Anoverview of TMD'S categories and main types of interocclusal appliances( occlusal splints ) used during the management of these musculoskeletal disorders .
Anoverview of TMD'S categories and main types of interocclusal appliances( occlusal splints ) used during the management of these musculoskeletal disorders .
Prosthodontic management /certified fixed orthodontic courses by Indian denta...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.
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Management of mandibulectomy / /certified fixed orthodontic courses by Indian...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
00919248678078
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
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Fenestration
Dehiscence: lack of cortical bone at the level of dental root, at least 4mm apical to the margin of interproximal bone, the measurement was per found by graduated probe.
Or: lowering the crestal bone margin to expose root surface.
Fenestration: localized defect in the alveolar bone that exposed the root surface usually the apical or the medium third but did not involve the alveolar margin.
Or: is isolated areas in which the root is denuded of bone and the root surface is covered only by periosteum and overlying gingiva.
Fenestration is a term derived from Latin ward fenestra, meaning window, describe area of alveolar process devoid of bone, creating a window exposing the root surface.
Gingival recession: is the apical movement of the marginal soft tissue surrounding the tooth exposing root surface.
According to some studies that irreversible recession can be caused by fixed appliances for 1.3% to 10.0% of treated cases.
We can use CBCT to measure the labial and lingual thickness of the bone related to roots.
ABT: apical buccal thickness. MBT: middle buccal thickness. CBT: cervical buccal thickness.
ALT: apical lingual thickness. MLT; middle lingual thickness. CLT: cervical lingual thickness.
== naturally occurring alveolar bone dehiscence and fenestration are common finding in different type of malocclusion especially in anterior region of class III.
== fenestration and dehiscence may lead to gingival recession and additional bone loss during orthodontic treatment in addition to large amount of labial inclination such as decompensation in class III malocclusion may pose a greater risk of periodontal complication such as:
Alveolar dehiscence, fenestration, gingival recession.
Clinically gingival recession, is always accompanied by alveolar bone dehiscence whether underlying bone dehiscence is developed before or parallel to gingival recession.
N:B- gingival recession; is described as exposure of root surface by an apical shift in the position of gingiva.
Factors affect recession increase:
1- Difficulty of plaque control due to fixed appliances
2- Proclination of teeth.
3- Coronally attached Frenum.
4- Muscle attachment.
5- Abnormal tooth position.
6- Overhanging restoration or crowns.
7- Fenestration and dehiscence.
** Classification of fenestration according to their apicocoronal location in relation to root length to:
1- At the level of the apical third of the dental root 48% all in maxilla.
2- At the level of the middle third of dental root 28% in maxilla and mandible.
3- At the level of the coronal third of the dental root 19% all in mandible.
4- Extending from the apical to the middle third of the dental root 4.3% of them located in maxilla.
** Etiology of dehiscence:
1- Ectopically positioned teeth which are outside of the bony limits of the alveolus are often lacking the normal amount of bone on the overlying facial surface.
2- Roots of the toot
Dentist in pune.(BDS) MDS- OMFS - Dr. Amit T. Suryawanshi.. Mandibular fractu...All Good Things
Dentist in pune. (BDS. MDS) - Dr. Amit T. Suryawanshi. Seminar-Canine Impaction.
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Fabrication of functional complete dentures for edentulous patients who have undergone hemimandibulectomy is a very arduous and demanding endeavor.
The most challenging situation encountered during this procedure is the deviation of the mandible to the resected side. The deviation of the mandible to the resected side is directly proportional to the loss of tissues in the area hemi-mandibulectomy has been performed.
In cases with Cantor and Curtis classes II, III, IV, and V, guide flange prosthesis would be a treatment modality. For guide flange prosthesis to be effective, the sufficient number of posterior teeth that are periodontally sound should be present in the opposite arch.
In patients where reconstruction is not done after resection of the mandible, scar tissue formation occurs over a period of time that stiffens the tissues and worsens prosthetic rehabilitation, leading to compromised treatment planning.
Embracing GenAI - A Strategic ImperativePeter 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.
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.
Instructions for Submissions thorugh G- Classroom.pptxJheel Barad
This presentation provides a briefing on how to upload submissions and documents in Google Classroom. It was prepared as part of an orientation for new Sainik School in-service teacher trainees. As a training officer, my goal is to ensure that you are comfortable and proficient with this essential tool for managing assignments and fostering student engagement.
How to Make a Field invisible in Odoo 17Celine George
It is possible to hide or invisible some fields in odoo. Commonly using “invisible” attribute in the field definition to invisible the fields. This slide will show how to make a field invisible in odoo 17.
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.
2024.06.01 Introducing a competency framework for languag learning materials ...Sandy Millin
http://sandymillin.wordpress.com/iateflwebinar2024
Published classroom materials form the basis of syllabuses, drive teacher professional development, and have a potentially huge influence on learners, teachers and education systems. All teachers also create their own materials, whether a few sentences on a blackboard, a highly-structured fully-realised online course, or anything in between. Despite this, the knowledge and skills needed to create effective language learning materials are rarely part of teacher training, and are mostly learnt by trial and error.
