《Intraoral Radiographic Anatomy(口内X线解剖)》由会员分享，可在线阅读，更多相关《Intraoral Radiographic Anatomy(口内X线解剖)（78页珍藏版）》请在金锄头文库上搜索。
1、 Intraoral Radiographic AnatomyThe following slides identify the anatomical structures that may be seen on intraoral films. These structures are more likely to be seen when using the bisecting angle technique because of the increased vertical angulation (increased positive in the maxilla and increas
2、ed negative in the mandible) commonly used with this technique. Since some of the structures may be confused with pathology, it is important to understand their normal appearance in order to make a proper diagnosis.Maxillary Incisor a = nasal septumb = inferior conchac = nasal fossad = anterior nasa
3、l spinee = incisive foramenf = median palatal sutureg = soft tissue of nosebagfedcefa = nasal septumb = inferior conchac = nasal fossad = anterior nasal spinee = incisive foramenf = median palatal suturebadcfacial viewpalatal viewNasal septumfacial viewaInferior conchafacial viewNasal fossafacial vi
4、ewAnterior nasal spinefacial viewIncisive foramenpalatal viewMedian palatal suturepalatal viewSoft tissue of the noseRed arrow points to periapical lesion (post-endo).abeadbRed arrows = lip linegRed arrow = mesiodens (supernumerary tooth)dfBlue arrow = chronic periapical periodontitis. Tooth # 9 is
5、non-vital (trauma) and needs endo.Superior foramina of the nasopalatine canals (red arrows). These foramina lie in the floor of the nasal fossa. The nasopalatine canals travel downward to join in the incisive foramen.dbaThe red arrows point to an incisive canal cyst; the orange arrow identifies the
6、root of tooth # 7. All the incisors are non-vital and have periapical lesions. The purple arrows point to external resorption; the blue arrow identifies internal resorption.fThe red arrows point to the soft tissue of the nose. The green arrows identify the lip line.a = floor of nasal fossab = maxill
7、ary sinusc = lateral fossad = noseMaxillary Cuspid dcbaa = floor of nasal fossab = maxillary sinusc = lateral fossa(a & b form inverted Y)acbacbfacial viewFloor of nasal fossa (red arrows) and anterior border of maxillary sinus (blue arrows), forming the inverted (upside down) Y.Yfacial viewLateral
8、fossa. The radiolucency results from a depression above and posterior to the lateral incisor. To help rule out pathology, look for an intact lamina dura surrounding the adjacent teeth.facial viewSoft tissue of the noseRed arrows point to nasolabial fold. Also note the inverted Y.The maxillary sinus
9、surrounds the root of the canine, which may be misinterpreted as pathology.The white arrows indicate the floor of the nasal fossa. The maxillary sinus (red arrows) has pneumatized between the 2nd premolar and first molar The red arrow identifies the lateral fossa. The pink arrow points to CPP (chron
10、ic periapical periodontitis = abscess, granuloma, etc.).a = malar processb = sinus septumc = sinus recessd = maxillary sinusabcdMaxillary Premolar a = malar processb = sinus recessc = sinus septumd = maxillary sinusbacdbdcafacial viewMalar (zygomatic) process. U or j-shaped radiopacity, often superi
11、mposed over the roots of the molars, especially when using the bisecting-angle technique. The red arrows define the lower border of the zygomatic bone. facial viewSinus septum. This septum is composed of folds of cortical bone that arise from the floor and walls of the maxillary sinus, extending sev
12、eral millimeters into the sinus. In rare cases, the septum completely divides the sinus into separate compartments.facial viewSinus recess. Increased area of radiolucency caused by outpocketing (localized expansion) of sinus wall. If superimposed over roots, may mimic pathology.facial viewMaxillary
13、Sinus. An air-filled cavity lined with mucous membrane. Communicates with nasal cavity through 3-6 mm opening below middle concha. Red arrows point to neurovascular canal containing superior alveolar vessels and nerves.facial viewBlue arrows identify radiopacity which is a mucous retention cyst. Not
14、e relatively recent premolar extraction sites. Green arrow points to neurovascular canal. The red arrows point to the nasolabial fold. The thicker cheek tissue makes the area more radiopaque posterior to the line.Pneumatization. Expansion of sinus wall into surrounding bone, usually in areas where t
15、eeth have been lost prematurely. Increases with age. Maxillary Molara = maxillary tuberosityb = coronoid processc = hamular processd = pterygoid platese = zygomaf = maxillary sinusfedcbagdaefa = maxillary tuberosity* e = zygoma (dotted lines)b = coronoid process f = maxillary sinusc = hamular proces
16、s g = sinus recessd = pterygoid plates* image of impacted third molar superimposedcbfacial viewdbaecfgMaxillary Tuberosity. The rounded elevation located at the posterior aspect of both sides of the maxilla. Aids in the retention of dentures.facial viewCoronoid process. A mandibular structure someti
