A major connector joins the components on one side of the arch with those on the opposite side. Therefore, all components are attached to the associated major connector either directly or indirectly.
Prosthodontics seminar 3rd stage University of Anbar College Of Dentistry
Created By Mohammed Amer Hekma
Supervised by: Dr Osama Abdul Rasool Hammoodi
References
• FUNDAMENTALS OF REMOVABLE PARTIAL PROSTHODONTIC DESIGN by Kenneth R. McHenry, D.D.S., M.S and Terrence McLean, D.D.S.
• Stewart's Clinical Removable Partial Prosthodontics, Fourth Edition by Rodney D Phoenix, D.D.S, M.S, David R Cagna, D.M.D, M.S and Charles F DeFreest, D.D.S
• McCRACKEN’S REMOVABLE PARTIAL PROSTHODONTICS, TWELFTH EDITION BY Alan B. Carr, D.M.D, M.S, and David T. Brown, DDS, MS
Components of removable partial denture prosthesis /certified fixed orthodont...Indian dental academy
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and offering a wide range of dental certified courses in different formats.
Indian dental academy provides dental crown & Bridge,rotary endodontics,fixed orthodontics,
Dental implants courses.for details pls visit www.indiandentalacademy.com ,or call
0091-9248678078
Prosthodontics seminar 3rd stage University of Anbar College Of Dentistry
Created By Mohammed Amer Hekma
Supervised by: Dr Osama Abdul Rasool Hammoodi
References
• FUNDAMENTALS OF REMOVABLE PARTIAL PROSTHODONTIC DESIGN by Kenneth R. McHenry, D.D.S., M.S and Terrence McLean, D.D.S.
• Stewart's Clinical Removable Partial Prosthodontics, Fourth Edition by Rodney D Phoenix, D.D.S, M.S, David R Cagna, D.M.D, M.S and Charles F DeFreest, D.D.S
• McCRACKEN’S REMOVABLE PARTIAL PROSTHODONTICS, TWELFTH EDITION BY Alan B. Carr, D.M.D, M.S, and David T. Brown, DDS, MS
Components of removable partial denture prosthesis /certified fixed orthodont...Indian dental academy
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and offering a wide range of dental certified courses in different formats.
Indian dental academy provides dental crown & Bridge,rotary endodontics,fixed orthodontics,
Dental implants courses.for details pls visit www.indiandentalacademy.com ,or call
0091-9248678078
A precise and summarized presentation on Mandibular Major Connector's with vivid pictures and sketches.
This includes various contents like what different types of connectors are explained precisely with their characteristics and location, blocking and relief & how they look like on casts.
Hope this presentation helps you understand the concept
by Dr. Ishaan Adhaulia
Raju major n minor connectors/certified fixed orthodontic courses by Indian d...Indian dental academy
Description :
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.for more details please visit
www.indiandentalacademy.com
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.for more details please visit
www.indiandentalacademy.com
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.for more details please visit
www.indiandentalacademy.com
Indian Dental Academy: will be one of the most relevant and exciting training
center with best faculty and flexible training programs for dental
professionals who wish to advance in their dental practice,Offers certified
courses in Dental implants,Orthodontics,Endodontics,Cosmetic Dentistry,
Prosthetic Dentistry, Periodontics and General Dentistry.
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.for more details please visit
www.indiandentalacademy.com
A precise and summarized presentation on Mandibular Major Connector's with vivid pictures and sketches.
This includes various contents like what different types of connectors are explained precisely with their characteristics and location, blocking and relief & how they look like on casts.
Hope this presentation helps you understand the concept
by Dr. Ishaan Adhaulia
Raju major n minor connectors/certified fixed orthodontic courses by Indian d...Indian dental academy
Description :
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.for more details please visit
www.indiandentalacademy.com
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.for more details please visit
www.indiandentalacademy.com
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.for more details please visit
www.indiandentalacademy.com
Indian Dental Academy: will be one of the most relevant and exciting training
center with best faculty and flexible training programs for dental
professionals who wish to advance in their dental practice,Offers certified
courses in Dental implants,Orthodontics,Endodontics,Cosmetic Dentistry,
Prosthetic Dentistry, Periodontics and General Dentistry.
