normal radiographic .ppt

INTERPRETATION OF NORMAL INTERPRETATION OF NORMAL RADIOGRAPHIC ANATOMYRADIOGRAPHIC ANATOMY

DRG. SHANTY CHAIRANIDRG. SHANTY CHAIRANI

►The most dense area of a The most dense area of a normal toothnormal tooth is the is the enamel capenamel cap, which , which typically appears more radiopaque typically appears more radiopaque (white) than the other tissues. (white) than the other tissues.

►The The dentindentin is less dense and appears is less dense and appears as a uniform grey area. as a uniform grey area.

►The The junction between the enamel and dentjunction between the enamel and dentinin is very distinct. is very distinct.

TEETH AND THE TEETH AND THE SUPPORTING STRUCTURESSUPPORTING STRUCTURES

►The layer of The layer of cementumcementum on the root on the root surface is nearly the same density as surface is nearly the same density as the dentin, thus it is usually not the dentin, thus it is usually not apparent radiographically. apparent radiographically.

►The soft tissues of the The soft tissues of the pulppulp are much are much less dense than the other tooth less dense than the other tooth structures and typically appear structures and typically appear radiolucent. radiolucent.

► In normal, fully-formed teeth the root In normal, fully-formed teeth the root canal may be apparent extending to canal may be apparent extending to the the apex of the rootapex of the root with a with a recognizable recognizable apical foramenapical foramen..

►Supporting structures of the tooth that Supporting structures of the tooth that are visible radiographically include the are visible radiographically include the lamina dura, the alveolar crest, the lamina dura, the alveolar crest, the periodontal ligament space, and the periodontal ligament space, and the cancellous bone. cancellous bone.

►When the x-ray beam is projected When the x-ray beam is projected directly through the long axis of the directly through the long axis of the lamina lamina duradura, it is seen clearly as a thin, , it is seen clearly as a thin, white line. If the beam passes through at white line. If the beam passes through at an angle, the lamina dura may appear an angle, the lamina dura may appear more diffuse or not be visible at all. more diffuse or not be visible at all.

► The radiographic appearance of theThe radiographic appearance of the alveolar crestalveolar crest varies from a dense layer of varies from a dense layer of cortical bone to a smooth surface without cortical bone to a smooth surface without cortical bone. The level of the bony crest is cortical bone. The level of the bony crest is considered normal when it is not more than considered normal when it is not more than 1.5 mm from the cementoenamel junction of 1.5 mm from the cementoenamel junction of the adjacent teeth. the adjacent teeth.

► The The periodontal ligament spaceperiodontal ligament space appears as a appears as a radiolucent space between the root and radiolucent space between the root and lamina dura, beginning at the alveolar crest, lamina dura, beginning at the alveolar crest, extending around the portion of the root extending around the portion of the root within the alveolus, and returning to the within the alveolus, and returning to the alveolar crest on the opposite side. The alveolar crest on the opposite side. The width of the PDL varies from tooth to tooth, width of the PDL varies from tooth to tooth, although it is typically thinner in the middle although it is typically thinner in the middle of the root and wider near the alveolar crest of the root and wider near the alveolar crest and root apex. and root apex.

►Cancellous bone lies between the Cancellous bone lies between the cortical plates of both jaws and shows cortical plates of both jaws and shows many small radiolucent pockets of many small radiolucent pockets of marrow which create the marrow which create the trabeculartrabecular pattern pattern.. The The trabeculartrabecular pattern varies pattern varies considerably from patient to patient considerably from patient to patient and even within the same patient. and even within the same patient.

►The The trabeculaetrabeculae in the maxilla in the maxilla are are typically small and form a dense typically small and form a dense granular pattern while the granular pattern while the trabeculartrabecular pattern of the mandible pattern of the mandible is larger and is larger and coarser.coarser.

LANDMARKS IN RADIOGRAPHS LANDMARKS IN RADIOGRAPHS

OF THE MAXILLAOF THE MAXILLA

►The The median palatal suturemedian palatal suture appears as a thin radiolucent line appears as a thin radiolucent line between the central incisors between the central incisors extending roughly from the alveolar extending roughly from the alveolar crest to the apices of the central crest to the apices of the central incisors. incisors.

►The The incisive foramenincisive foramen is seen as an is seen as an oval radiolucent area between the oval radiolucent area between the apices of the central incisors. apices of the central incisors.

►The The nasal septumnasal septum is seen as a is seen as a radiopaque area extending vertically radiopaque area extending vertically down the center of the image from down the center of the image from the posterior of the image to the the posterior of the image to the apices of the central incisors. It is apices of the central incisors. It is bordered on each side by the bordered on each side by the nasal nasal fossafossa which appear as radiolucent which appear as radiolucent lines parallel to the nasal septum.lines parallel to the nasal septum.

