Skeletal System Part II Flashcards
Greater palatine foramen
Posterolateral region of horizontal plates
Carries the greater palatine nerve and blood vessels
** landmark for “greater palatine nerve block” to anesthetize the posterior palatal gingiva
What does the “greater palatine nerve block” anesthetize?
Posterior palatal gingiva
Lesser palatine foramen
Posterior to the greater palatine foramen
Carries the lesser palatine nerve and blood vessels
Innervate s the soft palate and palatine tonsils
Maxilla
Paired bone
Body of maxilla has orbital, nasal, infratemporal and facial surfaces
Houses maxillary sinuses which are located over the maxillary premolars and molars
Maxillary process
Frontal process
Zygomatic process
Alveolar process
Frontal process of maxilla
Forms the medial rim of the orbit and articulates with the frontal, lacrimal and nasal bones
Nerves and veins of the inferior orbital fissure
Infraorbital and zygomatic nerves (maxillary division (DII) of trigeminal)
Infraorbital artery
Inferior ophthalmic vein- passes to pterygoid venial plexus
Infraorbital sulcus
Groove in the orbital floor of the maxilla
Infraorbital canal
Travels from the infraorbital sulcus and terminates at the infraorbital foramen
Infraorbital foramen
Located on the facial surface of the maxilla
Carries the “infraorbital nerve and blood vessels”
Landmark for “infraorbital block”
Canine fossa
Elongated depression just posteriosuperior to the roots of the canine
Canine eminence
Prominence of alveolar bone over the canine route
Anterior to canine Fossa
Anesthesia landmark for “anterior superior alveolar (ASA) block”
Injection site at height of mucobuccal fold at canine root
Alveolar process (crest) of maxilla
Prominent ridge of bone that supports the maxillary teeth
Maxillary alveolar process is less dense than mandible
Zygomatic process of maxilla
Articulates with zygomatic bone and forms the infraorbital rim
Frontal process of maxilla
Articulates with frontal bone and forms part of the nasolacrimal duct
Alveolar process of the maxilla
Supports the upper teeth
Maxillary tuberosity
Most posterior aspect of maxillary arch
Posterior superior alveolar foramen
Superior to the maxillary tuberosity
Carries the posterior superior alveolar (PSA) nerve and maxillary blood vessels
Enters the maxilla from the alveolar canal
Landmark for “posterior superior alveolar (PSA) block“
Palatine process of maxilla
Forms the anterior 2/3 of the hard palate
Median Palatine suture
Junction of the right and left halves of the maxillary palatine processes
Incisive foramen
Opening for nasopalatine nerve
Landmark for the “nasopalatine block“. Anesthetize anteriors palatal gingiva canine to canine
Incisive papilla
Raised area of gingiva positioned over the incisive foramen
Maxillary tuberosity
Most posterior aspect of the maxilla
Mandible
Single bone — only movable bone of the skull and the strongest and largest facial bone
Mental protuberance
Prominence of the chin
Mandibular Symphysis
Faint ridge, marks fusion of the right and left halves of the mandible
Mental foramen
Bilateral openings for mental nerve and blood vessels to exit the mandible
Located between the apices of the first and second mandibular premolars
Anesthesia landmark for “mental incisive block“ to anesthetize canine, lateral and central incisor, along with associated facial gingiva
Body of the mandible
Heavy horizontal portion of the mandible
Alveolar process/ridge/crest of mandible
Ridge of bone that supports the mandibular teeth, found on the superior edge of the body of the mandible
Ramus
Vertical portion of the mandible (posterior portion)
Coronoid process
Anterior process of the ramus (first projection)
Coronoid notch
Concave curve found on the anterior border of the ramus
Landmark for the “inferior alveolar block”
(Front of coronoid process, behind retromolar pad)
External oblique line/Ridge
Inferior to the coronoid notch, crest on anterior border of the ramus where the ramus and mandibular body meet
Angle of the mandible
Posterior border of the body of the mandible
Mandibular notch
Depression between the coronoid process and condyle
Pterygoid fovea
Depressed area anterior and inferior to the condyle of the mandible
Condyle
Posterior process of the ramus, thicker than the coronoid process
