1. BY- DR. AKANKSHA NARELA PG 1ST YEAR Maxillary Anatomical
landmarks
2. Contents - Introduction Intraoral landmarks Maxillary Arch
i. Histology ii. Supporting areas iii. Peripheral/limiting areas
Conclusion References
3. INTRODUCTION M.M Devan Dictum Aim of a prosthodontist is not
only the meticulous replacement of what is missing, but also
perpetual preservation of what is present A prosthesis must
function in harmony with the tissues that support them and those
that surround them. Hence the dentist must understand the
macroscopic as well as microscopic anatomy of the supporting and
limiting structures of the denture.
4. This knowledge aids in determining - i. The selective
placement of forces by the denture bases upon the supporting
tissues. ii. The form of the denture borders that will be
harmonious with the normal function of the limiting structures that
surround them.
5. INTRAORAL LANDMARKS
6. INTRAORAL LANDMARK SUPPORTING STRUCTURES LIMITING STRUCTURES
RELIEF AREA STRESS BEARING AREA
7. Stress bearing areas Primary stress bearing areas Secondary
stress bearing areas Stress Bearing Areas -
8. According to 9th edition of Boucher & 12th edition of
Zarb & Bolender MAXILLARY ARCH STRESS BEARING AREA RELIEF AREA
PRIMARY: RESIDUAL RIDGE SECONDARY: RUGAE INCISIVE PAPILLA, MEDIAN
PALATAL RAPHE, FOVEA PALATINI.
9. ACCORDING TO BOUCHERs 13 EDITION MAXILLARY ARCH STRESS
BEARING AREA RELIEF AREA PRIMARY: FIRM TUBEROSITY, HARD PALATE ON
EITHER SIDEOF PALATAL RAPHE SECONDARY: RUGAE, ALVEOLAR RIDGE
PALATAL TORUS, MEDIAN PALATAL RAPHE ,FOVEA PALATINI.
10. Maxilla Firm tuberosities Slopes of the hard palate on
either side of palatal raphae Primary stress bearing area - Areas
which are able to resist the vertical forces of occlusion.
11. Maxilla Alveolar ridge Rugae area Secondary Stress Bearing
Areas - Areas that resist the lateral forces of occlusion and can
aid the resistance to the vertical forces.
12. Relief Areas - That portion of the denture which is
relieved to eliminate excessive pressure on specific parts of the
denture supporting tissues. Maxilla Incisive papilla Mid palatine
raphe Torus palatinus Sharp bony prominences Fovea palatinae
13. Alveolar ridge (Residual ridge) Hard palate Incisive
papilla Palatal rugae Median raphe Maxillary tuberosity Fovea
palatinae Supporting Areas -
14. Labial frenum Labial sulcus Buccal frenum Buccal sulcus
Distobuccal space Hamular notch Posterior palatal seal area
Peripheral / Limiting Areas -
15. Correlation of anatomical landmarks - No . Landmark on
mouth Landmark in impression 1 Labial frenum Labial notch 2 Labial
vestibule Labial flange 3 Buccal frenum Buccal notch 4 Buccal
vestibule Buccal flange 5 Coronoid bulge Coronoid contour 6
Residual alveolar ridge Alveolar groove 7 Maxillary tuberosity
Maxillary tubercular fossa 8 Hamular notch Pterigomaxillary seal 9
Posterior palatal seal region Posterior palatal seal 10 Foveae
palatinae Foveae palatinae 11 Median palatine raphae Median
palatine groove 12 Incisive papilla Incisive fossa 13 Rugae region
rugae 14 Displacable soft & hard palate Butterfly outline of
pps
16. Mucous Membrane - Mucosa - Submucosa - Formed by stratified
squamous epithelium and a subjacent narrow layer of connective
tissue is present called as lamina propria. Composed of connective
tissue that varies from dense to loose areolar tissue. In
edentulous people mucosa covering hard palate + crest of residual
ridge + residual attached gingiva = Masticatory Mucosa. Thickness
varies and may contain glandular, fat or muscle cells and transmits
the blood and nerve supply to the mucosa. Characterized by well
defined keratinized layer on the outermost surface. Attachment
occurs between submucosa and periosteal covering of the bone and it
makes the bulk of the mucous membrane.
17. Oral Mucous Membrane Mucous Membrane -
18. The residual ridge is the remnant of the alveolar process
which originally contained sockets for natural teeth. After natural
teeth are extracted, the alveolar ridge can be expected to get
smaller (resorb). The rate of resorption varies considerably from
person to person. Alveolar Ridge (Residual Ridge) -
19. Histology of the mucous membrane covering the crest of the
residual ridge The submucosal layer is sufficiently thick to
provide resiliency for support of complete denture The bone
covering the crest of the upper ridge is often compact. Thus the
crest is the primary stress bearing area. submucosa
20. Hard Palate - The hard palate is made up of the anterior
two- thirds of the palatal vault supported by bone (palatine
processes of the maxillae and the horizontal plates of the palatine
bones). The palatine process are joined together at the medial
suture.
