Transcript Margins of major connectors adjacent to gingival tissues should be

Major connectors
March 19, 2004
Sunhong Hwang DDS
Components of a typical
removable partial denture
Major connectors
 Minor connectors
 Rests
 Directs retainers
 Stabilizing or
reciprocal
components
 Indirect retainers
 Denture bases

Major connectors 란?

The component of the partial denture that
connects the parts of the prosthesis
located on one side of the arch with those
on the opposite side.
국소의치의 모든 구성요소가 직간접적으로 결
합되어 있다.
 Cross-arch stability-functional stress에 저
항하는데 돕는다.

Rigidity is eveything
Flexing, torque 가 지대치로 가해지는 것
차단
 Major connector가 flexible 할 경우 발생할
수 있는 문제
1. Jeopardize the supporting structure
ex) Traumatic damage to periodontal support of

abutment teeth,Injury to residual ridges, and Impingement
of underlying tissues
2. Be a detriment to the comfort of the
patient
Location of major connector

Guidelines in mind when the major connectors are designed and located
with;
1.
Major connectors should be free of movable tissues
2.
Impingement of gingival tissues 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 palatal median sutures.
5.
Major connectors should be located and/or relieved to
prevent to prevent impingement of tissues as the distal
extension denture rotates in function
Planned relief beneath the major
connector
주연결장치가 닿아서 조직이 눌릴 경우 조직손상(tissue damage)이
발생한다. 이를 미리 방지하기 위하여 relief을 해준다.
Planned relief를 적절히 시행 못 했을 경우 생기는 문제점
1.
2.
이를 조절 하기 위해 major connector를 grinding하는데 시간을
소모한다.
Major connector의 rigidity를 약화 시켜서 파절의 위험이 생긴다.
*참고* relief 완압緩壓: 의치상 하부의 특정 부위에 미치는
부적절한 압력이나 힘을 제거 또는 약화시키거나, 인상용
트레이 내에 인상재를 위한 공간을 만드는 것.
Relief가 필요한 부위
1.
2.
3.
Beneath lingual bar connectors or the bar portion of linguoplates
when indicated.
Areas in which major connectors will contact the thin tissue,
such as hard areas so frequently found on lingual of mandibular
ridges and elevated median palatal raphes
Beneath framework extensions onto ridge areas for attachment
of resin bases
Relief가 필요한 부위
1.
2.
3.
Beneath lingual bar connectors or the bar portion of linguoplates
when indicated.
Areas in which major connectors will contact the thin tissue,
such as hard areas so frequently found on lingual of mandibular
ridges and elevated median palatal raphes
Beneath framework extensions onto ridge areas for attachment
of resin bases
Relief가 필요한 부위
1.
2.
3.
Beneath lingual bar connectors or the bar portion of linguoplates
when indicated.
Areas in which major connectors will contact the thin tissue,
such as hard areas so frequently found on lingual of mandibular
ridges and elevated median palatal raphes
Beneath framework extensions onto ridge areas for attachment
of resin bases
일반적 고려사항
1.
2.
3.
4.
5.
Margins of major connectors adjacent to gingival tissues should be
located far enough from those tissues to avoid any possible impingement
ex) lingual bar의 상부는 gingival margin에서 4mm 하방에 위치
하부는 height of the moving tissues in the floor of the mouth에 의해 제
한 될 경우 linguoplate, sublingual bar, cingulum bar가 선택된다.
Palatal connector의 border는 free gingival margin에서 6mm 떨어져야 하고
gingival margin의 형태에 따라 평행하게 형성한다.
Palatal connectors ordinarily require no relief except for a palatal torus or
prominent median palatal suture area.---the presence of firm
submucosal connective tissue and an adequate, deep blood supply.
주연결장치와 지지조직 사이에 밀접한 접촉이 이루어지면, 의치의 stability,
retention, support에 도움이 된다. Gingival area는 제외된다.
An anterior palatal strap or the ant. Border of a palatal plate should be
located as far posteriorly as possible to avoid interference with the tongue
in the rugae(구개추벽).
It should be uniformly thin or straplike, rather than half-oval, and located
so that its anterior border follows the contours between crests of the
rugae.
The posterior limitation of a maxillary major connector should be just
anterior to the vibrating line. Hard palate
일반적 고려사항
1.
Margins of major connectors adjacent to gingival tissues should be
located far enough from those tissues to avoid any possible impingement
ex) lingual bar의 상부는 gingival margin에서 4mm 하방에 위치
하부는 height of the moving tissues in the floor of the mouth에 의해 제
한 될 경우 linguoplate, sublingual bar, cingulum bar가 선택된다.
Palatal connector의 border는 free gingival margin에서 6mm 떨어져야 하고
gingival margin의 형태에 따라 평행하게 형성한다.
일반적 고려사항
2.
Palatal connectors ordinarily require no relief except for a palatal torus or
prominent median palatal suture area.---the presence of firm
submucosal connective tissue and an adequate, deep blood supply.
주연결장치와 지지조직 사이에 밀접한 접촉이 이루어지면, 의치의 stability,
retention, support에 도움이 된다. Gingival area는 제외된다.
Mucous
Adipose tissue
membrane
Mucosa: stratified squamous epithelium+ lamina
propria(narrow layer of CT)
Submucosa: 다양한 형태
dense to loose areolar tissue
glandular, fat, muscle cells
mucosa에 blood, nerve 공급
periosteum에 부착
Submucosa의 thickness와 consistency가 support
에 중요한 역할
Glandular tissue
Thin submucosa
Loose CT and elastic fiber
Dense collagenous fibers
일반적 고려사항
3.
4.
An anterior palatal strap or the ant. Border of a palatal plate should be
located as far posteriorly as possible to avoid interference with the tongue
in the rugae(구개추벽).
It should be uniformly thin or straplike, rather than half-oval, and located
so that its anterior border follows the contours between crests of the
rugae
일반적 고려사항
5.
The posterior limitation of a maxillary major connector should be
just anterior to the vibrating line. Hard palate
A rule to be used throughout partial
denture design
1.
2.
Try to avoid adding
any part of the
denture framework
to an already
convex surface.
Try to use existing
contours and
embrasures for the
location of
component parts of
the framework.
3. All components should be tapered where they join
convex surfaces
Characteristics of major connectors contributing to
the maintenance of health of the oral environment.
1.
2.
3.
4.
5.
6.
7.
8.
9.
Made from an alloy compatible with oral tissues
Rigid and uses the principles of broad distribution of stress
Does not interfere with and is not irritating tongue
Does not substantially alter the natural contour of the
lingual surface of the mandibular alveolar ridge or of the
palatal vault
Does not impinge on oral tissues when the restoration is
placed, is removed, or rotates in function
Covers no more tissue than is absolutely necessary
Does not contribute to the retention or trapping of food
particles
Has support from other elements of the framework to
minimize rotation tendencies in function
Contributes to the support of the prosthesis
Mandibular major
connectors

