Facial Bone, Nasal Bone Anatomy, Facial Bone, Nasal Bone Projections Week 6 Facial Bone, Nasal Bone Anatomy, Facial Bone, Nasal Bone Projections

14 bones in the face, not including the hyoid bone FACIAL BONES 14 bones in the face, not including the hyoid bone 6 paired bones 2 unpaired bones

Nasal bone 13 2 1 3 4 11 10 6 7 9 There are 14 bones that make up the facial bones. 6 of which are paired and 2 single bones: mandible and vomer. The facial bones contribute to the shape and form of a person’s face. They also serve as protective housing for the eyes. There are cavities of the orbits, nose and mouth that are largely made up of the facial bones. 2 Maxillae 2 Zygomatic bones 2 Lacrimal bones 2 Nasal bones 2 Inferior nasal conchae 2 Palatine bones (not visualized 1 vomer 1 mandible 8 8 5

Nasal Bones Two small, thin bones Vary in size and shape in individuals Form superior bony wall of nasal cavity Commonly called “bridge of nose” Articulations With each other in midsagittal plane Superior = frontal bone Posterosuperior = perpendicular plate of ethmoid bone On each lateral side = maxillae Nasion is the junction of nasal bone and frontal bone

Lacrimal Bones The two smallest bones in the skull Located in anterior part of medial wall of orbits between labyrinth of ethmoid and maxilla Each bone contains a lacrimal foramen through which the tear duct passes Articulations Frontal Ethmoid Maxilla Inferior nasal concha Smallest and most delicate bones in face

Maxillary Bones Largest immoveable bones of face Each articulates with all other facial bones, except for mandible Also articulate with frontal and ethmoid cranial bones Form part of lateral walls and most of floor of nasal cavity Form part of floor of orbit Articulates with 2 cranial bones- Frontal and ethmoid Articulates with 7 facial bones -zygomatic, nasal, palatine, inferior nasal concha, vomer, opposite maxilla

Maxillary Bones Form three fourths of roof of mouth Have zygomatic process that articulate with zygoma to form part of cheek Body contains large, pyramidal cavity = maxillary sinus Infraorbital foramen = located under each orbit for passage of infraorbital nerve and artery The 2 maxillae are the largest immovable bones of the face. The maxillae and united at the midline below the nasal septum. Each maxillae assists is forming three cavities: mouth, nasal cavity, and one orbit. Each maxillae consists of 4 processes: 1) frontal process 2) zygomatic process 3)Alveolar process 4) Palatine processes 1) Frontal process projects superiorly along the lateral border of the nose toward the frontal bone. 2) Zygomatic process extends laterally toward the zygoma on each sided. 3) Alveolar process is the inferior aspect. Along the inferior margin of each alveolar process are 8 upper teeth. 4) Palatine process can only be demonstrated inferiorly and form the anterior portion of the mouth called the hard, or bony palate. This bone also contains and important landmark for radiography of the skull and facial bones: acanthion. The acanthion is at the base of the anterior nasal spine at a point where the nose and upper lip meets. The maxillae contain pyramidal shaped cavities called the maxillary sinuses. The infraorbital foramen is located under each orbit on each maxillae which serves as a passage through which infraorbital nerve and artery reach the nose. The maxillae articulate with 2 cranial bones: frontal and ethmoid. Also articulates with all facial bones with the exception of the mandible.

Maxillary Bones Alveolar process = inferior borders of spongy bone that support roots of teeth Anterior nasal spine = forward, pointed process at their midline junction Acanthion = midpoint of this junction Maxilla helps form 3 facial cavities: nasal cavity, oral cavity and orbits Frontal process helps form the lateral border of nasal cavity, and medial wall of orbit Palatine process helps form anterior portion of hard palate Largest immovable facial bone

Maxillary Bone

Palatine Bones Two L-shaped bones composed of vertical and horizontal plates Horizontal plates articulate with maxillae to complete the posterior fourth of bony palate (roof of mouth) Vertical portions extend upward between maxillae and pterygoid processes of sphenoid in posterior nasal cavity Superior tips of vertical plates assist in forming posteromedial orbit

Palantine Bones Cut away view of face: palatine bone not seen on frontal view Helps form oral cavity, small portion of orbit

Hard Palate Inferior view of hard palate: Maxilla forms the anterior portion, the horizontal portion of palatine forms the posterior ¼th. Congenital defect: opening in between the palatine processes of the maxilla….Cleft palate NOTE: pterygoid hamulus of sphenoid bone….cranial bone articulation

Inferior Nasal Conchae Extend diagonally and inferiorly from lateral walls of nasal cavity at its lower third Long, narrow, very thin bones with a lateral curl Gives scroll-like appearance Upper two nasal conchae are processes of ethmoid bone The superior and middle nasal conchae are processes of the ethmoid bone, while the inferior nasal conchae are separate facial bones. The inferior nasal conchae are thin, narrow and extremely thin bones which curl laterally and look like miniature scrolls. The inferior nasal conchae articulate with the ethmoid bone and the maxilla, lacrimal and palatine bones.