Condyle has an oval shaped head that articulates with the temporal bone forming the temporomandibular joint
Genial tubercles or mental spine
At midline, cluster of small projections, muscle attachment for geniohyoid muscle
Lingual foramen
Opening for the lingual nerve and blood vessels
Digastric fossa
Position of attachment for anterior belly of the digastric muscle
Retromolar fossa/triangle
Bilateral, bony landmark on the lateral edge of the alveolar ridge just distal of the last mandibular molar, retromolar pad fills this area
Mylohyoid line/Ridge
Aka Internal oblique line
Extends posteriorly and superiorly across the inner surface of the body of the mandible, becoming more prominent as it ascends; point of muscle attachment for mylohyoid muscle
Sub mandibular Fossa
Posterior and inferior to the mylohyoid line, contains the submandibular salivary gland
Sublingual fossa
Anterior and superior to the mylohyoid line, contains the sublingual gland
Mandibular foramen
Central opening of the mandibular Canal, found near the middle of the medial surface of the ramus
Mandibular canal
Carries inferior alveolar nerves and blood vessels
Lingula
flange of bone which overhangs the mandibular foramen
Mylohyoid groove
Passes anteriorly and inferiorly from the mandibular foramen
Articulating surface of the condyle
Roughened area on the upper anterior part of the mandibular condyle
Paranasal sinuses
4 pairs
Air filled cavities in cranial and facial bones that communicate with the nasal cavity through the Ostia in the lateral nasal wall (ethmoid conchae & inferior nasal conchae)
Function of the paranasal sinuses
Lighten the skull
Warm the inhaled air
Provide mucus secretions for the nasal cavity
Act as sound resonators
Frontal sinuses
Located bilaterally in the frontal bone, superior to the nasal cavity
Asymmetrically shaped
Frontonasal duct drains via the frontal sinus ostia into the middle nasal meatus along the hiatus semilunaris
Sphenoid sinuses
Located bilaterally in the body of the sphenoid bone
Often asymmetrical
Drains via sphenoid all aperture‘s into the superior nasal meatus along The spheno-ethmoidal recess
Ethmoid sinuses
Located bilaterally in the ethmoid bone
3 divisions (anterior, middle, posterior)
Small cavities of varying sizes
Drainage of the anterior ethmoid sinus
Via anterior ethmoidal Ostia into the middle nasal meatus above the hiatus semilunaris
Drainage of the middle ethmoid sinus
Via middle ethmoidal Ostia into the middle nasal meatus above the bulla ethmoidalis
Drainage of the posterior ethmoid sinus
Via posterior ethmoidal Ostia into the superior nasal meatus along The spheno-ethmoidal recess
Maxillary sinuses
Largest of the paranasal sinuses and significant to dentistry
Located bilaterally in body of the maxilla, just superior and posterior to the maxillary pre-molars and extending over the maxillary molars
Size varies to the individual and their age
Drain via maxillary ostia into the middle nasal meatus along the hiatus semilunaris
Primary sinusitis
Congestion and inflammation caused by allergies and infection
Symptoms- headache, foul smelling/tasting nasal drainage, fever and weakness
Serious complications – Spread of infection to ethmoid and sphenoid = close proximity to the cavernous sinus and optic nerve
Blockage of the ostia
Prevents normal Eric’s change and drainage; may require surgery to enlarge the ostia openings to restore function
Chronic maxillary sinusitis is common; ostia is superior to the floor of the sinus cavity, this may also require surgery
Secondary sinusitis
Inflammation from another source, an infection or trauma associated with a posterior maxillary tooth; such as a periapical and/or periodontal infection or surgical trauma
Sinus perforation
Hole in the wall of the sinus, can occur with an infection or a surgical complication of an extraction or sinus lift. Requires additional surgery to repair
Dental pain
Sinus infections can cause tooth pain, due to pressure from the infected sinus on the apical periodontium of the tooth
No decay or abscess
Aging and tooth loss
Affect the maxillary sinuses
Maxillary sinuses enlarge with aging, may surround the roots of the posterior maxillary teeth and extend into the body of the zygomatic bone