17、mes seen on the maxillary molar periapical film when using the bisecting angle technique with finger retention (The mouth is opened wide, moving the coronoid down and forward). Note the supernumerary molar.facial viewHamular process (white arrows) and pterygoid plates (purple arrows). The hamular pr
18、ocess is an extension of the medial pterygoid plate of the sphenoid bone, positioned just posterior to the maxillary tuberosity. facial viewZygomatic (malar) bone/process/arch. The zygomatic bone (white/black arrows) starts in the anterior aspect with the zygomatic process (blue arrow), which has a
19、U-shape. The zygomatic bone extends posteriorly into the zygomatic arch (green arrow).facial viewMaxillary sinus. As seen in the above film, the floor of the maxillary sinus flows around the roots of the maxillary molars and premolars. The walls of the sinus may become very thin. As a result, sinusi
20、tis may put pressure on the superior alveolar nerves resulting in apparent tooth pain, even though the tooth is perfectly healthy. Note coronoid process (green arrow), zygomatic bone (blue arrow), sinus septum (yellow arrow) and neurovascular canal (orange arrows).facial viewThe maxillary sinus is e
21、vident anterior to the second molar (black arrows) but it disappears posteriorly due to the superimposition of the zygomatic bone. The orange arrows identify a mucous retention cyst (retention pseudocyst) within the sinus. This film shows the coronoid process (green arrow) and a distomolar (blue arr
22、ow) that has erupted ahead of the third molar (red arrow). A distomolar is a supernumerary tooth that erupts distal (posterior) to the other molars.The zygomatic process (green arrows) is a prominent U-shaped radiopacity. Normally the zygomatic bone posterior to this is very dense and radiopaque. In
23、 this patient, however, the maxillary sinus has expanded into the zygomatic bone and makes the area more radiolucent (red arrows). The coronoid process (orange arrow), the pterygoid plates (blue arrows) and the maxillary tuberosity (pink arrows) are also identified.This film shows the expansion of t
24、he borders of the maxillary sinus through pneumatization (red arrows). This expansion increases with age and it may be accelerated as a result of chronic sinus infections. It is most commonly seen when the first molar is extracted prematurely, as in the film at right (the second and third molars hav
25、e migrated anteriorly to close the space). The coronoid process is seen in the lower left-hand corner of each film. The green arrow identifies a sinus recess. Note the two distomolars in film at right (blue arrows).a. lingual foramenb. genial tuberclesc. mental ridged. mental fossaMandibular Incisor
26、 abcdb = genial tuberclesa = lingual foramenc = mental ridged = mental fossaabcdfacial viewlingual viewLingual foramen. Radiolucent “hole” in center of genial tubercles. Lingual nutrient vessels pass through this foramen. lingual viewGenial tubercles. Radiopaque area in the midline, midway between t
27、he inferior border of the mandible and the apices of the incisors. Serve as attachments for the genioglossus and geniohyoid muscles. May have radiolucent hole in center (lingual foramen), but not on this film. Note double rooted canine (red arrows).lingual viewMental ridge. These represent the raise
28、d portions of the mental protuberance on either side of the midline. More commonly seen when using the bisecting angle technique, when the x-ray beam is directed at an upward angle through the ridges.facial viewMental fossa. This represents a depression on the labial aspect of the mandible overlying
29、 the roots of the incisors. The resulting radiolucency may be mistaken for pathology. facial viewThe radiolucent area above corresponds to the location of the mental fossa. However, this slide represents chronic periapical periodontitis; these teeth are non-vital, due to trauma.The orange arrows abo
30、ve identify nutrient canals. They are most often seen in older persons with thin bone, and in those with high blood pressure or advanced periodontitis.Mandibular Canine aba = mental ridgeb = genial tubercles/ lingual foramenc = mental foramencb2a = mental ridgec = mental foramenb2 = lingual foramenb
31、1 = genial tuberclesfacial viewlingual viewd cd ad b1d b2Mental ridge. The raised portions of the mental protuberance, sloping downward and backward from the midline. facial view Lingual foramen/genial tubercles. (See description under mandibular incisor above). lingual viewThe red arrows identify t
32、he mandibular canal and the blue arrow points to the mental foramen.facial viewMandibular Premolar a = mylohyoid ridgeb = mandibular canalc = submandibular gland fossad = mental foramencb = mandibular canald = mental foramena = mylohyoid ridge (internal oblique)c = submandibular gland fossafacial vi
