接觸力學:顳顎關節內部紊亂之預後因素

Contact Mechanics: A Prognostic Factor of TMJ Internal Derangement

張景程(Ching-Cheng Chang)

指導教授 ： 陳韻之

國立臺灣大學/醫學院/臨床牙醫學研究所/碩士(2006年)

https://doi.org/10.6342/NTU.2006.02944

摘要

實驗目的：
同樣是顳顎關節盤前置異位且不可復位( disc anterior displacement without reduction )的病人，在臨床上的表現和預後卻有很大的差別，而且在MRI 的檢查上往往可以看到關節髁頭被吸收之後各種不同的形狀，而那些因素造成這些不同的關節髁頭形狀，以及這些不同的形狀對於預後之影響，是我們想探討的。
本文利用靜態磁振攝影( static MRI )以及動態磁振攝影( dynamic MRI )，來觀察在開口過程中顳顎關節髁頭( condylar head )和關節盤( disc )的關係，希望能夠藉此探討在顳顎關節盤前置異位且不可復位的情形下，影響顳顎關節髁頭形變的機制。
本實驗也經由半年到一年的時間，觀察數個顳顎關節盤前置異位且不可復位的病人，藉由前後MRI影像的變化，希望能夠觀察關節髁頭在退化性關節炎( degenerative joint disease )中形態上的變化。
實驗方法：
本研究觀察對像包括2003年至2005年臺大醫院牙科部顳顎關節障礙門診中的病人，共88人( 平均年齡為23.2歲)，其中有6位男性以及82位女性。受試者皆至少有一側顳顎關節有顳顎關節盤前置異位且不可復位的情形。受試者都接受靜態磁振攝影檢查，根據檢查的結果把關節髁頭的形態分為以下幾類：type 0：正常的關節髁頭，具完整且圓滑的外形，且有緻密的皮質骨。type 1：骨頭的破壞在關節髁頭的前上方。type 2：骨頭的破壞在關節髁頭的上方 ( 超過中心點即成立 )。type 3：骨頭的破壞在關節髁頭的後上方。受試者同時也接受動態磁振攝影的檢查，藉此檢查把關節髁頭和關節盤之間在最大開口時的關係分為以下幾類：C-position 0：關節髁頭和關節盤在運動過程中沒有卡住，即正常。C-position 1: 關節髁頭和關節盤在運動時互相接觸( 即卡住 )的位置，是在關節髁頭的前方。C-position 2: 關節髁頭和關節盤在運動時互相接觸( 即卡住 )的位置，是在關節髁頭的上方。( 接觸的地方超過關節髁頭的中心點即成立 )。 同時我們也把關節髁頭和隆凸 ( eminence ) 之間在最大開口時的關係做一個分類：E-position 1: 在最大開口時，關節髁頭能夠運動到超過隆凸的頂點。E-position 2: 在最大開口時，關節髁頭能夠運動到剛好達到隆凸的頂點。E-position 3: 在最大開口時，關節髁頭無法運動到超過隆凸的頂點。再對關節髁頭的形態、關節髁頭和關節盤在最大開口時的相關位置、及關節髁頭和隆凸在最大開口時的相對位置，這三個變項彼此間分別採用Marginal model，並使用GEE (generalized estimating equation)方法做係數估計。
從中選了六個病人中的九個顳顎關節，經過至少半年的觀察，這九個關節都是於第一次掃描時呈現type 0的關節髁頭，而且關節髁頭和關節盤在運動時的相關位置則是C-position 1，或是C-position 2。