Loss of the posterior maxillary teeth allows the maxillary sinus to expand further resorbing the alveolar process to a thin shell
Hyoid bone
Suspended horizontally on the neck. No bone articulations
Posteriorly suspended from the styloid processes of the Stylohyoid ligament
Anteriorly suspended from the thyroid cartilage by the thyrohyoid membrane
Function of the hyoid bone
Formed the base of the tongue and larynx and serves for many muscle attachments
Mobility aids in mastication, swallowing and phonation
Components of the higher the phone
5 parts
Body Greater Cornu (horns,2) Lesser Cornu (horns,2)
Oral Tori
Bony enlargements
Found on: the median Palatine Raphe, just inferior to mandibular premolars or on the facial and buccal aspects of the alveolar process
Facial bone fractures
Affect several bones and soft tissues due to the many articulation and close Association of soft tissues
Frontal bone fracture
May affect the forehead and eyes
Temporomandibular joint
Bilateral joint Located between the temporal bone and mandible found just anterior to the tragus of the ear
Enables the mandible to move during phonation and mastication
Innervated by the mandibular division of the trigeminal nerve
Movements of the temporomandibular joint
Rotational- A long transverse access, allows the mandible to open and close
Gliding- Along an incline plane, allows the mandible to move forward and backward
Combination movements- Allows for the finer movements needed for opening closing and shifting during speech and mastication
Power stroke- Movement is utilized during mastication when the teeth crush food
Articular eminence of the Temporal bone
Round, raised bony structure, stop point for the moving mandibular condyle
Articular Fossa (mandibular/Glenoid)
Depression where mandibular condyle articulates
Postglenoid process
Sharp Ridge, just posterior to articular Fossa
Articulating surface of the condyle
Head of the condyles, superior surface
Joint capsule
Completely encloses the TMJ
Superiorly covering the articular eminence and articular fossa
Inferiorly covering the mandibular condyles onto the neck of the condyles
Articular disc (meniscus of the TMJ)
Biconcave desk located in the capsule between the temporal bone and mandibular condyles
Synovial cavities
Divided by articular desk into upper synovial cavity and lower synovial cavity
Synovial fluid
Lubricates the joint, fills the synovial cavities
Secretions are produced by membrane lining the synovial cavities
TMJ ligaments
Form from bands of fibrous connective tissue
Temporomandibular ligament
Stylomandibular ligament
Sphenoidmandibular ligament
Temporomandibular ligament
Located on the lateral sides of each joint, extends from the posterior surface of the neck of the condyle to the zygomatic arch
Functions in reinforcement of the joint capsule and prevents excessive retraction of mandible
Stylomandibular ligament
Located on the posteriomedial surface of the ramus, extends from the styloid process of temporal bone to the angle of the mandible
Prevents the mandible from protruding too far
Sphenoidmandibular ligament
Located on the medial side of the ramus, extends from the angular spine of the sphenoid to the lingula of the mandibular foramen
Prevents the mandible from protruding too far
TMJ dysfunction (TMD)
Acute or chronic joint tenderness, swelling, muscle spasms, limited or deviated opening of the mandible
referred pain to the head and neck region: ears, neck, shoulders etc.
Causes of TMD
Clenching and bruxism, malocclusion‘s, posterior bite collapse, trauma
Treatment of TMD
Diagnosis through head and neck exam with palpation of the TMJ and MRI
Treatment uses relaxation therapy, stress management to consciously control clenching and grinding
OTC pain control, RX pain control and/or RX muscle relaxants. Orthodontic correction of malocclusion, replacement of missing posterior teeth, night/occlusal guard
TMJ sounds
Disc displacement, posterior portion of the disc gets caught between the head of the condyle and the articular eminence
Popping, clicking, grinding
Subluxation or partial dislocation of both TMJ joints
Patient cannot close the mandible
Condyles have moved too far forward on to the articular eminence
Clinic chairside, have patient illicit their gag reflex, this may help to spontaneously reduce jaw dislocation
