# Final determination of the dental arch form depends on:
A. Angle’s classification
B. Growth pattern
C. Facial type
D. Balance between extraoral and intraoral muscle forces
The correct answer is D. Balance between extraoral and intraoral muscle forces.
Although negative pressure is created within the mouth during sucking, there is no reason to believe that this is responsible for the constriction of the maxillary arch that usually accompanies sucking habits. Instead, arch form is affected by an alteration in the balance between cheek and tongue pressures. If the thumb is placed between the teeth, the tongue must be lowered, which decreases pressure by the tongue against the lingual of upper posterior teeth. At the same time, cheek pressure against these teeth is increased as the buccinator muscle contracts during sucking. Cheek pressures are greatest at the corners of the mouth, and this probably explains why the maxillary arch tends to become V -shaped with more constriction across the canines than the molars. A child who sucks vigorously is more likely to have a narrow upper arch than one who just places the thumb between the teeth.
# How much root formation is complete when tooth erupts into the oral cavity?
A. 100%
B. 75%
C. 60%
D. 50%
The correct answer is B. 75%.
The eruption of a permanent tooth can be delayed if its primary predecessor is retained too long. When this happens, the obvious treatment is to remove the primary tooth. As a general guideline, a permanent tooth should erupt when approximately three-fourths of its root is completed. If root formation of the permanent successor has reached this point while a primary tooth still has considerable root remaining, the primary tooth should be extracted.
# Which of the following cephalometric values should decrease for an individual between the ages of 8 and 18 years?
A. FMA
B. ANB
C. GoGn-SN
D. All of the above
The correct answer is D. All of the above.
With the possible exception of those who have an openbite malocclusion, patients who have a Frankfort mandibular angle (FMA) within the normal range can generally be expected to show a reduction in this angle with continued growth. If, during orthodontic treatment, the FMA increases, then it may be expected to return to its former relationship, or less, if the patient continues to grow. If no further growth takes place, then the return to the original FMA will likely not occur. If, however, further growth occurs and the maxillary and mandibular teeth are retained in a position of minimal overbite, then the subsequent increase in posterior facial height and a leveling of the FMA may occur without an accompanying increase or relapse in the deep overbite.
The magnitude of the ANB angle, however, is influenced by two factors other than the anteroposterior difference in jaw position. One is the vertical height of the face and the second is that if the anteroposterior position of nasion. During growth, as the vertical height of face occurs, ANB angle decreases generally.
# Gingival involvement is an unusual finding in one of the following conditions?
A. Recurrent aphthae
B. Pemphigoid
C. Primary herpes
D. Pyogenic granulomas
The correct answer is A. Recurrent aphthae.
The first episodes of RAS most frequently begin during the second decade of life. The lesions are confined to the oral mucosa and begin with prodromal burning or the sensation of a small bump in the mucosa from 2 to 48 hours before an ulcer appears. During this initial period, a localized area of erythema develops. Within hours, a small white papule forms, ulcerates, and gradually enlarges over the next 48–72 hours. The individual lesions are round, symmetric, and shallow (similar to viral ulcers), but no tissue tags are present from ruptured vesicles, which helps distinguish RAS from diseases that start as vesicles, such as pemphigus, and pemphigoid. Multiple lesions are often present, but the number, size, and frequency vary considerably.
The buccal and labial mucosae are most commonly involved. Lesions rarely occur on the heavily keratinized palatal mucosa or gingiva. In mild RAS, the lesions reach a size of 0.3–1.0 cm and begin healing within a few days. Healing without scarring is usually complete in 10–14 days.
Reference: Burket’s Oral Medicine, 12th Edition Page no 75
High blood pressure or Hypertension is blood pressure higher than normal. Blood pressure is expressed in A/B form where A is systolic pressure and B is diastolic pressure. High blood pressure is blood pressure above 140/90 mm Hg. Uncontrolled hypertension can lead to heart and kidney disease, stroke and blindness. But researches have shown that high blood pressure can be prevented by following the Dietary Approaches to stop Hypertension (DASH) eating plan. Dietary Approaches to Stop Hypertension (DASH) diet originated in the 1990s.
Many researches were conducted in 1992 by National Institute of Health to find the effectiveness of DASH eating plan. The research concluded that dietary interventions alone can lower systolic blood pressure by 6-11 mm Hg. The DASH diet offer an alternative to drug therapy in hypertensives and may prevent hypertension in normotensives. In a study done in 2014,the DASH diet was found to result in significant decreases in systolic BP ( − 5·2 mmHg, 95 % CI − 7·0, − 3·4; P< 0·001) and diastolic BP ( − 2·6 mmHg, 95 % CI − 3·5, − 1·7; P< 0·001). These changes predicted a reduction of approximately 13 % in the 10-year Framingham risk score for CVD.
DASH includes consumption of fruits and vegetables, lean meat and fat free or low fat dairy products, whole grains, fish, poultry, beans, seeds, and nuts and foods rich in nutrients —mainly potassium, magnesium, calcium, protein, and fiber. It also limits the intake of sodium in the diet to 1500 mg/day. DASH emphasizes on decrease consumption of processed food and increase consumption of fresh food.
DASH plan is as follows:
1.Vegetables: about five servings per day
2.Fruits: about five meals per day
3.Carbohydrates: about seven servings per day
Healthy carbohydrates included under DASH include:
Green leafy vegetables: kale, broccoli, spinach, mustards
Whole grains: cracked wheat, millets, oats
Low glycemic index fruits
Legumes and beans
4.Low-fat dairy products: about two servings per day
DASH includes good fats. Good fat prevent inflammation and help in promotion of health. These fats increase HDL and decrease LDL.
- Olive oil
- Avocados
- Nuts
- Hempseeds
- Flax seeds
- Fish rich in omega-3 fatty acids
5.Lean meat products: about two or fewer servings per day
6.Nuts and seeds: 2 to 3 times per week
The DASH diet contains large amount of fiber and can cause bloating and diarrhoea. To avoid these problems, gradually increase the fruit, vegetables and whole grains in your diet over the weeks. Make these changes over a couple of days or weeks.
1.Add a serving of vegetables at lunch one day and dinner the next, and add fruit at one meal or as a snack.
2.Increase your use of fat-free and low-fat milk products to two servings a day.
3.Limit lean meats to 6 ounces a day—3 ounces a meal.
DASH diet helps you to control blood pressure and stay healthy. It helps to keep metabolic syndromes in check. Compliance to DASH has been associated with improvements of outcomes in type 2 Diabetes.
Know about JNC-8 Recommendations for Hypertension in the following video:
The correct answer is C. Remove long wavelength X rays.
Although an x-ray beam consists of a continuous spectrum of x-ray photon energies, only photons with sufficient energy to penetrate through anatomic structures and reach the image receptor (digital or film) are useful for diagnostic radiology. Low-energy photons that cannot reach the receptor contribute to patient risk but do not offer any benefit. Consequently, it is desirable to remove these low-energy photons from the beam. This removal can be accomplished in part by placing a metallic disk (filter) in the beam path. A filter preferentially removes low-energy photons from the beam, while allowing high-energy photons that are able to contribute to making an image to pass through.
Energy of x-rays depends directly on its frequency (E~f) and inversely related to wavelength (E~1/λ). Electromagnetic waves with higher frequencies have proportionally higher energies. The wave with the shorter wavelength, will have higher frequency. Since we know that the energy scales directly with the frequency we know that the wave that has the shorter wavelength will have higher energy.
Reference: Oral Radiology Principles and Interpretation, 7th Edition, White and Pharoah, Page no 10
