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