ORAL HISTOLOGY DIAGRAMS- Enamel- Incremental Lines of Retzius and Neonatal line

E- Enamel
D- Dentin
SR- Striae of Retzius ( Concentric rings produced by incremental enamel deposition)
NL- Neonatal line A prominent SR seen in deciduous teeth and at times cusps of permanent first molar
DEJ- Dentinoenamel Junction


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ORAL HISTOLOGY DIAGRAMS- Advanced Bell Stage of Tooth Development

Advanced Bell Stage

EO- Enamel Organ                                
OEE- Outer Enamel epithelium                                                                        
SR- Stellate Reticulum                                                        
SI- stratum Intermedium                                        
IEE- Inner Enamel Epithelium                                 EM- Enamel Matrix
CL- Cervical Loop
A- Ameloblast ( showing Reversal of polarity)
OEE Folds ( Invagination of OEE- Reversal of nutrition)

                                           
DP- Dental Pulp                                   
OD- Odontoblast                                                            D- Dentin                                     
UMC- Undifferentiated mesenchymal  cells
 
DS- Dental Sac

Contributed by Dr. Vimi Mutalik


Advanced Bell stage by Vimi Mutalik is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License

ORAL HISTOLOGY DIAGRAMS- Human Tooth Development

Early Bell Stage:

Early Bell Stage

A1- Remaining Dental Lamina

A2- Secondary/Permanent Tooth Bud

B- Dental Papilla

C- Bell Shaped Enamel Organ

      C1- Outer Enamel Epithelium

      C2- Stellate Reticulum

      C3- Stratum Intermedium

      C4- Inner Enamel Epithelium

      C5- Cervical Loop

D- Dental Sac

E- Developing Bone

Early Bell Stage by Mandana Donoghue is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License

ORAL HISTOLOGY DIAGRAMS- Human Tooth Development

Cap Stage:

Cap Stage of Tooth Development

A- Oral Epithelium

B- Dental Lamina

C- Developing tooth germ

     C1- Cap shaped Enamel organ -

                              C1 a-  Outer Enamel Epithelium( a  layer of cuboidal cells)

                              C1 b- Stellate reticulum -Central star shaped cells    

                              C1 c- Inner enamel epithelium( tall columnar cells lining the                                                                             concavity of the enamel organ                                                  

     C2- Dental Papilla- Condensation of ectomesenchymal cells adjacent to the inner enamel  epithelium.

     C3- Dental Sac/Follicle- Ectomesenchymal cells that surround the dental papilla and the enamel   organ.

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

ORAL HISTOLOGY - TOOTH DEVELOPMENT

Drawing Oral histology diagrams are perhaps the most challenging task for undergraduate students. having seen the difficulty my students have experienced through the last 20 years I have decided to draw and post the diagrams usually required. Those who have worked with me or were taught by me know that I am not a very artistic person. I have always relied more on the science than art of dentistry and its subjects. As such these diagrams only aim to be scientifically accurate and not aesthetically perfect.
Dear students , I do hope the diagrams will ease the burden of drawing the diagrams and help you  understand the subject better. I plan to post one diagram at a time so wait for the rest. Please leave your comments and let me know if you find the diagram helpful.

Happy learning

Mandana Donoghue


TOOTH DEVELOPMENT- BUD STAGE

BUD STAGE OF TOOTH DEVELOPMENT

A- Oral Epithelium consisting of stratified Squamous Epithelium
 
B - Dental Lamina- a band like thickening of the oral epithelium along each future dental arch that grows into the ectomesenchyme.
 
C- Vestibular lamina- another band of epithelium that  develops buccal or labial to the dental lamina. It's cells multiply rapidly and are lost in the center, hollowing out the band and forming the future vestibule.

E- Tooth Bud- The round or ovoid swellings seen at ten sites along each dental lamina,

    1- Low columnar basal cells.
    2- Polygonal cells
    3- Ectomesenchymal condensation (around the epithelial proliferation)

D- Developing mandible



This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported License.

Professor Sol Silverman Jr, Passes Away

"Longtime UCSF School of Dentistry faculty member Sol "Bud" Silverman, Jr., MA, DDS, Professor of Oral Medicine in the Department of Orofacial Sciences, UCSF School of Dentistry, passed away on August 13 following a brief illness."UCSF Announcement

Professor Silverman known globally for his extensive contributions to the field of oral medicine passed away on the 13th of August. His contributions ensure that his loss will be felt right across the world of dentistry and special oral medicine and pathology.
We in India were provided the chance to meet him and interact with him in March this year at Bangalore.
During a two day program he shared his knowledge and vast experience  with us and left  us with pleasant memories of a knowledgeable, kind senior who was so full of life it almost seems impossible that he is no longer with us.

Moments from a short  association  that  will always  be cherished..

BLOGGER'S NOTES

Introduction to Epigenetics In Cancer:

Cancer development depends on the survival and multiplication of genetically transformed /altered cells. Genetic transformation alone does not lead to cancer since the epigenetic or external controls on the expression of the genome also need to be lost or modified for the development of cancer.  This second line of control consists of a set of chemicals outside the DNA that control the expression of various parts of the DNA by acting like on-off switches. Epigenetic factors and processes are thus additional points at which the regulatory function may fail, leading to cancer development. Consequently they also provide additional opportunities in oncology for treatment by targeting processes that lead to cancer development.

Various epigenetic changes have been found in cancer cells. Most common are DNA methylation and histone modification, which alter the expression of specific parts of the genome by inactivating the cancer suppressor genes and activating oncogenes.  Chromatin remodeling and MicroRNA variations lead to faulty and excessive coding of oncogenes and noncoding of tumor suppressor genes.

The current knowledge on the role of the epigenome on cancer development can be used in screening, diagnosis, treatment planning and prognostication of cancers. Changes linked with specific tumor types can be used for screening. Epigenetic changes known to occur early in the disease course can be used for early diagnosis of the primary tumor and identification of tumor recurrence. More specific typing of cancers by finding the different subtypes can lead to targeted therapies with   reduced side- effects. On the other hand, some treatment modalities may be unified across various cancer types which show the same epigenetic changes thus reducing development costs and approval time.  

References:

•   Brait M, Sidransky D. cancer epigenetics: above and beyond. Toxicol Mech Methods. 2011 May;21(4):275-88. doi: 10.3109/15376516.2011.56267

·        J Lopez, M Percharde, HM Coley, A Webb and T Crook. The context and potential of epigenetics in oncology. British Journal of Cancer. 2009, 100(4), 571 – 577

 ·         http://learn.genetics.utah.edu/content/epigenetics/intro