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.for more details please visit
www.indiandentalacademy.com
A Clinical Review of Spacer Design for Conventional_124155.pptxDrIbadatJamil
One of the key factors affecting the outcome of the treatment is the impression procedure involved in the fabrication of complete denture prosthesis. Selective-pressure impression technique is most accepted. In this technique, by using custom trays with spacers of different materials and designs, vulnerable tissues are relieved and stresses are distributed selectively to biomechanically sound tissues. But the uses stock tray for making primary impression as well as final impression due to the lack of knowledge of the following: optimum material for making custom impression tray, adequate extension, required thickness and designs of spacer, tissue stops, escape holes, tray handles, and polymerization time regarding custom impression trays in prosthodontics. This seminar will give a clear view to use accurate spacer design, material and thickness, tissue stops, and escape holes, based on various clinical situations.
The soft tissues along the junction of hard and soft palate on which pressure within the physiological limits of tissues can be applied by the denture to aid in retention of the denture.
Articulators is a mechanical device which represents the temporo-mandibular joints and jaw members to which maxillary and mandibular casts may be attached.’’
It occurs when a hard, rough surface slides along a softer surface and cuts a series of grooves.
The wearing away of a substance or structure through a mechanical process, such as grinding, rubbing or scraping .
Polishing is production of smooth mirror like surface without use of any external form.
A prosthetic device or alloplastic material
implanted into oral tissues beneath the mucosal
or periosteal tissues and/or within the bone to provide retention and support for fixed or removal prosthesis.
Denture Duplication aims the transfer of contours from old to new dentures to maintain neuromuscular control. New dentures will have successful features of old ones. Any modifications done to the basic shape of old denture should be : those needed to correct loss of fit and those considered essential by the dentist i.e replacement of worn acrylic teeth.
Fracturing and chipping of denture is common problem which need repair . Possible causes for fracture of denture is fall of the prosthesis on a hard surface , careless retrieval after processing of the prosthesis , manufacturing defect of the denture.
An immediate complete denture is a dental prosthesis constructed to replace the lost dentition and associate structure of the maxillae and/or mandible and inserted immediately following removal of remaining teeth.
Direct Filling Gold is the oldest filling material that is still being used in restorative dentistry. The vision to utilize this noble metal for the replacement of lost tooth structure stemmed from the perfect harmony of its biological and mechanical properties, excluding esthetics. Direct gold restorations exhibit excellent marginal integrity and biocompatibility in the oral environment.
A biomaterial can be defined as any substance other than a drug that can be used for any period of time as part of a system that treats, augments, or replaces any tissue, organ or function of the body.
June 3, 2024 Anti-Semitism Letter Sent to MIT President Kornbluth and MIT Cor...Levi Shapiro
Letter from the Congress of the United States regarding Anti-Semitism sent June 3rd to MIT President Sally Kornbluth, MIT Corp Chair, Mark Gorenberg
Dear Dr. Kornbluth and Mr. Gorenberg,
The US House of Representatives is deeply concerned by ongoing and pervasive acts of antisemitic
harassment and intimidation at the Massachusetts Institute of Technology (MIT). Failing to act decisively to ensure a safe learning environment for all students would be a grave dereliction of your responsibilities as President of MIT and Chair of the MIT Corporation.
This Congress will not stand idly by and allow an environment hostile to Jewish students to persist. The House believes that your institution is in violation of Title VI of the Civil Rights Act, and the inability or
unwillingness to rectify this violation through action requires accountability.
Postsecondary education is a unique opportunity for students to learn and have their ideas and beliefs challenged. However, universities receiving hundreds of millions of federal funds annually have denied
students that opportunity and have been hijacked to become venues for the promotion of terrorism, antisemitic harassment and intimidation, unlawful encampments, and in some cases, assaults and riots.
