Dentosphere : World of Dentistry: October 2023

Procedures undertaken in preventive orthodontics are all EXCEPT:

# Procedures undertaken in preventive orthodontics are all EXCEPT:

A. Parents education

B. Checkup for oral habits

C. Extraction of supernumerary teeth

D. Space regaining

The correct answer is D. Space regaining.

Procedures of preventive orthodontics:

1. Parent education

2. Caries control

3. Care of deciduous dentition

4. Management of ankylosed tooth

5. Maintenance of quadrant wise tooth shedding timetable.

6. Checkup for oral habits and habit-breaking appliances if necessary.

7. Occlusal equilibration if there are any occlusal pre-maturities.

8. Prevention of damage to occlusion, e.g. Milwaukee braces

9. Extraction of supernumerary teeth

10. Space maintenance

11. Management of deeply locked first permanent molar

12. Management of abnormal frenal attachments

Simple retraction of maxillary incisors using maxillary molars as anchorage is an example of:

# Simple retraction of maxillary incisors using maxillary molars as anchorage is an example of:

A. Simple anchorage

B. Reciprocal anchorage

C. Stationary anchorage

D. Intermaxillary anchorage

The correct answer is C. Stationary anchorage.

An anchor tooth or source, which does not move against the forces of teeth to be pulled is stationary

anchorage. In a real sense, only the extraoral source of anchorage derived from headgear would be a stationary anchorage. The anchor tooth being housed in a bioactive environment would show some degree of movement and hence cannot be classified as a stationary anchorage in a real sense.

Bone can be induced to grow at surgically created sites by the method called:

# Bone can be induced to grow at surgically created sites by the method called:

A. Osteogenesis

B. Distraction osteogenesis

C. Bone wax

D. Green stick fracture

The correct answer is B. Distraction osteogenesis.

• Distraction osteogenesis is the method of inducing bone to grow at surgically created sites.

• Russian Surgeon Ilizarov discovered in 1950's that if cuts were made through the cortex of a long bone of the limbs, the arm or leg then could be lengthened by tension to separate bony segments.

• Currently it is believed that best results are obtained if this type of distraction starts after a few days of initial healing and callus formation and if the segments are separated at a rate of 0.5 - 1.5 mm/day.

• Also this technique is employed for lengthening of mandible and inducing maxillary growth by separating cranial and facial bone at their sutures.

Perspiration and redness of the cheek and ear after eating

# A 58-year-old woman underwent left superficial parotidectomy for a pleomorphic adenoma 2 years ago. She presents with complaints of occasional perspiration and redness of the left cheek and ear after eating. Which of the following nerves is the most likely source of these complaints?

A. Great auricular

B. Frontal branch of the facial nerve

C. Auriculotemporal

D. Lingual

The correct answer is C. Auriculotemporal.

The auriculotemporal syndrome is an unusual phenomenon, which arises as a result of damage to the auriculotemporal nerve and subsequent reinnervation of sweat glands by parasympathetic salivary fibers.

The patient typically exhibits flushing and sweating of the involved side of the face, chiefly in the temporal area, during eating. The severity of this sweating may often be increased by tart foods. Of further interest is the fact that profuse sweating may be evoked by the parenteral administration of pilocarpine or eliminated by the administration of atropine or by a procaine block of the auriculotemporal nerve.

Reference: Shafer's Textbook of Oral Pathology, 7th Edition.

The diameter of the tip of a periodontal probe is:

# The diameter of the tip of a periodontal probe is:

A. 0.25 mm

B. 0.5 mm

C. 0.75 mm

D. 1 mm

The correct answer is B. 0.5 mm.

Periodontal probes are used to measure the depth of pockets and to determine their configuration. The typical probe is a tapered, rodlike instrument calibrated in millimeters, with a blunt, rounded tip. There are several other designs with various millimeter calibrations. The World Health Organization (WHO) probe has millimeter markings and a small, round ball at the tip. Ideally, these probes are thin, and the shank is angled to allow easy insertion into the pocket. Furcation areas can best be evaluated with the curved, blunt Nabers probe. When measuring a pocket, the probe is inserted with a firm, gentle pressure to the bottom of the pocket. The shank should be aligned with the long axis of the tooth surface to be probed. Several measurements are made to determine the level of attachment along the surface of the tooth.

Reference: Carranza's Clinical Periodontology 12th edition.

Which of the following may create gingival deformities that require gingivoplasty to eliminate the defects?

