteration of common nasal meatus as seen on the DV
4 conditions of paranasal sinuses
Nasal polyps
Maxillary cysts or max. sinus cysts
Neoplasia
What is a sialolith?
calcified lump in parotid salivary duct
