Positioning review Flashcards
Finger positions
PA
PA oblique
Lateral
Finger evaluation Criteria
2-5th fingers
-include all anatomy-distal phalange to MCP
-no superimposition
PA finger criteria
-equal concavity on both side of phalangeal bodies
-equal amount of soft tissue
-open IP and MCP joints
lateral 2-5 finger criteria
fingernail in profile
-concave anterior surfaces of phalanges
-no superimposition
-open IP joint spaces
oblique 2-5 finger criteria
-rotated 45 seen by concavity of elevated side
-no superimposition of prox phalanx or MCP
-open IP and MCP
Hand positions
PA
PA oblique
Lateral
ball catchers if looking for RA
PA hand criteria
-fingertips to distal radius and ulna
-no soft tissue overlap of digits
-equal concavity of MC and phalangeal bodies
-equal soft tissue
-open MCP and IP joints
PA oblique hand criteria
-fingertips to distal radius and ulna
-digits separated with no soft tissue overlap
-45 rotation
-decreasing amount of separation btw MC bodies 2-5
-partial superimposition of third,4,5 MC bases and heads
-open MCP and IP joints
Lateral hand criteria
-fingertips to distall radius and ulna
-in fan position all phalanges individually seen
-if not in fan phalanges superimposed
-superimposed metacarpals
-superimposed radius and ulna
Norgaard method(ball-catchers)
-used for RA
-AP with hands on a 45
-both hands from carpals to tips of digits
-MC heads and prox phalangeal bases free of superimposition
Wrist positions
PA,PA oblique, Lateral
PA wirst criteria
-distal 1/3 radius and ulna and prox half of MC
-no rotation
-open radioulnar joint
can do AP to show carpal interspaces better
PA oblique wrist criteria
-distal 1/3 of radius and ulna and prox half of MC
-45 degree rotation
-slight overlap of distal radius and ulna
-trapezium and distal half of scaphoid without superimposition
-open trapeziotrapezoid and scaphotrapezial joint space
can do pA to show pisiform separated from adjacent carpal bones, also shows triquetrum and hamate better
lateral wrist criteria
distal 1/3 of radius and ulna, carpals, and prox half of MC
-superimposed distal radius and ulna
-superimposed MC
Other wrist positions
-radial deviation
-opens interspaces btw carpals on medial side
-ulnar deviation
-reduces foreshortening of scaphoid
Scaphoid positions
-PA with ulnar deviation
-PA with 20 cephalic(towards elbow) angle or hand on 20 degree sponge
scaphoid criteria
-distal radius and ulna, carpal and prox half of MC
-scaphoid with adjacent articulations open
-no wrist rotation
Forearm positions
AP
lateral
AP forearm criteria
-entire forearm including wrist and distal humerus
-slight superimposition of radial head, neck and tuberosity over prox ulna
-partial open elbow joint when shoulder is on same plane as forearm
-open radioulnar space
lateral forearm criteria
-entire forearm including wrist and distal humerus in true lateral
-superimposition of radius and ulna at distal end
-superimposition of radial head over coronoid process
-superimposition of humeral epicondyles
-elbow flexed 90 degrees
elbow positions
AP
AP oblique-medial and lateral rotation
Lateral
AP elbow criteria
-radial head, neck and tuberosity slightly superimposed over rprox ulna
-open humeroradial joint
-no rotation of humeral epicondyles( coronoid and olecranon equidistant)
Lateral elbow criteria
-superimposed humeral epicondyles
-radial tuberosity facing anteriorly
-radial head partially superimposing coronoid process
-olecranon process in profile
-elbow flexed 90
AP elbow medial rotation criteria
shows coronoid process free of superimposition
-45 medial rotation
-coronoid process in profile
elongated medial humeral epicondyle
-ulna superimposed by radial head and neck
AP Elbow lateral rotation criteria
shows radial neck and head free of superimposition
-45 lateral rotation of elbow
-radial, neck, head and tuberosity projected free of ulna
-elongated lateral humeral epicondyle
-capitulum
other Elbow positions
distal humerus
-AP partial flexion
-AP acute flexion
prox forearm
-AP partial flexion
-PA acute flexion
elbow-axiolateral(Coyle method) position
-elbow flexed 90 with hand pronated
-angle CR 45 towards shoulder
-radial head and neck free of superimposition
trauma elbow
AP, Lateral and axiolateral
Humerus Positions
AP
lateral
AP humerus Criteria
-supinate hand
-elbow and shoulder joints visible