# Which of the following may create gingival deformities that require gingivoplasty to eliminate the defects?

A. Erosive linchen planus

B. Desquamative gingivitis

C. Acute herpetic gingivostomatitis

D. Necrotising ulcerative gingivitis

The correct answer is D. Necrotising ulcerative gingivitis.

■ Shelf-like gingival margins after healing may result in plaque accumulation.

■ The gingiva is reshaped with periodontal knife or with electrosurgery. This process of eliminating the defects by reshaping is called as gingivoplasty.

■ Gingival deformities are seen in gingival disease: (Asked in AIIMS 1999) (ANUG)

Surgical procedure for severe tissue destruction in ANUG infection is: (Asked in COMED 2011) (Reshaping the gingiva, Gingivoplasty)

Site of Antidiuretic hormone (ADH) action is:

# Site of Antidiuretic hormone (ADH) action is:

A. Proximal tubule

B. Loop of Henle

C. Vasa recta

D. Collecting tubule

The correct answer is D. Collecting tubule.

Human vasopressin, also called antidiuretic hormone (ADH), arginine vasopressin (AVP) or argipressin, is a hormone synthesized from the AVP gene as a peptide prohormone in neurons in the hypothalamus, and is converted to AVP. It then travels down the axon terminating in the posterior pituitary, and is released from vesicles into the circulation in response to extracellular fluid hypertonicity (hyperosmolality). AVP has two primary functions. First, it increases the amount of solute-free water reabsorbed back into the circulation from the filtrate in the kidney tubules of the nephrons. Second, AVP constricts arterioles, which increases peripheral vascular resistance and raises arterial blood pressure.

Acute increase of sodium absorption across the ascending loop of Henle. This adds to the countercurrent multiplication which aids in proper water reabsorption later in the distal tubule and collecting duct.

Pyruvate dehydrogenase complex contains all EXCEPT:

# Pyruvate dehydrogenase complex contains all EXCEPT:

A. Biotin

B. NAD

C. FAD

D. Co-A

The correct answer is A. Biotin.

Pyruvate dehydrogenase complex (PDC) is a complex of three enzymes that converts pyruvate into acetyl-CoA by a process called pyruvate decarboxylation. Acetyl-CoA may then be used in the citric acid cycle to carry out cellular respiration, and this complex links the glycolysis metabolic pathway to the citric acid cycle. Pyruvate decarboxylation is also known as the "pyruvate dehydrogenase reaction" because it also involves the oxidation of pyruvate.

The enzymes involved in PDC are Pyruvate dehydrogenase (E1), Dihydrolipoyl transacetylase (E2), and Dihydrolipoyl dehydrogenase (E3). The cofactors involved are: TPP (thiamine pyrophosphate), magnesium, lipoate, coenzyme A, FAD and NAD+.

Reference: https://en.wikipedia.org/wiki/Pyruvate_dehydrogenase_complex

The benign neoplasm of ‘brown fat’ noted in oral/pharyngeal region is:

# The benign neoplasm of ‘brown fat’ noted in oral/pharyngeal region is:

A. Lipoma

B. Hibernoma

C. Teratoma

D. Brown tumor

The correct answer is B. Hibernoma.

Hibernomas are uncommon neoplasms of brown adipose tissue. The most frequent sites of occurrence include the thigh, shoulder, and back. Less common myxoid and spindle cell hibernoma variants are likely to be located in the posterior neck and shoulder. Hibernomas are benign lipomatous neoplasms and have no potential for malignant transformation. Hibernomas contain brown fat, and the name was coined about the presence of brown fat in hibernating animals. First described by Merkel 1906, these tumors are similar to lipomas in clinical behavior but have unique imaging and histopathologic features. Hibernomas generally present in young adults with a mean age of 38. In summary, these tumors are:

Composed of brown fat
Represent benign neoplasms
Generally well-circumscribed masses
Generally are small in size
Exhibit slow growth
Histopathologically composed of brown fat cells
Chief differential diagnosis include well-differentiated liposarcomas (WDLS)
Most often involve the thigh, trunk, and chest.
Rare locations seen in less than 10% of cases include retroperitoneal, thorax, and intraabdominal regions.
Fewer than 20% are intramuscular in location.

Reference: Tafti D, Cecava ND. Hibernoma. [Updated 2023 May 22]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK570579/

SNA angle describes the relationship of the:

# SNA angle describes the relationship of the:

A. Maxilla to the cranial base

B. Mandible to the cranial base

C. Maxilla to mandible

D. Maxilla to the upper incisors

The correct answer is A. Maxilla to the cranial base.

