Frontal bone : short questions with answer (short review)

Frontal bone

1.       Anatomical points:

·   Squamous part of frontal bone lies vertically

·   Orbital plates are directed downward and horizontally

·   Nasal spine is directed downward and forward

2.       Morphological type: pneumatic flat bone   

3.       Structure of bone : Frontal bone is formed by inner and outer table (compact bone) and middle diploe (sgongy bone)

4.       Ossification : intramembranous ossification (it is ossify from membrane )

5.       Development : Neural crest ( derived from ectoderm)

6.       Parts:  Identify

·         Squamous part:

-          External surface of squamous part : Frontal tuberosity / supercilliary arch / supraorbital margin/ superobital notch or foramen / glabella

-          Internal surface of squamous part : impression for cerebral sulci and gyri / sagittal sulcus or groove for superior sagittal sinus / frontal crest / foramen caecum

·         Orbital part                                                                                                                                              

·         Zygomatic processes

·         Nasal notch : name of the bones articulate with nasal notch

·         Right side (from medial to lateral ) right nasal bone,  right frontal process of maxilla and right lacrimal bone

·         Left side (from medial to lateral ) left nasal bone,  left frontal process of maxilla and left lacrimal bone                                                                                                                                             

·         Ethmoidal notch:  name of the bone articulate with ethmoidal notch?

·          Ethmoid notch is situated in between two orbital plates and articulated by cibriform plate of ethmoid

1.       What is metopic suture?

Ans: developmentally frontal bone is derived from two segment , later join in mid line . in 9% cases a suture may persist at median plane and inferiorly . It is sometime associated with frontal sinus agenesis and hypoplasia

2.        coronal suture: which bones forms this suture

Ans : in front frontal bone behind right and left parietal bone

3.       Foramen related to this bone and structure passing through it

Ans: foramen caecum : transmit an emissary vein from nasal mucosa to superior sagittal sinus

Supra orbital foramen or notch : transmits supra orbital nerve and vessel

4.       Show lacrimal fossa, what structure lodge within it:

 Ans : lacrimal gland

5.       Nerve supply of lacrimal gland

Ans: lacrimal nerve