Mandible : Bony features

hello students today we will discuss about the Bony features of this mandible now when we will see the mandible mandible is having the two major part now one is known as the body of the mandible so you can see that this is the body of mandible and when you will see the mandible From Below you can see that this body is u-shaped or you can say it is a horse shoe shaped body clear now behind the body you can see that these are the two plates these are known as rammus of the mandible so there is a one right ramus another is the left Remus of the mandible so what are the Bony parts of the mandible so first you have to understand that there is a body of the mandible and there are two rammus of the mandible now we will see first body of the mandible now the body of the mandible is having the external surface which is visible here and it is having the inner surface clear then you can see that it is having a border on upper side where you you are having the teeth and this upper border is known as alveolar Arch now this is the lower border of the body of the mandible it is known as base of the mandible clear so base means you are talking about this lower border of the body of the mandible now this body is continue posteriorly with the ramus of the mandible so this is the line of an assume that this is the Ramos meeting with the body clear now what are the important features first we will see on the body of your mandible so when you will see the mandible the outer surface is showing very important Landmark the first is known as symphysis mentee now symphysis mentee is a feature which is present anteriorly in midline now here you can see that this is a triangular projection is visible now this triangle Apex is having this much portion of symphysis mentee and this triangular projection is known as mental protuberance this triangle is known as mental protuberance so if you will see from the profile view if you will see the side you can see that there is anterior projection now this projection is known as mental protuberance now this triangle when you will see the triangle now these two angles of the triangles are having the two small projections and these are known as mental tubercle so what is this Center projection protuberance and what is these angle points these are the mental tuberclear now from the mental tubercle if you will go posteriorly you will find the foramen on the external surface of the body of mandible now these are known as mental foramen which are present on both right and left side now these mental foramens are very important for the assessment of the age of the mandible now this given bone is the adult age group because this mental foramen lies in middle of the two borders of the body if it is a mandible of old person then what will happen this alveolar process will damage it will no not there this much of upper part is not there so what will happen the upper border will lies here and in that condition the mental foramen is near the upper Border in Old edges but in case of the child this mental foramen is near the lower border so mental foramen is very important medical legal importance to identify the age group of the mandible so this is what you have to first understand on the external surface now on the external surface if you will see in this view you can see there is a oblique line is visible now where is the oblique line you can see if you will trace this anterior border now from this a line is coming downward now this line may be longer in some mandible or may be shorter in some mandible now this line is known as oblique line of the external surface of mandible and this line is very important which is present here on the external surface of mandible clear so what are the features I just told you we will revise in the midline anteriorly you will have the symphysis mentee below the symphysis mentee this is known as mental protuberance the angle of the this triangle is having the tubercles which are mental tubercles then you will have the mental foramina and here you will have the oblique line now apart from that anteriorly below the incisive teeth you will have this depression on both the side this is known as incisive fossa clear what is that incisive fossa now we will move to the inner side features of the mandible now when you will rotate the mandible and if you will see on the inner side of the body part of the mandible the first and most important thing is you will find a prominent line now this prominent line which is visible Here is known as Milo hyoid line now this myelo hard line divide this inner surface into the two part this lower part is known as submandibular fossa and this upper part is known as sublingual fossa so this is a very commonly asked question in your exam what is Milo hard line so Milo headline is a feature on the inner side of your body of mandible below that you have some mandibular fossa above you have sublingual fossa then on the inner side of the anterior part of the mandible here you are having the four spinous tubercle which are known as genial tubercle so there are superior and inferior genial tubercle and these tubercles are four in numbers so two Superior tubercle and two inferior genial tubercle now when you will see the Border I already told you that upper border is known as alveolar process which enlarges the teeth and the lower border is known as base now there is a very important feature is seen on the interior part of the base or anterior border now here you can see there are two depressions now these depressions are known as digastric fossa so where is the digestric fossa now these are the two digestric forces which are present on the base so if you