Inferior Nasal Concha

Zygomatic Bones Articulations Superior = frontal bone Lateral = zygomatic process of temporal bone Anterior = maxilla Posterior = sphenoid Forms “cheek” of the face Another name is malar bone Articulates with 3 cranial bones-frontal, temporal, sphenoid Articulates with only one facial bone-maxilla

Zygomatic Bones Together with the zygomatic process of temporal bone and the temporal process of zygomatic bone forms the zygomatic arch Zygomatic prominence is a palpable landmark Zygomatic arch is easily fractured. Specialized views taken. Will be reviewed later.

Vomer Thin plate of bone situated in MSP of floor of nasal cavity Forms inferior nasal septum Superior border articulates with body of sphenoid bone Superior part of anterior border articulates with perpendicular plate of ethmoid bone Posterior border is free Together the perpendicular plate of the ethmoid bone and the vomer form the bony nasal septum. Anteriorly the septal septum is cartilaginous and is called the septal cartilage. A deviated nasal septum describers the clinical condition where the nasal septum is displaced laterally from the midline of the nose. This deviation occurs at the site of the septal cartilage and the vomer. If there is a severe deviation the nasal passageway can be blocked, not allowing the patient to breathe from their nose. The vomer has small furrow-like depressions for blood vessels. In a trauma this can be a source for nosebleed. Articulates with the sphenoid and ethmoid bones of the cranium. Articulates with the R/L palatine bones and the R/L maxillae.

Vomer Cut away diagram, Vomer is not readily seen on lateral view Notice the posterior border-does not articulate with any bone

Mandible Largest and densest bone of the face Body = curved horizontal portion Rami = two vertical portions on each side of body Angle of mandible = junction of body and ramus Also called gonion Mental protuberance = anterior, triangular prominence

Mandible Symphysis = most anterior and central part where left and right halves of mandible fuse Alveolar process = superior border of body; consists of spongy bone that supports roots of teeth Mental foramina = small openings on each side below the second premolar; transmit nerves and blood vessels

Mandible Coronoid process = anterior process on top of ramus Condylar process = posterior process on top of ramus; articulates with mandibular fossa of temporal bone to form temporomandibular joint (TMJ) Mandibular notch = concave area at top of ramus between coronoid and condylar processes

Anterior and lateral aspects of mandible Anatomy: Mandible Anterior and lateral aspects of mandible

Hyoid Bone Small U-shaped bone situated at the base of the tongue Accessory bone of axial skeleton – not a facial or cranial bone Only bone in the body that does not articulate with another bone

Lateral aspect of facial bones Anatomy: Facial Bones Lateral aspect of facial bones

Clicker Question Which facial bones form part of the hard palate? Palatine Mandible Zygoma Lacrimal A – Palatine

Clicker Question All of the following are part of the bony orbit, except: Palatine Zygoma Lacrimal Vomer D – Vomer

Essential Projections: Facial Bones Lateral Parietoacanthial (Waters method) Acanthioparietal (reverse Waters method) Posteroanterior (PA) axial (Caldwell method)

Lateral Facial Bones Patient position Part position Semi-prone or seated in upright anterior oblique Part position MSP of head parallel with image receptor (IR) Interpupillary line (IPL) perpendicular to IR Infraorbitomeatal line (IOML) perpendicular to front edge of IR Note the difference phrasing of the positioning of the IOML. This is the EXACT same position as in the cranium but since the collimation is different…but it sounds like it is changed. Long axis of collimated area is now vertical, not horizontal as in lateral view of cranium.

Lateral Facial Bones Central ray (CR) Collimated field Perpendicular to IR center Enters patient on lateral surface of zygomatic bone halfway between outer canthus and external acoustic meatus (EAM) Collimated field 8 x 10 inches (18 x 24 cm)

Lateral facial bones Zygomatic bones superimposed and centered Mandibular rami S/I (no rotation) Orbital roofs and greater wings of sphenoid are S/I (no tilt)

Lateral facial bones

Lateral facial bones Frequently collimated to 8x10 field

PA Axial (Caldwell) Patient position Part position Seated erect or prone MSP centered to midline Forehead and nose resting on table or upright Bucky Part position OML perpendicular to IR plane MSP perpendicular to IR IR centered to nasion Petrous ridges in lower 1/3 (proper angulation) Crista galli equidistant to outer orbital margin, superior orbital fissures symmetrical (rotation) Petrous at same level (tilt) If petrous ridges are shown in the lower ½ of orbits. What positioning error? How fix?

PA Axial (Caldwell) CR Collimated field Angled 15 degrees caudad Exits nasion For orbital rims, angle 30 degrees caudad (“exaggerated” Caldwell) Collimated field 10 x 12 inches (24 x 30 cm) Orbital rim, maxillae, nasal septum, zygomatic bones and anterior nasal spine

PA Axial (Caldwell)

PA Axial(Caldwell) Orbital rims, superior orbital fissures, crista galli, inferior nasal concha,

PA Axial (Caldwell) Notice the parietal bones have been clipped. Is this cause for repeat?

