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Number of lobes in a tooth

 # The minimum number of lobes from which any tooth may develop is:
A. Two
B. Three
C. Four
D. Five




The correct answer is: C. Four.

Tooth development begins with increased cell activity in growth centers in the tooth germ. A growth center (lobe) is an area of the tooth germ where the cells are particularly active. These lobes are primary centers of calcification and are primary sections of formation in the development of the crown of a tooth. They are represented by a cusp on posterior teeth and mamelons and cingula on anterior teeth. They are always separated by developmental grooves, which are very prominent in the posterior teeth and form specific patterns. With anterior teeth, their presence is much less noticeable and these lobes are separated by what are known as developmental depressions.

Summary of number of lobes:
•All anterior teeth: three labial and one lingual (cingulum)
• Premolars: three buccal and one lingual.
Exception: The mandibular second premolar has three buccal and two lingual lobes.

• First molars (maxillary and mandibular): five lobes, represented by five cusps - one lobe for each cusp
•Second molars (maxillary and mandibular): four lobes, one for each cusp
• Third molars: at least four lobes. one for each cusp ***variations arc seen

Lethal dose of Fluoride

# The lethal dose of fluoride for a typical three-year-old child is approximately :
A. 100 mg
B. 200 mg
C. 350 mg
D. 500 mg
 

The correct answer is D. 500 mg.

The studies and surveys link fluorosis to three factors:
• Fluorosis is more common in geographic areas where the endemic levels of fluoride in the drinking water is higher than three parts per million
• Fluorosis is associated with fluoride supplementation at inappropriately high levels
• The use of fluoridated toothpaste has been implicated in fluorosis

In acute fluoride toxicity, the goal is to minimize the amount of fluoride absorbed. Therefore, syrup of ipecac is administered to induce vomiting. Calcium-binding products, such as milk or milk of magnesia, decrease the acidity of the stomach, forming insoluble complexes with the fluoride and thereby decrease its absorption. Note: Emergency Medical Service should be activated.

In acute fluoride toxicity, symptoms may appear within 30 minutes of ingestion and persist for up to 24 hours. Patients may experience some nausea, vomiting, diarrhea, and abdominal cramping. This may be due to the fact that 90-95% of ingested fluoride is absorbed through the stomach and small intestines. Fluorides are primarily eliminated from the body by way of the kidneys. However, the fluoride that does remain in the body is found mostly in skeletal tissue. In acute fluoride poisoning (which is rare), the most common causes of death are cardiac failure and respiratory paralysis. Fluoride toxicity shows up in the bones as osteosclerosis.

Important: The lethal dose of fluoride for a typical 3-year-old child is approximately 500 mg and would be proportionately less for a younger child and smaller child. To avoid the possibility of ingestion of large amounts of fluoride it is recommended that no more than 120 mg of supplemental fluoride be prescribed at any one time.

Note: If a six-year old child were receiving fluoridated water in the amount of 3 ppm, the result would most likely be fluorosis but not systemic toxicity. On the other hand, if a child in the same age range (6-7) were receiving 8 ppm of fluoridated water, there would be a good chance of systemic toxicity and moderate to severe fluorosis occurring.

Koplik's Spots are seen in

# "Koplik's spots" are associated with:
A. Smallpox (Variola)
B. German measles (Rubella)
C. Mumps
D. (Rubeola)


The correct answer is. D. Measles (Rubeola)

Before immunization, measles was very common during childhood so that 90% of the population had been infected by age 20.

Measles (also called Rubeola) is a highly contagious viral illness characterized by a fever, cough, and a spreading rash. It is caused by a paramyxovirus. The incubation period is 1 to 2 weeks before symptoms generally appear. The oral lesions are pathognomonic of this disease. These characteristic "Koplik's spots" usually occur on the buccal mucosa. They are 1-2 mm, yellow-white necrotic ulcers that are surrounded by a bright red margin.

Rubella (or German measles) is a fairly benign viral disease. The symptoms usually include
a red, bumpy rash, swollen lymph nodes (most often around the ears and neck), and a mild fever. Some people will feel a little achy. The virus can manifest in the oral cavity as small petechiae-like spots of the soft palate. The defects of congenital infection from an infected mother are more severe -enamel defects, hypoplasia, pitting, and abnormal tooth morphology.

