外傷及感染之放射線影像檢查 Radiographic Interpretation of Trauma and Infection

內容綱要 顎顏面外傷之影像檢查

• 技術• 顎顏面外傷分類• 判讀

感染的影像檢查• 軟硬組織感染• 判讀

影像檢查在顎顏面外傷的應用 Plays a critical role Identify the location and orientation of

fractures Indicate the degree of separation or

displacement

顎顏面外傷常用放射線影像檢查技術 -I

Routine view1. Posterior-anterior (PA) view of facial bones2. Lateral view of facial bone3. Panorex4. Water’s ( Occipitomental )

• Suspect mid-face fracture

顎顏面外傷常用放射線影像檢查技術 -II

5. Periapical view

6. Occlusal view• Occlusal view of nasal bone• Occlusal view of mandible

7. Submental-vertex view

8. Lateral view of nasal bone

顎顏面外傷常用放射線影像檢查技術 -III

9. Tomography

10. Towne’s view

11. PA view of mandible

12. Oblique view of mandible

1. PA view

Skull Jaws

2. Lateral view Skull Jaws Neck

3. Panex Mandible, maxilla, dentition,70 % of mid-face fracture

4. Water’ view(Occipito-mental ) Maxillary fracture Orbital fracture Frontal bone / sinus

5. Periapical view

Tooth and alveolar injury

6. Occlusal view - Mandible

Fracture line , direction Axial section

6. Occlusal view - Maxilla

7. Submental vertex view Zygomatic arch fracture Coronoid fracture

8. Lateral nasal view

9. Tomography

185 180

Blow –out fractureTMJ fracture

175 170

165 160

10. Modified Town’s view Condylar fracture Mandibular angle fracture

11.PA symphysis view

12. Oblique lateral view Was replaced by Panoex Used when patient can not sit or stand

CT scan

Reconstructive 3-D CT scan

顎顏面外傷之影像檢查判讀 General interpretation of fracture line Condyle and other mandibular fracture Middle facial fracture Cavity: sinus, orbital Dento-alveolar fracture

General interpretation of fracture line

Displacement ( deviation, dislocation ) Step, gap, overlapping Discontinuity Asymmetry Comminuted Malocclusion Cavity: (air-fluid level )

*** Degree and direction

Mandibular fracture

Angle and symphysis fracture

Malocclusion

Step

Condyle and symphysis fractureOverlap , discontinuity and

displacement Asymmetry

Comminuted

Coronoid and ramus fracture Gap, Discontinuity Step , Displacement

Condyle

Deviation Displacement Dislocation

Dislocation

DeviationUndisplaced

Displacement

condyle fractureDisplacement

Bilateral condyle fracture

Dislocation

Bone gap

Split fracture Coronoid fracture

Chin horizontal fracture

Mid-facial trauma Cavity: sinus, hernia of orbital soft tissue

• Tomography of orbital fracture • CT

Air-emphysema Middle fracture ( Le Fort I, II, III ) ZMC fracture Basilar skull fracture: air-fluid level in

sphenoid sinus

Le fort I fracture

Air-fluid level

Le Fort IIfracture

Le Fort III fracture

Blow-out fracture

Zygomatic arch fracture

Zygomatico-maxillary complex ( ZMC) fracture

Classification of dentoalveolar injuries

1. Crown craze or crack

2. Crown fracture

1) Enamel

2) Enamel-Dentin

3) Enamel-Dentin- Pulp

3. Crown and root fracture

1) Pulp involvement

2) No pulp involvement

A. Tooth structuresB. Supporting structures

Classification of dentoalveolar injuries

4. Root fracture

1) Apical third

2) Middle third

3) Cervical third

Shift to another angle

B. Supporting Structure

1. Sensitivity ( concussion ) * percussion pain * no displacement * no mobility * Image widening of PDL space

2. Subluxation * loosening, no displacement, * Image portion of PDL widening

Classification of dentoalveolar injuries

3. Tooth displacement

1) Intrusion

2) Extrusion

3) Labial displacement

4) Lingual displacement

5) Lateral displacement

4. Avulsion

5. Alveolar process fracture

感染的影像檢查技術 Plain film radiography CT scan MRI Nuclear bone scans Tomography Ultrasonography

齒源性感染的常用影像檢查

Plain film radiography 根尖片 : 對於根尖及早期病變的顯示最佳

咬合片 : (Axial) Garrie’s osteomyelitis 全口片 (panoex)

• 有張口困難的病人 ,• 同時對牙齒的情況做 , 骨頭的破壞檢查 ,

CT Scan

Space infection Neck: Air way, pharynx Sinus Orbit Intracranial abscess Soft tissue

MRI Noninvasion, no radiation, high soft tissue

resolution high sensitivity and specificity﹐ 對骨的細部變化

space infection, presence of pus, cavitation TMJ abscess

選擇的要領 Plain film : 一般診斷及治療反應後的追蹤

CT / MRI : Extension into soft tissue ,

air way Bone scan: Response to treatment

Image finding and Bone changes

Difficult to visualize by conventional techniques in early stage

Until substantial mineral .. removed 35 - 50 %

After infection :5 -14 days

感染部位與描述名稱Margin: well or poor demarcation / defined Lesion: radiolucent / radiopaque

Periapical changes: PDL , trabeculae . Cavity (sinus) : cloudy, air-fluid level… Osteomyelitis: periosteal reaction moth ﹐

eaten , rarefaction, …. Sinus tract ( fistula )

1. Periapical Infection

( acute / chronic ) Widening of PDL Lamina dura discontinuity Trabeculae destruction Chronic

• Periapical abscess• Periapical granuloma • Fistula • Root resorption

2. Osteomyelitis ( 骨髓炎 )

Acute suppurative osteomyelitis Trabeculae: fuzzy, diffuse destruction﹐ Radiolucent area

• Poor demarcation• Irregular border

Chronic suppurative osteomyelitis

Moth eaten* Radiolucent area with poor demarcation Necrotic bone Sequestrum

• Radiopaque with peripheral rediolucent area

Rarefaction Necrotic Bone

Moth eaten

Sequestrum Radiopaque with peripheral radiolucent area

Pathologic fracture

RarefactionExpansion

Sclerosing Osteomyelitis

Focal type Increasing density ( disposition of the

bone ) rarefaction Periapical area Thickening of PDL Bone scar

Sclerosing Osteomyelitis

Diffuse type Border between normal and sclerosis ..

poor defined Cotton wool appearance 。

Garre’s proliferative periostitis (Osteomyelitis)

Subperiosteal reaction: onion skinning﹐ Duplication of the cortical layer of bone

ORN ( Osteo-Radio Necrosis )

No remodeling

90.1.18

90.3.12

Bone necrosis due to Arsenic Tooth germ, nerve damage…

軟組織感染 Infections involving soft tissues are not

readily Demonstrated by many imaging techniques Gas producing organism

Infratemporal space Submasseteric space

Air way

MRI of TMJ space abscess

Sinusitis CloudyAir-Fluid level

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