Knowledge and skills frameworks, generally called competency frameworks, for ELT teachers, trainers and managers have existed for a few years now. However, until I created one for my MA dissertation, there wasn’t one drawing together what we need to know and do to be able to effectively produce language learning materials.
This webinar will introduce you to my framework, highlighting the key competencies I identified from my research. It will also show how anybody involved in language teaching (any language, not just English!), teacher training, managing schools or developing language learning materials can benefit from using the framework.
Synthetic Fiber Construction in lab .pptxPavel ( NSTU)
Synthetic fiber production is a fascinating and complex field that blends chemistry, engineering, and environmental science. By understanding these aspects, students can gain a comprehensive view of synthetic fiber production, its impact on society and the environment, and the potential for future innovations. Synthetic fibers play a crucial role in modern society, impacting various aspects of daily life, industry, and the environment. ynthetic fibers are integral to modern life, offering a range of benefits from cost-effectiveness and versatility to innovative applications and performance characteristics. While they pose environmental challenges, ongoing research and development aim to create more sustainable and eco-friendly alternatives. Understanding the importance of synthetic fibers helps in appreciating their role in the economy, industry, and daily life, while also emphasizing the need for sustainable practices and innovation.
Read| The latest issue of The Challenger is here! We are thrilled to announce that our school paper has qualified for the NATIONAL SCHOOLS PRESS CONFERENCE (NSPC) 2024. Thank you for your unwavering support and trust. Dive into the stories that made us stand out!
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.
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.
5. Prosthetic rehabilitation of edentulous patient
Management of discontinuity defect
Factors determining prosthetic program for CD
Impression
Centric registration
Occlusal schemes and lateral registration
Anterior border defects
Review of literature
Summery and conclusion
References
7. Mandible is a single bone that creates:
Peripheral boundaries of the floor of the mouth
Facial form
Speech
Swallowing
Mastication
Respiration
Disruption of the mandible has the potential to
disrupt any of these.
8. Rehabilitation of mandibulectomy patients should
therefore consider both form and function.
9. Surgical resection of tumor often includes a partial
mandibulectomy resection, a partial glossectomy , a
partial resection of the floor of the mouth and a
radical neck dissection.
The extent of surgery and effect of radiation therapy
and chemotherapy determine the amount of
rehabilitation needed to a patient.
10.
11.
12.
13. Classification of mandibular defects
According to Laney(1979)
Based on etiology
1. Acquired: - Marginal
- Segmental :- a) Lateral to midline
- Body only
- Ramus- Body with disarticulation
b) Anterior body
- Subtotal
- Total
14. 2. Congenital
- Incomplete formation
- Incomplete ossification
i.e. hypoplasias, mandibulofacial dysostosis,etc
3. Developmental
as a result of postnatal insults
i.e. trauma during birth, surgery,etc
15. Based on amount of resection (Laney)
Continuity defect
(marginal resection)
- Inferior border and its continuity
preserved
- No deviation
- Less facial disfigurement
- Occlusion rarely changed
- Can be :- anterior defect
posterior defect
Discontinuity defect
(segmental resection)
- Complete segment - from alveolar
crest to inferior border removed
- Mandible deviates to resected side
- Marked facial disfigurement
- Occlusion altered
- Can be :- lateral discontinuity
defect
midline discontinuity
defect
16. According to Cantor and Curtis (1971)
Class 1 : Radical alveolectomy with preservation of
mandibular continuity
17. Tissues resected :
Portion of alveolar process and body
of mandible
Lingual and buccal sulcus mucosa
Portion of base of tongue and
mylohyoid muscle
Lingual and inferior alveolar nerves
Sublingual and Submaxillary
salivary glands
Sometimes anterior part of digastric
muscle
18. FEATURES:-
1. Least debilitating.
2. Sometimes resection of part of mylohyoid muscle and resultant scarring
can raise the floor of the mouth causing reduction in tongue mobility.
3. Ability to shape and control the tongue form may be lost due to loss of
some intrinsic muscles.
4. Resection of lingual and inf. alveolar nerves results in a loss of sensation
in the mucosa of cheek, alveolar process, lower lip and loss of taste on
anterior 2/3rd of the tongue.
19. Class 2 : Lateral resection of mandible distal to cuspid
20. Tissues resected:
Condyle, ramus and body of mandible
distal to cuspid
Mylohyoid, hypoglossal
Pterygoid, masseter, external pterygoid,
Palatoglossal muscles, most of intrinsic
muscles of tongue.
Hypoglossal , lingual and inferior alveolar
nerves.
Sublingual & Submaxillary salivary glands.