Parietoacanthial (Waters) Facial Bones Patient position Prone or seated upright Center MSP to midline of upright Bucky Be sure to practice both types of positioning, upright and prone in lab. Water’s view frequently done for air-fluid levels.

Parietoacanthial (Waters) Facial Bones Part position Rest head on tip of extended chin Place orbitomeatal line (OML) to form 37-degree angle with plane of IR Mentomeatal line (MML) perpendicular to IR MSP perpendicular to IR Center IR to level of acanthion

Parietoacanthial (Waters) Facial Bones CR Perpendicular to exit acanthion Collimated field 8 x 10 inches (18 x 24 cm)

Parietoacanthial (Waters) Facial Bones Note position of nose, ¾ “ away from IR

Parietoacanthial (Waters) Facial Bones

Parieto-acanthial (Waters) Facial Bones It is important that the petrous ridges lie below the maxillary sinuses.

Parietoacanthial (Waters) Facial Bones

Parietoacanthial (Waters) Facial Bones

Water’s view with accurate positioning What do you think the artifact is?

Parietoacanthial (Waters) Facial Bones Modifications for the Water’s projection: done to see entire orbital rims OML at a 55° angle to IR (use the LML for positioning) petrous ridges just below IOM

Parietoacanthial (Waters) Facial Bones-Modified

Parieto-acanthial (Waters) Facial Bones Modifications for the Water’s projection: Done in order to better see the entire orbital rims Petrous rideges in lower ½ of maxillary sinus Orbital floors should be centered in image.

Acanthioparietal (Reverse Waters) Facial Bones   When patient cannot be upright or prone, usually due to trauma

Acanthioparietal (Reverse Waters) Facial Bones CR Perpendicular to enter acanthion Center IR and CR Collimated field 10 x 12 inches (24 x 30 cm) Patients will have difficulty in getting MML ⊥ to IR, if they cannot, then angle CR so it is ∥ to MML

Acanthioparietal (Reverse Waters) Facial Bones

Acanthioparietal (Reverse Waters) Facial Bones

Acanthioparietal (Reverse Waters) Facial Bones

Acanthioparietal (Reverse Waters) Facial Bones

Acanthioparietal (Reverse Waters) Facial Bones Patient with difficulty in positioning MML ⊥ to IR so change CR angle to be ∥ to MML Be sure to practice this position in lab.

Essential Projections: Nasal Bones Lateral Water’s Caldwell A nasal bones series often includes a Modified Water’s, a PA axial (Caldwell), or a modified Caldwell Both these images will demonstrate deviation of bony nasal septum or fluid levles in sinuses due to trauma.

Lateral Nasal Bones Patient position Part position Semiprone MSP of head horizontal Part position MSP parallel with tabletop IPL perpendicular to tabletop IOML is parallel with transverse axis of IR Note the wording on the IOML. Used to be done on one film. Used detail film for imaging. Needs to be tightly collimated.

Lateral Nasal Bones CR Collimated field Perpendicular to bridge of nose Enters at a point ½ inch (1.3 cm) distal to nasion Collimated field 3 x 3 inches (8 x 8 cm) Field should extend from the glabella to the acanthion and ½ inch beyond the tip of the nose Note the size of the collimated field. Should include from glabella to acanthion.

Lateral Nasal Bones

Lateral Nasal Bones

Lateral Nasal Bones

Lateral Nasal Bones Be sure to include frontonasal suture (nasion ) and the anterior nasal spine (acanthion) Collimate from glabella to acanthion.

Pathologic Indications for Facial Radiography Fractures Blowout Tripod LeFort Coutrecoup Foreign Body Osteomyelitis Neoplasms Secondary Osteomyelitis TMJ Syndrome Fractures- a break in the structure of a bone caused by some sort of trauma. Blowout fracture- is a fracture of the floor of the orbit, caused by a direct blow to the orbital region. The floor ruptures and the inferior rectus muscle is forced through the fracture into the maxillary sinuses. This often causes diplopia (perception of two images), double vision. Tripod- is a fracture caused by a blow to the zygoma. It causes a break in 3 places- orbital process, maxillary process, and the arch. This causes a free floating zygomatic bone. LeFort- is a fracture that is bilateral horizontal fractures of the maxillae. Results in an unstable detached fragment. Countrecoup- is an fracture on one side of a structure caused by a blow from the other side. Fractures are evaluated by routine radiograph projections and/or CT imaging Foreign body of the eye- metal or other fragments in the eye. This usually occurs in an industrial setting. Evaluated by routine radiograph projections. Neoplasms- new and abnormal growth (tumor). Can be evaluated by routine radiograph projections but also CT/MRI Osteomyelitis- localized infection of the bone/bone marrow. This is usually a result of a trauma, fracture or postoperative bacteria. It also can be spread by blood from a distant site. Secondary Osteomyelitis- an infection of the bone and marrow secondary to sinusitis, results in erosion of the bony margins of the sinus. (CT/MRI) TMJ syndrome- set of symptoms that includes pain and clicking that indicates dysfunction of the TMJ’s. It can be caused by malocclusion, stress, muscle spasm, or inflammation. Evaluate by routine radiographs or by CT/MRI