3 Technical Considerations Head is mobile and high off the groundSedationLowers headCan use portable equipment14x17 cassettesFilm holding deviceRope halter – no bucklesRope halter – anatomy beneath the buckle can still be visualized
4 Lateral and Oblique Views Standing or recumbentCan visualize sinuses, teeth and skull fractures (frontal bone)Obliques are needed to carefully assess tooth rootsMust label correctlyCan use barium as marker on skin if neededLabeling
11 Cranium Foals: dome-shaped Adult lateral view Face lengthens with growth; accommodates teeth and expanding sinusesAdult lateral viewPetrous temporal bones (tympanic bullae not visible)Nuchal crestOccipital condylesEthmoid turbinatesVentral jaw in foals can be bumpy = from root of unerupted permanent cheek teeth.
12 A - Nuchal crest D - Occipital condyle BCDEFDyce et. alA - Nuchal crest D - Occipital condyleB - Coronoid process E - Ramus of mandibleC - Condylar process F - Body of mandible
13 Equine Skull A = Petrous temporal bone B = Cranium C = Condyloid processD = Coronoid processE = BasioccipitalF = EpiglottisG = Ethmoid turbinates
14 A – Choncofrontal sinus B – Maxillary sinusC – Condylar process of mandibleD – Guttoral pouchE – Stylohyoid boneF – EpiglottisG – Maxillary 3rd MolarH – Mandibular 2nd PremolarACBDGEFH
16 Equine Sinuses Frontal Dorsal, ventral and middle conchal Maxillary Dorsal part of the skull, medial to orbitCombines with dorsal conchal = conchofrontalDorsal, ventral and middle conchalMaxillaryRostal and caudalImportant relationship with the molar cheek teethSphenopalatineTrephination to remove cheek teeth = through frontal sinus into the caudal maxillaryThe ones of clinical importance are the frontal, dorsal conchal and maxillaryMaxillary: Rostral extends into the ventral choncalCaudal continues into the sphenopalatineSphenopalatine = superimposed with the vertical ramus of the mandible.
18 Equine Sinuses Normally air-filled on radiographs Fluid or a soft tissue mass can be seenAir-fluid linesHard to tell if one or both sides are affectedMaxillary sinusPM4, M1, M2, M3 tooth roots in sinusTooth root infections can easily cause sinusitis
19 Sinuses A = frontal B = dorsal conchal C = stylohyoid bone D = maxillary sinusD
20 Sinuses A - Nasal bone B - Frontal sinus C - Dorsal conchal sinus D - Maxillary sinusE - Mandible
22 Guttural Pouches Ventral diverticulum of the auditory tube Paired; lateral and medial compartmentsSuperimposed and air-filled on radiographsDorsal pharyngeal wall separates the ventral wall of the GP from the pharynxStylohyoid bones can be seen through the air filled GP’sRetropharyngeal lymph nodesCaudal to the GPInfection can spread from LN to GPGuttoral pouches = diverticulum of the auditory tubeMucosal lining of the tube through a ventral slit between the medial and lateral supporting cartilagesmlTympany and empyema
24 ABA = Petrous Temporal BoneB = Basioccipital boneC = Coronoid Process of the MandibleC
25 Basisphenoid / Basiocciptal Fractures Occur primarily in young horses that flip over backwardPoll strikes against groundClinical signs depend upon amount of displacementMinimal = usually recover but may have residual head tiltSevere = cerebral hemorrhage and deathIf horse can stand, death is not likely
29 Pharynx / Larynx Pharynx Epiglottis Larynx Where nasopharynx and oropharynx joinEpiglottisDorsal to the soft palateLarynxMade up of many cartilages which are rarely seen and their location is approximated anatomically on the radiograph
30 Equine Teeth Herbivores = hypsodont teeth Continuously erupt to compensate for attrition (wearing)Grinding surfaceDental enamel is more dense than boneSinuses will be very overexposedLateral, obliques +/- VD
31 Equine Dental Formula Temporary teeth: Permanent teeth: 3-0-3 Maxillary3-0-3 Mandibular“Baby” teeth are shorter and smallerPermanent teeth:3-1-3(4)-3 MaxillaryMandibularMaxillary premolar 1 is wolf toothCanine teethRudimentary and commonly fail to erupt in maresWolf teeth may not erupt. Upper jaw only.