Development of tooth (Odontogenesis) made easy- Part 1

Dental Histology is a very interesting subject but initially many students face a lot of problem understanding it.I can say this as I have been through this phase but don't worry, I'll try to make it easy for you and I hope you like my effort :)
We'll study development of teeth under the following headings-
1.FORMATION OF DENTAL LAMINA
2.STAGES IN TOOTH DEVELOPMENT-     (a)Bud stage
                                                                        (b)Cap stage
                                                                        (c)Bell stage- (  c.1) Early bell stage
                                                                                                 (c.2) late bell stage
 In this post we'll study formation of dental lamina.

Where are your teeth present? In your mouth obviously :D
So imagine yourself in your mothers womb okay... So you are just developing right.. and so is your mouth or oral cavity. Now this oral cavity (which is in the process of development) is called PRIMITIVE ORAL CAVITY or STOMODEUM and it is lined by stratified squamous epithelium. And we'll call this epithelium ORAL ECTODERM.
This ORAL ECTODERM contacts the ENDODERM (of the foregut) by a BUCCOPHARYNGEAL MEMBRANE.

 Here's a pic that will help you visualize this-

Figure 1

At the 27th day of pregnancy the buccopharyngeal membrane ruptures and the primitive oral cavity establishes a connection with the endoderm of the foregut (Fig2) -

Fig.2.The ectoderm contacts the endoderm after the rupture of buccupharyngeal membrane

 Underlying the oral ectoderm we have a connective tissue and most of these connective tissue cells are ectomesenchyme in origin (Fig3) These cells are though to instruct the ectoderm to start tooth development. And the development of tooth first occurs in the the anterior portion of future maxilla & mandible (We call it 'Future maxilla & mandible' because they haven't developed yet)

Figure 3

 NOTE- In the diagram, within the ectomesenchyme the lines represent the collegen fibres but their orientation might not be correct in the above pic because I made it in a hurry & forgot to consider this.Sorry for this mistake!

Now we arrive at 'DEVELOPMENT OF DENTAL LAMINA'

Remember the buccupharyngeal membrane ruptured at 27th day of gestation? So 2 or 3 weeks after the rupture of this membrane certain areas of the basal cell of the oral ectoderm proliferate more rapidly (Fig.4) This leads to the formation of primary epithelial band (Fig 5)

Fig4.Proliferation of basal cells of oral ectoderm

Fig 5.Primary epithelial band

This primary epithelial band divides into inner lingual and outer buccal process.The lingual process is called Dental Lamina and outer Buccal process is called vestibular lamina (Fig6)

Fig6.Dental Lamina & vestibular lamina

 

This how the dental Lamina and vestibular lamina looks

DENTAL LAMINA- Will form the ectodermal portion of deciduous teeth. The permanent successors will arise from the LINGUAL extension of dental lamina & Permanent molars will arise from its DISTAL extension. (Now you'll have to cram it :P )

VESTIBULAR LAMINA- Forms the vestibule of the mouth

(WHAT IS VESTIBULE??
Put your tongue in between your gums and cheeks. You find a space there right? That is the vestibule)

FATE OF DENTAL LAMINA-

• Total activity of dental lamina extends for the period of 5 years.
• Dental lamina may still be active in the third molar region after it has disappeared elsewhere.
• Remnants of dental lamina persist as epithelial pearls or islands within the jaw and gingiva and these remnants are called rest of Serres  

Another boring note- The diagrams above are just for your visualization & you should make standard diagrams in your exams (diagrams from your book) to get good marks.


Hey before you leave,Did you understand it? Please leave your comments below :)

Tips for studying Human Anatomy!

Hello!
How's your studies going on?
Well this post is specifically targeted to the beginners...............
Well before I can dare to give you some tips that will probably help you in learning human anatomy I need to ask you 3 questions-
1.Do you like Anatomy?
 OR
2.Do you hate it?
OR
3.Are you a beginner?

So no matter what your answer is... I would first ask you to wipe all negativity about anatomy. Because as you follow my tips you'll gradually start getting more interest.

So, First repeat in you mind thrice a day that 'Anatomy is fun' (It would really help)

Be thorough with bones-
For dental students,you should first be thoroughly familiar with the bones and surface anatomy of the skull.
Having trouble remembering the bones?
Refer to a book (such as Anand's anatomy) for osteology part. It has photographs of skull rather than just diagrams so you'll grasp more from it.
AND dont forget to have a skull (or any other bone that you're studying) in your hand. First read from the book and look for it in the photograph and then close your book and try to locate in the skull. Repeat this process.

If you revise Twice a week for 3 weeks then you will not forget it.

Visualization really helps-
Now coming to the other point.I feel the best way to learn anatomy is visualization.
Its almost impossible to cram everything and recall exactly when you need it particularly in Viva.
For example if the examiner asks you the origin of lateral pterygoid muscle (one of the muscle of mastication) you can't just say that it arises from 2 head-
Upper head- From lateral pterygoid plate of spheniod bone.
Lower head- From the greater wing of spheniod bone.

This answer is incomplete and you wont get enough marks for it.
 So the correct answer would be
Upper head origin- From the lateral surface of the lateral pterygoid plate of the spheniod bone.
Lower head- From the infratemporal surface of the greater wing of spheniod bone.

So for remembering these minute details the "Cram cum visualization technique" works.

What you have to do is to learn to visualize. It doesn't necessarily means that your imagination should be correct. It should just be buried in your mind so that you can recall it.

So if you are learning for example the origin and insertion of masseter muscle (a muscle of mastication)
Then its origin is- Temporal fossa upto the inferior temporal line.
So at this point you need to imagine the muscle originating from the inferior temporal line and covering the temporal fossa.

