Yi Fan

Peking University School of Stomatology · Orthodontics

Purpose: To evaluate the incidence and associated factors of pulmonary seed migration after parotid brachytherapy using a novel migrated seed detection technique. Methods and materials: Patients diagnosed with parotid cancer who underwent permanent parotid brachytherapy from January 2006 to December 2011 were reviewed retrospectively. Head and n...

Objectives:: To propose a reliable and practical method for automatically segmenting the mandible from CBCT images. Methods:: The marker-based watershed transform is a region-growing approach that dilates or 'floods' predefined markers onto a height map whose ridges denote object boundaries. We applied this method to segment the mandible from th...

Introduction This study aimed to develop an automatic pipeline for analyzing mandibular shape asymmetry in 3-dimensions. Methods Forty patients with skeletal Class I pattern and 80 patients with skeletal Class III pattern were used. The mandible was automatically segmented from the cone-beam computed tomography images using a U-net deep learning n...

Background Assessment of growth-related or treatment-related changes in the maxilla requires a reliable method of superimposition. Such methods are well established for two-dimensional (2D) cephalometric images but not yet for three-dimensions (3D). The aims of this study were to identify natural reference structures (NRS) for the maxilla in growin...

Background The determining effect of facial hard tissues on soft tissue morphology in orthodontic patients has yet to be explained. The aim of this study was to clarify the hard-soft tissue relationships of the lower 1/3 of the face in skeletal Class II-hyperdivergent patients compared with those in Class I-normodivergent patients using network ana...

Segmentation of the masseter muscle (MM) on cone-beam computed tomography (CBCT) is challenging due to the lack of sufficient soft-tissue contrast. Moreover, manual segmentation is laborious and time-consuming. The purpose of this study was to propose a deep learning-based automatic approach to accurately segment the MM from CBCT under the refineme...

Introduction To objectively quantify nasal characteristics of patients with asymmetric mandibular prognathism and to evaluate the association between nasal asymmetry and dentofacial abnormalities. Methods Ninety adult patients with asymmetric mandibular prognathism were included. Images were captured during pretreatment using 3-dimensional stereop...

Brachytherapy has the advantages of being minimally invasive and highly conformal, and it achieves good results in head and neck tumors. To precisely implant the radioactive seeds according to the preplan in deep head and neck regions, the surgical navigation is applied. This study aims to explore the clinical application and accuracy of imaging-ba...

Objectives to evaluate three-dimensional postsurgical stability of surgery-first approach with 2-jaw surgery and maxillary premolar extraction in skeletal class III patients and excavate factors influencing the relapse. Material and methods 24 patients were enrolled in this prospective cohort study. Serial cone-beam computer tomography images were...

Purpose: To apply geometric morphometrics and multivariate statistics to evaluate changes of the face for female Chinese patients who underwent orthodontic treatment with different type of anchorage control. Methods: Forty-six adult female patients were enrolled including 33 four first premolars extraction cases (17 patients with mini-implants f...

The lateral cephalogram (LC)-based volumetric image estimation is feasible to relieve the hazardous radiation exposure and study patient-specific 3D morphology of craniofacial structures in clinical orthodontics. The deep learning-based approach has potential in volumetric reconstruction of computed tomography in recent years. However, existing wor...

Objectives: Palatal shape contains a lot of information that is of clinical interest. Moreover, palatal shape analysis can be used to guide or evaluate orthodontic treatments. A statistical shape model (SSM) is a tool that, by means of dimensionality reduction, aims at compactly modeling the variance of complex shapes for efficient analysis. In th...

Objective Quantification and visualization of the location and magnitude of facial asymmetry is important for diagnosis and treatment planning. The objective of this study was to analyze the asymmetric features of the face for skeletal Class III patients using spatially-dense geometric morphometrics. Methods Three-dimensional facial images were ob...

Objectives To develop and evaluate a geometric deep-learning network to automatically place seven palatal landmarks on digitized maxillary dental casts. Settings and Sample population The sample comprised individuals with permanent dentition of various ethnicities. The network was trained from manual landmark annotations on 732 dental casts and ev...

