Ladha Komal G, Gill Shubhra, Gupta Rekha, Verma Mahesh, Gupta Meena
Department of Prosthodontics, ESIC Dental College and Hospital, New Delhi, India.
Department of Prosthodontics, Maulana Azad Institute of Dental Sciences, New Delhi, India.
J Prosthodont. 2013 Oct;22(7):566-574. doi: 10.1111/jopr.12055. Epub 2013 May 31.
Several studies have evaluated electromyographic (EMG) activity of perioral muscles in patients using unsatisfactory old complete dentures and after the insertion of new clinically acceptable dentures; however, studies evaluating EMG activity of orbicularis oris (OO) and buccinator (BUC) muscles in patients wearing complete dentures fabricated using swallowing (SNZ) and phonetic neutral zone (PNZ) techniques are lacking in the literature. The purpose of this study was to evaluate differences in muscle activity of the superior orbicularis oris (SOO), inferior orbicularis oris (IOO) and BUC muscle during the use of unsatisfactory old complete dentures, in comparison with the satisfactory dentures fabricated using the two neutral zone techniques.
Ten completely edentulous participants dissatisfied with their existing mandibular complete dentures participated in the study. Each patient received two sets of new dentures fabricated using the SNZ and PNZ techniques. Surface EMG activity of the OO and BUC muscles was recorded using a 4-channel Medelec premier plus electromyography machine while the patients still used their old dentures (group A) and with the SNZ (group B) and PNZ (group C) dentures. On the basis of participation in the study, five participants first received the SNZ dentures and five the PNZ type. After having worn the prosthesis for a minimum of 2 months, EMG recordings were repeated for the first set of dentures. The prostheses were then changed and the procedures repeated. The activity of OO and BUC muscles was recorded at rest, while pursing and laughing, and during pronunciation of various syllables. Results are expressed as mean ± SD and as absolute numbers and percentage. ANOVA with appropriate correction (Bonferroni or Tamhane) and Student's t-test were used for statistical analysis. A p-value < 0.05 was taken to indicate a significant difference.
There was no statistically significant difference in the mean EMG activity of SOO, IOO, and BUC muscles at rest, or during pursing or laughing among the three groups. No significant difference was observed in the mean EMG activity of SOO and BUC muscle among the groups for all the syllables pronounced. For IOO, a statistically significant difference was observed among the groups for the words "baby" and "cheese." Within-group comparisons of the mean EMG activities of SOO and IOO during pronunciation and pursing showed no significant difference; however, at rest a statistically significant difference was observed in group B.
OO and BUC muscle activities did not significantly differ, irrespective of the technique used for fabrication of complete dentures.
多项研究评估了佩戴效果不佳的旧全口义齿患者以及佩戴新的临床可接受义齿后的口周肌肉肌电图（EMG）活动；然而，文献中缺乏对使用吞咽中性区（SNZ）和语音中性区（PNZ）技术制作全口义齿患者的口轮匝肌（OO）和颊肌（BUC）肌电图活动的评估。本研究的目的是评估使用效果不佳的旧全口义齿时，与使用两种中性区技术制作的满意义齿相比，上唇口轮匝肌（SOO）、下唇口轮匝肌（IOO）和颊肌的肌肉活动差异。
10名对现有下颌全口义齿不满意的无牙颌参与者参与了本研究。每位患者接受了两套分别使用SNZ和PNZ技术制作的新义齿。使用4通道Medelec premier plus肌电图仪记录OO和BUC肌肉的表面肌电图活动，记录时间为患者仍佩戴旧义齿时（A组）、佩戴SNZ义齿时（B组）和佩戴PNZ义齿时（C组）。根据参与研究的情况，5名参与者先接受SNZ义齿，5名先接受PNZ义齿。在佩戴义齿至少2个月后，对第一套义齿重复进行肌电图记录。然后更换义齿并重复上述过程。记录OO和BUC肌肉在静息、噘嘴和大笑时以及发音不同音节时的活动。结果以平均值±标准差、绝对数和百分比表示。采用适当校正的方差分析（Bonferroni或Tamhane）和学生t检验进行统计分析。p值<0.05表示有显著差异。
三组患者在静息、噘嘴或大笑时，SOO、IOO和BUC肌肉的平均肌电图活动无统计学显著差异。在所有发音音节中，各组SOO和BUC肌肉的平均肌电图活动均未观察到显著差异。对于IOO，在“baby”和“cheese”这两个单词的发音中，各组间观察到统计学显著差异。组内比较发音和噘嘴时SOO和IOO的平均肌电图活动无显著差异；然而，在静息时，B组观察到统计学显著差异。
无论制作全口义齿使用何种技术，OO和BUC肌肉活动均无显著差异。
