原文題目(出處)： Superolateral dislocation of an intact mandibular condyle into the temporal fossa: case report and literature review (Dental Traumatology 2017; 33: 64-70)
原文作者姓名： Divashree Sharma
通訊作者學校： Department of Dentistry, Shyam Shah Medical College 報告者姓名(組別)： 樊叡（L 組）
報告日期： 2017.07.06
內文：
Abstract TMJ dislocation
− Non- self-limiting displacement of condyle
− Outside its functional positions
− (glenoid fossa and posterior slope of the articular eminence)
− Anterior and anteromedial --- most common
− Superolateral --- rarest, being misdiagnosed and neglected Case Report
30 y/o male patient
20 days after a road traffic accident, left ear bleed facial nerve testing --- no damage
Extra-oral examination:
− Laceration over the chin: 2 x 1 cm
− Retrusion of left side of the chin, tender on palpation
− Decreased mandibular height on the left side
− Deviation towards the left on mouth opening
− Bony hard, tender elevation on the left preauricular region: 3 x 2 cm
− Unable to close his mouth, mandibular movement restricted and painful
Intra-oral examination
− Anterior open bite and cross bite on the left side
− Step defect between 31, 32 Pano finding
− Left parasymphysis fracture
− Left condyle is intact and overlapping on the articular eminence
− Right condyle is intact and in its normal position
Treatment
− First closed manual reduction under local anaesthesia --- fail
− Second closed manual reduction under general anaesthesia --- fail
− Left mandibular incision to expose the angle region, with two traction wire pulling the entire fragment downward --- fail
− Alkayat – Bramely incision to expose the left condyle --- success
− Condyle was hooked over the zygomatic arch, while the disc was dislocated antero-medially
− Condyle was manipulated back to the fossa with the help of Molt #9 periosteal elevator, and the disc was repositioned over the condyle and sutured with the articular capsule in the mandibular fossa laterally
− Parasymphysis fracture was then reduced and fixed with miniplate intra-orally
− 36 mm mouth opening and satisfactory occlusion
− IMF with elastics for 2 weeks
− 6-month follow up: no problem
Discussion
Allen and Young subdivided superolateral dislocation into:
− Type I (lateral subluxation) --- condyle has been laterally dislocated out of the fossa
− Type II (complete dislocation) --- condyle has passed laterally and then superiorly to enter the temporal fossa outside the zygomatic arch
− An associated fracture of the anterior mandible, near the symphysis, is a prerequisite for a type II dislocation
Satoh et al. further classified type II dislocations into:
− Type IIA --- condyle is not hooked above the zygomatic arch
− Type IIB --- condyle is hooked above the zygomatic arch
− Type IIC --- condyle is lodged inside the fractured zygomatic arch Rattan
− Lateral dislocation should always be with a history of trauma to the side of the chin and an associated fracture in the symphyseal or body region (usually on the contralateral side) Li et al.
− Prerequisite factors are multiple multidirectional impacts of force, wide open mouth and flabby joint capsule and pterygoid muscles
Dislocation of the TMJ:
− Stretching of the ligaments around the joint
− Intraarticular effusion, causing painful mandibular movements
− Muscle spasms and joint pain make speech and mastication difficult
− Anterior open bite and crossbite with loss of ramus height on the affected side
− A slight retrusion of the anterior mandible with a fracture in the mandible
− Palpation may become difficult because of the oedema
− Facial nerve damage may also occur but not very frequently reported and it is wise to evaluate the condition of the facial nerve and document it before the treatment Worthington --- some diagnostic features to superolateral dislocation:
− Malocclusion persisting after the reduction of jaw fracture
− Persistence of an open bite
− Persistent restriction of mandibular movement
− An apparent loss of ramus height with elevation of the ramus fragment
− Facial asymmetry
Treatment --- Closed reduction
− Closed reduction with or without anaesthesia first, may with splints or IMF
− Placing a mouth gag in between the occlusal surfaces of molars and opening it wide to open the patient’s mouth and then rotating it to pull in the outlocated condyle
− Application of a percutaneous traction force with a bone hook placed at sigmoid notch
− Use of traction with wires placed in holes drilled in the exposed angle region
− Classical bimanual intra-oral manual reduction --- imparts unnecessary pressure to the unaffected side which may cause problems in the healthy TMJ and the thumbs may be bitten by the patient which may cause traumatic damage or infection (approximately 3-cm-thick gauze pad in the affected molar region and applying an upward pressure on the chin extra-orally)
− Successful in early-diagnosed cases
− Delayed closed reduction --- impossible, because of development of fibrosis within the joint cavities, myospasm, bony union or combination of these
Treatment --- Open reduction
− Under general anaesthesia --- if closed reduction fails, open reduction can be attempted simultaneously
− Vary from direct exposure of condyle and reduction
− Coronoidectomy performed through posterior vestibular incision followed by attempts to reduce the superolaterally dislocated condyle by placement of a Seldin elevator lateral to ramus and applying a downward and medial pressure, utilizing an intra-oral Keens
vestibular incision to pass a zygomatic hook to engage the sigmoid notch and exerting a downward and lateral force to reduce the dislocation
− Mandibular sagittal split ramus osteotomy for condylar reduction through submandibular and preauricular incisions
− Condylectomy with or without arthroplasty is indicated in fibro-osseous ankylosis of the joint induced by unsuccessful or imperfect reduction
Conclusion
− Superolateral dislocations of the mandibular condyle are not frequently encountered in clinical practice and demand special attention in diagnosis and treatment planning
− Associated mandibular fracture is a prerequisite for such dislocations --- debatable
− Early reduction is advisable
− The decision of the preferred treatment modality (either closed or open reduction) depends on the time elapsed since injury, the degree and type of dislocation, other associated mandibular fractures and the general condition of the patient
− Open reduction after closed methods
題號 題目
1 顳顎關節有Chronic recurrent dislocation 的病人該如何將下顎復位？
(A) 下顎後牙往下壓，下巴往下推，同時將下顎往後推 (B) 下顎前牙往下壓，下巴往下推，同時將下顎往後推 (C) 下顎後牙往下壓，下巴往上推，同時將下顎往後推 (D) 下顎前牙往下壓，下巴往上推，同時將下顎往後推
答案(C) 出處：Contemporary Oral and Maxillofacial Surgery, Sixth Edition p. 635
題號 題目
2 下列何者代表Anterior disk displacement with reduction 時，閉口的示意圖？
(A)
(B)
(C)
(D)
答案(D) 出處：Contemporary Oral and Maxillofacial Surgery, Sixth Edition p. 632 ~ 634