-humeral epicondyles without rotation
-humeral head and greater tubercle in profile
-lesser tubercle outline seen btw humeral head and greater tubercle
Lateral humerus criteria
-elbow and shoulder joint visible
-superimposed humeral epicondyles
-lesser tubercle in profile on medila aspect
-greater tubercle superimposed over humeral head
trauma humerus
transthoracic lateral
-CR perpendicular to mid shift of affected humerus
-prox half of shaft of humerus to include humeral head and glenoid cavity
Shoulder positions
AP-neutral,interal or external rotation
inferosuoerior axial-lawrence( axillary)
oblique-grashey method(glenoid)
lateral- scapular Y
AP shoulder criteria
-superior scapula, clavicle and prox humerus
-external rotation
-humeral head in profile
-greater tubercle in profile on lateral side
-slight overlap of humeral head on glenoid cavity
-outline of lesser tubercle btw humeral head and greater tubercle
neutral rotation
-greater tubercle partially superimposing humeral head
-humeral head in partial profile
-slight overlap of humeral head on glenoid cavity
internal rotation
-lesser tubercle in profile and pointing medially
-outline of greater tubercle superimposing humeral head
-humeral glenoid cavity overlap
Inferosuperior axial( Lawrence)
-scapulohumeral joint with slight overlap
-coracoid process, pointing anteriorly
-lesser tubercle in profile and directed anteriorly
-AC joint, acromion projected through humeral head
posterior oblique-grashey method(glenoid) criteria
-open joint space btw humeral head and glenoid cavity
-glenoid cavity in profile
lateral Scap Y shoulder Criteria
-humeral head and glenoid cavity superimposed
-humerla shaft and scapular body superimposed
-no superimposition of scapular body over bony thorax
-acromion projected laterally and free of superimposition
-scapula in lateral profile with lateral vertebral borders superimposed
Clavicle Positions
AP
AP Axial
AP clavicle criteria
-entire clavicle entered on image
-lateral half of clavicle above scapula with medial half superimposing the thorax
AP Axial clavicle
-15-30 degree cephalic angle
-entire clavicle with AC and SC joints
-lateral 2/3 projected above ribs and scapula
-medial end superimposing thorax
-more horizontal orientation
Scapula Positions
AP
lateral
some places do obliques
AP scapula criteria
-lateral portion of scapula free of superimposition
-scapula horizontal
-acromion and inferior angle
Lateral scapula criteria
-lateral and medial scapular borders superimposed
-no superimposition of scapular body over ribs
-no superimposition of humerus on area of interest
-inclusion of acromion and inferior angle
AP oblique Scapula criteria
-oblique scapula
-lateral scapular border adjacent to ribs
-acromion and inferior angle
AC joints positions
AP with and without weights
some places do AP axial (with a 15 degree cephalic angle)
AP AC with and without weights Criteria
-both AC joints on one image
-no rotation or leaning
AP axial AC joints Criteria
15 cephalic angle
-AC joint and clavicle projected above acromion
Toes projections
AP
AP oblique
lateral
AP toes criteria
-entire toe including distal ends of metatarsals
-toes separated from each other
-no rotation-equal soft tissue and concavity on both sides
-ope interphlangeal and metatarsophalangeal joint spaces on axial
AP oblique Toe
-entire toe including distal ends of metatarsals
-toes separated
-proper rotation as shown by more soft tissue/concavity on elevated side
-open interphalangeal and 2-5 metotarsophalangeal joint spaces
-first MTP joint
Lateral toes criteria
-entire toe without superimposition of adjacent toes
-concave, plantar surfaces of phalanges
-no rotation
-open interphalanageal joint spaces
Foot positions
AP or AP axial
AP oblique
Lateral
AP/AP axial foot criteria
10 degree toward heel for axial
-all anatomy from toes to tarsals
-no rotation as seen by equal amounts of space btw 2-4 metatarsals
-overlap of 2-5 metatarsal bases
-open joint space btw medial and intermediate cuneiforms
-axial shows improved demonstration of interphalangeal, metatarsophalangeal and tarsometatarsal joint spaces
AP oblique foot criteria
-entire foot toes to heel
-1/2 metatarsal bases free of superimposition
-minimal superimposition btw medial and intermediate cuneiforms
-navicular seen with less foreshortening