21. CONFIGURATION OF HARD PALATE :- Hard palate has been
classified by various authors : Nichols - Tapering Square Arched
/flat Heartwell ,Elinger Shay - based on different slopes V- shaped
Flat U-shaped High Medium
22. Gland tissueAdipose tissue Anterolateral part of the hard
palate, with abundant adipose tissue Posterolateral part of the
hard palate, with abundant gland tissue
23. It is a pad of fibrous connective tissue overlying the
orifice of the nasopalatine canal. Significance : 1. Stable
landmark and gives its relation to incisive foramen through which
the neurovascular bundle emerge and lie on the surface of bone.
Incisive Papillae -
24. 2. It is a biometric guide giving information on positional
relation to central incisors which are about 8-10 mm anterior to
incisive papilla. 3. Biometric guide which gives us information
about location of maxillary canines (A perpendicular drawn
posterior to the centre of incisive papilla to sagittal plane
passes through canines).
25. Clinical Consideration : During final impression procedure,
care should be taken not to compress the papilla. Hence the
incisive papilla should be relieved with a spacer. Reason : a.
Compression of blood vessels obliteration of the lumen deprive
nutrition to tissues breakdown of tissues. b. Pressure on nerve
causes parasthesia in the region of upper lip.
26. N. P. nerve and vessles Nassopalatine nerve and vessels in
submucosa layer
27. They are raised areas of dense connective tissue radiating
from the median suture in the anterior 1/3rd of the palate. It is
seconadary stress bearing area. Significance : 1.Said to be
concerned with phonetics. 2.Increase the surface area of the
foundation and thus supplement the values of retention. 3.It is the
denture stabilizing area in the maxillary foundation. Palatal Rugae
-
28. It is the area extending from the incisive papilla to the
distal end of the hard palate. Significance : 1.Area of sutural
joint and covered with firmly adherent mucous membrane to the
underlying bone with little submucosal tissue. 2.This sutural joint
is formed by the median fusion of two maxillary processes and two
horizontal plates of palatine bone. Mid palatine suture -
29. 3. Function of sutural joint is growth and sometimes there
will be overgrowth of the bone at the sutural joint resulting in
torus palatinus. Clinical Considerations : During final impression
procedure this raphe is relieved in order to create an equilibrium
between the resilient and non resilient tissues.
31. It is a narrow cleft of loose areolar tissue which is
approximately 2mm in extent antero-posteriorly. It is situated
between the distal surface of the tuberosity and the hamulus of
medial pterygoid plate. Located by using T-burnisher. Significance
: Constitutes the lateral boundary of posterior palatal seal area
in maxillary foundation. The pterygomandibular raphe attaches to
hamulus. Hamular Notch -
32. Clinical Consideration : 1.Denture should not extend beyond
the hamular notch, failure of which will result in : a.Restricted
pterygomandibular raphe movement. b.When mouth is wide open the
denture dislodges.
33. It is the distal most part of the residual alveolar ridge
and presents the hard tissue landmarks. They are primary stress
bearing area. Significance : The last posterior tooth should not be
placed on the tuberosity. Clinical Significance : Often there is
lateral and vertical growth of tuberosity and the area assumes
importance when maxillary antrum extends laterally with undercuts
at the tuberosity region. Maxillary Tuberosity -
34. It is important to prevent oro-antral fistula so it is
important to have radiograph before resection of the tuberosity. It
can be used for the retention of the denture.
35. They are the remnants of ducts of coalescence. Usually two
in number on either side of the midline. They indicate the vicinity
of posterior palatine seal area. Its position also influences the
position of the posterior border of the denture. Denture can extend
1-2 mm across it. In patients with thick saliva, the fovea palatine
should be left uncovered or else thick saliva flows between the
tissue and increase the hydrostatic pressure and hence lead to
denture displacement. Fovea Palatine -
36. Peripheral / Limiting areas
37. It appears as a fold of mucous membrane extending from the
mucous lining of the lip to the crest of residual ridge on the
labial surface. It may be single . It may be narrow / broad. It
contains no muscle fibers of significance. It starts superiorly as
a fan shape and converges as it descends to its terminal attachment
on the labial side of the ridge. Labial Frenum -
38. Clinical Consideration : 1.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. 2.During impression procedure the lip
should be stretched horizontal outwards for the proper recording of
frenum. 3.If frenum is attached close to the crest frenectomy is
done, failure of which will lead to the denture border being placed
on the bone tissue which will cause decreased border seal.