Mucoperiosteum & adjacent buccal &
lingual sulcus mucosa
21. FEATURES:-
1. Speech, swallowing, saliva control, manipulation of food impaired.
2. Facial disfigurement apparent.
3. Disarticulation and loss of muscles of mastication will hamper
mandibular movements.
4. Taste, sensory and motor losses are more extensive as compared to class 1.
22. Class 3 - Lateral resection of the mandible to the midline
23. Tissues resected :
All those described in class 2 in addition to the anterior portion of the
mandible, geniohyoid, genioglossus, remaining portion of mylohyoid
muscle with lingual and buccal mucosa.
24. FEATURES:-
1. Restricted tongue mobility due to loss of tip of tongue and
genioglossus muscle.
2. Speech, swallowing, saliva control and manipulation of food is severely
restricted.
3. Facial disfigurement is worse due to loss of anterior part of mandible.
4. Disarticulation and reduction in amount of basal bone reduce prosthodontic
prognosis.
5. Scarring of orbicularis oris can interfere with expression of emotion
26. Lateral bone and split
thickness skin or pedicle graft
can be performed on patients
who have had:
- radical alveolectomies
- resection of mandible
distal to cuspid with or
without disarticulation.
-midline resections with or
without disarticulation.
27. 3 Types of bone grafts are possible:-
1. Mandibular augmentation procedures.
2. Bone graft that connect a residual condyle with the large
mandibular fragment.
3. Lateral bone grafts that extend from the mandibular
fragment into the defect area to establish a pseudo TMJ.
29. Tissues resected :
anterior portion of the mandible
large bilateral portions of mylohyoid,
geniohyoid
genioglossus and anterior digastric muscles
bilateral lingual and inferior alveolar nerves
bilateral submaxillary and submandibular
salivary glands
mucosa of lower lip
anterior floor of the mouth
ventral surface of the tongue
30. The mucosa retained in the labial and buccal regions is sutured to the
residual stump of the tongue and a Kirschner wire is often positioned to
maintain the mandibular fragments .
Bone graft and split thickness skin graft or pedicle graft procedures can
be used to restore anterior facial contour and bilateral mandibular
function.
32. Dentures – Chronic irritation – epidermoid carcinoma
– squamous cell carcinoma
Alcohol – squamous cell carcinoma in the floor of the
mouth – related to direct tissue contact or indirectly
with live cirrhosis and altered nutritional status
Tobacco - cigarette , cigar, pipe , chewing tobacco
Leukoplakia – white patch - can not be scraped off –
reversed by removing local irritants
Oral lichen planus – recticular, plaque, and erosive
forms
34. 1. Location and extent of mandibular defects
Radical alveolectomy
- Least debilitating.
- Main problems – loss of vertical ridge height and vestibular depth –
decreased stability for soft tissue-supported prosthesis as well as the loss
of load bearing tissues available for support.
- Vertical discrepancy most important when prosthesis supported by dental
implants are considered.
35. Discontinuity defects
RULE OF THUMB:-The further anterior the defect, the more
disfiguring and functionally debilitating
it is likely to be.
Osbon DB. Early treatment of soft tissue injuries of the face. J Oral Surg 1969;27:480–7.
36. - Most debilitating and difficult to treat.
- Greatest facial disfigurement.
- Surgical reconstruction necessary or at least segmental stabilization
before prosthodontic treatment can be initiated.
- Mandibulectomy defects of the molar region of the mandibular body are
more well suited for surgical reconstruction compared to anterior defects.
- If muscle attachments are intact – Good prognosis
Near normal appearance and function is achievable.
Defects of the symphyseal region
37. 2. Presence of remaining natural teeth/pre-existing
implants
Patients after mandibulectomy present with few or no
remaining natural teeth.
2 reasons:
1. Patients at greatest risk for squamous cell carcinoma - heavy
users of tobacco products and alcohol.
2. Teeth are usually extracted prior to radiotherapy to prevent
complications such as osteoradionecrosis.
38. Greater the number of teeth, better the prognosis
- Teeth present on both sides of the midline permit greater
prosthesis support since the problem of straight line design
can be avoided.
- Maximum number of abutment teeth should be
incorporated in the design of the prosthesis to maximize
stability and dissipate functional forces.
40. A maxillary complete denture will function well for
mandibulectomy patient against a reconstructed mandibular
dentition
Exceptions:
Collapse of residual proximal mandibular stump; coronoid
process against the posterior maxillary alveolus - prohibiting
adequate denture flange extension.
When a guide flange prosthesis is planned to correct mandibular
deviation - pressure from the guide flange will tend to dislodge
the maxillary denture.
41. 3. Degree of post mandibulectomy rotation and deviation
- Loss of mandibular continuity causes deviation of the
remaining mandibular segment towards the defect and
rotation of mandibular occlusal plane inferiorly.
Deviation: Primarily due to loss of tissue involved in surgical
resection.
