The community structure and ecological function of marine ecosystems are critically dependent on phytoplankton. However, our understanding of phytoplankton is limited due to the lack of detailed information on their morphology. To address this gap, we developed a framework that combines scanning electron microscopy (SEM) with photogrammetry to create realistic 3D (three-dimensional) models of phytoplankton. The workflow of this framework is demonstrated using two marine algal species, one dinoflagellate Prorocentrum micans and one diatom Halamphora sp. The resulting 3D models are made openly available and allow users to interact with phytoplankton and their complex structures virtually (digitally) and tangibly (3D printing). They also allow for surface area and biovolume calculations of phytoplankton, as well as the exploration of their light scattering properties, which are both important for ecosystem modeling. Additionally, by presenting these models to the public, it bridges the gap between scientific inquiry and education, promoting broader awareness on the importance of phytoplankton.

In recent years, illegal felling of and damage to the incense tree Aquilaria sinensis (Lour.) Spreng. have been reported in Hong Kong. Their native populations are under increasingly severe threat. Therefore, the development of a standard and efficient method to classify and document wounds on vulnerable trees is urgently needed for conservation purposes. In this study, photogrammetry was used to document wounds in A. sinensis through 3D modeling. A total of 752 wound records from 484 individual A. sinensis trees from Hong Kong were included to establish a new wound classification system. Our major findings include a novel standardized procedure for photogrammetric documentation and a wound classification system. The results of this study will facilitate A. sinensis conservation, by enhancing wound documentation and information transfer to law enforcement and education.

BACKGROUND: The reliability and repeatability of stereophotogrammetry and CT in 3-dimensional anthropometric facial analysis were investigated in this study, which also explored the clinical application of supine CT.
METHODS: In this study, 3D CT and 3dMD stereophotogrammetry were used on 20 healthy volunteers. The fitting distance between stereophotogrammetry and CT scans at landmark points was measured, along with facial feature measurements (Al-Al) face width (Go-Go, Zy-Zy, Ex-Ex), and hemi-face height (Sn-Gn). The intraclass correlation coefficient (ICC) was employed to assess interrater agreement and to verify the reliability of the measurement methods. Paired t -analysis was utilized for analyzing intramethod displacement.
RESULTS: The alare, nasion, and pronasale points were found to be minimally influenced by different positions and are more recommended as landmark points for registration. CT demonstrated good interrater reliability on all indicators. In stereophotogrammetry, measurements for Go-Go and Zy-Zy displayed an interclass correlation coefficient (ICC) of less than 0.75. Significant differences between the 2 methods were observed for En-En, Ex-Ex, and Go-Go ( P < 0.05). Specifically, CT analysis for Go-Go showed a measurement 2.34 mm larger than that obtained with the 3dMD method.
CONCLUSIONS: Both CT and stereophotogrammetry were found to be reliable methods for evaluating facial soft tissue. It is speculated that Go-Go measurement is primarily influenced by factors such as different positions, facial expressions, and gravity. These variables should be carefully considered during the evaluation of the mandibular angle region.

With the rapid development of implant techniques and digital technology, digital impressions have become a commonly used impression method in implant restoration. At present, the accuracy of intraoral digital impressions directly applied to implant-supported full-arch prostheses remains inadequate, which is due to the high accuracy requirement of full-arch implant impressions, while there are still technical challenges in intraoral digital impressions about recognition and stitching. In this regard, scholars have proposed a variety of scanning strategies to improve the accuracy of intraoral scan, including mucosal modifications, auxiliary devices and novel scan bodies. At the same time photogrammetry, as a new digital impression technique, has been developing steadily and exhibits promising accuracy. This article reviews the research progress on the accuracy of edentulous full-arch implant impressions and techniques which can improve the accuracy of intraoral digital impressions, to provide reference for clinical application.
随着种植技术和数字化技术的快速发展，口内数字化印模已是口腔种植修复中常用的印模方法。目前，口内数字化印模直接应用于无牙颌患者种植修复的准确性尚有所缺欠，这是由于无牙颌种植印模的准确性要求较高，而口内数字化印模尚存在识别和拼接的技术难点。对此，学者们提出了多种优化扫描策略的方法，如黏膜修饰法、辅助结构法、改良扫描杆法等，可在一定程度上提高无牙颌种植口内数字化印模的准确性。同时，立体摄影法作为一种新兴的数字化印模方法正逐步发展成熟，准确性良好。本文从无牙颌种植修复口内数字化印模的准确性研究现状出发，综述了提高无牙颌种植口内数字化印模准确性的策略，以期为临床应用提供参考。.

