下顎舌側及唇側前庭的研究調查

隨著醫學進步，人類生命延長，相對地，老年人口比例就越來越高，傳統全口義齒地製作就越見普遍，然而，對一個補綴科醫師而言，如何讓傳統全口義齒有很好的固位性、穩定性，常是充滿挑戰的，尤其是下顎全口活動義齒的製作比上顎義齒更困難，主要的原因是下顎的主要支持區(primary stress bearing area)的範圍只有上顎的45%，再加上舌和口底的活動，不容易建立理想的邊緣封閉性( peripheral sealing )。尤其是下顎齒嵴吸收嚴重的狀況下，要做出一個穩固的義齒更不容易，因此熟悉解剖構造並善用之，是做好義齒的基本條件。一直以來，有許多的學者著重研究在下顎義齒的頰側邊緣(buccal vestibule)延伸的寬度和長度以增加假牙支持力，還有舌側遠心處的假牙邊緣(distolingual flange) 型態和深度延伸以增進假牙固位性，但對於前方假牙邊緣延伸之研究較少。然而，若能有效地利用下顎前方唇側和舌側的前庭深度，應該是可以增進義齒的周圍封閉性，以及提升義齒的前方固位力(anterior retention)，但這個部位卻很容易被臨床醫師所忽略。 Roberto認為義齒的舌下邊緣延伸(sublingual flange extension)善加利用是有助於改善全口下顎義齒的固位性和穩定性，原因是適度的延伸可以增加組織和義齒的接觸面積，增大黏著性(adhesion)；同時也可以配合舌的運動去維持住下顎義齒增進假牙的穩定性。本研究的目的有二：一方面是評估一般牙科診所所製作的全口義齒在下顎前方唇側及舌側邊緣的長度和口內下顎前方前庭深度是否有差異，此外，再探討適度的增加下顎前方舌側假牙邊緣的深度和寬度，對於假牙固位性(retention)的影響。此研究是針對275位在一般牙科診所製作全口假牙的患者進行測量。測量內容包括受測者口腔內解剖構造和下顎全口義齒結構兩部分，分別測量口內及義齒之五個參考點 (中間參考點（Ｍ）相對於唇繫帶（labial frenum）卅舌繫帶（lingual frenum）附著點的齒脊上，以此為基準向左側５ｍｍ定之為參考點L1，再向左10ｍｍ定之為參考點L2;中間參考點向右側５mm定之為參考點R1，再向右側10mm定之為參考點R2)的唇側及舌側前庭深度和義齒深度，再利用牙周探針測量深度並記錄之。接著從中選出66位受測者。利用green compound增加假牙前方舌側的深度及寬度，利用牙周探針記錄調整前後深度的變化，利用Boley gauge測量調整前後寬度的變化，再用strain gauge測量調整前後固位力的差異。在下顎唇側前庭的深度方面，結果發現下顎唇側前庭區域於M點的平均深度是7.6mm;在L1點的平均深度是8.4mm;在L2點的平均深度是8.6mm;在R1點的平均深度是8.5mm;在R2點的平均深度是8.6mm，而相對應位置的義齒唇側凸緣(flange)，測量的深度都比口內測量的深度來得短。在下顎舌側前庭的深度方面，下顎舌側前庭區域在M點平均深度是7.4mm；在L1點的平均深度是8.1mm；在L2點的平均深度是8.5mm；在R1點的平均深度是8.2mm；在R2點的平均深度是8.5mm，而相對應位置的義齒舌側凸緣(flange)所測量的深度都比口內側得的深度少。由結果發現一般牙醫診所所製作的全口義齒在下顎前方舌側或唇側邊緣的深度與口內相對位置實際的深度有顯著性的差異;故建議臨床牙醫師可以使用牙周探針來測量前庭深度，有助於個人牙托製作的精準性,也可以減少假牙裝戴後調整的時間和精力。此外，在義齒固位力的測量發現，將舌側邊緣加寬加深的結果確實有助於義齒固位力的提升，而且現有義齒裝戴超過5年者，義齒固位力會有統計上顯著的減少。

關鍵字

下顎義齒；固位力；舌側前庭；下顎唇側前庭

並列摘要

The mandibular lingual/labial vestibule is the area bounded by the alveolar gingiva, the lip, the buccal frenum, and the floor of mouth. When fabricating a mandibular denture, the lingual/labial flange of the denture should fit into this space. It can then enhance the border seal of the dentures and increase retention. The lingual/labial flange has a profound influence on the fabrication of complete denture but is usually not faced squarely by the clinicians. The aim of this study was to identify whether there is a significant difference between the depths and widths of the lingual/labial vestibule and the corresponding portions of mandibular complete dentures from the dental clinics of general dentists. In addition, to analyze the sublingual extension and its relation to the retention of mandibular complete denture. More two hundred patients were measured in M point ( near labial/lingual frenum ), L1 ( left to M point 5 mm ), L2 (left to M point 10 mm ), R1(right to M point 5 mm), and R2(right to M point 10 mm) depths of the lingual/labial vestibule with a periodontal probe . This measurement was then made with that of the corresponding portion of the existing denture. The mean depth of the M point labial vestibule is about 7.6 mm, the L1 portion is about 8.4 mm, the L2 portion is about 8.6 mm, the R1 portion is about 8.5 mm, and the R2 portion is about 8.6 mm. The mean depth of the M point lingual vestibule is about 7.4 mm, the L1 portion is about 8.1 mm, the L2 portion is about 8.5 mm, the R1 portion is about 8.2 mm, and the R2 portion is about 8.5 mm. At each portion, there is a statistical significant difference in the depths of the lingual and labial vestibule and that of the corresponding portion of the existing denture. There is not a significant difference between the depths of the lingual and labial vestibule and the corresponding portions of mandibular dentures from dental clinics of general dentists. Therefore, we suggest that the clinicians could use the periodontal probe to measure the depth of the lingual and labial vestibule to help fabricating the dentures. And we found it could improve the retention of mandibular denture to extend the length and width of lingual flange. Besides, there is a significant statistically difference between the duration of the present lower denture to use and the retention of mandibular dentures.