SNA: the angle between the sella/nasion plane and the nasion/A plane (normal value at the end of growth 82 ± 2°). This angle assesses the antero-posterior position of the maxilla relative to the upper cranial structures.

Analysis of skull shape and size, supraorbital ridge, extension of zygomatic arch beyond external meatus, measurement of angle of mandible helps in:

# Analysis of skull shape and size, supraorbital ridge, extension of zygomatic arch beyond external meatus, measurement of angle of mandible helps in:

A. Sex determination

B. Racial determination

C. Age determination

D. Ethnicity determination

The correct answer is A. Sex determination.

Skull and facial features like mastoid process, supraorbital ridges, size and architecture of skull can help in determining the sex of patient in 94% cases.

Sex differentiation (Sexing) of a specimen: It can be done using methods as below:

Using craniofacial morphology: The following 6 traits give accurate results 94% times:

- Mastoid process

- Supraorbital ridge \

- Size and architecture of skull

- Extension of the zygomatic arch beyond the external auditory canal

- Nasal aperture and

- Gonial angle (on the mandible) (Including more features increases accuracy by 2%)

Prolonged retention is usually needed in:

# Prolonged retention is usually needed in:

A. Diastema

B. Mild crowding

C. Anterior cross bite

D. Deep bite

The correct answer is A. Diastema.

Fixed (bonded) orthodontic retainers are normally used where intra-arch instability is anticipated and prolonged retention is planned. There are three major indications:

• Maintenance of lower incisor position during late growth

• Diastema maintenance

• Maintenance of posterior tooth position in adults

Reference: Proffit's Contemporary Orthodontics, 6th Edition.

Root shape before and after orthodontic treatment with radiographic evidence was first given by:

# Root shape before and after orthodontic treatment with radiographic evidence was first given by:

A. Kaley and Phillip

B. Newman and Proffit

C. Ketcham AH

D. Malmgren and Lavendar

The correct answer is C. Ketcham AH.

Albert H. Ketcham was born on August 3, 1870, and grew up in Whiting, Vermont. He graduated from the Boston Dental School in 1892, then moved to Colorado due to ill health. Inspired by the challenges

of the young profession of orthodontics, he chose to enter the Angle School of Orthodontia in 1902. As a deep thinker with an inquiring mind, Ketcham explored many of the philosophical and mechanical

problems, as well as the controversies of the profession of his day. He was one of the first to investigate root resorption, which continues to be a challenge today. He began to question some of Angle’s arbitrary pronouncements, causing Angle to attack him vehemently as a deviationist. He was smart enough to travel his own way from that time on. He worked hard to improve the American Society of Orthodontists (ASO) and served as their president in 1929. He was also instrumental in founding the American Board of Orthodontists (ABO), serving as its first president. In recognizing his lifetime of service, the Albert H. Ketcham Memorial is made to the individual member annually in recognition

of contributions made to the art and science of orthodontics. This award was meant to perpetuate and inspire the member as a leader in orthodontics following the example set by Dr. Ketcham.

He pioneered dental radiography and was the first US orthodontist to install an x-ray laboratory. He delivered the first paper on x-rays in orthodontics to the American Society of Orthodontists in 1910. In 1926 he presented the first comprehensive data on root resorption.46 Although the earliest mention of root resorption in permanent teeth goes back to 1856, it was a report by Ketcham in 1927 (followed by a second in 1929) that finally aroused the concern of orthodontists.

Reference: ORTHODONTICS Current Principles and Techniques, Lee W. Graber, 7th Edition.

Non caseating granuloma with bilateral Hilar lymphadenopathy is a feature of:

# Non caseating granuloma with bilateral Hilar lymphadenopathy is a feature of:

A. Histoplasmosis

B. Sarcoidosis

C. Silicosis

D. Tannosis

The correct answer is B. Sarcoidosis.

Sarcoidosis is described as a multisystem granulomatous disease of unknown origin characterized by the formation of uniform, discrete, compact, non-caseating epithelioid granulomas. It is more common in blacks than in whites. Though many investigators have regarded this disease, of unknown etiology, both infective and noninfective agents have been implicated. Currently the infectious etiology is more favored with focus on Mycobacterium and Propionibacterium. It is interesting to note that there was a belief that sarcoidosis is in some way related to tuberculosis. The factors which stood against were inability to culture the bacteria from the pathological tissues and difficulty in identifying them in stained sections.

Reference: Shafer's Textbook of Oral Pathology 7th Edition.

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