在經過至少半年的追蹤之後，病人同樣接受靜態磁振攝影以及動態磁振攝影的檢查。比較受試者前後兩次檢查的結果，即可得到一個受時間因素影響的結果。且為了去除MRI 攝影時可能在兩次角度有所不同、兩次斷面可能也不一致的變項，將兩次的影像做3D重組，再利用重組之後的影像，來比較半年多來的變化。
希望藉由以上的研究，證明或推翻假設：關節髁頭在經過退化性關節炎的影響之後，其形態上的變化，是受關節盤和關節髁頭在最大開口時的相對關係所影響。
結果：
關節髁頭形態為type 1 這一組中，有58個關節盤相關位置是C-position 1，而沒有一個關節盤相關位置是C-position 2；而在關節髁頭形態為type 2 這一組當中有69個關節盤位置是C-position 2，而有3個關節盤位置是C-position 1。這代表著關節髁頭形態大致是和關節盤所接觸到的位置是一致的。
關節髁頭形態為type 1 的有19個在最大開口時關節髁頭能夠運動至超過隆凸頂點；有9個最大開口時關節髁頭能夠運動至剛好隆凸頂點的位置；有30個最大開口時關節髁頭無法運動至隆凸頂點的位置。而在關節髁頭形態為type 2 的有31個在最大開口時關節髁頭能夠運動至超過隆凸頂點；有31個最大開口時關節髁頭能夠運動至剛好隆凸頂點的位置；有10個最大開口時關節髁頭無法運動至隆凸頂點的位置。由以上的數據看來，關節髁頭形態為type 1的，其活動度會比關節髁頭形態為type 2的來的小。
在關節髁頭和關節盤在運動時的相關位置是C-position 1 的有20 個在最大開口時關節髁頭能夠運動至超過隆凸頂點；有19個最大開口時關節髁頭能夠運動至剛好隆凸頂點的位置；有42個最大開口時關節髁頭無法運動至隆凸頂點的位置。在關節髁頭和關節盤在運動時的相關位置是C-position 2 的有32 個在最大開口時關節髁頭能夠運動至超過隆凸頂點；有31個最大開口時關節髁頭能夠運動至剛好隆凸頂點的位置；有8個最大開口時關節髁頭無法運動至隆凸頂點的位置。由以上的數據看來，關節髁頭和關節盤在最大開口時的相關位置是C-position 1的，其活動度會比關節髁頭和關節盤在最大開口時的相關位置是C-position 2的來的小。
有四個關節第一次MRI檢查時關節髁頭和關節盤在最大開口時的相關位置為C-position 1，而在經過了至少半年的期間，其關節髁頭的形態則由type 0變成了type 1。
有一個關節在第一次MRI檢查時關節髁頭和關節盤在最大開口時的相關位置為C-position 1，而在經過了至少半年的期間，其關節髁頭的形態則沒有變。
有兩個關節第一次MRI檢查時關節髁頭和關節盤在最大開口時的相關位置為C-position 2，而在經過了至少半年的期間，其關節髁頭的形態則沒有變。
有一個關節第一次MRI檢查時關節髁頭和關節盤在運動時的相關位置為C-position 2，而在經過了至少半年的期間，其關節髁頭的形態則由type 0變成了type 2。
有一個關節在第一次MRI檢查時關節髁頭和關節盤在最大開口時的相關位置為C-position 1，而在經過了至少半年的期間，其關節髁頭的形態則由type 0變成了type 3。
所有有變化的關節在第一次掃描時都是E-position 2或 E-position 3。
結論：
對於顳顎關節盤前置異位且不可復位的關節，當關節活動度受到限制時，關節髁頭的形狀會有所改變，其關節髁頭的變化區域是和關節髁頭與關節盤所接觸到的位置一致。關節盤如果接觸到關節髁頭的前方，則關節活動度較小；同樣的，關節髁頭的變化如果是在前方，其關節活動度也較小。