39. It extends on both sides of the midline from labial frenum
anteriorly to the buccal frenum posteriorly. It is bounded
laterally by the labial mucosa, medially by maxillary residual
alveolar ridge. It is lined by linig mucosa. Reflection of the
mucous membrane superiorly reflects the height. The area of mucous
membrane reflection has no muscle. Clinical Consideration : For
effective border contact between denture and tissue, vestibule
should be completely filled with impression material. Labial
Vestibule -
40. Fold or folds of mucous membrane extending from mucous
membrane reflection area to the slope or crest of residual alveolar
ridge. It forms the dividing line between the labial and the buccal
vestibule. Significance : LEVATOR ANGULIORIS (CANINUS MUSCLE) lies
beneath it and affect position of frenum. ORBICULARIS ORIS muscle
pulls frenum forward. BUCCINATOR MUSCLE pulls frenum backword.
Buccal Frenum -
41. Clinical Consideration: 1.During final impression procedure
and in final prosthesis sufficient relief should be given for the
movement of frenum because over-riding of function of frenum will
cause pain and dislodgement of denture. 2.During impression
procedure the cheek should be reflected laterally and posteriorly.
3.If frenum is attached close to the crest of alveolar ridge,
frenectomy is called for.
42. Boundaries : It is bounded anteriorly by the buccal frenum,
laterally by the buccal mucosa and medially by residual alveolar
ridge. Size of vestibule varies with contraction of BUCCINATOR
MUSCLE, POSITION OF MANDIBLE , AND AMOUNT OF BONE LOSS FROM
MAXILLA. Buccal Vestibule -
43. Clinical Consideration : 1.During impression procedure the
vestibule should be completely filled with impression material for
proper border contact between denture and tissues. 2.When the
vestibular space that is distal and lateral to the alveolar
tubercles is properly filled with denture flange the stability and
retention of the maxillary denture is greatly enhanced.
44. 3.The buccal flange borders depend upon movement of ramus
of mandible at the distal end of buccal vestibule and hence the
patient should move the mandible laterally and protrusively to make
sure the mandible does not interfere with these functions. 4.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.
45. N. S. Arbree, D.D.S.,* A. A. Yurkstas, D.M.D., M.S.,** and
J. H. Kronman, D.D.S., Ph.D.*** Tufts University, School of Dental
Medicine, Boston, Mass Also known as Buccal space or vestibule,
Buccal pocket, Tuberosity sulcus, Distobuccal angle of the buccal
vestibule, Buccal sulcus Buccal pouch, Buccal mucous membrane
reflection region Postmalar area
46. The coronomaxillary space: Literature review and anatomic
description The coronomaxillary space is that anatomic region that
lies medial to the coronoid process and lateral to the maxillary
tuberosity. It is bounded anteriorly -by the base of the zygomatic
process. posterior boundary-pterygomaxillary or hamular notch
inferior boundary - crest of the residual ridge. The
coronomaxillary flange of the maxillary denture is that portion of
the buccal flange that extends from the zygomatic eminence to the
hamular notch
47. Muscular influence Muscles affecting distobuccal space
interaction b/w buccinator& masseter Superior constrictor of
pharynx Medial pterygoid muscle , temporalis muscle
Pterygomandibular raphae
48. The coronoid process may be relatively straight or vertical
in some individuals . For these patients opening of the mandible
can result in narrowing of the space. In some individuals, however,
the coronoid process appears to flare laterally at its height With
a stronger temporal muscle insertion, this flare can be increased.
If the individual with a lateral flare of the coronoid process is
observed during opening, the space often remains the same or
becomes wider.
49. Various studies demonstrates alteration in coronomaxillary
space on wide opening of mouth, and some says no change in opening.
If the coronomaxillary space broadens or remains the same size on
opening , the functional filling of this space with the denture
flange becomes important. If the space is not completely filled or
even slightly overfilled,, maximum retention may be lost. In this
instance it is advisable not to have the patient open wide,
protrude, or move laterally during border molding or impression
procedures., A gentle molding of the region by pulling the cheek
out, down, and in will be more successful
50. Posterior Palatal Seal Area - It is also called as Post
dam, Post palatal seal . Defined as The soft tissue area at or
beyond the junction of the hard and soft palates on which pressure,
within physiologic limits, can be applied by a denture to aid in
its retention. (GPT -7) Hardy and Kapur stated that retention and
stability that is achieved from adhesion ,cohesion and interfacial
surface tension are able to resist those dislodging forces that are
perpendicular to the denture base. Horizontal and lateral torquing
of the maxillary denture can be resisted only by adequate border
seal.