OBJECTIVE: The purpose of this in vitro study was to compare the trueness and precision of complete arch implant impressions using conventional impression, intraoral scanning with and without splinting, and stereophotogrammetry.
METHODS: An edentulous model with six implants was used in this study. Four implant impression techniques were compared: the conventional impression (CI), intraoral scanning (IOS) without splinting, intraoral scanning with splinting (MIOS), and stereophotogrammetry (SPG). An industrial blue light scanner was used to generate the baseline scan from the model. The CI was captured with a laboratory scanner. The reference best-fit method was then applied in the computer-aided design (CAD) software to compute the three-dimensional, angular, and linear discrepancies among the four impression techniques. The root mean square (RMS) 3D discrepancies in trueness and precision between the four impression groups were analyzed with a Kruskal-Wallis test. Trueness and precision between single analogs were assessed using generalized estimating equations.
RESULTS: Significant differences in the overall trueness (p = .017) and precision (p < .001) were observed across four impression groups. The SPG group exhibited significantly smaller RMS 3D deviations than the CI, IOS, and MIOS groups (p < .05), with no significant difference detected among the latter three groups (p > .05).
CONCLUSIONS: Stereophotogrammetry showed superior trueness and precision, meeting misfit thresholds for implant-supported complete arch prostheses. Intraoral scanning, while accurate like conventional impressions, exhibited cross-arch angular and linear deviations. Adding a splint to the scan body did not improve intraoral scanning accuracy.

BACKGROUND: In East Asian individuals, the nasal bone already has sufficient height for an ideal dorsal profile, but the tip requires enhancement for a desired projection. Consequently, the gap between the intrinsic bony structure and the established nasal tip requires appropriate management. The options are either to reduce the keystone region to create a smooth bed for a conventional dorsal onlay graft or to preserve the original osseocartilaginous structures and then customize a supplementary graft. The aim of this study was to detail and validate the utilization of a relay graft, a transition graft that fills the structural gap between the upper dorsum and established tip graft. The proper application of this graft could prevent osteotomy and preserve the intrinsic dorsum.
METHODS: Relay grafts were applied during rib-based rhinoplasty in East Asian patients. Three-dimensional stereophotogrammetric evaluations of the patients were performed. Anthropometric points were analyzed in a blinded fashion. Outcome variables were tip projection improvement, radix elevation, and the angulation of kyphion and pronasale.
RESULTS: Fifteen female patients, ranging in age from 21 to 40 years (average 24.5 years), were included. In all cases, the relay graft was applied as one essential element for filling the structural gap. No crooked dorsal profile or visible graft was noted in all cases. Fifteen patients completed the pre- and postoperative stereophotogrammetric study. Postoperative analysis showed great improvement of tip position as well as a slight elevation of the radix, evidenced by the consistent change of kyphion/pronasale angulation and sellion elevation.
CONCLUSIONS: The relay graft effectively mitigates the necessity of a disruptive dorsal reduction. It is entirely possible for East Asians to achieve a smooth dorsal profile when only the lower half of the dorsum is transitioned to the proposed tip position.
METHODS: Level IV, case series.

OBJECTIVE: The re-measurement of full-arch implant digital impressions is an important step in denture restoration. This paper provides an efficient oral photogrammetry technology using projective invariant marker, applied in the re-measurement of full-arch implant digital impressions.
METHODS: We have developed a self-recognizing marker with projection invariance, along with its detection code. The marker is installed on the scanning body and used for photogrammetric measurements. Triangulation is utilized to determine the 3D coordinates of the marker, followed by a series of post-processing steps to obtain more accurate 3D coordinates.
RESULTS: The experimental data indicate that the optimal working distance is between 200 and 250 mm, with a minimum measurement error of less than 0.05 mm and an average measurement error of 0.10 mm. The measurement time is less than 2 min.
CONCLUSIONS: The experimental results show that the photogrammetric system can obtain reliable positions of full-arch implants with efficient photogrammetry, without the need to enter the patient\'s oral cavity, and has potential clinical application value.

