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%)