MASTER DAY2 NORMAL RADIOGRAPHIC ANATOMICAL LANDMARKS a : enamel B : dentin a C : pulp c b Cervical burnout : Radiographs sometimes show Diffuse radiolucent areas With ill defined borders Present on mesial n distal Aspects of teeth in cervical region These regions appear between The edge of the enamel cap And the crest of the alveolar Ridge. It should not be confused with Root caries. Lamina dura: It is a thin radio-opaque Layer Of dense bone surrounding the Tooth socket. It is thicker than the surrounding Trabecular bone and thickness Increases with increase in amount In the occlusal stress Alveolar crest The gingival margin of the Alveolar process that extends Between the teeth is Apparant on radiographs As radiopaque line called Alveolar crest. It is considered as normal If it is not > than 1.5 mm From cej of adjacent teeth. Periodontal ligament space PDL space is primarily composed of collagen, so appers as radiolucent Space between tooth root and lamina dura. Cancellous bone : it lies between the cortical plates in both the jaws. It is composed of thin radiopaque plates and rods surronding many Small radiolucent marrow spaces. •Email •Likd × •Save Landmarks of maxilla •Embed median palatine suture Nasal fossa Nasal septum Anterior nasal spine Incisive foramen Lateral fossa Maxillary sinus Malar bone Maxillary tuberosity Hamular process Nasolacrimal duct Maxillary anterior region Nasal septum Nasal fossa Nasal spine Insicive foramen Nose Median palatine suture e b a c d A-Nasal septum D-Incisive foramen B-Nasal fossa E-Median palatine suture C-Anterior nasal spine Nasal cavities Nasal septum Anterior nasal spine Median palatine suture 1 .Nasal septum (17): appears as a radio-opaque line that separates the two nasal fossa in the midline. 2. Anterior nasal spine (16): appears as a V-shaped radio-opaque structure in the midline above the incisive foramen. 3. Incisive foramen (12): or the anterior palatine fossa, it usually appears as a prominent radiolucent area above or between roots of two central incisors, it usually appears round or oval in shape and doesn’t exceed 6mm in diameter. Palatal view Median palatine suture Median palatine suture Appears as a vertically oriented Radiolucent line in true image projections through the midline. Usually prominent between the two central incisor roots in Young individuals. Palatal view Incisive foramen Red arrow points to periapical cyst periapical lesion Red arrow :mesiodens mesiodens Incisive canal cyst Facial view Nasal septum Facial view Nasal fossa Soft tissues of nose Red arrow : soft tissues of nose Green arrow :lip line Maxillary canine Floor of nasal fossa Maxillary sinus Lateral fossa Nose a c b a: Floor of nasal fossa b: Maxillary sinus c: Lateral fossa Floor of nasal fossa (red arrow) and anterior border of maxillary sinus (blue arrows),forming the inverted (upside down ) Y Lateral fossa : the radiolucency results from a depression Above and posterior to the lateral incisor. To help rule Out a pathology, look for an intact lamina dura Surrounding the adjacent bone. The maxillary sinus surrounds Black arrows indicate the floor The root of the canine, of the nasal fossa ,the max Which may be misinterpreted sinus (red arrows) has As pathology. pneumatized bet the 2nd PM And 1st molar. Maxillary premolar region Sinus septum Zygomatic process Maxillary sinus d c a c a d a: Malar process c: Sinus septum d: Maxillary sinus Maxillary molar region zygoma Maxillary sinus ptrygoid plate Hamular process Coronoid process maxillary tuberosity Maxillary sinus : The maxillary sinus with Its thin bony walls, its thin mucosa, and its vast Air space, produce an Extremely dark image Deep to the maxillary Teeth. Its outlines, particularly its Floor, are clearly delineated By delicate radio-opaque lines 1- body of zygoma 6- apices of roots 7 - floor of the sinus 8- septum of the sinus molar region In general ,the floor of the sinus is Approximately coincidental with The location of the apices of the Roots of the upper teeth (bicuspids And first two molars ). But there is often as much as two Or even three mm of maxillary Bone between the root ends and Sinus floor. In other cases the sinus floor dips so deeply between the roots of the Maxillary teeth that the latter appear to project into it for as much as One half of their length Pneumanization :expansion of sinus wall into surrounding bone, usually in an area where teeth have been lost prematurely. It increases with age . e e g g d d f c c a f a b A :max tuberosity e : zygoma (dotted lines) B :coronoid process f : max sinus C : hamular process g :sinus recess D: pterygoid plates Image of the imacted third molar superimposed Malar (zygomatic) process. U or j- shaped Radio-opacity, often superimposed over the roots Of the molars, specially when using the bisecting Angle technique. The red arrows define the Lower border of the zygomatic bone. Maxillary tuberosity : the rounded elevation located at the posterior aspect of both sides of the maxilla. Malar bone : or the zygomatic Process. The inferior portion Of the malar bone appears As a radio-opaque, U shaped structure Related to the roots of the first Maxillary molar. It represents the Attachment of the zygomatic bone To the maxilla. Maxillary tuberosity: appears As a radio-opaque structure that Extends distally and upward from Posterior to maxillary sinus. It Represents the end of maxilla. Black arrows : hamular process Purple arrows : pterygoid plates Coronoid process : it is seen as a radio-opaque structure in maxillay molar iopa. Hamular process: It is a bony spine extending from Pterygoid process of the sphenoid Bone. It appears as a radio-opaque Spine that is recorded on radiographs Distal to the tuberosity of maxilla And extends downward. Coronoid process of the mandible: Appears as a triangular radio-opaque structure projected into the same general area of max periapical film projections distal to the maxillary teeth. The zygomatic process (green) is a U shaped rationality. Normally the Zygomatic bone posterior to this is very dense and radio-opaque. In this, however the max sinus has expanded into the zygomatic bone and makes the area more radiolucent (red). The coronoid process (orange), the pterygoid plates (blue) and the max tuberosity (pink) are also identified . Nasolacrimal duct : It is seen in occlusal view of the maxilla as a round radiolucent area superimposed on the posterior region of the hard palate. Landmarks of mandible Lingual foramen Genial tubercles Mental ridge Mental foramen Mental fossa External oblique line Internal oblique line Mylohyoid line Mandibular foramen Inferior alveolar canal Submandibular gland fossa Nutrient canals Mandibular symphysis Symphysis In a new born infant Fracture Mandibular incisor region Mental ridge mental fossa Genial tubercle Lingual foramen d c a b A: lingual foramen C :mental ridge b: genial tubercles D: mental fossa Lingual foramen : radiolucent ‘hole ’ in centre of genial tubercles. Lingual nutrient vessels pass through this foramen . Lingual foramen It is set in the midline deep To the apices of the Anterior teeth. It appears as a small Radiolucent dot at the Symphysis area usually Surrounded by a radio Opaque structure. Genial tubercles : radio-opaque area in the midline surrounding The lingual foramen Genial tubercles:They appear as radio Opaque circle that surrounds the lingual foramen just below the apices of the Of the incisors. mental ridge Mental ridge : it is a bony prominence found on the labial Aspect of the mandible near its inferior border and extended From the premolar region to the symphysis area on wchich It takes an upward turn as it approaches it. It appears as a Radio opaque line below the apices of anterior teeth. mental fossa : this represents the depression on the labial aspect of the mandible overlying the roots of the incisors. The resultant radiolucency may be mistaken for pathology Nutrient canals : The arrows above identify nutrient Canals. They are most often seen in Persons with thin bone and in Those with high blood pressure Or advanced periodontitis. Nutrient canals Mental foramen (3) It appears as a radiolucent, ill defined area between the apices of bicuspids. it represents the anterior Terminates of the mandibular canal. 6- caries 7- prepared cavity 8- enostosis 9 –mental foramen Mandibular premolar region A – mylohyoid ridge B - mandibular canal c – submandibular gland fossa d – mental foramen b a d c b -Mandibular canal a- Mylohyoid ridge d -Mental foramen c -Submandibular gland fossa mental foramen Mandibular molar region A – external oblique ridge B – mylohyoid ridge C – mandibular canal D- submandibular gland fossa a b c d A -External oblique ridge B - Mylohyoid ridge c -Mandibular canal D -Submandibular gland fossa External oblique ridge - a continuation of the anterior border of ramus passing downward and forward on the buccal side of the mandible. It apperas as a radio-opaque line which usually ends anteriorly in the Area of the first molar. The red arrow points to the mylohyoid ridge. The external oblique ridge (red) and the mylohyoid ridge (blue) Usually run parallel to each other , with the external oblique ridge Always being higher on the film . Internal oblique ridge - It appears as a radio opaque Line, descending downwards And forward from coronoid Process, in a horizontal Position, stop at the third Molar area or become cotinuous With the mylohyoid line Its placed below the external Oblique ridge. Mylohyoid ridge (internal oblique) – located on the lingual Surface of the mandible , extending from third molar area to Premolar region Mandibular canal : arises at the mandibular foramen on the Lingual side of the ramus and passes downward and forward, Moving from the lingual side in the third molar region to the buccal Side in the premolar region.