BACKGROUND: Microform cleft lip is the mildest type of cleft lip without obvious defects of the upper lip. The nose deformities of microform cleft lip include flattened nostril rim, alar base asymmetry, and septal deviation. A hidden skin incision with nasal base muscle reconstruction was introduced in nose deformities of microform cleft lip.
METHODS: To investigate the operative effect, we reviewed 21 patients with microform cleft lip treated with a hidden skin incision with nasal base muscle reconstruction from May 2020 to October 2022. Photogrammetric nasal morphometric measurements were compared preoperatively and six months postoperatively. The proportional value was obtained from the cleft and the noncleft sides, and paired t-test analysis was used to evaluate the surgical outcome.
RESULTS: Significant differences were found in all nasal morphologic measurements at 6 months postoperatively compared to preoperatively (p < 0.05). After surgery, the alar base and nostril were narrowed, while the lateral lip height was increased on the affected side. The height of the nostrils on the affected side was increased, and the nasal columella deviation was released. In addition, the ratio of the cleft-to-noncleft nostril area was closer to 1.0 after surgery.
CONCLUSIONS: The unilateral microform cleft lip nasal deformity can be repaired through a small hidden incision.
METHODS: This journal requires that authors assign a level of evidence to each article. For a full description of these evidence-based medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

OBJECTIVE: This study aimed to develop a structured light scanning system with a planar mirror to enhance the digital full-arch implant impression accuracy and to compare it with photogrammetry and intraoral scanner methods.
METHODS: An edentulous maxillary stone cast with six scan bodies was scanned as the reference model using a laboratory scanner. Three scanning modalities were compared (n = 10): (1) self-developed structured light scanning with a mirror (SSLS); (2) intraoral scanner (IOS); and (3) photogrammetry system (PG). The scanners were stopped for 1 min after each scan. Six scan bodies were analysed within each scan model. Linear deviations between the scan bodies (1-2, 1-3, 1-4, 1-5, and 1-6) and 3D mucosal deviations were established. The overall deviation was calculated as the mean of all linear deviations. \"Trueness\" represented the discrepancy between the test and reference files, while \"precision\" denoted the consistency among the test files. Kruskal-Wallis and Mann-Whitney U tests were used for statistical analyses.
RESULTS: Significant overall linear discrepancies were noted among the SSLS, PG, and IOS groups (p < .001). SSLS showed the best overall trueness and precision (6.6, 5.7 μm), followed by PG (58.4, 6.8 μm) and IOS (214.6, 329.1 μm). For the 3D mucosal deviation, the trueness (p < .001) and precision (p < .001) of the SSLS group were significantly better than those of the IOS group.
CONCLUSIONS: The SSLS exhibited higher accuracy in determining the implant positions than the PG and IOS. Additionally, it demonstrated better accuracy in capturing the mucosa than IOS.

BACKGROUND: Three-dimensional (3D) stereophotogrammetry has been widely used in anthropometry for both medical and esthetic purposes. However, no studies have assessed its reliability on measuring the lower eyelid by 3D imaging. This study aimed to establish a standardized 3D anthropometric protocol for lower eyelid region and validate its reliability.
METHODS: Fifty-eight participants (116 eyes) were recruited with mean age of 39.14 ± 11.25 years. Two sets of VECTRA 3D images were taken for each subject, and each set of images was individually measured twice by two raters. Twenty-seven landmarks were identified in the lower eyelid region, and then 19 linear, 4 curvilinear, 7 angular and 2 areal metrics were assessed for intrarater, interrater and intramethod reliability.
RESULTS: High reliability was found in this 3D imaging-based lower eyelid anthropometry. The mean absolute difference within 2 intrarater measurement were 0.22 and 0.08 units, the technical errors measurement were 0.31 and 0.15 units, the relative errors of measurement were 0.90% and 0.31%, the relative technical errors of measurement were 1.53% and 0.64%, and the intra-group correlation coefficient was 0.99 and 0.99. The results for interrater measurement were 0.53 units, 0.59 units, 2.94%, 3.41% and 0.96, and for intramethod measurement were 0.71 units, 0.77 units, 4.12%, 4.05% and 0.95 units, respectively.
CONCLUSIONS: 3D stereophotogrammetry is reliable for lower eyelid anthropometry. The standardized protocol can be further applied for many purposes such as lower eyelid aging evaluation, surgical related assessment and periocular rejuvenation plan.
METHODS: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .