anatomical landmarks of maxilla and prosthodontic considerations

1. Presented by : Dr. K. Mukesh kumar,
MDS 1st year
Department of Prosthodontics
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2. CONTENTS
1. Introduction
2. Anatomy of Maxilla
3. Macroscopic and microscopic features
4. Anatomical landmarks of maxillary arch
5. Clinical importance of each of the following
6. Limiting structures
7. Supporting structures
8. Relief areas
9. Conclusion
10.References
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3. INTRODUCTION
• Knowledge of orofacial anatomy is necessary for making
impressions, recording jaw relations, adjusting dentures,
etc.;
• It is necessary to review the important structures and their
functions and aware of anatomical variations
3

4.  Objective in fabrication of a complete denture is to provide a
prosthesis that restores lost teeth and associated structures
functionally, anatomically and aesthetically as much as possible
with preservation of underlying structures.
 A successful complete denture treatment should meet patients’
functional needs and gain their acceptance.
 The anatomy of the edentulous ridge in the maxilla and
mandible is very important for the design of a complete denture.
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5. ANATOMY OF MAXILLA
 Maxilla is a paired bone and is the second largest bone of
the face.
 The maxillary denture is supported by two pairs of bones:
• The maxillary bone and
• The palatine bone
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6.  Maxillae consists of a central body and four processes.
 The osseous structures not only supports the dentures, but
have a direct bearing on the impression-making procedures,
the position of the teeth, and the contours of the finished
denture bases.
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7. Macroscopic and microscopic features
 An understanding of the macroscopic and microscopic
anatomy of the areas in edentulous mouth is important
since it has direct clinical implications.
 Each type of tissue found in the oral cavity has its own
characteristic ability to resist external forces.
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8.  This will help to the selective placement of forces by the denture
bases on the supporting tissues.
 The foundation for dentures is called the basal seat, and it is
made up of bone that is covered by mucous membrane, mucosa
and submucosa.
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9. Oral mucosa:
 The bones of the upper and lower edentulous jaws are covered
with soft tissue and the oral cavity is lined with mucous
membrane.
 It serves as a cushion between the denture bases and the
supporting bone.
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10. The oral mucosa is composed of two layers :
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The Mucosa The Sub Mucosa
The mucosa in the oral cavity is
formed by stratified squamous
epithelium, which may or may not be
keratinized.
The submucosa is formed of the
connective tissue (lamina propria),
which may vary in thickness.

11. 11

12. Bone:
 Bone is a specialized mineralized connective
tissue consisting of 33 % organic matrix and
67% of inorganic matrix.
 The configuration of the bone that provides
the support for the dentures varies
considerably with each patient.
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13.  The consistency of the mucosa and the architecture of the
underlying bone is different in various parts of the edentulous
ridge.
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14. ANATOMICAL LANDMARKS OF
MAXILLA
Anatomical landmark is a recognizable anatomic structure used
as a point of reference.
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15. 15

16. LIMITING STRUCTURES
1. Labial frenum :
It is the fibrous band covered by mucous
membrane that extends from the labial
aspect of the residual ridge to the lip.
It has no muscle fibres, therefore passive
frenum.
Normally it is a single band of fibrous
connective tissue and may consists of two
or more fibrous bands.
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17. Microscopic feature :
It consists of thin band of mucous membrane, which is non-
keratinized.
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18. Clinical Considerations:
 It serves as guide to locate the midline in the upper occlusal
rim.
 Sufficient relief should be given during final impression
procedure and in completed prosthesis because overriding of
function of frenum will cause pain and dislodgement of
denture.
 During impression procedure the lip should be stretched
horizontal outwards for the proper recording of frenum.
International Journal of Applied Dental Sciences Anatomic landmarks in a maxillary and mandibular ridge - A clinical perspective 2017; 3(2): 26-
29
18

19. 2. Labial vestibule
 It is defined as that portion of the oral cavity which is
bounded on one side by the teeth, gingiva, and alveolar
ridge and on other side by lips and cheeks.
19

20. Microscopic features :
Histological section of the mucous membrane lining the
vestibular spaces depicts a relatively thin epithelium that is
non-keratinized.
The submucosal layer is thick and contains large amounts of
loose areolar tissue and elastic fibers.
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21. Clinical Considerations:
 Orbicularis oris is the main muscle of the lip.
 Its tone depends on the support received from the labial flange
of the denture and the position of artificial teeth.
 For effective border contact between denture and tissue,
vestibule should be completely filled with impression
material.
International Journal of Applied Dental Sciences Anatomic landmarks in a maxillary and mandibular ridge - A clinical perspective 2017; 3(2): 26-29
21

22.  3. Buccal frenum
It separates the labial and buccal vestibule and overlies the
levator anguli oris muscle.
Muscle attachments -
a.Levator anguli oris – attaches beneath the frenum and
hence influenced by other muscles of facial expression.
b.Orbicularis oris - pulls the frenum forward
c.Buccinator - pulls the frenum backward
22

23. Microscopic features :
Thin mucous membrane or band of tissue, which is non-
keratinized.
23

24. Clinical considerations -
 These muscles influence the position of the buccal frenum
hence it needs greater clearance on the buccal flange of the
denture.
 During final impression procedure and in final prosthesis
sufficient relief should be given for the movement of frenum
because overriding of function of frenum will cause pain
and dislodgement of denture.
 During impression procedure the cheek should be reflected
laterally and posteriorly.
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25.  4. Buccal vestibule
It extends from the buccal frenum anteriorly to the hamular
notch posteriorly and houses the buccal flange of the denture.
It is also called as
• Coronomaxillary space
• Buccal space
• Buccal pocket
• Tuberosity sulcus
• Buccal sulcus
• Buccal pouch
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26. The size of the buccal vestibule varies with
• Contraction of buccinator.
• Position of mandible
• Amount of bone loss in maxilla
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27. Microscopic features :
The histological section reveals like the labial vestibule, which is
thin non-keratinized epithelium with thick submucosa that
contains loose areolar tissue and elastic fibers.
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28.  The coronomaxillary space is that anatomic region that lies
medial to coronoid process ,lateral to maxillary tuberosity and
bounded anteriorly by base of zygomatic process and
posteriorly by pterygo-maxillary / hamular notch. Its inferior
boundary is at crest of the residual ridge.
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29. Clinical considerations –
 The buccal flange borders depend upon movement of ramus of
mandible at the distal end of buccal vestibule and hence the
denture should be adjusted in such a way that there is no
interference to the coronoid process during mouth opening.
 To effectively record the maxillary buccal sulcus the mouth
should be half way closed because wide opening of the mouth
narrows the space and does not allow proper contouring of
sulcus because the coronoid process of mandible comes closer
to the sulcus.
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30. 5. Hamular or Pterygomaxillary notch
It is the depression situated between the maxillary tuberosity and
the hamulus of medial pterygoid plate.
It is a narrow cleft of loose connective tissue which is
approximately 2mm in extent anteroposteriorly.
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31. Microscopic features :
The submucosa of the mucous membrane contained within the
hamular notch is thick and made up of loose or areolar tissue.
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32.  Clinical considerations :
• Denture should not extend beyond the hamular notch,
failure of which will result in restricted pterygomandibular
raphe movement.
• If the border is located anteriorly near the maxillary
tuberosity, the denture will not have any retentive
properties because the border seal is absent when placed
over non resilient tissues.
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33.  6. Posterior palatal seal
It is defined as the soft tissues at or along the junction of the
hard and soft palates on which pressure within the physiologic
limits of the tissues can be applied by a denture to aid in the
retention of the denture. – GPT-9
The posterior palatal seal is divided into two separate but
confluent areas based upon anatomic boundaries.
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34. Pterygomaxillary seal
Post palatal seal
Laterally the pterygomaxillary seal
extends through the
pterygomaxillary notch or hamular
notch continuing for 3-4 mm
anterolaterally approximating the
mucogingival junction.
The post palatal seal
extends medially from one
tuberosity to the
other.
Journal of Datta Meghe Institute of Medical Sciences University ,Volume 15, Issue 4,Techniques to record PPS : a review October-December
2020. 34

35. European Journal of Prosthodontics, Volume 2 ,Issue 2 The posterior palatal seal: Its rationale and importance: An overview41-47 ,2014-05-06
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36. VIBRATING LINES
 It is defined as "the imaginary line across the posterior part of
the soft palate marking the division between the movable and
immovable tissue". – GPT -8
 The posterior palatal seal area lies between anterior and
posterior vibrating lines.
 The anterior vibrating line is an imaginary line located at the
junction of the attached tissues overlying the hard palate and the
movable tissues of the immediately adjacent soft palate.
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37.  The Posterior Vibrating Line is an imaginary line at the
junction of the aponeurosis of the tensor veli palatine muscle
and the muscular portion of the soft palate.
 It represents the demarcation between the part of the soft
palate that has limited movement during function and the
remainder of the soft palate that is markedly displaced during
functional movements.
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38. 38

39. Microscopic features :
The submucosa in the region of the vibrating line on the soft
palate contains glandular tissue.
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Shape and contour of posterior palatal seal area in an
edentulous patient.

40. LOCATING POSTERIOR PALATAL SEAL REGION :
 Palpation method using a ‘T’ burnisher
 Nose blow method or Valsalva maneuver :
Closing both the nostrils of the patient and asking him to blow
gently through the nose.
 Phonation method :
Visualizing the vibrating lines as the patient says “ah”
 Anatomical landmarks :
Using fovea palatinae to identify vibrating area.
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41. Rationale of Posterior Palatal Seal
 This landmark presents a three dimensional seal area which
supplements values of retention of maxillary denture.
 It serves as a barrier and prevents ingress of fluid, food, air
between denture and tissue surface.
 It helps in decreasing gag reflex.
 It guides the positioning of custom tray during secondary
impression.
 By providing a thick border it compensates the warpage that
occur during polymerization.
 It provides comfort and confidence to the patient by increasing
the retention of denture.
Journal of Academy of Dental Education, 13-17, DOI: 10.18311/jade/2017/16451 41

42. SUPPORTING STRUCTURES
 These are the load bearing areas which show minimal ridge
resorption even under constant load.
 The denture should be designed such that most of the load is
concentrated on these areas.
1. Primary stress bearing area
2. Secondary stress bearing area
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43.  1. Hard palate
The anterior region of the palate is formed by the palatine
shelves of the maxillary bone, which meet at the centre to form
the median suture.
The horizontal plate of the palatine bone forms the posterior part
of the palate.
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44. Microscopic features :
 The soft tissues covering the hard palate vary considerably in
consistency and thickness in different locations.
 Anterolaterally, the submucosa of the hard palate contains
adipose tissue
 Posterolaterally, the submucosa contains glandular tissue.
Histology of the mucous membrane in the
posterolateral part of the hard palate
Histology of the mucous membrane in the
anterolateral part of hard palate
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45. Clinical considerations :
• It acts as the primary support area for maxillary denture.
• The trabecular pattern in the bone is perpendicular to the
direction of masticatory force, making it capable to
withstand any amount of force.
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46.  2. Residual ridge
It is defined as the portion of the residual bone and its soft tissue
that remain after the removal of teeth.
Microscopic features :
 The bone over the crest of the upper residual ridge is compact in
nature made up of haversian system.
 As the mucous membrane extends from the crest along the slope
of the upper residual ridge, it tends to loose its firm attachment
to the underlying bone, which marks the end of the residual
attached mucous membrane.
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47. Clinical considerations :
• It resorbs rapidly following extraction and continues
throughout life in a reduced rate.
• The submucosa over the ridge has adequate resiliency to
support the denture.
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48. 3. Palatal rugae
These are mucosal folds located in the anterior region of the
palatal mucosa.
They act as a secondary support area.
Clinical considerations -
• The folds of the mucosa play an important role in speech.
• It should be recorded under no pressure since the denture
unseats when rugae rebounds and tissue distorts.
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49. 4. Maxillary tuberosity
It is the bulbus extension of the residual ridge in the second and
third molar region.
Microscopic features :
Consist of fibrous tissue.
Clinical considerations :
The posterior part of the ridge and the tuberosity areas are most
important areas of support because they are least likely to
resorb.
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50. RELIEF AREAS
 These are the areas that resorb under constant load or contain
fragile structures within.
 The denture should be designed such that the masticatory load
is not concentrated over the areas.
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51. 1. Incisive papilla
It is a midline structure situated behind the central incisors.
It is the exit point of the nasopalatine nerves and vessels.
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52. Microscopic features :
Histological section through the incisive papilla and the
nasopalatine canal would reveal that the submucosa contains
the nasopalatine vessels and nerves.
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53. Clinical considerations :
• It should be relieved and if not the denture will compress the
vessels and nerves.
• It might lead to necrosis of the distributing areas.
• It may also cause paraesthesia of anterior palate.
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54. 2. Mid palatine raphe
This is the median suture area covered by a thin submucosa.
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55. Microscopic features :
The mucosa is firmly attached to the underlying bone in this
region with the submucosa very thin.
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56. Clinical considerations :
• It should be relieved during denture fabrication as this area is
the most sensitive part of the palate to pressure.
• In case of inadequate relief, fulcrum point is created which
might cause rocking of the denture.
• The exact amount of relief can be easily obtained in the
completed denture with the use of pressure-disclosing paste.
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57. 3. Fovea palatinea
These are two ductal openings into which the ducts of other
palatal mucous glands open.
Microscopic features :
The fovea is formed by a coalescence of several mucous
gland ducts.
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58. Clinical considerations :
• This acts as an arbitrary guide to locate the posterior border
of the denture.
• The secretion of the fovea spreads as a thin film on the
denture thereby aiding in retention.
• In patients with thick ropy saliva, this should be left
uncovered or else it can increase the hydrostatic pressure
and displace the denture.
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59.  4. Cuspid eminence
It is a bony elevation on the residual alveolar ridge formed after
extraction of canine.
It is located between the canine and first premolar region.
Clinical considerations -
It must be relieved to avoid the complication under pressure.
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60. 5. Torus palatinus
• This is a bony enlargement that occurs in the middle of the
palate in 20% of the population.
• It is covered by a thin mucosa which can act as a fulcrum and
is easily traumatised.
• Relief should be provided or surgical excision is planned.
Microscopic features :
It is covered by a thin mucosa.
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61. PROSTHODONTIC CONSIDERATIONS DURING ATYPICAL
MAXILLA