The House of Representatives will not countenance the use of federal funds to indoctrinate students into hateful, antisemitic, anti-American supporters of terrorism. Investigations into campus antisemitism by the Committee on Education and the Workforce and the Committee on Ways and Means have been expanded into a Congress-wide probe across all relevant jurisdictions to address this national crisis. The undersigned Committees will conduct oversight into the use of federal funds at MIT and its learning environment under authorities granted to each Committee.
• The Committee on Education and the Workforce has been investigating your institution since December 7, 2023. The Committee has broad jurisdiction over postsecondary education, including its compliance with Title VI of the Civil Rights Act, campus safety concerns over disruptions to the learning environment, and the awarding of federal student aid under the Higher Education Act.
• The Committee on Oversight and Accountability is investigating the sources of funding and other support flowing to groups espousing pro-Hamas propaganda and engaged in antisemitic harassment and intimidation of students. The Committee on Oversight and Accountability is the principal oversight committee of the US House of Representatives and has broad authority to investigate “any matter” at “any time” under House Rule X.
• The Committee on Ways and Means has been investigating several universities since November 15, 2023, when the Committee held a hearing entitled From Ivory Towers to Dark Corners: Investigating the Nexus Between Antisemitism, Tax-Exempt Universities, and Terror Financing. The Committee followed the hearing with letters to those institutions on January 10, 202
Honest Reviews of Tim Han LMA Course Program.pptxtimhan337
Personal development courses are widely available today, with each one promising life-changing outcomes. Tim Han’s Life Mastery Achievers (LMA) Course has drawn a lot of interest. In addition to offering my frank assessment of Success Insider’s LMA Course, this piece examines the course’s effects via a variety of Tim Han LMA course reviews and Success Insider comments.
The Roman Empire A Historical Colossus.pdfkaushalkr1407
The Roman Empire, a vast and enduring power, stands as one of history's most remarkable civilizations, leaving an indelible imprint on the world. It emerged from the Roman Republic, transitioning into an imperial powerhouse under the leadership of Augustus Caesar in 27 BCE. This transformation marked the beginning of an era defined by unprecedented territorial expansion, architectural marvels, and profound cultural influence.
The empire's roots lie in the city of Rome, founded, according to legend, by Romulus in 753 BCE. Over centuries, Rome evolved from a small settlement to a formidable republic, characterized by a complex political system with elected officials and checks on power. However, internal strife, class conflicts, and military ambitions paved the way for the end of the Republic. Julius Caesar’s dictatorship and subsequent assassination in 44 BCE created a power vacuum, leading to a civil war. Octavian, later Augustus, emerged victorious, heralding the Roman Empire’s birth.
Under Augustus, the empire experienced the Pax Romana, a 200-year period of relative peace and stability. Augustus reformed the military, established efficient administrative systems, and initiated grand construction projects. The empire's borders expanded, encompassing territories from Britain to Egypt and from Spain to the Euphrates. Roman legions, renowned for their discipline and engineering prowess, secured and maintained these vast territories, building roads, fortifications, and cities that facilitated control and integration.
The Roman Empire’s society was hierarchical, with a rigid class system. At the top were the patricians, wealthy elites who held significant political power. Below them were the plebeians, free citizens with limited political influence, and the vast numbers of slaves who formed the backbone of the economy. The family unit was central, governed by the paterfamilias, the male head who held absolute authority.
Culturally, the Romans were eclectic, absorbing and adapting elements from the civilizations they encountered, particularly the Greeks. Roman art, literature, and philosophy reflected this synthesis, creating a rich cultural tapestry. Latin, the Roman language, became the lingua franca of the Western world, influencing numerous modern languages.
Roman architecture and engineering achievements were monumental. They perfected the arch, vault, and dome, constructing enduring structures like the Colosseum, Pantheon, and aqueducts. These engineering marvels not only showcased Roman ingenuity but also served practical purposes, from public entertainment to water supply.
A Strategic Approach: GenAI in EducationPeter Windle
Artificial Intelligence (AI) technologies such as Generative AI, Image Generators and Large Language Models have had a dramatic impact on teaching, learning and assessment over the past 18 months. The most immediate threat AI posed was to Academic Integrity with Higher Education Institutes (HEIs) focusing their efforts on combating the use of GenAI in assessment. Guidelines were developed for staff and students, policies put in place too. Innovative educators have forged paths in the use of Generative AI for teaching, learning and assessments leading to pockets of transformation springing up across HEIs, often with little or no top-down guidance, support or direction.