關鍵字

顳顎關節內部紊亂之預後因素 ； 接觸力學

並列摘要

Objectives:
Clinically there exist huge variations of manifestations and prognoses associated with TMJ disc anterior displacement without reduction. The condyles of these TMJs also often show different degrees and patterns of remodeling/destruction revealed by the MRI. We are interested in knowing what kinds of factors affecting such morphological changes and whether such morphological changes are related to the prognosis. In this study both static and dynamic TMJ MRI were used to investigate the spatial and contact relationship among the disc/condyle/eminence complexes during mouth opening of the closed locked TMJs. We also performed longitudinal MRI studies of several closed locked TMJs to reveal the morphological changes over time.

Materials and Methods:
From the image database of the TMD and orofacial pain clinic, National Taiwan University Hospital, MRI of 88 patients (6 male, 82 female, mean age of 23.2 years old at the scanned time), from whom at least one TMJ was diagnosed as disc anterior displacement without reduction revealed by MRI, were included for the analyses.

According to the static images, morphologies of the condyles were classified as following: type 0: normal condylar form, i.e. convexly rounded, covered by thin cortical bone; type 1: the bony destruction/change was occurred on the anterior slope of the condyle; type 2: the bony destruction/change was occurred on the top of the condyle; and type 3: the bony destruction/change was occurred on the posterior condylar slope.

According to the dynamic scans, the disc/condyle relationship at the end of the allowed maximal mouth opening was classified as following: C-position 0: the condyle was stayed underneath the disc, i.e. not locked or with reduction; C-position 1: the disc was not reduced and the condyle met the non-reduced disc on the anterior slope of the condyle; and C-position 2: the disc was not reduced and the condyle met the non-reduced disc on the top of the condyle.

Also based on the dynamic scans, the condyle/eminence relationship at the end of the allowed maximal mouth opening was classified as following: E-position 1: the condyle could move beyond the vertex of the eminence; E-position 2: the condyle just reached to the vertex of the eminence; and E-position 3: the condyle was not able to reach the vertex of the eminence.

The association among the condylar morphology (type), C-position, and E-position were then tested by using the GEE (generalized estimating equation) Marginal model.

Nine TMJs, which were shown as type 0, C-position 1 or C-position 2 with the first scan were selected to have the second MRI study with the time interval of at least 6 months. The classification of type, C-position and E-position from the second MRI scans were also performed. 3D reconstruction of the codyles derived from both scans were performed and used to reveal the morphological changes between two scans.

Results:
Part I

For those condyles with type 1 morphology, 58 of them were classified as C-position 1 and none of them were C-position 2. For those type 2 condyles, 69 of them were C-position 2 and 3 were C-position 1. These results showed that the condyle morphology and the contact between disc/condyle complexes were associated.

For those type 1 condyles, 19 were classified as E-position 1, 9 were E-position 2, and 30 were E-position 3. For those type 2 condyles, 31 were classified as E-position 1, 31 were E-position 2, and 10 were E-position 3. These results seemed to indicate that the condylar mobility of the type 1 condyles was smaller than the type 2 condyles.

For those TMJs classified as C-position 1, 20 were classified as E-position 1, 19 were E-position 2, and 42 were E-position 3. For those TMJs classified as C-position 2, 32 were E-position 1, 31 were E-position 2, and only 8 were E-position 3. These results seemed to indicate that the condylar mobility of the TMJs with C-position 1 was smaller than that of the C-position 2 TMJs.

Part II

For the 9 TMJs (all were type 0 in the first scan) included for longitudinal study, 6 of them were classified as C-position 1 and 3 were classified as C-position 2 in the first scan.

Four of 6 TMJs with C-position 1, the condylar morphology was changed from type 0 into type 1, 1 was changed form type 0 into type 3, and 1 remained unchanged in the second scan.

Two of the TMJs with C-position 2 in the first scan, the condylar morphology was unchanged, and 1 was changed into type 2 in the second scan.

All TMJs showed morphological changes between the first and second scans were classified to be E-position 2 or E-position 3 in the first scan.

Conclusion:
For temporomandibular joints with disc anterior displacement without reduction, when their condylar mobility was limited (E-position 2 or E-position 3), their condylar morphology would be very likely changed over time. Once the condylar morphology changed, where the condyle deformed seemed to in accordance with where the contact occurred of the disc/condyle complex near the end of the allowed maximal opening (C-position). For those TMJs, if the condyles contacted the non-reduced disc on the top, their condylar mobility would be larger than those having contact on the anterior slope.

並列關鍵字

A Prognostic Factor of TMJ Internal Derangement ； Contact Mechanics

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