Sunday, June 27, 2010

Sem 1 Dental Summative Questions

OBA
1. The second branchial arch is innervated by the facial nerve. Which of the following is NOT a muscle derivative of this arch?
(a) Stylohyoid
(b) Orbicularis oris
(c) Mentalis
(d) Mylohyoid
(e) Posterior belly of digastrics

2. There are 12 pairs of cranial nerve. The nerve that provides only sensory innervations is the
(a) Trochlear
(b) Trigeminal
(c) Glossopharyngeal
(d) Oculomotor
(e) Olfactory

3. Oblique facial cleft results from non-fusion of the :-
(a) Maxillary and medial nasal process
(b) Two mandibular process
(c) Maxillary and lateral nasal process
(d) Lowermost part of frontonasal process
(e) Both maxillary processes with the medial nasal process

4. The trigeminal nerve is divided into 3 main divisions. The ophthalmic division innervates all of the following, except :-
(a) Maxillary sinus
(b) Lacrimal gland
(c) Frontal sinus
(d) Nasal cavity
(e) Sclera of the eye

5. The mandibular nerve has both motor and sensory functions. It provides motor innervations to all of the following muscles, except :-
(a) Anterior belly of digastric
(b) Masseter
(c) Posterior belly of digastric
(d) Tensor tympani
(e) Temporalis

6. All of the following are branches of the mandibular nerve, except :-
(a) Lingual nerve
(b) Superior alveolar nerve
(c) Buccal nerve
(d) Inferior alveolar nerve
(e) Auriculartemporal nerve

7. The Maxillary artery is divided into 3 parts by the
(a) Infratemporal fossa
(b) Medial pterygoid muscle
(c) Maxillary nerve
(d) Lateral pterygoid muscle
(e) Masseter muscle

8. The pterygopalatine part of maxillary artery give rise to all the following branches, except :-
(a) Inferior alveolar
(b) Infraorbital
(c) Descending palatine
(d) Artery of the pterygoid canal
(e) Posterior superior alveolar

9. The retromandibular vein
(a) Joins posterior auricular vein to form internal jugular vein
(b) Lies on the internal surface of sternocleidomastoid muscle
(c) Is formed by the union of superficial temporal vein and maxillary vein
(d) Has an anterior branch that joins the deep facial vein

10. The pterygoid venous plexus
(a) Is associated with the medial pterygoid muscle
(b) Receives the Maxillary vein
(c) Communicates with facial vein through anterior facial vein
(d) Is able to transmit infections from the face and teeth to the cavernous sinus

11. The carotid sheath contains all of the following, except :-
(a) Internal jugular vein
(b) Internal carotid artery
(c) External carotid artery
(d) Vagus nerve
(e) Common carotid artery

12. Which of the following nerve provides sense of taste to the anterior two third of the tongue?
(a) Vagus nerve
(b) Glossopharyngeal nerve
(c) Lingual nerve
(d) Mandibular nerve
(e) Chorda tympani nerve

13. Below the temporal fossa lies the infratemporal fossa. All the following structures lies in the infratemporal fossa, except :-
(a) Pharyngeal venous plexus
(b) Pterygoid venous plexus
(c) Pterygoid muscles
(d) Mandibular nerve
(e) Maxillary artery

14. The muscle acting when a person “pouts” is the
(a) Orbicularis oris
(b) Risorius
(c) Buccinator
(d) Mentalis

15. Contraction of the following muscles closes the mouth.
I. Masseter
II. Lateral pterygoid
III. Temporalis
IV. Medial pterygoid

(a) I, II, III
(b) I.II.IV
(c) I.III, IV
(d) II,III,IV
(e) All of the above

16. Choose the correct statement regarding the sternocleidomastoid muscle.
(a) Accessory nerve provides sensory innervations to SCM
(b) Bilateral contraction brings the chin to the chest
(c) Unilateral contraction turns the face to ipsilateral side
(d) It divides the mandible into 2 triangles

17. Choose the correct statement regarding the muscles of the tongue
(a) The origin of genioglossus is below the geniohyoid muscle
(b) The palatoglossus is supplied by the Vagus and Accessory nerve
(c) The intrinsic muscles changes the position of the tongue
(d) Hyoglossus and palatoglossus pulls the tongue upward and backward

18. The parotid gland has all the following structures passing within it, except :
(a) Ariculotemporal nerve
(b) External carotid artery
(c) Facial nerve
(d) Retromandibular vein
(e) Internal jugular vein

19. Which of the following cranial nerve provides preganglionic parasympathetic fibers through the otic ganglion to the parotid gland?
(a) Trigeminal nerve
(b) Facial nerve
(c) Vagus nerve
(d) Glossopharyngeal nerve

20. Choose the correct statement from the following :
(a) Submandibular gland is the largest salivary gland.
(b) The parotid gland contains both serous and mucous acini.
(c) Some of the ducts of sublingual gland opens into the submandibular duct.
(d) Mylohyoid muscle divides the sublingual gland into superficial and deep part.