This Gasta posits a strategic approach to integrating AI into HEIs to prepare staff, students and the curriculum for an evolving world and workplace. We will highlight the advantages of working with these technologies beyond the realm of teaching, learning and assessment by considering prompt engineering skills, industry impact, curriculum changes, and the need for staff upskilling. In contrast, not engaging strategically with Generative AI poses risks, including falling behind peers, missed opportunities and failing to ensure our graduates remain employable. The rapid evolution of AI technologies necessitates a proactive and strategic approach if we are to remain relevant.
Palestine last event orientationfvgnh .pptxRaedMohamed3
An EFL lesson about the current events in Palestine. It is intended to be for intermediate students who wish to increase their listening skills through a short lesson in power point.
Acetabularia Information For Class 9 .docxvaibhavrinwa19
Acetabularia acetabulum is a single-celled green alga that in its vegetative state is morphologically differentiated into a basal rhizoid and an axially elongated stalk, which bears whorls of branching hairs. The single diploid nucleus resides in the rhizoid.
Operation “Blue Star” is the only event in the history of Independent India where the state went into war with its own people. Even after about 40 years it is not clear if it was culmination of states anger over people of the region, a political game of power or start of dictatorial chapter in the democratic setup.
The people of Punjab felt alienated from main stream due to denial of their just demands during a long democratic struggle since independence. As it happen all over the word, it led to militant struggle with great loss of lives of military, police and civilian personnel. Killing of Indira Gandhi and massacre of innocent Sikhs in Delhi and other India cities was also associated with this movement.
Biological screening of herbal drugs: Introduction and Need for
Phyto-Pharmacological Screening, New Strategies for evaluating
Natural Products, In vitro evaluation techniques for Antioxidants, Antimicrobial and Anticancer drugs. In vivo evaluation techniques
for Anti-inflammatory, Antiulcer, Anticancer, Wound healing, Antidiabetic, Hepatoprotective, Cardio protective, Diuretics and
Antifertility, Toxicity studies as per OECD guidelines
2. A major connector joins the components on
one side of the arch with those on the
opposite side. Therefore, all components are
attached to the associated major connector
either directly or indirectly.
Components of a typical removable partial
denture are
1. Major connectors
2. Minor connectors
3. Rests
4. Direct retainers
5. Stabilizing or reciprocal components
6. Indirect retainers
3. To function effectively and minimize
potentially damaging effects, all major
connectors must be :
1. Rigid
2. Provide vertical support and protect the soft
tissues
3. Provide a means for obtaining indirect
retention where indicated
4. Provide a means for placement of one or
more denture bases
5. Promote patient comfort
4. Major connectors should be designed and
located with the following guidelines in mind:
1. Major connectors should be free of movable
tissue.
2. Impingement of gingival tissue should be
avoided.
3. Bony and soft tissue prominences should be
avoided during placement and removal.
4. Relief should be provided beneath a major
connector to prevent its settling into areas of
possible interference, such as inoperable tori or
elevated median palatal sutures.
5. Major connectors should be located and/or
5. Six basic types of maxillary major
connectors are considered:
1. Palatal bar
2. Palatal strap
3. Antero-posterior palatal bar
4. Horseshoe
5. Antero-posterior palatal strap
6. Complete palate
6. Palatal Bar
The palatal bar is a narrow half oval with its thickest
point at the center. The bar is gently curved and should
not form a sharp angle at its junction with the denture
base .
Advantages :
Palatal bar major connectors are used primarily in
interim applications. The palatal bar has few
advantages and should be avoided.
7. Disadvantages :
To provide the necessary rigidity, a palatal bar major
connector must be bulky.
Moreover, because of its narrow antero-posterior width,
a palatal bar derives little vertical support from the bony
palate. As a result, a palatal bar major connector must
derive nearly all of its support from rests on the
remaining teeth.