lateral foot criteria
-entire foot and distal leg
-superimposed plantar surfaces of metatarsal heads
-fibula overlapping posterior portion of tibia
-tibiotalar joint
calcaneus postions
plantodorsal Axial
Lateral
Lateral calcaneus criteria
-calcaneal tuberosity
-sinus tarsi
-cuboid, lateral cuneiform nd prox metatarsals
Ankle positions
AP
AP oblique(mortise)
Lateral
AP ankle criteria
-medial and lateral maleoli
-talus
-no rotation
-normal overlapping of tibiofibular articulation with anterior tubercle slightly superimposed over fibula
-talus slightly overlapping distal fibula
-no overlapping of medial talomalleolar articulation
-tibitalar joint space
AP oblique(mortise) ankle Criteria
-entire ankle mortise joint entered
-distal tibia, fibula and talus
-talofibular articulation open
-tibiotalar articulation open
-no overlap of the anterior tubercle of tibia and super-lateral portion of talus with fibula
Lateral Ankle criteria
-distal tibia and fibula, talus, calcaneus and adjacent tarsals
-ankle in tube lateral
-tibitalar joint well visualized with medial and lateral talar domes superimposed
-fibular over posterior half of tibia
-5th metatarsal base and tuberosity seen to check for fracture
Leg(Tib/Fib) positions
AP
Lateral
some do AP oblique-rotate leg 45
AP leg criteria
-ankle and knee joint on one or more images
-entire leg without rotation
-prox and distal articulations of fib/fib overlapped
-fibula mineshaft free of tibial superimposition
lateral leg criteria
-ankle and knee joint on one or more images
-distal fibula superimposed by posterior half of tibia
-slight overlap of tibia on prox fibula head
-moderate separation of tibial and fibular bodies(shafts)
AP knee criteria
-knee fully extended if able
-femoral condyles symmetric and tibia intercondylar eminence centered
-slight superimposition of fibular head if normal tibia
-patella completely superimposed on femur
-open femorotibial joint space
AP oblique criteria
lateral rotation
-medial femoral and tibial condyles
-tibial plateaus
-tibula superimposed over lateral half of tibia
-patella proceed slightly beyond edge of lateral femoral condole
-open knee joint
medial rotation
-tibia and fibula separated at prox articulation
-posterior tibia
-lateral condyles of femur and tibia
-both tibial plateaus
-patella projecting slightly beyond medial side of femoral condyle
-open knee joint
lateral knee criteria
-knee flexed 20-30 degrees
-fibular head and tibia slightly superimposed
-patella in lateral profile
-open patella femoral joint space
-open joint space btw femoral condyle and tibia
holmblad and camp-coventry method intercondylar fossa criteria
-open intercondylar fossa
-posteroinferior surface of femoral condyles
-knee joint space open, with one or both tibial plateaus in profile
-apex of patella not superimposing the fossa
-slight tibiofibular overlap and centered intercondylar eminence
PA patella criteria
-patella completely superimposed by femur
-no rotation
Lateral patella criteria
-knee flexed 5-10 degrees
-patella in lateral profile
-open patellofemoral joint space
Tangential Patella criteria
-patella in profile
-femoral condyles and intercondylar sulcus
-open patellofemoral articulation
AP femur criteria
-most of femur and joint nearest to injury site
-femoral neck not foreshortened on prox femur
-lesser trochanter not seen beyond medial border of femur
-no knee rotation on distal femur
-orthopedic appliance in its entirety
lateral femur criteria
-most of femur and joint nearest to site of injury
-orthopedic appliance in its entirety
with knee included
-superimposed anterior surface of femoral condyles
-patella in profile
-open patellofemoral space
-inferior surface of femoral condyles nor superimposed(b/c divergent rays)
with hip included
-opposite thigh not over prox femur and hip joint
-greater trochanter superimposed over distal femoral neck
-lesser trochanter visible on medial aspect of prox femur
AP pelvis Criteria
-entire pelvis and prox femora
-both ilia and greater trochanter equidistant from edge of image
-symmetric ilia
-symmetric obturator foramina
-ischial spines equally seen
-sacrum and coccyx aligned with pubic symphysis
-femoral necks in full extent without superimposition
-greater trochanters in profile
-lesser trochanters visible on medial border of femora