42. Rotation:- Due to
- Pull of the suprahyoid muscles on the residual mandibular
fragment causing inferior displacement and rotation around the
fulcrum of the remaining condyle.
- Gravity – Loss of anchorage of elevator muscles.
Sequelae:-
Facial disfigurement
Loss of occlusal contact
Loss of ability to bring lips together for saliva control
& to initiate swallowing process
43. Prosthodontic prognosis in such patients can be improved by
early post resection physical therapy to reposition the
mandibular fragment to a more normal position and to
minimize scar formation that will make deviation more
severe.
Should be carried out as early as possible. After 6-8 weeks
post operatively it will not be as beneficial.
Can be in the form of
1.Physical therapy carried out by the patient himself.
2.Mandibular resection guidance prosthesis
44. 4. Available mouth opening
- Trismus –due to surgical trauma
- Scar tissue formation will further reduce mouth opening.
- Physical therapy (Stretching exercise) should be started
immediately.
- Simple test to check mouth opening:
Insert a stock mandibular impression tray in the mouth.
If this cannot be accomplished, rehabilitation is unlikely to
occur.
- Surgery can be done to release scar tissue. However, not very
beneficial as it returns to the same in a short period of time.
45. 5. Functional limitation of the tongue
- Frequently the surgical wound is closed by suturing the
remaining tissues of the floor of the mouth or tongue to the
remaining buccal tissues.
This compromises: - Speech
- Swallowing
- Mastication
- Control of food bolus
- Ability to control removable prosthesis
46. - Lingual vestibuloplasty and skin or mucosal grafting can be
used to improve tongue mobility
- Evaluation of tongue mobility
- Patients in whom anterior resection has been done, ability to
lick the lips when the artificial prosthesis is placed in the
mouth may be difficult or impossible.
- In such cases consideration is given to lowering the anterior
occlusal plane or arranging the teeth slightly lingually.
47. Loss of sensory innervation will compromise tongue function
and prognosis of prosthodontic rehabilitation.
If lingual nerve is sacrificed - tongue on the defect side will
permanently remain without any feeling.
Loss of sensory capability:- Affects speech
Mastication
Prosthesis control on defect side
Loss of sensory innervation of the buccal mucosa(long buccal
nerve) and lower lip(mental nerve) will reduce patient’s
ability to control food and saliva.
48. 6. Compromise of vestibular extensions
Vestibular depth is critical for stability and peripheral seal.
It is also critical when mandibular continuity is restored
with bone grafting and implants are considered.
49. 7. Skin grafting
Skin grafts are used for surgical reconstruction either as lining for
the surface of resected soft tissue or as part of skin and connective
tissue grafts such as pedicle flaps, free flaps etc.
Advantages
1. Effective load bearing tissue.
2. Can withstand pressure from prosthesis.
3. Protects underlying bone and connective tissue well due to
rapid turnover of keratin producing cells.
Disadvantages
1. No sensory innervation.
2. Full thickness grafts may incorporate hair follicles.
3. Skin is not very compatible with titanium surface of implants.
50. 8. Radiation therapy
Careful treatment planning is required for patients with
radiation therapy.
Irradiated tissue is fragile, sensitive to manipulation,
dessicated, slow to heal, prone to infection and at risk of
osteoradionecrosis.
51. 9. Altered anatomic relationships following restoration
of mandibular continuity
Reconstruction of anterior defects
- Most difficult situation for grafting
- Frequently results in a graft that is deficient anteriorly.
- Results in a severe Class II like situation.
The prosthodontic difficulties seen in rehabilitating such a patient are:-
- Inability to provide proper lower lip support for esthetics.
- Speech problems associated with mandibular dentition placed too
far lingually to allow normal articulation.
52. - Inability to control food bolus due to lack of motor function of
lips and muscles of the lower face.
- Excessive display of mandibular teeth due to patient’s inability
to maintain normal lower lip posture.
- Difficulty gaining adequate space for prosthesis placement
without encroaching on function of tongue.
- Misalignment of remaining unresected mandibular fragments
and resultant relationship between maxillary and mandibular
teeth.
53. Reconstruction of posterior defects
- More predictable from prosthodontic point of view as compared
to anterior defects.
- The mediolateral position of the graft is frequently seen lateral to
the original position of the mandibular body.
- Thus the prosthesis must be built in cross bite to maintain the
denture teeth over the supporting base of the bone graft.
54. Angled dental implants- the prosthesis they support must be
cantilevered lingually to permit tooth contact.
Inadequate space after surgical
reconstruction- limits prosthesis
or implant placement.
Excessive space after surgical
reconstruction- problem to control
forces on remaining teeth or implants
55. Immediate vs delayed reconstruction
Factors determining whether to reconstruct at the
time of tumor resection (immediate) or as a secondary
procedure (delayed).