A seed-loading device was designed and modeled using the Monte Carlo method to verify the biological effect of iodine-125 (125I) particles on blood vessels through animal experiments. The dose distribution characteristics of irradiated vessels were established by adjusting the design variables and geometry. The deviation between the actual value an...

Purpose: The purpose of this study was to characterize the facial morphology of Chinese children with hypohidrotic ectodermal dysplasia (HED) and quantify facial changes after prosthetic treatment. Methods: 3-D facial images of 12 HED children were taken and their facial morphology was compared against 28 healthy controls. Facial changes due to de...

Abstract Background A functional appliance is commonly used to optimize the development of the facial skeleton in the treatment of Class II malocclusion. Recent three-dimensional(3D) image-based analysis offers numerous advantages in quantitative measurement and visualization in orthodontics. The aim of this study was to localize in 3D the skeletal...

Dense surface registration, commonly used in computer science, could aid the biological sciences in accurate and comprehensive quantification of biological phenotypes. However, few toolboxes exist that are openly available, non-expert friendly, and validated in a way relevant to biologists. Here, we report a customizable toolbox for reproducible hi...

Objectives: The aim of the present study was to use Fourier analysis to quantify and study age-related changes in midsagittal facial profile. Materials and methods: Midsagittal facial profiles were extracted as lists of x and y coordinates from 125 pairs of 3D facial scans captured at an average of 10.5 years apart for adult Japanese males aged...

In the post-genomics era, an emphasis has been placed on disentangling 'genotype-phenotype' connections so that the biological basis of complex phenotypes can be understood. However, our ability to efficiently and comprehensively characterize phenotypes lags behind our ability to characterize genomes. Here, we report a toolbox for fast and reproduc...

Objectives: To propose a reliable and practical method for automatically segmenting the mandible from low-dose CBCT images. Methods: The marker-based watershed transform is a region-growing approach that dilates or 'floods' predefined markers onto a height map whose ridges denote object boundaries. We applied this method to segment the mandible fro...

Many disorders present with characteristic abnormalities of the craniofacial complex. Precise descriptions of how and when these abnormalities emerge and change during childhood and adolescence can inform our understanding of their underlying pathology and facilitate diagnosis from craniofacial shape. In this paper we develop a framework for analys...

3D facial images are becoming increasingly common. They provide more information about facial form than their 2D counterparts and will be useful in future forensic applications. These include age estimation and predicting changes in appearance of missing persons (synthetic growth). We present a framework for both age estimation and synthetic growth...

Many disorders present with characteristic abnormalities of the craniofacial complex. Precise descriptions of how and when these abnormalities emerge and change during childhood and adolescence can inform our understanding of their underlying pathology and facilitate diagnosis from craniofacial shape. In this paper we develop a framework for analys...

3D facial images are becoming increasingly common. They provide more information about facial form than their 2D counterparts and will be useful in future forensic applications. These include age estimation and predicting changes in appearance of missing persons (synthetic growth). We present a framework for both age estimation and synthetic growth...

Congenital midline cervical cleft (CMCC) is a rare condition that consists of a cutaneous midline neck lesion with a sinus extending inferiorly towards the sternum. A fibrous band that extends superiorly to the mandible is a consistent feature of the condition. Restriction of growth of the mandible, possibly due to incomplete removal of the band, i...

To evaluate seed stability after permanent implantation in the parotid gland and periparotid region via a three-dimensional reconstruction of CT data. Material and methods Fifteen patients treated from June 2008 to June 2012 at Peking University School and Hospital of Stomatology for parotid gland tumors with postoperative adjunctive 125 I intersti...

Oral squamous cell carcinoma (OSCC) is predominantly a disease of middle-aged men with long-term exposure to tobacco and alcohol. An increasing trend has been reported at a younger age worldwide. Clinical records of 100 patients under the age of 45 years treated specifically for oral cavity SCC in our hospital during a 10-year period were retrospec...