AP bilateral frog (Cleaves method)
-symmetric appearance
-acetabulum, femoral head and femoral neck
-lesser trochanter on medial side of femur
-femoral neck without superimposition by greater trochanter
AP hip criteria
-hip joint
-prox 1/3 of femur
-femroral head penetrated and seen through acetabulum
-entire long axis of femoral neck not foreshortened
-greater trochanter in profile
-any orthopaedic appliance in its entirety
lateral(lauesten-hickey) criteria
-hip joint centered to image
-hip joint,acetabulum and femoral head
-femroial neck overlapped by greater trochanter in lauenstein method
-femoral neck free of superimposition in hickey method(cause cephalic angle)
axiolateral(danelius-miller) criteria
-hip joint with the acetabulum
-femoral neck without overlap from the greater trochanter
-ischial tuberosity below femoral head and neck
-small amount of lesser trochanter on posterior surface of femur
-small amount of greater trochanter on anterior and posterior surface of prox femur when properly inverted
AP axial criteria
-inlet
-pelvic ring in its entirety
-ischial spines are demonstrated and symmetric
-outlet
-superior and inferior pelvic rami
-obturator foramina are equal size
Acetabulum Județ method criteria
-acetabulum centered to IR
-iliopubic column and posterior rim of affected acetabulum on the internal oblique(LPO-L side down)
-ilioischial column and anterior rim of acetabulum on external oblique(RPO-R side down)
PA chest criteria
-entire lungs(apices to costrophrenic angles)
-sternal ends of clavicles equal distant from vertebral column
-equal distance from vertebral column to lateral border of ribs on each side
-scapula projected outside lung field
-10 posterior ribs above diaphragm
-sharp outline of heart and diaphragm
Lateral chest criteria
-arm/soft tissue not overlapping superior lung field
-costophrenic angles and apices not obscured by arms and shoulders
-hila in centre of image
-superimposition of ribs posterior to vertebral column
-sternum in profile
-trachea visible ein midline
-long axis of lung field shown in vertical position without leaning
-open thoracic vertebral joint spaces
-sharp outline of heart and diaphragm
AP chest criteria
-entire lungs(apices to costrophrenic angles)
-sternal ends of clavicles equal distant from vertebral column
-equal distance from vertebral column to lateral border of ribs on each side
-clavicles more horizontal
-approx 1inch of pulmonary apices should be seen superior to clavicles
AP axial(lordotic) chest criteria
shows apices and conditions such as interloper effusions
lordotic position
-entire apices and appropriate portion of lungs
-clavicles superior to apices
-sternal ends of clavicles equal distant from vertebral column
-ribs anterior and posterior portions superimposed
Decubitus chest criteria
(laying on side)
fluid side down, air side up
-affected side in its entirety, from apex to costophrenic angles
-sternal ends of clavicles equidistant from spine
-patients arms not visible in the field of interest
-faintly visible spine and vascular markings
ventral or dorsal chest criteria
patient supine(dorsal) or prone(ventral)
-entire lung field,including anterior and posterior surfaces
-upper lung field not obscured by arms
-T7 in centre of IR
-no rotation of thorax from true lateral position
AP soft tissue neck criteria
-air filled upper airway, from the pharynx to the proximal trachea( for upper airway)
-air filled airway from mid cervical to mid thoracic region(for trachea and superior mediastinum)
-no rotation with spinous processed equal distant to pedicles and aligned in midline of cervical bodies
lateral soft tissue criteria
-air filled upper airway, from the pharynx to the proximal trachea( for upper airway)
-air filled airway from mid cervical to mid thoracic region(for trachea and superior mediastinum)
-no rotation or tilt of C spine
-superimposed zygapopyseal joints and open intervertebral joint
-superimposed or nearly mandibular rami
PA Oblique(RAO) sternum criteria
-entire sternum from jugular notch to tip of diploid process
-sternum projected over heart, but free of superimposition of T spine
-minimally oblique vertebrae to prevent excessive rotation of sternum
-lateral portion of manubrium and SC joint free of superimposition by vertebrae
-blurred pulmonary markings if breathing technique is used