Amount and character of remaining soft tissue
Anatomic location of the defect
Size of bone defect
General health of patient
Prognosis for tumor control
Experience of the surgeon
56. Extensive soft tissue loss – require additional procedure
for soft tissue augmentation, thus precluding
immediate graft.
If immediate reconstruction is desired but soft tissue
appear inadequate for proper watertight oral closure – a
forehead flap may be useful
Flaps should be – broadly based, as thick as possible.
57. The size, extent and prognosis of tumors requiring
resection are important factors.
Relatively small defect – immediate reconsturction
Spectrum malignant tumors requiring extensive hard
and soft tissue resection with a radical neck dissection –
immediate implant followed by delayed graft.
Since tumor recurrences occur frequently within 1st year
58. Medically compromised patients – observe the response
to primary surgery before subjecting to second
procedure
Location of resection is another important factor
Defects at symphysis require immediate stabilization,
or remaining mandibular fragments will colapse
medially and superiorly because of muscle pull and scar
contracture
Immediate stabilization is less important in lateral
mandibular defects.
60. Marginal mandibulectomy:-
Soft tissues are mainly used to reconstruct marginal
mandibulectomies.
They may be: - Skin graft
- Local flap
- Pedicle flap
- Microvascular free flaps
(MVFF)
Skin grafts serve as excellent prosthesis-bearing surfaces.
However when soft tissue bulk is required or recipient bed is
previously irradiated - Microvascular free flaps are the
treatment of choice.
61. Discontinuity mandibulectomy:-
- Previously soft tissue local flaps (mainly the residual tongue
sutured to the border of the defect) and pedicle flaps
(pectoralis muscle) were used.
- MVFF have revolutionized the treatment of discontinuity
defects.
- Microvascularized bone is mainly obtained from:
1.Fibula- most common
2.Iliac crest
- Soft tissue MVFF are obtained from:
1.Forearm
2.Rectus muscle
62. Mandibular malposition after bony reconstruction
May be due to:
1. Minimal proximal mandible on the surgical
side to attach the bone graft.
2. Mandibular segments are not stabilized and
maintained in their pre-operative relation to
each other during grafting procedures.
3. Delayed reconstruction may not be able to
overcome scar tissue formation completely.
63. 4. The bone grafts used i.e the fibula and the iliac crest graft
have some inherent problems:
- Lacks height compared to the residual mandible
-Pyramidal in shape being narrower at the occlusal surface
-Fibula is grafted to restore inferior border of the mandible,
which is necessary to restore facial form. This tends to place
fibula buccally in the plane of the cheek.
-Since bone is placed buccally in the cheek, implants distal to
the premolar area cause constant soft tissue and infection
problems.
65. Mandibular Guidance
Loss of continuity of the mandible destroys the balance and
symmetry of mandibular function
Leading to altered mandibular movements and deviation of
the residual fragment towards the surgical side.
Methods to reduce mandibular deviation
Intermaxillary fixation
Use of mandibular based guidance restorations
Use of palatally based guidance restorations
66. Intermaxillary Fixation
One approach to reducing the deviation associated with
resection of the mandible
- use arch bars and elastics or wire in dentulous patients.
- “gunning splint” in edentulous patients.
67. Resection guidance restorations
If intermaxillary fixation is not employed –
2weeks postsurgically, the patient should be placed on an
exercise program.
Following maximum opening, grasping the chin and
moving the mandible away from the surgical side.
These movements tend to loosen scar contracture
reduce trismus, and improve maxillomandibular
relationships.
68. If extensive resection and a considerable period of
time has elapsed, guidance procedures are much more
difficult and a compromised occlusal relationship may
result.
For guidance prosthesis mandibular teeth must be
present.
Once an acceptable occlusal relationship is
established, the guidance prosthesis may be discarded
or used occasionally to reinforce proprioceptive
mechanism.
69. Guidance prosthesis
Robinson and Rubright described Mandibular
guidance prosthesis
It consists of a RPD framework with a metal flange
extending 7 to 10 mm laterally and superiorly on the
buccal aspect of the bicuspids and molars on the
nondefect side.
This flange engages the maxillary teeth during
mandibular closure.
70. If the completed guidance ramp is to be
formulated in acrylic resin,
autopolymerizing material is added to the
prosthesis which is seated in the mouth.
As the resin reaches dough stage, the
mandible is manipulated into the desired
interocclusal relationship.
The resin should be manipulated to
extend 7 to 10 mm superiorly. The
prosthesis is removed from the mouth and
the resin is allowed to polymerize.
71. Palatally based guidance restoration
This is a guidance ramp and an index to a maxillary
prosthesis.
Indicated for patients who has severe deviation
which prevents manipulation of mandible into any
form of acceptable contact.
These maxillary prosthesis are usually constructed of
acrylic resin with either cast or wrought wire
retainers.
72. The full palatal coverage prosthesis is constructed
following conventional prosthodontic guidelines.
