Y shaped occlusal pattern is found in which teeth?

 # Y shaped occlusal pattern is found in which teeth?

A. Mandibular first premolar

B. Mandibular second premolar

C. Maxillary first premolar

D. Maxillary second premolar

The correct answer is B. Mandibular second premolar. 

The three cusp type mandibular second premolar manifests as a Y shaped occlusal pattern. The three-cusp type appears square lingual to the buccal cusp ridges when highly developed. Each cusp has well-formed triangular ridges separated by deep developmental grooves. These grooves converge in a central pit and form a Y shape on the occlusal surface. 

Y axis is used to analyze:

 # Y axis is used to analyze:

A. Maxillary growth

B. Mandibular growth

C. Both maxillary and mandibular growth

D. To design appliance

The correct answer is B. Mandibular growth.

Y-axis is obtained by joining the sella - gnathion line with the F.H. plane. The mean value is 59 degree with a range of 53 to 66 degree. The angle is larger in Class II Facial patterns than in patient exhibiting Class III pattern. In addition, Y axis indicates the growth pattern of the individual. If the angle is greater than normal, it indicates greater vertical growth of mandible. If the angle is smaller than normal, it indicates greater horizontal growth of mandible. 

Perikymata are the external surface manifestations of:

 # Perikymata are the external surface manifestations of:

A. Enamel rods

B. Incremental lines of Retzius

C. Nasmyth’s membrane

D. Pellicle

The correct answer is B. Incremental lines of Retzius.

The number of perikymata gradually decreases form cervical region to occlusal or incisal region because of undisturbed development of enamel prior to birth. Perikymata are usually absent in prenatally developed occlusal parts of deciduous teeth, whereas they are present in postnatal cervical parts. 

Abnormal function of epithelial chloride channel protein is the cause of:

 # Abnormal function of epithelial chloride channel protein is the cause of:

A. Ehlers Danlos Syndrome

B. Marfan Syndrome

C. Cystic fibrosis

D. Diabetes insipidus

The correct answer is C. Cystic fibrosis.

Cystic Fibrosis (Mucoviscidosis) Among the genetic paediatric disorders, cystis fibrosis is the most important. It is fundamentally a widespread disorder in epithelial transport affecting fluid secretion in exocrine glands and the epithelial lining of the respiratory, gastrointestinal, and reproductive tracts.

Cystic fibrosis follows simple autosomal recessive transmission. The primary defect is in the regulation of epithelial chloride transport by a chloride channel protein encoded by the cystic fibrosis gene. The impact of this defect in chloride transport differs in various tissues. 

Amyloidosis most commonly occurs in:

 # Amyloidosis most commonly occurs in:

A. Kidney

B. Spleen

C. Liver

D. Heart

The correct answer is A. Kidney.

Amyloidosis of the kidneys is most common and most serious because of ill effects on renal function. Kidneys affected by amyloidosis may be normal sized or enlarged; the cut surface is pale, waxy and translucent. Amyloidosis of spleen has two patterns - Sago spleen and lardaceous spleen. 

CSF rhinorrhea is found in:

 # CSF rhinorrhea is found in:

A. Frontal bone fracture

B. Zygomatico maxillary fracture

C. Nasoethmoidal fracture

D. Condylar fracture

The correct answer is C. Nasoethmoidal fracture.

CSF rhinorrhea is seen in nasoethmoidal, Le Fort II and Le Fort III fractures, associated with comminuted cibriform plate of ethmoid. Tramline effect and halo on pillow effect are diagnostic signs of CSF rhinorrhea. 

Wounds which are clean, uninfected and surgically incised, with edge of wounds approximated by sutures heal by:

 # Wounds which are clean, uninfected and surgically incised, with edge of wounds approximated by sutures heal by:

A. Primary intention

B. Secondary intention

C. Cauterization

D. All of the above

The correct answer is A. Primary intention.

Clean, uninfected, surgically incised wounds that are approximated by surgical sutures heal by primary intention. Infected, open large wounds that are not approximated by surgical sutures heal by secondary intention. Healing after flap surgery is by primary intention where as gingivectomy, gingivoplasty and extraction socket heal by secondary intention.