21. Which of the following nerves does not pass through the jugular foramen?
(a) Hypoglossal nerve
(b) Glossopharyngeal nerve
(c) Vagus nerve
(d) Accessory nerve

22. Which of the following has the most extensive distribution of all the cranial nerves?
(a) Facial nerve
(b) Vagus nerve
(c) Trigeminal nerve
(d) Hypoglossal nerve

23. Which of the following is the principle artery to the nasal cavity, supplying the conchae, meatus, and paranasal sinuses?
(a) Anterior tympanic
(b) Descending palatine artery
(c) Sphenopalatine artery
(d) Middle meningeal artery

24. Which branch of the external carotid artery listed below supplies the submandibular gland?
(a) Lingual artery
(b) Maxillary artery
(c) Ascending pharyngeal artery
(d) Facial artery

25. Which lobe of the cerebrum listed below is responsible for hearing?
(a) Frontal lobe
(b) Temporal lobe
(c) Occipital lobe
(d) Parietal lobe


26. All of the following statements concerning the buccinator muscle are true, except:
(a) It originates from the outer surface of the alveolar margins of the maxilla and mandible opposite the molar teeth and from the pterygomandibular raphe.
(b) It compresses the cheeks and lips against the teeth
(c) It is innervated by the buccal branch of the hypoglossal nerve
(d) It is pierced by the parotid duct
(e) It inserts at the orbicularus oris muscle and skin at the angle of the mouth

27. Which extrinsic tongue muscle listed below depresses the tongue
(a) Hyoglossus muscle
(b) Genioglossus muscle
(c) Styloglossus muscle
(d) Palatoglossus muscle

28. All of the following structures empty into the cavernous sinus, except:
(a) Superior ophthalmic vein
(b) Inferior ophthalmic vein
(c) The cerebral veins
(d) Maxillary artery

29. The common carotid artery divides into its external and internal branches at the level of the superior border of the
(a) Hyoid cartilage
(b) Thyroid cartilage
(c) Cricoid cartilage
(d) First cervical vertebra

30. Which of the following is not a branch of the external carotid artery?
(a) Occipital artery
(b) Ascending pharyngeal artery
(c) Maxillary artery
(d) Superficial temporal artery
(e) Anterior cerebral artery


Ans:
D E C A C
B D A C D
C E A D C
B B E D C
A B C D B
C A D B E

SAQ
1. (a) What structure lies immediately behind the soft palate? (1m)
Uvula

(b) What is the palate derived from? (4m)
Premaxilla/Primary palate from the frontonasal process
Palatal process/Secondary palate from the maxillary process



2. Mr. Chan had a mandibular posterior tooth extracted recently. Following the surgery he
experienced loss of sensation of the lower jaw.

(a) Which nerve is responsible for the loss of sensation in Mr. Chan’s condition? (2m)
Inferior alveolar nerve

(b) Briefly describe the course of the nerve. (4m)
It originates from the mandibular branch of the trigeminal nerve. It passes thtough the
mandibular foramen into the mandibular canal and exits the mental foramen as mental

nerve. Before entering the mandibular foramen, it branches off as the mylohyoid nerve.


(c) What structures does the nerve supply? (4m)
- lower teeth and gums
- lower lip and chin
- mylohyoid muscle
- anterior belly of the digastric muscle


3. Complete the following table


Ans : refer to pg. 244 of Netter’s. Besides muscle of mastication, try to remember the origins, insertion and function of all the muscles you have learnt. These are bonus marks!



All The Best!!

Wednesday, June 16, 2010

Midnight snacking damages the teeth, experts warn

By Michelle Roberts
Health reporter, BBC News

Eating food in the middle of the night can seriously damage your teeth, Danish experts have warned.

Researchers found midnight snacking ups the risk of tooth loss, regardless of the type of food eaten.

The University of Copenhagen team blamed changes in saliva flow - it tends to dry up at night.
Enough saliva is important to remove food debris from the mouth
.



Night nibbles **Nocturnal eaters - meaning they consumed a quarter or more of their daily calories after dinner or would wake up in the middle of the night at least twice a week for a little moonlight snack.

The nocturnal eaters ended up losing more teeth, even after accounting for other factors such as age, smoking and sugar/carbohydrate consumption.

While dentists may not be able to stop their patients feasting in the middle of the night, Dr Jennifer Lundgren and colleagues say they should make them aware of the associated risks.

"Practitioners should be aware of the oral health implications of nocturnal eating, increase screening and oral health education efforts among nocturnal eaters and make treatment referrals when appropriate," they say.

Professor Damien Walmsley, scientific adviser to the British Dental Association, said: "Eating at night, when the mouth is driest and any food remains in the mouth longer, accentuates the impact of consuming sugary and acidic food and drinks. "

"To minimise damage, it is important to brush teeth twice a day with fluoride toothpaste, with one of those brushes coming immediately before bedtime.

"Where possible, consume only water for at least an hour before the final brush of the day."