A mix of autopolymerizing acrylic resin is prepared and
added to the palatal prosthesis along the lateral and
anterior borders on the nondefect side.
The prosthesis is replaced in the mouth and the
mandible is manipulated to the desired position, thus
establishing an index in the palate.
73. The patient should be able to close into the index with
appropriate manual manipulation of the mandible.
When the patient returns, the mandible will usually
exhibit more movement laterally toward the non
surgical side, requiring adjustment of the palatal ramp.
• If and when an acceptable intercuspal
position is achieved, a cast mandibular
guidance prosthesis may be necessary to
maintain mandibular position.
74. Speech aids and speech therapy
Cantor et al 1969, noted speech improvement by lowering
palatal vault prosthetically into the space of Donders to
accommodate for restricted tongue movements.
The palate was lowered by means of a retainer for the
dentulous patients and by a palatal acrylic resin extension
onto the upper denture for edentulous patients.
• Misarticulation of speech sounds by
mandibular resections.
75. Scott 1970, investigated the potential benefit of intensive
speech therapy for mandibulectomy patients and
concluded that:
Placement of a prosthesis, although improves the quality of
specific sounds, does not improve discourse and
Intensive speech therapy improved speech significantly for
patients both with and without prosthesis.
• Speech therapy is most effective
means of improving articulation in
mandibulectomy.
76. Tongue prosthesis
The loss of tongue impairs functions of stomatognathic
system.
Moore 1972, suggested that tongue prosthesis provides
articulation along with movements of the mandible and
cheeks.
Loss of tongue leads to difficulty in controlling saliva and
liquids.
Pooling of the fluids in the altered floor of the mouth
stimulates cough reflex and/or leading to aspiration.
78. Lateral Discontinuity Defects
(Class 2 And 3)
Often resected in the region of 2nd premolar and 1st
molar. If there are no other missing teeth in the arch, a
prosthesis is usually not indicated.
Framework design should be similar to a Kennedy class
2 design, with extension into the vestibular areas of the
resection.
79. The forces of occlusion are unilateral and consequently
the axis of rotation (fulcrum line) of the partial
denture deviates from the norm.
80. Major connector – depends on the
height of floor of the mouth.
Minor connector – minimize the
stress on abutment teeth.
Occlusal rests – near the defect
Retention – use of various types of
clasp assemblies on distal
abutments.
81. If anterior and posterior teeth from resected side
missing and posterior teeth on unresected side are
missing, prosthesis have 3 denture base regions.
Rests – on as many teeth as possible
Minor connectors – enhance stability and wroght wire
retainers are acceptable alternative to bar clasps.
Altered cast impression – used to get max. soft tissue
coverage.
82. Maxillomandibular records – made with soft wax and
minimum occlusal pressure applied.
Acrylic resin teeth
When less than ideal occlusal relationships must be
accepted, it may be necessary to establish an occlusal
ramp lingual to maxillay teeth on the unresected site.
83. Class 3 resection – defect to the midline or
farther toward the intact side, leaving half
or less of the mandible remaining.
Design of framework – similar to type 2
resection
In this resection – greater chance of
prosthesis dislodgement caused by lack of
support under anterior extension.
84. Defects With Mandibular Continuity
Anterior Defects (Class 5)
Patients with anterior inner table resections and
patients with anterior composite resections in whom
mandibular continuity has been reestablished by
reconstructive surgery.
These patients display unusual soft tissue
configurations and compromised bony support.
Prosthesis for these patients enhance esthetics, speech
and control of saliva.
85. Indirect retention – long
mesial rests on the 2nd Molars
Minor connector – relieve
distal aspect and proximal
plates
Edentulous areas are recorded
with an altered cast impression
Thermoplastic waxes are used
to record movable tissue beds.
86. Esthetics, occlusion and speech – verify at try-in stage
Prosthesis is delivered with periodic monitoring.
87. Defects with Mandibular Continuity
Lateral Defects (Class 1, 4)
Inferior border of the mandible is intact, and normal
movements can be expected.
Compromised denture bearing area – because of closure
of the defect using adjacent lining mucosa or presence
of split thickness skin graft.
If defect is unilateral and posterior – kennedy class 2
framework design
If marginal resection in anterior area – kennedy class 4
framework design
88. Anterior marginal resections some times include part
of the anterior tongue and floor of the mouth.
The remaining teeth often collapse lingually and
necessitate labial bar as major connector.
Buccal, lingual and labial functional contours – helps
in stabilization of the prosthesis.
89. Extremely long lever arms & compromised edentulous
bearing surfaces contribute to excessive movement of
prosthesis during function.
The ‘ribbon rest’ closely parallels the axis of rotation.
The anterior and posterior proximal plates move freely
during function.
The buccal retainer on the molar and the labial
retainer on the cuspid are placed at the height of
contour.
90. The occlusion should be refined to achieve contact in
centric occlusion only and patient should be
instructed to masticate on the side of the residual
mandibular dentition.