1.
2.
3.
4.
5.
6.
Six types of mandibular major connectors
Lingual bar
Sublingual bar
Lingual bar with cingulum bar(continuous bar)
Cingulum bar(continuous bar)
Linguoplate
Labial bar
Lingual bar



Half-pear shape; the superior border of a lingual bar should
be tapered toward the gingival tissue with its greatest bulk at
the inferior border
Made of reinforced 6-gauge, half-pear-shaped wax or a
similar plastic pattern and 24-gauge casting wax(rigidity을
위해 보강해준다)
Located above moving tissues but as far below the gingival
tissues as possible( 하연이 기능시 방해가 안되면서도, 음식물
이 끼지 않도록, 혀의 위치에 방해 안되는 위치가 요구된다.)
Lingual bar
Two methods to determine the height of the
floor of the mouth
1.
2.
Periodontal probe를 사용하는 법
치은연에서 구강저까지의 거리를 측정하여 진단모형
에 기록한 후, 구강형성 후 제작된 주모형에 표시한
다. 혀를 상순의 vermilion border에 가볍게 접촉한
거리를 측정한다..
less variable and more clinically acceptable
Individual tray을 이용한 인상 채득
거상시킨 구강저보다 3mm 짧게 한 개인용 트레이로
인상채득한다. 이때 혀를 상순의 vermilion border에
가볍게 접촉한다
Sublingual bar
1.
2.
3.
4.
Lingual bar를 사용할 공간이 부족한 경우 (6mm 이하의 공간
이 있는 경우)
형태는 lingual bar와 같고, 위치는 보다 후방, 하방에 놓인다.
구강저에 수평으로 놓인다.
Linguoplate가 사용되는 곳에 대신 사용될 수 있다.( lingual
frenum에 방해 안되고, llingual undercut이 있는 곳에 사용됨
Contraindication; lingual tori, high attachment of a lingual
frenum, interference to elevation of the floor of the mouth
during functional movements.
Cingulum bar(continuous bar)
1.
2.
3.
4.
5.
6.
When a lingual plate or sublingual bar is otherwise
indicated but the axial alignment of the anterior teeth is
such that the excessive blockout of interproximal
undercuts would be required
위치는 전치의 cingulum상에 놓인다.
Lingual bar와 함께 사용될 수 도 있다.
전치가 심하게 설측 경사 진 경우, 전치부 spacing이 있는 경
우 심미적으로 문제가 있다. 이 경우 상대적으로 linguoplate
보단 금속 노출이 적다.
3mm 넓이의 얇은 금속 판의 형태이다.
인접한 주 지대치에 rest를 부여하고 이곳에서 시작된다.
Cingulum bar(continuous bar)
Linguoplate


