Prostho 3 Anatomic Landmark
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Transcript of Prostho 3 Anatomic Landmark
P3- ANATOMIC LANDMARKS
BASAL SEAT (where the denture base/supporting structure is seated)
Boneo Spongy or cancellous (crest of lower
ridge)o Compact bone- max. residual
ridge/buccal shelves) Mucosa
o Masticatory (ridge, crest, hard palate) (keratinized, can withstand forces)
o Lining (sulcus region) (non-keratnized)
o Specialized (tongue)
MAXILLARY LANDMARKS
(Supporting/Denture Bearing Structures)A. Residual RidgeB. RugaeC. Hard palateD. Maxillary tuberosity
(Limiting Structures)A. Labial vestibuleB. Buccal vestibule C. Hamular notchD. Fovea palatineE. Vibrating line
(Relief Structures)A. Incisive papillaB. Median palatine raphaeC. Labial frenumD. Buccal frenumE. Pterygomandibular raphae
MANDIBULAR LANDMARKS
(Supporting Structures)A. Residual ridgeB. Buccal shelf
Boundaries:Anteriorly- buccal frenumPosteriorly- retromolar padLaterally- external oblique ridgeMedially- Crest of the residual ridge
(Limiting Structures)A. Labial vestibuleB. Buccal vestibuleC. Retromolar padD. Alveolingual sulcusE. Retromylohyoid space
(Relief Structures)A. Labial frenumB. Buccal frenumC. Crest of the residual ridgeif sharpD. Mental foramen area if ridge is flat
Definition of terms:Maxillary Ridge
Primary stress bearing area Has compact bone Fibrous connective tissue that is firmly
attached
Rugae Secondary stress bearing area Should be recorded without pressure For stability, support
Hard palate Anterolateral (fatty zone)
o Secondary stress bearing area Posterolateral (glandular zone)
o Secondary retentive area
Incisive Papilla Relief area to prevent pressure on the
nasopalatine nerves and vessels Can cause paraesthesia , pain, burning
sensations and other vague complaints
Median Palatine Raphae Relief area due to very thin and non resilent
mucosa Causing soreness or severe pain Can act as fulcrum point leading to rocking of
the denture
Zygomatic Process (Malar Process) Relieved when prominent to prevent
soreness Located on the 1st molar region
Maxillary Tuberosity Teeth are not set on the tuberosity region Covered by impression
Labial Frenum Relief area if not can lead to irritation Can affect denture seal and retention if close
to the ridge
Buccal Frenum Maybe single or double, broad or fan shape Relief area
Labial Vestibule Provide valve seal Affects appearance if not properly supported Elastic so easily underextended or
overextended
Buccal Vestibule Provide peripheral seal Width affected by masseter muscle and
coronoid process
Coronoid Process Affects the maxillary buccal flange as the
mandible moves forward, side to side or open wide
Masseter Muscle Reduced mandibular buccal vestibule space
under heavy biting pressure
Pterygomaxillary Notch Marks the posterior limit of the denture Additional pressure can be placed to
produce a seal (posterior palatal seal)
Pterygomandibular Raphae Extend from the hamulus to the distolingual
of the retromolar pad Recorded when mouth is open wide
Fovea Palatina
Formed by the joining together of several mucous gland ducts
Serves as a guide for the location of the position of the border of the denture (2mm anterior)
Posterior Palatal Seal Area Area between the anterior and posterior
vibrating line Shape of a cupid’s bow Additional pressure placed in this area to
effect seal Posterior vibrating line marks the posterior
limit of the denture
Lower Residual Ridge Crest (secondary relief area, made up of
cancellous bone) Slope (secondary stress bearing area, has
thin plate of cortical bone)
Buccal Shelf Area Primary stress area with dense smooth
cortical bone
Mylohyoid Ridge Where mylohyoid muscle is attached
(muscle of the floor of the tongue) Affects the height of the lingual flange
o Denture flange should extend below the ridge
o If border rest above the ridge, causes displacement and soreness
o Can cause irritation of thin and sharp
Mental Foramen Relief area in extremely resorbed ridges Pressure can cause numbness of the lip
External Oblique Ridge Buccal flange may extend up to or over it
Masseter Groove Contraction of the masseter muscle pushes
inward against the buccinators muscle and affects the distobuccal border of the lower border
Retromolar Pad Forms the part of the valve seal area
Retromylohyoid Curtain Limits the distolingual part of the denture
flange This is pulled forward when tongue is thrust
out Supported superiorly by the superior
constrictor muscle and lingually by the anterior tonsillar pillar
Alveolingual Sulcus Anterior region
o Shallowest Portion, from frenum to premylohyoid fossa
Middle regiono Slope toward the tongue o From premylohyoid fossa to distal
end of mylohyoid ridgeo Allows room for the action of the
mylohyoid muscle o Flange height increased in these
region Posteror region
o Slopes away from the tongue and towards the ridge
o From postmylohyoid to retromylohyoid curtain
Lingual Frenum Attaches the tongue anteriorly Failure to relieve can cause soreness and
dislodgement
Genial Tubercle Prominent only in severe ridge resorption Relieve to avoid pain and soreness Denture border should not rest on it
Sublingual Gland Region Sublingual gland comes close to the crest of the
ridge when floor of the mouth is raised Affects height of the flange
POSTERIOR PALATAL SEAL (Post Dam) – the seal along the posterior border of the maxillary denture
Functions: Primary purpose is retention Serves as barrier and prevent food accumulation
beneath the denture Mantains contact with the moving soft palate
thus reducing gag reflex Compensate for curing shrinkage Reduces tongue irritation as posterior border
merge better with palate
Boundaries of the Post DamAnteriorly
Anterior vibrating line Shaped like cupid’s bow Located by valsalva maneuver or saying “ah”
with a short vigorous burst
Posteriorly Posterior vibrating line Located by saying “ah” in normal fashion Junction between the aponeurosis of the tensor
veli palkatini muscle and muscular portion of the soft palate
Laterally Pterygomaxillary seal