Most aggresive odontogenic tumor

# Which of the following tumors is most aggressive? (AIPG 91, AIIMS2004)
a) Ameloblastoma
b) Odontoma
c) Odontogenic myxoma
d) Fibrocarcinoma

The answer is C. Odontogenic myxoma

ODONTOGENIC MYXOMAS

Aggressive, intraosseous neoplasms derived from embryonic odontogenic mesenchyme probably arise from the dental papilla or follicular mesenchyme. Nearly all lesions are found in the tooth bearing areas of maxillary and mandibular bone.

Mandibular lesions are commonly found in the premolar-molar area. The lesions often produce multilocular radiolucency with a "soap bubble' or "honey comb" appearance in the bone.

Thin and extremely delicate septa of bone are often seen to course through the radiolucent area and produce a "spider- web" like or "tennis racket" like appearance.

 (Ref: Shafer's Textbook of oral pathology 7h ed., p 299)

Type II Diabetes Causes

# Obesity, genetic profile, and aging all contribute to the development of Type II diabetes. Of the following, which is the most important additive factor for these three conditions in the development of Type II diabetes?

A. elevated hepatic ketogenesis
B. elevated pancreatic glucagon secretion
C. impaired renal clearance of glucose
D. muscle resistance to insulin

Answer: D - Muscle resistance to insulin is the most important additive factor for these three conditions in the development of Type II diabetes. The progressive loss of skeletal muscle sensitivity to insulin leads to increased rates of visceral cell lipolysis and pancreatic beta-cell compensation.

Parasympathetic Cranial nerves

# # All of cranial nerve have parasympathetic outflow except :
A. 5th nerve
B. 7th nerve
C. 3rd neve
D. 9th nerve

The correct answer is A. 5th nerve

Cranial nerves having parasympathetic now are 3,7,9 and 10.

Preganglionic parasympathetic neuron cell bodies are located in certain cranial nerve nuclei of the brain stem and in the grey matter of the second to fourth sacral segments of the spinal cord. Efferent fibres, which are myelinated, emerge from the CNS only in cranial nerves III, VII, IX, and X and in the second to fourth sacral spinal nerves. Preganglionic parasympathetic neurons are cholinergic. 

The only cranial nerve which arises on the dorsal aspect   -       Trochlear

The cranial nerve with longest intracranial coarse              -        Abducent

The cranial nerve with longest coarse                                 -       Vagus

The cranial nerve involved in raised intracranial tension   -       Abducent nerve

Cranial nerve carrying parasympathetic fibres                      -       3,7,9,10

Commonest cranial nerve affected in spinal anesthesia     -       Abducent nerve

Cranial nerve involved in Bell's palsy                                 -       VII Nerve

Cranial nerve involved in Ramsay Hunt Syndrome             -       VII nerve

Cranial nerve arising from the pons                                    -     V, VI, VII, VII nerves

Pure sensory nerves                                                          -       1,2,8

Branchiomeric nerves                                                       -       5.7.9,10,11

Referred pain in Orofacial region:

# ___________most often refer pain to the temporal region,
while _________most often refer pain the ear.
A. Maxillary second premolars, mandibular molars
B. Maxillary molars, mandibular molars
C.  Maxillary second premolars, mandibular premolars
D. Maxillary molars, mandibular premolars

The correct answer is A. Maxillary second premolars, mandibular molars.

If careful diagnosis does not reveal the affected tooth, other teeth and related anatomic structures

become suspect. Pulpitis in one tooth may cause pain in other areas - the pain is referred.

Site of Pain Referral                             Pulp of Tooth Causing Pain

Forehead region                                    Maxillary incisors

Nasolabial area                                      Maxillary canines. premolars

Temporal region                                     Maxillary second premolars

Ear. angle of jaw, or posterior                 Mandibular molars

regions of neck

Mental region of mandible                        Mandibular incisors, canines. and premolars

Zygomatic, parietal, and occipital              Maxillary molars

regions of head

Opposing quadrant or to other                      Maxillary and mandibular molars

teeth in the same quadrant

Important: The nerve endings of cranial nerves VII, IX, and X are widely distributed within the subnucleus caudalis of the trigeminal (V) nerve. A profuse intermingling of these nerve fibers creates the potential for the referral of dental pain to many sites.

Orofacial pain can be the clinical manifestation of a variety of diseases involving the head and neck region. The cause of the pain must be differentiated between odontogenic and nonodontogenic.

Characteristics of nonodontogenic involvement:

• Episodic pain with pain-free remissions

• Trigger points

• Pain travels and crosses the midline of the face

• Pain that surfaces with increasing stress

• Pain that is seasonal or cyclic

• Pain accompanied by paresthesia