Vinnakota Dileep Nag, Kanneganti Krishna Chaitanya, Pulagam Mahesh, Keerthi Gopala Krishna
Department of Prosthodontic Dentistry, Narayana Dental College and Hospital, Nellore, Andhra Pradesh, India.
J Indian Prosthodont Soc. 2016 Oct-Dec;16(4):323-327. doi: 10.4103/0972-4052.176531.
To hypothesize a new theory based on soft tissue reference points on lateral profile photographs (LPPs) for determining the vertical dimension of occlusion (VDO), as there is need to explore for simple strategies.
Fifty-three participants in the age range of 20-27 years who met the inclusion criteria were recruited. LPPs were taken for all participants using standard protocol and duplicate copies obtained, on which five soft tissue reference points, nasion (Stn), subnasale (Stsn), porion (Stp), gnathion (Stgn), and gonion (Stg) (Stg prenoted on the face) were marked and joined to form angles; distance between Stsn and Stgn was considered as VDO in LPP (VDO-LP). The angle formed between Stn-Stsn-Stgn and Stn-Stsn-Stg; Stp-Stg-Stgn and Stp-Stg-Stsn was correlated; two simple linear regression models were developed to predict Stn-Stsn-Stgn and Stp-Stg-Stgn using Stn-Stsn-Stg and Stp-Stg-Stsn as independent variables. Using the formulae, VDO-LP predicted was constructed and correlated with the actual values.
The angle Stn-Stsn-Stgn had a statistically significant moderate positive correlation with Stn-Stsn-Stg ( = 0.57, < 0.001) and angle Stp-Stg-Stgn, a significant strong positive correlation with Stp-Stg-Stsn ( = 0.81, < 0.001). Using simple linear regression analysis, the following formulae were obtained: Stn-Stsn-Stgn (in degrees) = 0.776 Stn-Stsn-Stg (in degrees) +79.01 and Stp-Stg-Stgn (in degrees) =1.331 Stp-Stg-Stsn (in degrees) +10.2. The predicted and actual VDO-L values were in strong positive correlation with a coefficient of 0.8.
With the use of simple landmarks on LPP, it is possible to reconstruct the lost facial dimensions during prosthetic replacement of lost teeth.
鉴于需要探索简单的策略，基于侧面轮廓照片（LPP）上的软组织参考点提出一种用于确定咬合垂直距离（VDO）的新理论。
招募了53名年龄在20至27岁之间符合纳入标准的参与者。使用标准方案为所有参与者拍摄LPP并获得副本，在其上标记五个软组织参考点，鼻根点（Stn）、鼻下点（Stsn）、耳点（Stp）、颏下点（Stgn）和下颌角点（Stg）（预先在面部标记Stg）并连接形成角度；将Stsn与Stgn之间的距离视为LPP中的VDO（VDO-LP）。分析Stn-Stsn-Stgn与Stn-Stsn-Stg之间形成的角度；Stp-Stg-Stgn与Stp-Stg-Stsn之间形成的角度的相关性；建立两个简单线性回归模型，以Stn-Stsn-Stg和Stp-Stg-Stsn作为自变量来预测Stn-Stsn-Stgn和Stp-Stg-Stgn。使用这些公式构建预测的VDO-LP并与实际值进行相关性分析。
角度Stn-Stsn-Stgn与Stn-Stsn-Stg具有统计学意义的中度正相关（ = 0.57，< 0.001），角度Stp-Stg-Stgn与Stp-Stg-Stsn具有显著的强正相关（ = 0.81，< 0.001）。通过简单线性回归分析，得到以下公式：Stn-Stsn-Stgn（度数） = 0.776 Stn-Stsn-Stg（度数） + 79.01，Stp-Stg-Stgn（度数） = 1.331 Stp-Stg-Stsn（度数） + 10.2。预测的和实际的VDO-L值具有强正相关，系数为0.8。
通过在LPP上使用简单的标志点，可以在缺失牙的修复性替换过程中重建丧失的面部尺寸。