51. Boundaries of posterior palatal seal area i. Anteriorly
Anterior vibrating line ii. Posteriorly - Posterior vibrating line
iii.Laterally Pterygomaxillary notch
52. Anterior Vibrating line An imaginary line located at the
junction of the attached tissues overlying the hard palate and the
movable tissues of the immediately adjacent hard palate. Shape bow
shaped anteriorly, sometimes referred to as Cupids Bow. Located by
a) Valsalva Maneuver - Both the nostrils are held firmly while the
patient blows gently through the nose. This positions the soft
palate downwards at its junction with the hard palate. b) Patient
is asked to say ah with short vigorous bursts. .
53. Posterior vibrating line An imaginary line at the junction
of the aponeurosis of the tensor veli palatini and the muscular
portion of the soft palate. Located by - it can be visualised when
the patient says ah in a normal un exaggerated fashion
54. Significance : 1) It maintains contact of denture with soft
tissue during functional movements of stomatognathic system
(mastication, deglutition and phonation etc.) 2) Decreases gag
reflex. 3) Decreases food accumulation with adequate tissue
compressibility. 4) Decrease patient discomfort of tongue with
posterior part of denture
55. 5) Compensation of volumetric shrinkage that occurs during
the polymerization of PMMA. 6) Permits normal movement of muscles
and ligaments. 7) Increases retention and stability by creating a
partial vacuum. 8) Increased strength of maxillary denture
base.
56. Classification of PPS based on soft palate configuration
(BERNARD LEVIN)- Class I:- Greater than 5 mm of movable tissue
available for post damming. It is the ideal for retention. Usually
thin denture base is advisable. Class II: - 1-5 mm of movable
tissue available for post damming, good retention is usually
possible. A medium thickness of denture base is quite
adequate.
57. FACTORS INFLUENCING PPS The accuracy of PPS reproduction in
complete denture depends on various factors :- Configuration of
hard palate. Investing medium Factors involved in processing of
acrylic resin. Denture base thickness. Head position
58. PPS determination methods can be broadly categorized based
on stage of denture construction as follows: PPS determination in
final impression stage. PPS determination or designing on master
cast. Recording PPS in Secondary Impression Appointment Stage
Methods to record pps
59. Determining PPS on Master Cast 1. Boucher's Technique 2.
Bernard Levin's Technique 3. Swenson's Technique 4. Calomeni,
Feldman,Kuebker's Technique 5. Pound's Technique 6. Apple Baum 7.
Winkler's Technique 8. Silverman's Technique 9. Hardy and Kapur
Technique
60. The basic goal of a successful complete denture therapy is
reaching the patients expectations in fulfillment of better
masticatory ability, unaltered speech and a better esthetics.
Extensions of the borders to get a good seal facilitates the
clinician to obtain the compromised treatment approach. The
clinician should have the anatomical knowledge to fabricate
prosthesis which inturn aids in proper maintenance of
stomatognathic system. Conclusion -
61. The knowledge of oral anatomy, microscopic as well as
macroscopic better equips us as prosthodontists to - i. Decide how
to make the impression. ii. What material to use? iii. How to plan
the treatment? All this will result in a successful prosthetic
treatment
62. 1. Zarb,Bolender,Carlson Bouchers prosthodontic treatment
for edentulous patients,12th edition 2. Sharry J.J. Complete
denture prosthodontics;ed.3.New York, 1974 3.Heartwell Charles
syllabus for complete dentures Ed.4,Philadelphia 4 .Sheldon Winkler
Essentials of complete denture Prosthodontics,ed.2 5. O Boucher
Swensons complete denture Prosthodontics,ed.6
63. 11.Benard Lynn,Detriot,Mich Significance of anatomic
landmarks in complete denture service,JPD,1964,14:456-459
12.H.R.Kolb-Variable denture limiting structures of the edentulous
mouth,Part 1 ,maxillary border areas,JPD 1966,16:194-204 13.Colie H
Millsap-The posterior palatal seal area for complete denture.
DCNA,Nov.1964,663 14.Nallaswamy-Textbook of prosthodontics,ed. 1
15.Inderbir Singh-Textbook of human histology with colour
atlas,ed.3 17.Orban-Oral histology & embryology,ed.10
16.Elinger-synopsis of complete denture prosthodontics,ed.1 18.N.
S. Arbree, D.D.S.,* A. A. Yurkstas, D.M.D., M.S.,** and J. H.
Kronman, D.D.S., Ph.D.***Tufts University, School of Dental
Medicine, Boston, Mass