will see the mandible in such position you will find that this is the two impression one on this right side one is on the left side of the midline so these depressions are known as digestric fossa then we will move to the features of the rammus of mandible so when you will see the rammus of the mandible the ramus is a quadrangular plate now here you can see that this is the ramus now this ramus is having the anterior border now upper part of the border is free but this lower part is making a connection with with the body then this is the upper border now this upper border is having a notch now this upper border Notch is known as mandible or Notch what is that mandible or Notch now this is the posterior water of the ramus and this is the inferior border of the Rams this inferior border anteriorly continue with the base and posteriorly this meeting point of the base or lower border with the posterior border is marked as a angle of mandible this is known as angle of mandible now when you will trace the anterior Border in upper side you will find a projection now this projection is known as coronoid process what is that it is known as coronoid process so on both the side you can see that this is the coronoid process of the right side and this is the coronoid process of the left side now on the upper part of the posterior border here you can see that there is a process again and this is known as condylar process now the this condylar process is going to make joint with the mandibular fossa of temporal bone which is known as temporomandibular joint so this is your condylar process this anterior one is known as coronoid process and this u-shaped gap between the two process is known as mandibular Notch clear now there are very important features present on the inner side of the ramus now when you will see the inside of the ramus you will find there is a very big foramen is present so I am passing this probe into this foramen and this is known as mandibular foramen now you can see that as I am pressing this black color wire it is going more deeper and deeper so this is the foramen and this foramen inside continue with the canal so this is known as mandibular foramen and this foramen continue as a mandibular Canal now on the the initial part of this foramen you are able to see a bony projection now this bony projection which is visible here now this bony small spine is known as lingula so it is very important to keep in mind that lingula is a very small bony spine which is present at the entry of this foramen which is known as mandibular foramen so you can see that mandibular foramen is present on this side also here it is visible and here you can see this black color probe inside the foramen and just at the entry of this foramen you will find a small bonus projection is known as lingula killer now apart from this what you are going to see is the Milo hyoid Groove now where is the myelohyoid group now when you will come below this mandibular foramen now there is a small depression is visible now this depression is known as myelohyde group clear so myelohyde Groove is a different thing and myelohyde line is a different thing so this is the myeloid line and this is our Milo hyoid group clear so again I will repeat what are the important things which we have discussed so there is one more important feature on the condylar process now when you see the condylar process this condylar process is having head and neck now this is the head of the condylar process now this head is connected with the ramus by a constricted area and this constricted area is known as neck of the condylar process now when you will see the condylar process on anterior part of the condylar process there is a small depression is present now this depression on the anterior surface of both the condylar processes is known as terrygoid fovea what is that pterygoid phobia so this is the pterygoid phobia on this side and this is the position of pterygoid phobia on this side but here my dear friends you have to keep this thing in mind that pterygoid fovea is a feature of the anterior surface of the neck of condylar process so when you will see that condylar process this upper part is known as head which is going to make a joint and just below the head this depression on the neck of mandible is known as sterigoid phobia so now in nutshell I am again repeating all the Bony features one by one first when you will see from the front what you have to understand this is symphysis mentee this is mental protuberance these are the mental tubercle then this is mental foramen this is the incisive fossa then you will have the oblique line then you will have the coronoid process then you will have condylar process then you will have the notch that is known as mandibular Notch then you will come on the inner side of the mandible on inner side of the mandible first you will find anteriorly that Superior inferior genial tubercle then Below on the base you will have the right and left digestric fossa then on the inner side of the body you will have this myelo headline below the myeloid line you have the submandibular fossa above you will have the sublingual fossa then on posterior side you will have this myelohyde groove then you will have this mandibular foramen and this small bony projection is known as lingula clear now this point is known as angle of the mandible and there is a one important thing that whenever you are holding this bone sometimes the cushion has been asked that it is ossified in which manner so answer is that it is a membranous as well as endocondral so it is a a by ossification it is a membranocartilaginous in origin killer so these are the Bony features of the mandible thank you