If used, the palatal bar should be limited to short span
Class III applications (e.g, replacing one or two teeth on
each side of the arch).
In addition, the palatal bar should not be placed
anterior to the second premolar position, otherwise its
bulk may produce noticeable discomfort and alteration
of speech.
8. Palatal Strap
The palatal strap consists of a wide band of
metal with a thin cross-sectional dimension .
Because of its minimal depth, this major
connector may be used to cross the palate in
an unobtrusive manner.
9. Nevertheless, the antero-posterior dimension
of a palatal strap major connector should not
be less than 8 mm to avoid compromise of its
rigidity .
The width of a palatal strap major
connector should be increased as the
edentulous space increases in length. This
increase in width not only ensures rigidity, but
also permits greater support from the hard
palate.
10. While wide palatal strap may be used for
unilateral distal extension partial dentures
(i.e, Kennedy Class II), it should not be used
for bilateral distal extension applications (i.e,
Kennedy Class 1).
Advantages :
• Palatal strap is located in two or more
planes, it offers great resistance to bending
and twisting forces.
• Palatal strap is inherently strong, it can be
kept relatively thin.
• Well accepted by patients.
• The increased tissue coverage helps
distribute applied stresses over a larger area.
11. Disadvantages :
In some instances, a patient may complain of
excessive palatal coverage. Frequently, this
complaint can be traced to improper positioning of
the strap borders. Therefore, the anterior border of
the major connector should be positioned posterior
to the palatal rugae if possible.
The increased soft tissue coverage associated with
a wide palatal strap also may predispose the
patient to papillary hyperplasia.
Therefore, it is essential that each removable
partial denture patient be provided with thorough
oral and written instructions regarding the wear,
12. Antero-posterior palatal bar
The antero-posterior palatal bar displays
characteristics of palatal bar and palatal strap
major connectors .
The anterior bar is relatively flat. Its cross-
sectional shape is similar to that of a palatal
strap.
13. Borders of the anterior bar are positioned on
the appropriate slopes of prominent rugae,
thereby allowing it to blend with the contours
of the anterior palate.
The posterior bar is a half oval, similar to the
palatal bar major connector.
The two bars are joined by flat longitudinal
elements on each side of the palate. The two
bars, lying in different planes, produce a
structurally strong L-beam effect.
14. Advantages :
It is rigid.
Minimizes soft tissue coverage, yet provides
exceptional resistance to deformation.
May be used when support is not a major
consideration and when the anterior and
posterior abutments are widely separated.
May be chosen for patients with large palatal
tori that cannot be removed for health
reasons.
15. Disadvantages :
Uncomfortable.
The bulk and contour of the connector may
be bothersome to the tongue and may
interfere with phonetics.
Because of its limited contact with the palatal
tissues, it derives little support from the bony
palate.
Contraindicated in patients with reduced
periodontal support.
16. Horseshoe connector
It consists of a thin band of metal running
along the lingual surfaces of the remaining
teeth and extending onto the palatal tissues
for 6 to 8 mm .
17. The medial borders of this connector should
be placed at the junction of the horizontal
and vertical slopes of the palate.
Rigidity can be increased by extending the
borders slightly onto the horizontal surfaces
of the hard palate.
The connector should display symmetry
and should extend to the same height on
both sides.
All borders of the connector should be
gently curved and smooth.
18. Advantages :
It is used primarily when several anterior
teeth are being replaced.
It is a strong connector that can derive some
vertical support from tissues of the hard
palate.
In the presence of a prominent median
suture line or an inoperable torus, this major
connector may offer distinct advantages.
May be designed to avoid bony
prominences without sacrificing vertical
19. Disadvantages :
When vertical force is applied to one or both
ends of a horseshoe major connector, there is a
tendency for the connector to flex or deform .
It is a poor choice for distal extension partial
dentures.
This is not a good connector when cross-arch
stabilization is required.
The horseshoe connector displays limited
resistance to flexing, and noticeable movement
can occur at the open end.
It should be considered only if more rigid
connectors cannot be used.