► If the If the maxillary sinusmaxillary sinus appears in the appears in the image it is seen as a radiolucent area image it is seen as a radiolucent area in the posterior lateral aspect of the in the posterior lateral aspect of the image. image.

► The borders of theThe borders of the maxillary sinus maxillary sinus are are formed of thin cortical bone which appear as formed of thin cortical bone which appear as thin radiopaque lines on periapical thin radiopaque lines on periapical radiographs. radiographs. The size of the maxillary sinus varies The size of the maxillary sinus varies

considerably although the right and left considerably although the right and left sinuses are typically symmetrical. sinuses are typically symmetrical.

TheThe floor of the sinus floor of the sinus is seen on is seen on periapical radiographs near the apices of periapical radiographs near the apices of the molars and premolars, and may extend the molars and premolars, and may extend down as far as the crest of the alveolar down as far as the crest of the alveolar ridge, particularly ridge, particularly in edentulous areasin edentulous areas. .

Radiopaque lines traversing the Radiopaque lines traversing the sinus either horizontally or vertically sinus either horizontally or vertically are are septaeseptae,, bony projections from bony projections from the floor and wall of the antrum. the floor and wall of the antrum. Septae give the sinus the Septae give the sinus the appearance of being divided into appearance of being divided into compartments, although this is not compartments, although this is not the case. the case.

The radiolucent compartments The radiolucent compartments formed by the septae sometimes formed by the septae sometimes mimic periapical pathoses.mimic periapical pathoses.

► TheThe zygomazygoma appears as a U-shaped appears as a U-shaped radiopaque line with the round portion radiopaque line with the round portion superimposing the area of the first and superimposing the area of the first and second molars. Depending on the angle in second molars. Depending on the angle in which the x-ray beam passes through the which the x-ray beam passes through the zygoma, it will vary in size, width, and zygoma, it will vary in size, width, and definition.definition.

► TheThe nasolabialnasolabial fold fold may appear as an may appear as an oblique line traversing the premolar region. oblique line traversing the premolar region. The line of contrast is well-defined and the The line of contrast is well-defined and the area of increased radiopacity is caused by area of increased radiopacity is caused by the superimposition of the cheek tissue. This the superimposition of the cheek tissue. This feature increases with age and can be used feature increases with age and can be used to identify the side of the maxilla if the area to identify the side of the maxilla if the area is edentulous.is edentulous.

Zygoma

Nasolabial fold

►The The medial and lateral medial and lateral pterygoidpterygoid plates plates lying immediately posterior to the lying immediately posterior to the maxillary tuberosities have a variable maxillary tuberosities have a variable appearance, often not being visible at appearance, often not being visible at all. Typical appearance is a single all. Typical appearance is a single radiopaque shadow with no trabecular radiopaque shadow with no trabecular pattern. pattern.

►TheThe hamulushamulus may be seen extending may be seen extending inferiorly from the medial pterygoid inferiorly from the medial pterygoid plate and does show trabecular pattern. plate and does show trabecular pattern.

Hamulus

LANDMARKS IN RADIOGRAPHS LANDMARKS IN RADIOGRAPHS OF THE MANDIBLEOF THE MANDIBLE

►On periapical radiographs of the On periapical radiographs of the central incisors thecentral incisors the mental mental fossafossa appears as a radiolucent depression appears as a radiolucent depression extending laterally from the midline extending laterally from the midline and between the alveolar ridge and and between the alveolar ridge and the mental ridge. Due to the thinness the mental ridge. Due to the thinness of the bone in the area, the mental of the bone in the area, the mental fossa appears slightly radiolucent fossa appears slightly radiolucent compared to adjacent bone and may compared to adjacent bone and may be mistaken for periapical disease.be mistaken for periapical disease.

► In radiograph of the lower incisor area,In radiograph of the lower incisor area, lingual foramenlingual foramen is seen as a single is seen as a single radiolucent area located in the midline of the radiolucent area located in the midline of the mandible. Its size and prominence vary mandible. Its size and prominence vary widely.widely.

► Mental ridgeMental ridge is a bony prominence is a bony prominence extending from the midline of the mandible extending from the midline of the mandible to the area of the premolars. Located on the to the area of the premolars. Located on the labial side, it appears as a radiopaque line labial side, it appears as a radiopaque line parallel to the cortical plate. Its density and parallel to the cortical plate. Its density and prominence vary widely.prominence vary widely.