lateral sternum criteria
-sternum in its entirety
-manubrium free of superimposition by soft tissue of shoulders
-sternum free of superimposition by the ribs
-lower portion of sternum unobscured by breasts of females
AP upper anterior ribs criteria
-1-9 ribs in their entirety with posterior portion lying above diaphragm
-1-7 anterior ribs from both sides in their entirety and above diaphragm
AP posterior ribs criteria
-for ribs above diaphragm 1-10 posterior ribs from both sides in their entirety
-for ribs below diaphragm 8-12 posterior ribs on both sides in their entirety
-ribs visible through lungs or abdomen
AP oblique ribs criteria
-approx twice as much distance btw vertebral column and the lateral border of ribs on the affected side as is present on unaffected side as is present on unaffected side
-axillary portion of ribs free of superimposition with thoracic spine
-1-10 ribs visible above diaphragm for upper ribs
-8-12 ribs visible below diaphragm for lower ribs
-ribs visible through lungs or abdomen
AP axial C spine criteria
-area from superior portion of C3-T2
-shadows of mandible superimposed over atlas and most of axis
-open intervertebral disk spaces
-MSP of head and neck perpendicular to plane of IR
-spinous processes equidistant to the pedicles and aligned with midline of C Bodies
-mandibular and mastoid processes equidistant to vertebrae
Atlas axis C spine open mouth criteria ( odontoid)
-dens,atlas, axis and articulations btw first and second C vertebrae
-entire articular surfaces of atlas and axis
-mouth wide open
-superimposed occlusal plane of upper central incisors and base of skull
-shadow of tongue not projected over atlas and axis
-madibular rami equidistant from dens
Lateral(Grande method) C spine criteria
-all 7 vertebrae and 1/3 of T1
-C4 in centre of image
-neck extended so mandibular rami are not overlapping atlas or axis
-superimposed zygapophyseal joints and open intervertebral disk spaces
-superimposed or nearly superimposed rami of mandible
-spinous process shown in profile
Axial Oblique C spine Criteria
-all 7 C vertebrae and T1
-45 rotation of body
-uniform size and contour of foramina
-chin elevated
-mandible not overlapping atlas and axis
-occipital bone not overlapping the atlas and axis
-open intervertebral disk spaces
AP Axial
-open intervertebral foramina FARTHEST from IR C2-C3, C7-T1
PA axial
-open intervertebral foramina CLOSEST to IR C2-C3, C7-T1
AP T spine Criteria
-All 12 T vertebrae
-no rotation demonstrated by spinous processes at midline of vertebral bodies
-vertebral column aligned to midline of image
Lateral T spine criteria
-vertebrae clearly seen through rib and lung shadow
-12 vertebrae centered on image
-T1-T3 may not be well visualized
-ribs superimposed posteriorly to indicate patient was not rotated
-open intervertebral disk spaces
Swimmers Criteria
-adequate penetration through shoulder region demonstrating lower C spine and upper T spine
-humeral heads minimally superimposed on vertebral column
AP L spine Criteria
-lower T spine to sacrum
-collimated to lateral psoas muscle
-no artifact across mid abdomen
-symmetric vertebrae with spinous processes centered to bodies
-SI joints equidistant from vertebral column
-open intervertebral disk spaces
Lateral L spine criteria
-lower T spine to prox sacrum
-vertebrae aligned down middle of image
-superimposed posterior margins or each vertebral body
-nearly superimposed crests of ilia when beam in not angled
-spinous processes in profile
-open intervertebral disk spaces and intervertebral foramina(L1-L4)
lateral L5-S1 criteria
-lumbrsacral joint in centre of image
-open lumbosacral intervertebral disk space
-crest of ilia closely superimposing each other when bema is not angled
AP Axial Sacrum
-sacrum free of foreshortening, with sacral curvature straightened
-pubic bone not overlapping the sacrum
-no rotation of sacrum demonstrated by symmetric alae
AP axial coccyx criteria
-coccygeal segments not superimposed by pubic bones
-no rotation of coccyx, demonstrated by distal segment in line with pubic symphysis
lateral sacrum and coccyx criteria
-sacrum and coccyx
-closely superimposed posterior margins of ischia and ilia demonstrating no rotation
AP axial SI joint criteria
-lumbosacral junction and sacrum