20. Antero-posterior palatal strap
It is a structurally rigid major connector that may
be used in most maxillary partial denture
applications .
Indicated when numerous teeth are to be
replaced, or when a palatine torus is present.
21. Each strap should be at least 8 mm in width
and relatively thin in cross section .
Palatal borders should exhibit smooth,
gentle curves.
When anterior teeth are not being replaced,
the anterior strap should be in the farthest
posterior position possible.
The posterior strap also should be in a
posterior position, should not contact the
tissues of the movable soft palate.
22. Advantages :
It is a rigid connector that derives good
support from the tissues of the hard palate
despite its open design.
The corrugated contour of the metal over the
rugae adds strength to the connector and
allows the metal to be made relatively thin.
The structural encirclement produced by the
anterior and posterior straps contributes to
the rigidity of the connector.
23. Disadvantages :
Even though the metal over the rugae area
may be thinner than in some other major
connectors, interference with phonetics may
occur in some patients.
The extensive length of borders may cause
irritation to the tongue.
24. Complete palate
The complete palate provides the ultimate
rigidity and support . It also provides the
greatest amount of tissue coverage.
25. The anterior border of a complete palate
must be kept 6 mm from the marginal
gingivae, or it must cover the cingula of the
anterior teeth.
The posterior border should extend to the
junction of the hard and soft palates.
A slight mechanical seal may be formed by
ensuring the presence of a bead line along
the posterior border of the major connector.
This gently rounded elevation prevents
debris from collecting beneath the Major
connector.
26. Advantages:
When all posterior teeth are to be replaced.
May be indicated when the remaining teeth are
periodontally compromised.
When minimal ridge height is available, a complete
palate can provide additional stabilization for the
prosthesis.
Complete palate is generally comfortable and exerts
little or no effect upon phonetics.
The coverage of multiple palatal planes provides an
L-beam effect and makes the complete palate an
extremely rigid major connector.
Enhances thermal conductivity.
27. Disadvantages:
Because of the extensive tissue coverage, adverse soft
tissue reactions may occur in conjunction with complete
palate major connectors.
These reactions generally are characterized by soft
tissue hyperplasia and accompanied by poor oral
hygiene and prolonged periods of denture wear.
Occasionally, problems with phonetics may be
encountered.
28. Design of Maxillary Major Connectors
In 1953 Blatterfein described a systematic approach to
designing maxillary major connectors. His method
involves five basic steps:
Step 1: Outline of primary bearing areas. The primary
bearing areas are those that will be covered by
the denture base(s) .
Step 2: Outline of nonbearing areas. The nonbearing
areas are the lingual gingival tissue within 5 to 6 mm
of the remaining teeth, hard areas of the medial
palatal raphe (including tori), and palatal tissue
posterior to the vibrating line .
Step 3: Outline of connector areas. Steps 1 and 2, when
29. Step 4: Selection of connector type. Selection of the
type of connector(s) is based on four factors: mouth
comfort, rigidity, location of denture bases, and
indirect retention. Connectors must have a
maximum of rigidity to distribute stress bilaterally.
The double-strap type of major connector provides
the maximum rigidity without bulk and total tissue
coverage. In many instances the choice of a strap
type of major connector is limited by the location of
the edentulous ridge areas. When edentulous areas
are located anteriorly, the use of only a posterior
strap is not recommended.When only posterior
edentulous areas are present, the use of only an
anterior strap is not recommended. The need for
indirect retention influences the outline of the major
connector.
Step 5: Unification. After selection of the type of major
30. A, Diagnostic cast of partially edentulous maxillary arch. B, The palatal extent of the
denture base areas are located 2 mm from the palatal surface of the posterior teeth.
C, Nonbearing areas outlined in black, which include lingual soft tissue within 5 to 6
mm of teeth, an unyielding median palatal raphe area, and soft palate. The space
bounded by bearing and nonbearing area outlines is available for placement of major
connector. D, Major connector selected will be rigid and noninterfering with tongue and
will cover a minimum of the palate.