Now for insertion- It inserts on to the tip, anterior and posterior border and the medial surface of the coronoid process of the mandible. It doesn't inserts on to the lateral surface so here the visualization technique is very useful.

Imagine the coronoid process of the mandible.
Now we had imagined the muscle originating from the inferior temporal line covering the temporal fossa. Now just extent the muscle further upto the coronoid process and imagine its fibres inserting on to the tip, anterior and posterior border and the medical surface. Now repeat this visualization in your mind atleast thrice and you're done.

Mnemonics-

This is very useful for learning branches of artery and nerves.You may google it.
You should try making your own. 

Learn from diagrams-

Practice the diagrams and this will help you remember the contents.

Last day revision must-
No matter how many times I revised, I always felt that the last day revision proved to be most useful. So so revise a day before exam.

Hope its mildly useful :)

                                                       

Best textbooks for BDS 1st year!

So you have been selected in BDS and now you are confused what books to buy? Well I was in a similar condition and I ended up buying more books than I actually needed :P
So You have 5 subjects to handle in 1st yr (I can only say this for India) and the 6th one is dental material which you'll study both in 1st and 2nd year but you'll give its exam in 2nd year only.

1.Anatomy

B.D.Chaurasia (volume that includes head and neck)
Anand's anatomy for dental students

I liked both of them but I ended up studying more from Anand's anatomy because its layout and presentation is very catchy. You'll enjoy reading form it.

For embryology-
Inderber

Neuroanatomy-
Its given in B.D. chaurasia's head & neck volume but if you wanna study in detail you may read Inderber's neuroanatomy.

2.Physiology-

Guyton is a great one but too vast to study if you are not so studious (like me) so I would suggest
1. A.K.Jain physiology
2. Sembulingam's physiology (Choose the medical one because the dental one is too concise but may be enough for some)

Dental Histology-

Orbans (love it :*)
Okay so let me tell you your first reaction when you start with its 1st chapter "development of face and oral cavity" ... OMG! Its so tough.. i cant get anything out of it and blah blah! But relax! Dont care for the 1st chapter because all the other ones are explained in a simplified way. Infact dental histology was my favourite subject in 1st year. I even got highest marks many times :)
And yes! for the 'development of face' you can refer to Inderber embryology.


Another book I like is ten cates

Dental Anatomy-

Wheeler's dental anatomy
Dental anatomy & histology by Balajhi

Biochemistry-

I didn't like this subject at all

1.By satyanarayan (for dental. I wont suggest buying the medical one because its too vast)
2. Vasudevan (its concise and well presented)

Hope it helps :)

Revlon Whipped Creme Makeup review!

Hi there! This is my first review ever! Hope you read it till the end :P

I have always loved foundations & would keep loving them forever.And this love of mine makes me search for the perfect one. It was a month ago that I came across Revlon whipped creme foundation. I had never heard of this one before so I was doubtful if buying it would be a good decision. But I am glad I did....umm.. not completely though...

PACKAGING- 

Comes in a jar with a black lid.
Though it looks classy but its a heavy (but that doesn't bother me :P)

SHADES- 
Website states that it comes in 12 shades-
Ivory, Buff, Sand Beige, Nude, Natural Beige, Medium Beige, Warm Golden, True Beige, Natural Tan, Early Tan, Rich Ginger and Caramel

In India 3 shades are available-
Natural Ochre, Warm golden, Natural tan


MY SHADE- The SA recommended the lightest of the 3 shades (Natural Ochre) available in India so I bought it. But I regret it isn't a match for me :(

Revlon whipped creme in Natural Ochre-

WHAT THE PRODUCT CLAIMS-

• Finally, truly decadent makeup offers ultimate performance. The mousse-like texture feels like silk on your skin. And, the time release formula balances skin for a flawless look. All day flexible wear without flaking, caking or feeling heavy. 

• Stays upto 24hrs (Wow)

MY EXPERIENCE-
Staying power-Everyone loves to see their makeup intact for as much as possible and that too without touch ups....isnt it?
This product claims to stay for upto 24hrs...what? I mean that claim is so exciting but who wants to wear makeup for that long (except when its your wedding :D ) 
Yeah so coming to the point, it does stay for 8 hrs or so but it starts fading after 6hrs because I dont use a primer ( silly me!) but its still enough for me.
I have a combination skin so results may very depending on your skin type and the weather. 

Product consistency-

Its creamy but hey wait! before you leave my blog let me tell you it glides on so easily on you skin,just like butter (but much better :D) 
When I first touched the product it felt as if its gonna give me a cakey look but that's 100% not!
Infact its one of the easiest foundation to apply and the finish is totally awesome :)

Coverage-

Medium-High
Its buildable without giving you a cakey look.

Finish-

Its gives a satin finish.

Application-

I felt it gives better results if stippling brush is used. Fingers work equally well.
Sponges didn't satisfy me so I wont use a sponge.

Suited for which skin type-
Definitely for normal,combination skin.
But heard people say it works fine with dry skin too.

Pros-

1. Staying power is great.
2. Covers imperfections quite well.
3. Contains no paraben (Yay!)
4. Has Salicylic acid (acne fighting ingredient)
5. Blends really well.
6. Gives a natural look (didn't give me because I got the wrong shade)

Cons-

1. Jar is heavy and not very sanitary..
2. The standard fluid ounces for the majority of foundations on the market is 1 oz. This foundation contains 0.8 oz so less product here.
3. Price may be issue.
4. Not easy to get your shade especially in India (why only 3 here?)

Swatch-

Blended -

 Price-
800INR

Will I buy again-

If I get a perfect shade.  


Recommended-
Yes


Please leave in your comments and suggestions :)