If the rectangular space bounded by the lingual bar,
continuous bar, and the bordering minor connectors is filled
in, a linguoplate results.
형태;
1.thin
2.치아와 embrasure의 형태를 따른다.
3.upper border- not straight but curved to follow the natural
curvature of the supracingular surface.
4.not located above the middle third of the lingual surface
except to cover interproximal spaces to the contact points
5. Inferior border-half-pear shape---bulk,rigidity부여
Linguoplate
Linguoplate




All gingival crevices and deep embrasures must be blocked
out parallel to the path of placement to avoid gingival
irritation and any wedging effect between teeth
Anterior crowding---The recontouring of lingual proximal
surfaces of overlapped ant. Teeth permits a closer
adaptation of the linguoplate.
The linguoplate does not in itself serve as an indirect
retainer. ---Definite rest is needed for indirect retainer
Both the linguoplate and the cingulum bar should ideally
have a terminal rest at each end regardless of the need for
indirect retention. These rest may serve as terminal rests for
the linguoplate or continuous bar if necessary.
Linguoplate
Terminal rests
Indications for the use of a linguoplate
1.
2.
3.
4.
When the lingual frenum is high or the space available for
a lingual bar is limited. ---- Less than 8mm
In Class I situations in which the residual ridges have
undergone excessive vertical resorption.—stability을 보강
For stabilizing periodontally weakened teeth
When the future replacement of one or more incisor teeth
will be facilitated by the addition of retention loops to an
existing linguoplate
Labial bar





Indications
May be used when the mandibular teeth are so severely inclined lingually
as to prevent the use of a lingual major connector
May be used when large lingual tori exist and their removal is
contraindicated.
Labial vestibule depth should be adequate to allow the superior border to
be placed at least 3mm below the free ginginval margins
The labial bar tends to lack rigidity since it is considerably longer than a
lingual bar.
Swing-lock design
 형태:
modification to the linguoplate
 Labial bar –hinge/latch
 Multiple rest
 linguoplate
Swing-lock design
Indication
1. Missing key abutments
2. Unfavorable tooth contours
3. Unfavorable soft tissue contours
4. Teeth with questionable prognoses
 Contraindication
1. Poor oral hygiene, lack of motivation for plaque
control by the patient
2. Shallow buccal or labial vestibule
3. High frenal attachment

Maxillary major connectors

1.
2.
3.
4.
5.
6.
Six basic types of maxillary major
connectors
Single palatal bar
Single palatal strap
U-shaped palatal connector
Anterior-posterior palatal bar
Combination anterior and posterior
palatal strap-type connector
Palatal plate-type connector
A cardinal rule for the location of the major
connector in relation to the remaining teeth
and to their surrounding gingivae is :

Either support the major connector by definite
rests on the teeth contacted, bridging the gingivae
with adequate relief, or locate the connector far
enough away from the gingivae to avoid any
possible restriction of blood supply and
entrapment of food debris.
Single palatal bar(단순구개바)
문제점
 견고성을 확보하기위해 bulky한 형태가 되거
나, 보통은 얇게 제작되는 경우가 많다.
 항상 너무 얇게되어 rigidty가 부족하거나 부
피가 커서 환자의 혀에 불편감을 준다.
 매우 좋지 않다.
 그림 5-26 text

Single palatal strap(단순 구개스트랩)