-open intervertebral disk space btw L5 and S1
-both SI joints
Oblique SI joint Criteria
AP(RPO,LPO)
-open SI joint space with minimal overlapping of ilium and sacrum
-joint centered on radiograph
PA(RAO,LAO)
-open SI joint space closest to IR or minimal overlapping of ilium and sacrum
-joint centered on radiograph
AP axial(Towne) skull criteria
equal distance from lateral borders of skull to lateral margins of foramen magnum on both sides
-symmetric petrous ridges
-MSP of cranium aligned wit long axis of collimated field
-dorsum sellae and posterior crinoid processes visible within foramen magnum
PA axial(Caldwell) skull criteria
-equal distances from lateral borders of skull to lateral borders of orbits on both sides
-symmetric petrous ridges
-MSP of cranium aligned with long axis collimated field
-petrous pyramids lying in lower 1/3 of orbits
PA shows orbits filled by petrous ridges
lateral skull criteria
-superimposed orbital roofs and greater wings of sphenoid
-superimposed mastoid regions and EAM
-superimposed TMjs
-sella turcica in profile
-no overlap of C spine by mandible
PA axial( caldwell) facial bones criteria
-entire orbits and facial bones
-equal distances from lateral borders of skull to lateral borders or orbits on both sides
-MSP of head aligned with long axis of collimated field
-symmetric petrous ridges lying in lower 1/3 of orbit
parietoacanthia ()waters) facial bones criteria
-entire orbits and facial bones
-equal distances from lateral borders of skull to lateral borders or orbits on both sides
-MSP of head aligned with long axis of collimated field
-petrous ridges projected below maxillary sinuses
lateral facial bone criteria
-all facial bones in their entirety with zygomatic bone in centre
-almost perfectly superimposed mandibular rami
-superimposed orbital roofs
-sella turcica in profile
PA axial orbits criteria
-petrous ridges in bottom 1/3 of orbits with a 15 caudal angle
-petrous ridges below orbits with 30 caudal angle
-no rotation shown by symmetry
parietoacanthial(modified waters) orbits criteria
-petrous ridges well below orbital shadow
-symmetric orbits
-close beam restricted to orbital region
lateral orbits criteria
-superimposed orbital roofs
-close beam restricted to orbital region
lateral nasal bone criteria
-nasal bones, anterior nasal spine,frontonasal suture
-no rotation of nasal bones and soft tissue
parietoacanthial(waters) zygomatic arches criteria
-Petrous ridges below maxillary sinuses
-Zygomatic arches shown bilaterally
-No rotation, no tilt, demonstrated by symmetry
AP axial (towne) zygomatic arches criteria
-no overlap of zygomatic arches
-symmetric arches
-zygomatic arches projected lateral to mandibular rami
-MSP of head aligned with long axis of collimated field
Tangential zygomatic arches criteria
-zygomatic arches free from overlaying structures
SMV zygomatic arches criteria
-bilateral zygomatic arches in profile
AP axial(modified Townes) mandible criteria
-Condyloid processes of mandible and temporomandibular (TM) fossae
PA and AP axial mandible criteria
-Mandibular body
-No rotation, mandibular rami should be symmetric
axiolateral obliques mandible criteria
-entire mandible to include mentum, TMJ and gonion
AP axial TMJ criteria
-no rotation of head
-minimal superimposition of petrosal on the condyle in the closed mouth
-condyle and temporomandibular articulation below pars petrosal in open mouth
Axiolateral TMJ criteria
-TMJ to anterior EAM
-condyle in mandibular fossa in closed mouth
-condyle inferior to articular tubercle in open mouth
Parietoacanthial(waters) sinus criteria
-petrous ridges lying immediately inferior to floor of maxillary sinuses
-equal distance between lateral border of skull and the lateral border of orbit on both sides
-sphenoid sinus shown through open mouth
PA axial(caldwell) sinus criteria
-frontal sinuses lying above the frontonasal suture and anterior ethmoidal air cells lying above the petrous ridges
-equal distance btw lateral border of skull and lateral border of orbits
-petrous ridge symmetric on both sides
-petrous ridge lying in lower 1/3 of orbit
Lateral skull criteria
shows all 4 sinuses
-superimposed orbital roofs and greater wings of sphenoid
-superimposed mastoid regions and EAM
-superimposed TMJs
-sella turcica in profile
-no overlap of cervical spine by mandible