92. Management Of Discontinuity Defects
Complete dentures in these patients are primarily for
esthetics.
They improve lip and cheek contour and replace missing
teeth.
93. Factors Determining The Prosthetic
Prognosis For Complete Dentures
The prognosis is more favourable if the resection is
limited to the cuspid region anteriorly.
If the motor and/or sensory control of the tongue has
been significantly compromised by the resection, the
prosthetic prognosis becomes extremely guarded.
Severe deviation of the mandible causes instability of
the dentures.
94. Post surgical lip posture and control, does have
important prosthodontics implications.
Due to radiation therapy, there will be reduction in
salivary flow which leads to increased risk of mucosal
irritation and compromised peripheral seal.
95. Impression
Primary impression – irreversible hydrocolloid
impression material
Final impression – border moulding with modeling
plastic and an elastic impression material
Some clinicians advocate making a functional
impression of the polished surfaces of mandibular
prosthesis
96. Centric Registration
In maxilla, wax rim used – widened on unresected side
in order to account for deviation of the mandible
Determine VDO and VDR
Centric occlusion registration – obtained with wax or
plaster
The clinician should manipulate the mandible and
place it in the most advantageous position within the
reach of the patient.
97. Occlusal schemes and Lateral registrations
Swoop 1969, suggested “non anatomic teeth” for
patients with abnormal jaw relationships and angular
path of closure.
“Neutral Zone” identification facilitates positioning of
the mandibular teeth.
The wax rim is fabricated according to the neutral
zone.
98. Special attention should be paid of developing
appropriate contours of the rim in contact with the
inside of the upper and lower lip.
After the wax rims have been altered and registations
obtained, the maxillary and mandibular casts are
mounted on a suitable articulator.
99. It is advisable to place the maxillary anterior teeth
lingual to, and mandibular anterior teeth labial to,
their accustomed position.
Lip tooth relationship can be improved if the vertical
overlap is increased so that the amount of tooth
displayed and the smile line are consistent with a more
labial or normal position of the maxillary teeth.
100. Generally, in mandible the posterior teeth on the
unresected side will be buccal to the crest of
edentulous alveolus, especially in the bicuspid region.
The posterior mandibular teeth on the surgical side
usually are placed lingual to the crest of the
edentulous ridge.
101. Contour and support for the corner of the mouth and
the lop on the resected side are best accomplished by
thickening the denture flange below the crest of the
ridge.
After arranging all teeth in the maxillary prosthesis,
ramps of 10mm wide and 3-4mm horizontal overlap
with the lower teeth should be provided.
102. After tooth arrangements have been finalized, the occlusal
contact of the mandibular teeth is checked with the
maxillary ramp.
The patient should be able to establish contact with ramps
without guidance.
After trial prosthesis have been perfected, they are
processed following customary procedures.
The use of prosthesis for mastication should be deferred
for at least a week. As the patient uses the prosthesis, some
adjustment of the ramps usually necessary.
103. Anterior Border Defects
The prognosis is usually favorable especially if a
vestibuloplasty has been completed.
The mandibular movements and maxillomandibular
relationships are usually within the normal limits for
these patients.
Careful placement of the mandibular anterior teeth
and flange contour in this area is suggested.
105. They supported this concept by quoting Fish (1933) who gave
this concept, and stressed on the importance of polished
surface for the retention and stability of the denture.
Shifman and Lepley(1982): Neutral zone or ‘denture
space’ concept for marginal mandibulectomy patients.
106. In this method short and narrow artificial teeth which will
not interfere with the denture space were selected.
They were arranged on the diagnostic cast; occlusion and
esthetics were verified clinically. This was done in self-cure
acrylic resin and space was present underneath the
occlusion for impression material. This prosthesis was
retained by simple Adams or embrasure claps.
107. A functional impression of the defect side is made using
modelling compound for muscle trimming and is
completed with an impression wax.
The released prosthesis is than cured and finished in the
usual manner.
108. Cantor and Curtis(1971): Swallowing technique
in edentulous patient
A preliminary alginate impression of the mandibular
fragment is made in a modified stock tray.
A narrow area, supported by bone and free of any muscular
activity, is drawn on the diagnostic cast and a perforated
acrylic resin custom tray is constructed that conforms to
this area.
Two lateral columns that extend toward the maxillary ridge
are formed on the tray.
109. Modeling compound “stops” are placed under the column
tray for stability and to provide space for the impression
material.
Modeling compound is then added to the lateral columns
extending them superiorly until firm bilateral contact is
made with the maxilllary residual alveolar ridge.
The vertical height of the columns should exceed the
postsurgical physiologic rest position by at least 2 to 3 mm.
110. The lower part of the oral cavity is filled with an alginate
impression material that has been mixed with approximately
one third more water than is recommended by the
manufacture.
The column tray is placed through the hydrocollooid material
until it is seated firmly on the alveolar mucosa.