31. Five types of mandibular major connectors
are used in removable partial denture
therapy:
1. Lingual bar
2. Lingual plate
3. Sublingual bar
4. Cingulum bar
5. Labial bar
32. Lingual bar
Most frequently used mandibular major connector
Because of its simplicity in design and construction,
It is indicated for all tooth-supported removable
partial dentures unless there is insufficient space
between the marginal gingivae and the floor of the
mouth.
It is usually made of reinforced, 6-gauge, half-pear-
shaped wax or a similar plastic pattern .
33. There are two clinically acceptable methods to determine
the relative height of the floor of the mouth to locate the
inferior border of a lingual mandibular major connector:
The first method is to measure the height of the
floor of the mouth in relation to the lingual gingival
margins of adjacent teeth with a periodontal probe.
During these measurements, the tip of the patient's
tongue should be just lightly touching the vermilion
border of the upper lip.
Height of floor of mouth (tongue elevated) in relation to lingual gingival sulci
measured with a
34. The second method is to use an
individualized impression tray having its
lingual borders 3 mm short of the elevated
floor of the mouth and then to use an
impression material that will permit the
impression to be accurately molded as the
patient licks the lips.
Impression made with functional movement of the tongue to demonstrate maximum
.
35. Advantages :
A lingual bar has minimal contact with the
remaining teeth and soft tissues. As a result,
there is decreased plaque accumulation and
increased soft tissue stimulation.
These factors may be critical in the long term
maintenance of teeth and soft tissues and
should not be overlooked by the practitioner.
36. Disadvantages:
If extreme care is not taken in the design and
construction of a lingual bar, the resultant
framework may not be rigid.
In either instance, the major connector can
become too thin and too flexible. This permits
the concentration of potentially destructive
forces upon individual teeth and segments of
the mandibular arch.
Care must be taken to avoid making the bar
so bulky that it interferes with patient comfort
and function .
37. Lingual plate
The structure of a lingual plate is basically
that of a half-pear-shaped lingual bar with a
thin, solid piece of metal extending from its
superior border.
This thin projection of metal is carried onto
the lingual surfaces of the teeth and presents
a scalloped appearance.
38. The inferior border of a lingual plate should be
positioned as low in the floor of the mouth as
possible, but should not interfere with the
functional movements of the tongue and soft
tissues.
The inferior portion of the lingual plate may be
slightly less bulky than the corresponding portion
of a lingual bar, but no compromise in rigidity
should be made.
The superior border of a lingual plate must be
contoured to intimately contact the lingual
surfaces of the teeth above the cingula.
The border should extend toward the contact
area of the tooth and then turn apically, following
39. The metal should cross the free gingival
margin at a right angle, assume a gently
curved path to the line angle of the adjacent
tooth, and follow the line angle toward the
contact area.
To ensure rigidity of the major connector, the
inferior border of the lingual plate should be
made thicker.
It is important to note that an anterior lingual
plate must always be supported by rests
located no farther posterior than the mesial
fossae of the first premolars. Failure to
provide rests may result in rotation of the
40. Advantages :
A lingual plate must be used because there
is insufficient vertical space for a lingual bar.
This lack of space may be related to gingival
recession, high muscle attachments, or high
frenum attachments on the lingual aspect of
the mandibular arch.
A lingual plate provides exceptional rigidity
yet does not interfere with the functional
movements of the tongue and the floor of the
mouth.
A lingual plate also may be indicated when
the remaining teeth have lost much of their
41. A lingual plate may be used to stabilize the
remaining teeth and to distribute applied
forces over the remaining teeth and soft
tissues.
May be indicated for patients with conditions
that prevent the removal of existing
mandibular tori. Moderate relief must be
provided during framework fabrication to
prevent irritation of the fragile soft tissues that
cover such tori.
One of the greatest advantages is its
exceptional rigidity. Patients often consider a
well-fitting lingual plate more comfortable
42. Disadvantages:
The lingual plate's extensive coverage may
contribute to decalcification of enamel surfaces
and irritation of the soft tissues in patients with
poor oral hygiene.
Consequently, a thorough examination is
essential to recognize those patients for whom a
lingual plate is contraindicated.