Smallpox (Variola) is an acute viral disease, it manifests itself clinically by the occurrence of a high fever, nausea, vomiting, chills, and headache. The skin lesions begin as small macules and papules which first appear on the face, but rapidly spread to cover much of the body. Oral manifestations include ulceration of the oral mucosa and pharynx. In some cases, the tongue is swollen and painful, making swallowing difficult.

Mumps is an acute contagious viral infection characterized chiefly by unilateral or bilateral swelling of the salivary glands, usually the parotid (parotitis). Although it is usually a disease of childhood, mumps may also affect adults. The papilla of the opening of the parotid duct on the buccal mucosa is often puffy and reddened.

3M Ketac Molar Easymix Glass Ionomer Cement

 This particular brand of Glass Ionomer Cement Ketac Molar Easymix by 3M Germany was available in the dental clinic where I work. The powder felt like wheat flour and even after mixing repeatedly, I couldn't get the required consistency. I had used exactly one scoop of powder by the scoop provided by the manufacturer with one drop of liquid. Have you experienced the same problem? Or is this a great GIC product What about its clinical success? Please leave your honest feedback.



Seizure in the dental clinic

# Which of the following is true concerning a young epileptic who has a grand mal seizure in the dental office?
A. It is generally fatal
B. It is best treated by injecting insulin
C. They generally recover if restrained from self-injury and oxygen is maintained
D. It can be prevented with antibiotics



 The correct answer is C. They generally recover if restrained from self-injury and oxygen is maintained

Of the multiple types of seizures, the tonic-clonic (grand mal) type is the most frightening and the one that most often requires treatment. Grand mal seizures are manifested in four phases: the prodromal phase, the aura, the convulsive (ictal) phase, and the postictal phase.

The prodromal phase consists of subtle changes that may occur over minutes to hours. It is usually not clinically evident to the clinician or the patient. The aura is a neurologic experience that the patient goes through immediately prior to the seizure. It is specifically related to trigger areas of the brain in which seizure activity begins. It may consist of a taste, a smell, a hallucination, motor activity, or other symptoms. As the CNS discharge becomes generalized, the ictal phase begins. The patient loses consciousness, falls to the floor, and tonic, rigid skeletal muscle contraction ensues. This usually lasts 1 to 3 minutes.

As this phase ends, the muscles relax and movement stops. A significant degree of CNS depression is usually present during this postictal phase, and it may result in respiratory depression. Management of the seizure consists of gentle restraint and positioning of the patient in order to prevent self-injury, ensuring adequate ventilation, and supportive care, as indicated, in the postictal phase, especially airway management. Single seizures do not require drug therapy because they are self-limiting.

Important: Should the ictal phase last longer than 5 minutes or if seizures continue to develop with little time between them, a condition called status epilepticus has developed. This may be a life-threatening medical emergency. This condition is best treated with intravenous diazepam, and transport should be arranged to take the patient to the hospital.

Oral manifestation of Achondroplasia

 # An outstanding oral manifestation of achondroplasia is:
A. Rampant caries
B. Periodontal disease
C. Overcrowding of teeth
D. Supernumerary teeth



The correct answer is C. Overcrowding of teeth.

Achondroplasia is the most common form of short-limb dwarfism. It occurs in all races and with equal frequency in males and females. An individual with achondroplasia has a disproportionate short stature -- the head is large and the arms and legs are short when compared to the trunk length. Other signs are a prominent forehead and a depressed bridge of the nose. Many of these children die during the first year of life. Deficient growth in the cranial base is evident in many children that survive.

Important: The maxilla may be small with the resultant crowding of the teeth.

Note: A Class III malocclusion is very common.

Remember: The oral manifestations of the following disorders in children:

• Gigantism: enlarged tongue, mandibular prognathism, teeth are usually tipped to the buccal or lingual side, owing to enlargement of the tongue. Roots may be longer than normal.

• Pituitary dwarfism: the eruption rate and the shedding of the teeth are delayed, clinical crowns appear smaller as do the roots of the teeth, the dental arch as a whole is smaller causing malocclusion, and the mandible is underdeveloped.


Iron content in each ml of blood

 # Each milliliter of red cells contain how much elemental iron ?
A. 1 mg
B. 2 mg
C. 3 mg
D. 4 mg


The correct answer is A. 1 mg.

Each milliliter of red cells contains 1 mg of elemental iron.
Ref: Harrison’s 18th Ed. 845