Mental fossa

Lingual foramen

Mental ridge

►TheThe inferior border of the inferior border of the mandiblemandible is seen in a mandibular is seen in a mandibular occlusal radiograph. Typically theocclusal radiograph. Typically the cortical platecortical plate can be seen as a can be seen as a radiopaque line along the border of radiopaque line along the border of the mandible. the mandible.

►The The genial tuberclegenial tubercle appears as a appears as a small pointed protrusion extending small pointed protrusion extending downward from the cortical plate. downward from the cortical plate.

►TheThe mental foramenmental foramen is seen on some is seen on some periapical radiographs and has a periapical radiographs and has a varying appearance; sometimes varying appearance; sometimes round or oblong, sometimes slitlike. round or oblong, sometimes slitlike. Typically it is positioned halfway between Typically it is positioned halfway between

the lower border of the mandible and the the lower border of the mandible and the alveolar crest, in the region of the apex of alveolar crest, in the region of the apex of the second premolar. the second premolar.

It may appear over the apex of a tooth, It may appear over the apex of a tooth, mimicking periapical pathoses. mimicking periapical pathoses.

A second radiograph from another angle A second radiograph from another angle will likely cause the appearance of the will likely cause the appearance of the foramen to shift in relation to the apex foramen to shift in relation to the apex and confirm its identity.and confirm its identity.

Mental foramen

► TheThe mandibularmandibular canal canal (inferior alveolar (inferior alveolar canal) appears inconsistently and is canal) appears inconsistently and is seen as a dark linear shadow with thin seen as a dark linear shadow with thin radiopaque borders. The canal extends radiopaque borders. The canal extends radiographically from the mandibular radiographically from the mandibular foramen to the mental foramen.foramen to the mental foramen.

► The The mylohyoidmylohyoid ridge ridge appears as a appears as a radiopaque line running from the area radiopaque line running from the area of the third molars to the premolar of the third molars to the premolar region, occasionally superimposing the region, occasionally superimposing the molar roots. The margin of the ridge is molar roots. The margin of the ridge is varies and is often not well defined.varies and is often not well defined.

Mylohyoid ridge

Mandibular canal

► Nutrient canalsNutrient canals appear in a small number appear in a small number of patients as radiolucent lines extending of patients as radiolucent lines extending vertically from the inferior dental canal to vertically from the inferior dental canal to the interdental space between the the interdental space between the mandibular incisors. Occasionally the mandibular incisors. Occasionally the canals may appear as small round canals may appear as small round radiolucencies perpendicular to the cortex radiolucencies perpendicular to the cortex and can be mistaken for pathology.and can be mistaken for pathology.

► The The submandibularsubmandibular gland gland fossafossa is located is located below the mylohyoid ridge in the molar below the mylohyoid ridge in the molar area and appears as a radiolucent area area and appears as a radiolucent area with a sparse trabecular pattern. When with a sparse trabecular pattern. When excessively pronounced, it may be excessively pronounced, it may be mistaken for a radiolucent “lesion”.mistaken for a radiolucent “lesion”.

Nutrient canalsSubmandibular gland fossa

► The The external oblique ridgeexternal oblique ridge is the is the continuation of the anterior border of the continuation of the anterior border of the mandibular ramus which disappears in the mandibular ramus which disappears in the area of the first molar. On periapical area of the first molar. On periapical radiographs it appears superior to the radiographs it appears superior to the mylohyoid ridge, running nearly parallel to it. mylohyoid ridge, running nearly parallel to it. Radiographically it appears as a radiopaque Radiographically it appears as a radiopaque line with varying width, density, and length.line with varying width, density, and length.

► TheThe coronoidcoronoid process process is often seen in the is often seen in the molar region and appears as a triangular molar region and appears as a triangular opacity superimposed on the area of the opacity superimposed on the area of the third molar. Trabecular pattern may or may third molar. Trabecular pattern may or may not be visiblenot be visible

External oblique ridge

Coronoid process

PANORAMIC RADIOGRAPHPANORAMIC RADIOGRAPH

INTERPRETATION OF NORMAL INTERPRETATION OF NORMAL GROWTH AND DEVELOPMENT OF GROWTH AND DEVELOPMENT OF

TEETH AND JAWSTEETH AND JAWS

Chronology of human dentitionChronology of human dentition

Newborn Boy 6 Month Old

1 Year Old 2 Year Old

Panoramic radiograph of 6 year Panoramic radiograph of 6 year oldold

Panoramic radiograph of 9 year Panoramic radiograph of 9 year oldold

Panoramic radiograph of 12 Panoramic radiograph of 12 year oldyear old

normal radiographic .ppt

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