111. The mandible is then closed until the maxillary ridge rests
are properly seated, and the custom tray is securely in place
with the tongue resting between the columns on the tray.
At this point, the patient begins to swallow, and between
each swallowing cycle, he puckers his lips.
The patient continues these two motions until the alginate
material has set.
112. Swatantra agarwal, Praveen G, Samarth Kumar
agarwal and Sankalp sharma (2011), suggested Twin
Occlusion in which they did functional rehabilitation of
hemimandibulectomy patient, who had undergone
resection without reconstruction.
117. Management of mandibular defects is one of the most
challenging aspects of maxillo-facial prosthetics. These
defects affect not only function but also appearance and
thus the prosthodontists has to fulfill the dual
responsibility of restoring function and appearance.
With the advent of advanced surgical and bone grafting
techniques, satisfactory prosthodontic prognosis can be
achieved for such patients. However there are still some
inherent problems in these procedures which have not
been completely overcome.
118. On his part the prosthodontists should be able to
efficiently plane and execute treatment because the scope
of patients with mandibular defects may vary form the
completely edentulous patient to the patient with few teeth
remaining or patients requiring implant supported
prosthesis.
119. References
John Beumer, Maxillofacial rehabilitation prosthodontic and surgical
reconstruction, 1st edition 1979
Taylor TD, Clinical maxillofacial prosthetics, 1st edition 2000.
William R Laney, Maxillofacial prosthetics, postgraduate dental hand
book series, Vol 4.
Kenneth L Stewart, Clinical removable partial prosthodontics, 2nd
edition.
Osbon DB. Early treatment of soft tissue injuries of the face. J Oral
Surg 1969;27:480–7.
120. Cantor R and Curtis TA Prosthetic management of edentulous
mandibulectomy patients - Part 1. J Prosthet Dent, 1971; 25:447-455.
Cantor R and Curtis TA Prosthetic management of edentulous
mandibulectomy patients - Part 2- J Prosthet Dent, 1971;25:547-555.
Cantor R and Curtis TA Prosthetic management of edentulous
mandibulectomy patients - Part 3- J Prosthet Dent, 1971;25:671-678.
Shifman A and Lepley JB Prosthodontic management of postsurgical
soft tissue deformities associated with marginal mandibulectomies. J
Prosthet Dent, 1982; 48:178-183.
Swoope CC Prosthetic management of resected edentulous mandibles.
J Prosthet Dent, 1969; 21:197-201.
121. Desjardins RP Occlusal considerations in partial mandibulectomy
patients . J Prosthet Dent, 1979; 41:308-311.
Kelly EK Partial denture design applicable to the maxillofacial patient. J
Prosthet Dent, 1965; 15:168-173.
Ackerman AJ The prosthodontic management of oral and facial defects
J Prosthet Dent, 1955; 5:413-432.
Aramany MA and Myers EN Intermaxillary fixation following
mandibular resection. J Prosthet Dent, 1977; 37:437-443.
Maxillofacial rehabilitation prosthodontic and surgical considerations,
John Beumer, Thomas A. Curtis & David N. Firtell; 1st edition 1979
122. Scannell JB Practical considerations in dental treatment of patients
with head and neck cancer. J Prosthet Dent, 1965; 15:764-778.
Schaff NG Oral reconstruction for edentulous patients after partial
mandibulectomies. J Prosthet Dent, 1976; 36:292-297.
Editor's Notes
External surface – Buccinator, Depressor anguli oris – from mental tubercle to platysma & cervical fasciae,
Platysma – upper part of pectoral and deltoid fasciae to base of the mandible,
Depressor labii inferioris - frm oblique line of the mandible, between the symphysis menti and the mental foramen to platysma,
Mentalis – incisive fossa to skin of chin; Temporalis- temporal fossa to coronoid process & ant border of ramus,
Massetor – zygomatic arch to ramus of the mandible (superficial , middle n deep layers)
Mylohyoid – mylohyoid line of mandible to body of hyoid bone
L P – Upper head frm inftra temporal Lower head frm lat. Surface of lateral pterygoid plate to neck of the mandible
M P – medial surface of lat pterygoid plate and maxillary tuberosity to med surface of ramus and angle of mandible
Genio hyoid / glossus – genial tubercle to body of hyoid / bottom of tongue
Digastric – lower border of the mandible at midline to hyoid bone
Mylohyoid, hypoglossal, Pterygoid, masseter, external pterygoid,
Palatoglossal muscles, most of intrinsic muscles of tongue.
Disarticulation – separation of two bones at their joints
Tissue resected at time of original operation
K – wire sterilized, sharpened, smooth stainless steel wire.
Introduced by Martin Kirschner in 1909
Which requires resection of mandible or tongue
The rule of thumb was to remove only that bone that was flushed out with aggressive irrigation. Any bone still with soft tissue attachment was considered potentially viable (able to live on its own)