33、ewlingual viewcad dbMylohyoid (internal oblique) ridge. This radiopaque ridge is the attachment for the mylohyoid muscle. The ridge runs downward and forward from the third molar region to the area of the premolars.lingual viewfacial viewMandibular canal. (Inferior alveolar canal). Runs downward fro
34、m the mandibular foramen to the mental foramen, passing close to the roots of the molars. More easily seen in the molar periapical.lingual viewSubmandibular gland fossa. The depression below the mylohyoid ridge where the submandibular gland is located. More obvious in the molar periapical film.Menta
35、l foramen. Usually located midway between the upper and lower borders of the body of the mandible, in the area of the premolars. May mimic pathology if superimposed over the apex of one of the premolars.facial viewThe mental foramen (blue arrow) is adjacent to a periapical lesion associated with too
36、th # 21 (red arrow). There is slight external resorption on # 21.The green arrow points to the mental foramen. The yellow arrow identifies a periapical lesion on # 30. Note the overextension of the silver point in the distal root, the perforation of the mesial root and the amalgam protruding through
37、 the perforation from the pulp chamber.Mandibular Molar a = external oblique ridgeb = mylohyoid ridgec = mandibular canald = submandibular gland fossafacial viewlingual viewbcaba = external oblique ridgec = mandibular canalb = mylohyoid ridged = submandibular gland fossad dabcd da = external oblique
38、 ridgeb = mylohyoid ridgec = mandibular canald = submandibular gland fossaExternal oblique ridge. A continuation of the anterior border of the ramus, passing downward and forward on the buccal side of the mandible. It appears as a distinct radiopaque line which usually ends anteriorly in the area of
39、 the first molar. Serves as an attachment of the buccinator muscle. (The red arrows point to the mylohyoid ridge).facial viewMylohyoid ridge (internal oblique). Located on the lingual surface of the mandible, extending from the third molar area to the premolar region. Serves as the attachment of the
40、 mylohyoid muscle.lingual viewfacial viewMandibular (inferior alveolar) canal. Arises at the mandibular foramen on the lingual side of the ramus and passes downward and forward, moving from the lingual side of the mandible in the third molar region to the buccal side of the mandible in the premolar
41、region. Contains the inferior alveolar nerve and vessels.lingual viewSubmandibular gland fossa. A depression on the lingual side of the mandible below the mylohyoid ridge. The submandibular gland is located in this region. Due to the thinness of bone, the trabecular pattern of the bone is very spars
42、e and results in the area being very radiolucent. The fact that it occurs bilaterally helps to differentiate it from pathology.The external oblique ridge (red arrows) and the mylohyoid ridge (blue arrows) usually run parallel with each other, with the external oblique ridge always being higher on th
43、e film.The mandibular canal (red arrows identify inferior border of canal) usually runs very close to the roots of the molars, especially the third molar. This can be a problem when extracting these teeth. Note the extreme dilaceration (curving) of the roots of the third molar (green arrow) in the f
44、ilm at left. The film at right shows “kissing” impactions located at the superior border of the canal. Identify the anatomical structures on the following eight slides. The answers are on the last slide. Slide # 1A. The red arrows identify the ?Slide # 2A. The red arrow points to the ?B. The white a
45、rrows identify the ?C. The blue arrow points to the ?D. The yellow arrow identifies the ?Slide # 3A.The small radioluceny identified by the green arrow is the ?Slide # 4A.The radiopacity identified by the blue arrows is the ?B. The orange arrow identifies the ?Slide # 5A.The yellow arrows point to t
46、he ?B.The red arrows identify the ?Slide # 6A.The red arrow points to the ?B.The orange arrow points to the ?C.The blue arrows point to the D. radiolucent line known as the ?Slide # 7A. The red arrows point to the ?Slide # 8A.The red arrows identify the ?B.What is the name of the radiolucent C. area
47、 surrounding the canal? KEYSlide # 1: A. Floor of the nasal fossaSlide # 2: A. Coronoid process B. Maxillary sinus (pneumatized into maxillary tuberosity) C. Sinus septum D. Zygomatic processSlide # 3: A. Lingual foramenSlide # 4: A. Mylohyoid ridge B. Submandibular gland fossaSlide # 5: A. Zygomatic process B. Maxillary sinusSlide # 6: A. Inferior concha B. Nasal septum C. Median palatal sutureSlide # 7: A. Mental ridgeSlide # 8: A. Mandibular canal B. Submandibular gland fossa