Tuesday, June 15, 2010

Toothbrushing May Stave Off Heart Woes

THURSDAY, May 27 (HealthDay News) -- Here's another reason to brush your teeth regularly:

People who don't perform this essential of oral hygiene seem to have a greater risk of heart disease compared to their more diligent peers.

"We were surprised to find a relationship between toothbrushing frequency and both cardiovascular disease and inflammatory markers in the blood," said Richard Watt, co-author of a study published this week in the BMJ.

The findings do make sense, however, in light of previous studies that have found a relationship between gum disease and heart disease. Periodontal disease has been associated with a 19 percent increase in the risk of heart disease. That number leaps to 44 percent in people under the age of 65, according to the study.

The most likely culprit is the inflammation associated with gum disease, which can go system-wide and contribute to plaque build-up in the arteries.

The study authors surveyed almost 12,000 people living in Scotland who admitted to how often they brushed their teeth.

Over an average eight years of follow-up, people who "rarely or never brushed" their teeth had a 70 percent increased risk of a heart attack, stroke or other event, compared to those who set to the task twice a day. The rarely/never brushers also had higher levels of C reactive protein, a marker of inflammation.

Overall, though, participants practiced good oral hygiene with almost two-thirds saying they went to the dentist every six months and almost three-quarters reporting brushing their teeth twice daily.

"We talk often about lifestyle behaviors such as smoking, exercise and diet, and one of the things we can't forget about when it comes to self-maintenance is oral hygiene," said Dr. Suzanne Steinbaum, a preventive cardiologist at Lenox Hill Hospital in New York City and spokeswoman for the American Heart Association. "It's one new thing. Don't smoke, eat right and brush your teeth."

"It's nice to have one more reason to brush your teeth," added Dr. Harmony R. Reynolds, associate director of the Cardiovascular Clinical Research Center at NYU Langone Medical Center and assistant professor of medicine at New York University School of Medicine. "Over time, it reduces inflammation."

Thursday, June 10, 2010

Sour Candy: Havoc for Healthy Teeth?

Sour candy may be stripping the protective surface from your teeth. Here's how to enjoy your favorite candies while saving your smile.



Pucker up with sour candy and you risk ruining your smile, says a new Minnesota Dental Association report on tooth enamel erosion. Treats like Sour Skittles, Lemonheads, and some flavored Altoids are high in acids that strip away teeth's protective surface. Dentist Robert J. Marolt offers this advice:

Rinse right away. Swishing water in your mouth after a candy helps wash away the acid.

Wait a half hour to brush. The acid of a sour candy softens the fragile surface of the teeth.
Brushing immediately after eating one could cause damage.

Skip fruit flavors. Lemon, grape, and cherry destroy more enamel than do cinnamon and mint, which are lower in acid.

Switch to sugar-free gum. It can satisfy your oral urge while stimulating saliva flow, which protects enamel.

From Reader's Digest - November 2008

Secrets From Your Dentist

Do you floss about as often as you flip your mattress? Do you spend more time putting toothpaste on your brush than actually cleaning your teeth? Dentists notice these things. And that's not all. They also know when you're asking for a procedure that's going to disappoint you and when insurance companies are stinting on the care your smile needs. We asked 22 dentists from across the country to tell us what they're really thinking as they peer at our teeth. What came out of their mouths will change the way you treat yours.



Some truly educated people think that if nothing in their mouth hurts, they're fine. High cholesterol doesn't hurt, either, but it's a big problem. I honestly think that the general population doesn't understand that their mouth is part of their body. -- Danine Fresch Gray, DDS, general dentist, Arlington, Virginia

If your hands bled when you washed them, you'd run to the doctor. But in the public's mind, bleeding gums are okay. Unless you're really whaling away with your brush, if your gums bleed even a little, that's periodontal disease, period. -- Ron Schefdore, DMD, general dentist, Chicago, Illinois

The advice to see your dentist twice a year applies only if you have healthy gums. Most people don't. -- Chris Kammer, DDS, cosmetic dentist, Middleton, Wisconsin

Many of my patients have periodontal disease affecting their back teeth, but their front teeth are fine. Evidently, they brush only what others see. -- Joel Slaven, DDS, general dentist, Valencia, California

Dentists often tell patients with advanced gum disease to floss more often. But flossing is useless at that point. Imagine trying to clean out the bottom of a shirt pocket with a piece of string tied to your fingers.-- Reid Winick, DDS, holistic dentist, New York, New York

People come to me with a mouthful of tooth decay and say, "I got my grandfather's soft teeth." I don't even know what soft teeth are. -- Bryan Tervo, DDS

When someone meets you for the first time, the first thing they notice is eyes. Second is teeth, and third is hair. But people spend way more money on their hair than their teeth. -- Damian Dachowski, DMD, general dentist, Horsham, Pennsylvania

Proper oral hygiene requires ten minutes of brushing and flossing every day. The average adult spends two or three minutes total, and kids do even worse. -- Joel Slaven, DDS