Palatal bar와의 구분은 8mm.
Bilateral tooth-supported restorations, even those with short
edentulous spaces, are more effectively connected with a
single, broad palatal strap connector, particularly when the
edentulous areas are located posteriorly.= Class III
More rigid and less bulky than palatal bar
A single bar or strap should not used to connect anterior
replacement with distal extension bases.
Sagital section. Midportion of major connector is slightly
elevated to provide rigidity.
그림 5-27 text
U-shaped palatal connector
(U-형 구개연결장치)
Indication
 Large inoperable palatal torus
 Anterior teeth are to be replaced

U-shaped palatal connector
(U-형 구개연결장치)
Least desirable of Mx. Major connectors
 1. Its lack of rigidity (compared with other designs)
can allow lateral flexure under occlusal forces,
which may induce torque or direct lateral force to
abutment teeth
 2.the design fails to provide good support
characteristics and may permit impingement of
underlying tissues when subjected to occlusal
loading
 3.Bulk to enhance rigidity results in increased
thickness in areas that are a hindrance to the
tongue.

U-shaped palatal connector
(U-형 구개연결장치)

A common error in the design of a Ushaped connector, however, is its
proximity to, or actual contact with,
gingival tissues.

Gingival irritation and periodontal damage
to the tissues adjacent to the remaining
teeth.
Combination anterior and posterior palatal
bar-type connectors
(전후방 구개바형 연결장치)

Single palatal bar와 같은 구조적 결함을 갖는다.

Bulky
혀에 방해가 된다.

Combination anterior and posterior palatal strap-type
connector
(전후방 구개스트랩형 연결장치)



Structrally, this is a rigid.
It may be used in almost any maxillary partial
denture design
It is used most frequently in classes II and IV.
Combination anterior and posterior palatal straptype connector
(전후방 구개스트랩형 연결장치)
A posterior palatal strap
1.
Flat, minimum of 8mm wide
2.
As posteriorly as possible
3.
On the hard palate
Longitudinal connectors
1.
Forming square or rectangular
frame
2.
Flexure is practically
nonexistent in such a design.
Anterior connector may be
extended anteriorly to support
anterior tooth replacements.
Palatal plate-type connector
(구개판형 연결장치)
 Any
thin, broad, contoured palatal
coverage used as a maxillary major
connector and covering ½ or more of
the hard palate.
 Anatomic replica palatal castings
have uniform thickness and strength
by reason of their corrugated
contours
The advantages of the anatomica replica
palatal major connector
Uniform thin, anatomic contours
열전도성 우수--- 이물감적고, 하방
조직에도 적응성 우수
2. Corrugation—strength, thin and
adequate rigidity
3. Uniform thickness is maintained
4. Intimate contact- retention
1.
The palatal plate may be used in any one of
three ways
A plate of varing width that covers the area
between two or more edentuous areas
 Complete or partial cast plate that extends
posteriorly to the juntion of the hard and
soft palates
 In the form of an anterior palatal connector
with a provision for extending an acrylic
resin denture base posteriorly.

The palatal plate may be used in any one of
three ways
Complete or partial cast plate that extends posteriorly to the juntion
of the hard and soft palates
 In the form of an anterior palatal connector with a provision for
extending an acrylic resin denture base posteriorly.(그림5-37 text)

Posterior palatal seal
 Palatal
plate should be located
anterior to the posterior palatal seal
area.
 Little posterior seal is ever necessary
with a metal plate. Accuracy and
stability.
Indication of the palatal plate
Frequently in Class I situation
 Canine or first premolar가 최후방 지대치이고,
residual ridge resorption이 심한 경우--complete palatal coverage is strongly
recommended.

Design of major connectors
Mandible
Step 1. Outline the basal seat areas
Step 2. Outline the inferior border
of the major connector
Step 3. Outline the superior border
of the major connector
Step 4. Connect the basal seat area
to the inferior and superior
borders of the major connector,
and add minor connectors to
retain the acrylic resin denture
base.
Maxilla
Step 1. Outline of primary
bearing areas
Step 2. Outline of nonbearing
areas
Step3. Outline of connector
areas
Step 4. Selection of connector
type
Step 5. unification
Beading of the maxillary cast
Purpose
1.
To transfer the major connector design to the investment cast
2.
To provide a visible finishing line for the casting.
3.
To ensure intimate tissue contact of the major connector with
selected palatal tissues
형성법
Cleoid carver를 사용한다.
0.5mm depth and width
Rounded V-shaped groove
Anterior--- valley of rugae
Happy Friday!!!!
경청해 주셔서 감사합니다