Method for automatically extracting feature points of digital model of preoperative nasal-alveolar process appliance

Abstract

The invention discloses a method for automatically extracting feature points of a digital model of a preoperative nasal-alveolar process appliance. The method comprises the following steps: S1, acquiring an oral impression model file and preprocessing the oral impression model file; S2, performing coordinate system transformation on the preprocessed oral impression model; S3, performing segmentation processing on the oral impression model after coordinate system transformation; S4, performing two-dimensional plane projection on digital models of the alveolar bones on the two sides, and performing image fitting on the projected images of the alveolar bones on the two sides to obtain a fitting graph; and S5, performing side plane projection on the alveolar bones of the healthy side and the affected side according to the fitting graph, segmenting a ridge line according to the side plane projection, and extracting feature point coordinates according to the trend of the ridge line. Dimension reduction processing is performed on three-dimensional digital model data, and feature points are extracted by using image fitting and feature recognition technologies; the method can provide guidance for the design of a preoperative cleft lip and palate correction model, reduces the operation risk, improves the correction success rate, and has good commercial prospect and values.

Description

technical field [0001] The invention relates to the field of medical image processing, in particular to a method for automatically extracting feature points from a digital model of a preoperative nasal-alveolar process appliance. Background technique [0002] The preoperative nasal-alveolar appliance (PNAM) digital model is an orthodontic model for cleft lip and palate patients in infancy, which helps to reduce the difficulty of cleft lip and palate surgery, improve the effect of surgery, and reduce the number of operations. The PNAM model is stored using a 3D file with the suffix .stl, which contains a limited number of triangle faces. [0003] The feature points of the PNAM digital model refer to the feature points marked in order to evaluate the orthodontic effect of the PNAM digital model, which are the last points T and T' of the bilateral alveolar ridges, the buccal frenulum C on the healthy side, the buccal frenulum C' on the affected side, and the lip Lace I. In th...

AI Technical Summary

Problems solved by technology

[0004] The existing processing method for the digital model is to use engineering software to manually punctuate the 3D model, which is heavily dependent on the doctor's experience level, has a low degree of automation, poor accuracy, and cannot realize automatic extraction

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