• Subcutaneous
• Develop from the Mesoderm of the2nd Branchial arch
• They are supplied by the facial nerve
• All of them are inserted into the skin

The Muscles which lead to various expressions:

1. Smiling and laughing – Zygomaticus Major
2. Sadness – Levator labii superioris, levator angulioris
3. Grief – Depressor Anguli Oris
4. Anger – Dilator naris and depressor septi
5. Frowning – Corrugator Supercilii, Procerus
6. Horror, terror, fright – Platysma
7. Surprise – Frontalis
8. Doubt – Mentalis
9. Grinning – Risorius
10. Contempt – Zygomaticus Minor
11. Closing the mouth – Orbicularis Oris
12. Whistling – Buccinator, Orbicularis Oris

© mplab.ucsd.edu

Muscles of Facial Expression are the Facial muscles which with the help of minute and major contractions and relaxation lead to appearance of facial expressions.

The following points about LA Dosage are explained in the post below:

1. What is the Maximum dose of LA which can be used with a Vasoconstrictor
2. What is the Maximum dose of LA which can be used without a Vasoconstrictor
3. What is the Maximum dose of LA which can be used with a Vasoconstrictor at 1:1,00,000 concentration
4. What is the Maximum dose of LA which can be used with a Vasoconstrictor at 1: 50,000 concentration

Dosage Of Local Anesthesia:

1) Safety dose of 2% Lignocaine is 4.5mg/kg without a Vasoconstrictor

• Without a Vasoconstrictor 300 mg (maximum dose)

2) Safety dose of 2% Lignocaine is 7mg/kg with a Vasoconstrictor

• With a Vasoconstrictor – 500 mg (maximum dose)

3) As 1ml of 2% Lignocaine contains 20mg – Where the Maximum safety dose being 300 mg

• So 15 ml of Drug can be given safely

4) 1:1,00,000 concentration means 1 part of Adrenaline is 1,00,000 parts of Solution

• Safety Dose of Adrenaline for Dental Use in noraml patients is 0.2 mg – which means 20 ml of LA can be given to normal patients containing Adrenaline
• For cardiac Patients the safety dose of Adrenaline is 0.04mg – Which means 4ml of LA can be given to Patients with cardiac problems containing Adrenaline

5) If the concentration of LA is 1:50,000 – 10 ml of LA can be given safely

Duration of action of various Local anesthetic agents used in dental practice:

1. Etidocaine – 200 min
2. Bupivacaine – 175 min
3. Tetracaine – 175 min
4. Lignocaine – 175 min (Commonly used for Tooth Extraction and also as a Topical Local Anesthetic agent)
5. Procaine – 50 min (Used in children because of the short duration of action, which prevents self inflicting injuries to the lip under anesthesia)

As you can see that Lignocaine is the widely used Local anesthetic agent for Tooth Extraction or any minor Surgical procedure, the

Duration of Action of Local anesthesia after a Dental or Tooth extraction – 3 hrs after the LA injection was given

So there is no need to worry about the numbness and lack of sensation after a tooth extraction which is not reduced even after returning home from the clinic, but you have to visit your dentist if the Numbness and Lack of sensation are not reduced even after 4-5 hrs of LA injection.

To know more about Local Anesthetic agents visit - Local Anesthetic agents Composition, Classification, Ideal Properties and Complication

These are the properties a Operator looks at, which make it easy for him/her to operate and get an Ideal Impression. The All the Properties should be fulfilled to produce an Ideal Impression material, till date such an impression material has not been discovered or invented, so we have to use different Impression materials in different situations based on the requirements.

1. Pleasant Odor (example of bad odor- Polysulphide)
2. Pleasant Taste
3. Pleasant color
4. Absence of Toxic or irritant constituent
5. Adequate shelf life for requirements of storage and distribution
6. Should be economical, in case of high cost should be having increased charecteristics
7. Should be Easy to Use without requirement of much equipments
8. Setting time should be adequate for clinical use – And such that the Practitioner can be able to alter it according to his requirement
9. Satisfactory consistency and texture
10. Should Readily wet the Oral tissues (Hydrophilic materials)
11. Should not release Gasses during setting of Cast/Die/impression material
12. Should be readily disinfected without loss of accuracy
13. Accurate in clinical use
14. Compatibility with Cast or Die materials
15. Dimensional stability over temperature and humidity changes which can be seen in clinical conditions
16. Should be stable long enough to make a cast or Die from the impression taken
17. Should have Adequate strength so it will not break, tear during removal from mouth
18. Elastic properties with freedom from permanent deformation after strain

List of Scientists given below are:

1. Fermin A. Carranza
2. Balint J. Orban
3. Bernhard Gottlieb
4. Henry H. Takei
5. Micheal G. Newman
6. John W. Riggs
7. Oskar Weski
8. Robert Neumann
9. Irving Glickman
10. Jens Waerhaug

Fermin A. Carranza

Dr. Carranza is a Periodontist who has vast contributions to the Dental world in basic and applied aspects of Periodontics and periodontal pathologies and Periodontal Therapies. He has writtena book on Periodontics which is widely followed by students and doctors all around the world

Fermin A. Carranza

Balint J. Orban

A Dental Scientist, who has done extensive Histological research on Periodontal tissue and has written a Book on the Histological aspect of tooth and its supporting structures which is still followed around the world. He was accompanied by Gottlieb.

Balint J. Orban

Bernhard Gottlieb

He was the major contributor for the modern Periodontics, he did extensive studies on the Histopathologic concepts of tooth supporting structures. He did extensive research on Histology and biology of tooth and supporting mechanism. He carried out extensive microscopic studies on periodontal diseases in humans.

Bernhard Gottlied

Henry H. Takei

Henry H. Takei is a renounced Professor in Periodontal Surgery and Implant Surgery. he has given lectures on these topics all around the world receiving many awards. He has contributed vastly in Periodontal Therapy and Implant Surgery.

Henry H.Takei

Micheal G. Newman

Micheal G. Newman who has done Psychology and has completed Oral Medicine and Periodontics from Harvard School of Dental Medicine is also the editor in chief of Evidence Based Dental Practice. Newman has contributed a lot on Risk factors, and diagnostic strategies for periodontal disease.

Micheal G. Newman

John W. Riggs

He was the pioneer of Periodontitis, in who’s honor Periodontitis was earlier known as Rigg’s Disease. He Graduated from Batlimore college of Dental Surgery. Rigg’s always quoted ” teeth with their accretions and roughened surfaces are the existing cause of the disease” Rigg’s was the first to have got the idea of “Reattachment” He was the first to treat the root of a cuspid with lactic acid and fix gum graft with “fine cambric needles”  which was a success.

John W.Riggs

Oskar Weski

Oskar Weski carried out pioneering studies correlating radiographic and histopathologic changes in periodontal disease. He contemplated that periodontium was formed by cementum, gingiva, periodontal ligament,  and bone and gave it a name – Paradentium

Oskar Weski

Robert Neumann

Robert Neumann has done extensive research on Principles of Periodontal Flap Surgery, Osseous Recountouring. He has also published a book on the same.

Robert Neumann

Irving Glickman

Irving Glickmann has contributed extensively on the knowledge of experimental pathology of the periodontal tissue.

Irving Glickman

Jens Waerhaug

Jens Waerhaug published a Book “The Gingival Pocket” which has changed the concept of understanding the gingival attachment and and Gingival Plaque and the Etiology of Periodontal Disease.

Jens Waerhaug