This document discusses the anatomical landmarks in the mandible that are important for denture construction. It describes the limiting structures like frenums and vestibules that define the borders for a mandibular denture. The supporting structures that provide stability, like the buccal shelf area and residual alveolar ridge, are also outlined. Finally, it identifies relief areas over bony prominences on the mandible, such as the mylohyoid ridge and mental foramen, that require relief in the denture base to avoid pressure and pain.

1. ANATOMICAL LANDMARKS IN
MANDIBLE
Dr.SaiMadhavi, BDS

3. ANATOMICAL LANDMARKS IN MANDIBLE
LIMITING STRUCTURES
• Labial frenum
• Labial vestibule
• Buccal frnum
• Bucacal vestibule
• Lingual frenum
• Alveololingual sulcus
• Pterygo mandibular raphae
• Rtromolar pad

4. SUPPORTING STRUCTURES
• Buccalshelf area
• Residual alveolar ridge
• RELIEF AREAS
• Crest of residual alveolar ridge
• Mental foramen
• Genial tuberose
• Torus mandibularis

5. LIMITING STRUCTURES
• LABIAL FRENUM
• It is fibrous band similar to that of maxilla built has
muscle attachment.
• The muscles insivus & orbicularis Oris influence
this frenum.
• The mandibular labial frenum receives attachment
from orbicularis Oris muscle. Hence ,it is quite
sensitive and active.

6. • LABIAL VESTIBULE
• This is the space between the residual alveolar ridge and the lips.
• The length and thickness of the labial flange of the denture occupying
this space is crucial in influencing lip support and retention
• BUCCAL FRENUM
• It overlies the depressor anguli Oris, The fibres of Buccinator are
attached to the frenum.
• It should be relieved to prevent displacement of the denture during
function

7. • BUCCAL VESTIBULE
• It extends posteriorly from the frenum till the retromolar region.
• It is bound by the residual alveolar ridge on one side and
Buccinator on other side.
• This space influenced by the action of masseter ,when masseter
contracts ,it pushes inward against the buccinator ,producing a
bulge into the mouth.
• It reproduced as a notch in the denture flange called masseteric
notch.

8. • LINGUAL FRENUM
• The height &width of the frenum varies
considerably.
• Relief should be provided in the Anterior
portion of lingual flange.
• The Anterior portion of the lingual flange is
called sublingual crescent area.
• A high lingual frenum is called tongue tie.
• It should be corrected if it affects the stability
of the denture.

9. • ALVELOLINGUAL SULCUS ;
• It extends from lingual frenum to the retromylohyoid ,it
is considered in three regions namely;
1. Anterior region:It extends from the lingual frenum to
the premylohyoid Fassa, where the Mylohyoid curves
below the sulcus
2. Middle region :it extends from the pre-Mylohyoid
fossa to the distal end of the Mylohyoid ridge.
3. Posterior region: the retro-mylohyoid Fassa is
present here.the denture flange in this region

10. • Should turn laterally towards the
ramus of the mandible to fill up the
Fassa and complete the typical S-form
of the lingual flange of the lower
denture this is also called lateral throat
form .

11. • PTERYGOMANDIBULAR RAPHAE:
• It is arises from the hamular process of the medial pterygoid plate
and gets attached to the Mylohyoid ridge.
• A raphae is a tendinous insertion of two muscles ,the superior
constrictor inserted posteromedially and buccinator is inserted
anterolaterally.
• RETROMOLAR PAD:
• The retromolar pad is an important structure that forms the
posterior seal of the mandibular denture.
• It is non keratinized pa of tissue seen as a posterior continuation of
the pear shaped pad.

12. • Pear shaped pad triangular non keratinized soft tissue at the
distal end of the ridge.
• Boundaries:
1. Posteriorly - tendons of the temporalis
2. Laterally - Buccinator
3. Meadially - pterygomandibular raphae&superior
constrictor
• The muscles limit the denture extent and prevent extra
pressure during impression making .
• Hence the denture base should extend only half to 2/3rd of
the retromllar pad.

13. SUPPORTING STUCTURES
• The support for a msndibilar denture comes from the body of the mandible
• The available denture bearing area for edentulous mandible is lower than the
maxilla
• Hence the mandible is less capable of resisting occlusal forces.
1. BUCCALSHELF AREA
• It is the area between the buccal frenum and Anterior border of masseter.
• Bounderies:1.meadially the crest of the ridge
• 2 .distally retromolar pad
• 3.laterally external oblique ridge
• Buccal shelf area serves as primary stress bearing area.

14. • RESIDUAL ALVEOLAR RIDGE
• The edentulous mandible may become flat
with a concave denture bearing surface.
• In such cases the attaching structures on the
lingual side of ridge attach over the ridge.
• Due to resorption ,the mandible inclines
outward and becomes progressively wider
• The maxilla resorb upward and inward making
it smaller, this gives prognosis appearance.

15. RELIEF AREAS
MYLOHYOID RIDGE
• It turns along the lingual surface of the mandible.
• Anteriorly the ridge lies close to the inferior border
of mandible while posteriorly it lies flush with
residual ridge.
• Mucosa over the Mylohyoid ridge may get
traumatized and should be relieved
• The area under this ridge is an undercut.
• MENTAL FORAMEN
• It lies between the first and second premolar region.
• Due to ridge resorption ,it may lie close to the ridge
• It should be relieved in these cases as pressure over
the nerve produce paraestheia.

16. • GENIAL TUBERCLE:
• These are a pair of bony trubercle found Anteriorly
on the lingual side of the mandible.
• Due to resorption ,it may become kncreasingly
prominent making usage difficult
• . TORUA MANDIBULARIS
• It is an abnormal bony prominence found bilaterally
on the lingual side,near the premolar region.
• It is covered by a thin mucosa.
• It has to be relieved or surgically removed as decided
by its size and extent.

17. THANK YOU
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