Extreme care must be taken to ensure that a
lingual plate major connector does not create
additional oral hygiene challenges for a patient.
The lingual plate must completely close the
interproximal spaces to the level of the contact
points. Sealing these spaces from the lingual
43. Sublingual Bar
A modification of the lingual bar that has been
demonstrated to be useful when the height of the
floor of the mouth does not allow placement of the
superior border of the bar at least 4 mm below the
free gingival margin is the sublingual bar.
The bar shape remains essentially the same as
that of a lingual bar, but placement is inferior and
posterior to the usual placement of a lingual bar,
lying over and parallel to the anterior floor of the
mouth.
44. Indications:
Can be used in lieu of a lingual plate if the lingual
frenum does
not interfere or in the presence of an anterior lingual
undercut
that would require considerable blockout for a
conventional
lingual bar.
Contraindications:
Interfering lingual tori.
High attachment of a lingual frenum.
Interference with elevation of the floor of the mouth
45. When a linguoplate is the major connector of
choice, but the axial alignment of the anterior
teeth is such that excessive blockout of
interproximal undercuts must be made, a
cingulum bar may be considered.
Cingulum Bar (Continuous Bar)
46. A cingulum bar located on or slightly above
the cingula of the anterior teeth may be
added to the lingual bar or can be used
independently.
Additionally, when wide diastemata exist
between the lower anterior teeth, a
continuous bar retainer may be more
esthetically acceptable than a linguoplate.
47. Labial bar
A labial bar runs across the mucosa on the facial
surface of the mandibular arch.
Like other mandibular major connectors, a labial
bar displays a half-pear shape when viewed in
cross section.
Because of its placement on the external
curvature of the mandible, a labial bar is longer
than a corresponding lingual bar, double lingual
bar, or lingual plate.
48. To ensure rigidity, the height and thickness of
a labial bar must be greater than those
described for a lingual bar.
The only justification for using a labial bar is
the presence of a gross uncorrectable
interference that makes the placement of a
lingual major connector impossible.
Interferences that commonly lead to the
selection of a labial bar are:
(1) Malpositioned or lingually inclined teeth
(2) Large mandibular tori that preclude the use
of a lingual bar or lingual plate.
49. The Swing-Lock removable partial denture represents a
useful modification of the labial bar. In this application,
the labial component does not serve as a major
connector. Instead, the modified labial bar has a hinge
at one end and a locking device at the opposite end.
This permits an opening and closing action similar to a
gate. The framework may be positioned in the mouth
with the gate in the open position.
Absence of mandibular canine requires that all remaining anterior teeth be used for
stabilization and retention of replacement restoration. Swing-Lock concept can be
used to ensure group function of these remaining mandibular teeth.
50. Advantages:
When the remaining mandibular teeth are
tipped so far lingually that a more
conventional major connector cannot be
used, a labial bar may be considered.
Nevertheless, every possible means of
avoiding the use of a labial bar should be
entertained before it is incorporated into the
design of a partial denture.
51. Disadvantages:
Patient acceptance of labial bar major
connectors generally is poor.
The bulk of the major connector distorts the
lower lip unless the lip is relatively immobile.
The presence of metal between the gingival
tissues and the lip causes significant
discomfort.
The labial vestibule usually is not deep
enough to permit a sufficiently rigid connector
without encroaching on the free gingival
52. Design of Mandibular Major
Connectors
The following systematic approach to designing a
mandibular lingual bar and linguoplate major
connectors can be readily used with the diagnostic
casts after considering the diagnostic data and
relating them to the basic principles of major
connector design:
Step 1: Outline the basal seat areas on the
diagnostic cast .
Step 2: Outline the inferior border of the major
connector.
Step 3: Outline the superior border of the major
connector.
53. A, Diagnostic cast with basal seat areas outlined. B, Inferior border of major
connector is outlined.
C, Superior border of major connector is outlined. Limited space for lingual bar
requires use of linguoplate major connector. Linguoplate requires that rest seats be
used on canines and first premolar for positive support.D, Rest seat areas on posterior
teeth are outlined, and minor connectors for retention of resin denture bases are
sketched.