61

62. CONCLUSION :
 A good architect will not attempt to design a building until
he or she is very familiar with the site. Likewise, the dentist
must know all the oral and facial anatomy that is associated
with the making of impressions -Bernard levin.
 A complete denture must be designed with an emphasis on
preservation of the remaining oral structures and
understanding of the psychological changes affected by the
loss of all natural teeth.
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63.  In order to construct a prosthesis a dentist requires an
understanding of its components , its properties , and its
qualities to assure support for the proposed prosthesis.
 A thorough knowledge of oral anatomy helps the clinician in
identifying enough landmarks that in turn act as positive guides
in treatment planning
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64. REFERENCES :
• Hobrink J, Zarb GA, Bolender CL, Eckert S, Jacob R, Fenton
A, Mericske-Stern R. Prosthodontic treatment for edentulous
patients: complete dentures and implant-supported prostheses.
Elsevier Health Sciences; 2003 Sep 17.
• Sheldon Winkler. Essentials of complete denture
prosthodontics. Section II , Chapter 7. Third Edition 2015.
AITBS Publishers
• Deepak Nallaswamy. Textbook of Prosthodontics. Chapter 5.
Second edition. 2017. Jaypee Brothers Medical publishers (P)
Ltd.
• Arthur O. Rahn, John R. Ivanhoe, Kevin D. Plummer,Charles
M Heartwell. Syllabus Of Complete Dentures. Chapter 6. 6th
Edition. People's Medical Publishing House ; McGraw-Hill
[distributor], Shelton, Conn., London, ©2009. 64

65. • Bernard L. Impressions for complete dentures. Quintessence:
Chicago. 1984:71-90.
• Rangarajan Padmanabhan. Textbook of Prosthodontics. Section
1, Chapter 4. Second edition. 2017. Elsevier. RELX India Pvt
Ltd.
• European Journal Of Prosthodontics , Volume 2, Issue 2 The
posterior palatal seal: Its rationale and importance: An overview,
41-47 ,2014-05-06
• Agrawal S, Sathe S, Shinde D, Balwani T. Techniques to record
posterior palatal seal: A review
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