Equine Skull 2


Part 2
Question | Answer |
---|---|
Radiographic signs of periapical infection (tooth root abscess) | Loss of lamina dura Lysis of periapical bone Widening of periodontal space Sclerosis of adjacent alveolar bone Plump/blunted appearance of affected tooth root(s), sometimes associated framents +/- associated granuloma formation in sinus/around tooth roots, may mineralize +/- sinusitis **Mandibular tooth root abscess may lead to formation of sinus with purulent discharge** Associated with infundibular necrosis |
What’s going on with these 2 rads?![]() | Left side: Periapical infection of M1: mineralized granulation tissue in adjacent maxillary sinus Right side: NORMAL! Need oblique projections of maxillary arcades to differentiate sides |
Mandibular tooth root abscesses often present how? | Discharging sinus with marked palisading periosteal reaction along the cortex of ramus |
![]() | Mandibular tooth root abscess with draining tract & palisading periosteal proliferation along it |
Dx? ** = ? (R maxilla oblique)![]() | Maxillary periapical infection ** = Blunted tooth root contour (possibly fragment) Shortened, widened periodontal space Interrupted lamina dura Sclerosis of surrounding alveolar bone |
Dx? ** = ? ((CT transverse @ M1)![]() | Maxillary periapical infection ** = thickening of R maxillary bone |
Features of periapical infection on CT? | Interrupted lamina dura Widened periodontal space, filled with ST-attenuating material Widened pulp cavity Maxillary sinus filled with ST-attenuating material Thickening of maxillary bone |
What’s going on here?![]() | Proliferation of mucosal lining in maxillary periapical infection Not just fluid! (Left side normal) |
Scintigraphy: what do hot areas represent? | Alveolar bone (teeth appear as bright areas without uptake)![]() |
Dentigerous cyst aka? | Dental ectopia Heterotopic polydontia Dental teratoma Ear tooth |
Wtf??![]() | Dentigerous cyst Development of dental material in an abnormal location, usually around base of ear (usually young) +/- associated discharging fistulous tract Can be sx removed if problem |
![]() | Dentigerous cyst (arrow = dental material) |
Problem? possible complications?![]() | Root fracture Gas inclusion, ST attenuating tissue in maxillary sinus --> Tooth root abscess |
What kind of image is this? * = ? @ = ?![]() | Sagittal reconstruction of maxillary cheek teeth (old horse) Maxillary sinusitis * = ST-attenuating material in rostral maxillary sinus @ = Air-filled caudal maxillary sinus |
![]() | Wave mouth (severe, old horse) |
Structure?![]() | TMJ |
How else can the TMJ radiographed? | Special tangential projection![]() |
US of the TMJ: label dis![]() | T = temporal bone M = mandible D = discus P = parotid gland Tranducer positions: ![]() |
Best method of imaging TMJ? | CT! |
What is temporohyoid osteoarthopathy? | Bony proliferation at the level of the jxn of the stylohyoid bone with the petrous temporal bone Fusion & traumatic fracture may occur |
Best method of imaging temporohyoud osteoarthopathy? | CT ALSO BEST FOR TMJ! |
![]() | Temporohyoid ostoarthropathy Thickening of styloid bone on left side, envelop temporo-hyoid articulation |
How are the ears imaged? | Tympanic bulla partially imaged radiographically Middle & inner ear: CT/MRI methods of choice |
What is PTB? Arrows? (CT transverse bone window)![]() | Petrous temporal bone Arrows = tympanic bullae |
What structure? (CT transverse)![]() | Guttural pouches |
What’s going on?![]() | Abnormal fluid in the guttural pouch Pus: eroding retropharyngeal abscess Hge: Erosion of internal carotids (fungal- aspergillosis; trauma- skull frax) |
![]() | Guttural pouch tympany Abnormal gas distention, causing compression of pharynx |
![]() | Chondroids Inflammatory debris after chronic empyema |
![]() | Chondroids |
How are the eyes imaged? | Ultrasound useful for eyes & adnexa A & P chambers, lens, ciliary apparatus: linear freq transducer Transpalpebral & direct corneal techniques: LA & sedation Retrobulbar space |
Arrows?![]() | Mass in anterior chamber of left eye. NORMAL right eye |
Most common location for neoplasia in horses = | HEAD! |
Types of tumors | SCC OsteoSA Melanoma Dental tumors (adamantinoma, ameloblastoma, ameloblastic odontoma) Odontoma/Cementoma Osteomas AdenoCA |
Appearance of adamantinoma (dental tumor)? | Foamy ST opacity |
Appearance of ameloblastoma (dental tumor)? | Radiolucent/ST opacity Internally divided |
Appearance of ameloblastic odontoma (dental tumor)? | Derived from enamal organ (embryolocial tooth precursor) Mostly dental opacity YOUNG horses |
Osteoma: how does it behave? looks like? | Benign, slow growth, may become very large Smooth outline, bone opacity |
Adenocarcinoma: where do they occur? in who? behavior? | Frontal sinus & nasal cavity of OLDER horses Very destructive, rapid growth |