A comparative study of 3D measuring methods for monitoring breast volume changes.

Three-dimensional (3D) imaging techniques are promising new tools for measuring breast volume, for example in gender-affirming therapy. Transgender individuals can be treated with gender-affirming hormone therapy (GAHT). A robust method for monitoring breast volume changes is critical to be able to study the effects of feminizing GAHT. The primary aim of this study was to compare the accuracy of three 3D devices (Vectra XT, Artec LEO and iPhone XR) for measuring modest breast volume differences using a mannequin. The secondary aim of this study was to evaluate these methods in several performance domains. We used reference prostheses of increasing volumes and compared the volumes using GOM-inspect software. For Vectra XT 3D images, manufacturer-provided software was used to calculate volumes as well. The scanning methods were ranked based on their performance in a total of five categories: volume estimations, costs, user-friendliness, test subject-friendliness and technical aspects. The 3D models analyzed with GOM-inspect showed relative mean estimate differences from the actual volumes of 9.1% for the Vectra XT, 7.3% for the Artec LEO and 14% for the iPhone XR. For the Vectra XT models analyzed with the built-in software this was 6.2%. Root mean squared errors (RMSE) calculated based on the GOM-inspect volume analyses showed mean RMSEs of 2.27, 2.54 and 8.93 for the Vectra XT, Artec LEO and iPhone XR, respectively. The Vectra software had a mean RMSE of 3.00. In the combined performance ranking, the Vectra XT had the most favorable ranking, followed by the Artec LEO and the iPhone XR. The Vectra XT and Artec LEO are the preferred scanners to monitor breast development due to the combination of higher accuracy and overall performance. The current study shows that 3D techniques can be used to adequately measure modest breast volume differences and therefore will be useful to study for example breast changes in transgender individuals using feminizing GAHT. These observations may also be relevant in other fields of 3D imaging research.

Addition of progesterone to feminizing gender-affirming hormone therapy in transgender individuals for breast development: a randomized controlled trial.

BACKGROUND: Feminizing gender-affirming hormone therapy (GAHT) for transgender individuals traditionally includes estradiol and androgen deprivation. Research has demonstrated that breast size as a result of GAHT in transgender women is often limited. Therefore, transgender women often choose to undergo breast augmentation surgery. Progesterone is important for breast development in cisgender women during puberty. A potential role for progesterone in breast development in transgender women has not been investigated in a randomized controlled experimental set-up. The primary objective of this study is to explore the effects on breast volume of addition of oral progesterone to GAHT with estradiol in transgender women after vaginoplasty or orchiectomy. Secondary objectives include assessment of safety, satisfaction, mood, sleep and sexual pleasure. METHODS: This is a non-blinded, non-placebo, randomized controlled trial using a factorial design in adult transgender individuals assigned male sex at birth who have undergone GAHT for at least one year and underwent vaginoplasty or orchiectomy. The study design allows for rapid assessment of potential synergistic effects of various dose combinations of estradiol and progesterone on breast volume change: Ninety participants will be randomized into six groups of 15 subjects each, receiving either the baseline dose of estradiol, the baseline dose of estradiol and progesterone 200 mg daily, the baseline dose of estradiol and progesterone 400 mg daily, twice the baseline dose of estradiol, twice the baseline dose of estradiol and progesterone 200 mg daily or twice the baseline dose of estradiol and progesterone 400 mg daily, all for a duration of 12 months. The main study parameters include changes in breast volume as determined by 3D measurements. Participants will be followed-up with laboratory testing including serum progesterone concentrations as well as surveys for satisfaction, mood, sleep quality and sexual pleasure. DISCUSSION: This study will indicate whether progesterone is safe and of additional value with regard to breast volume change in transgender individuals receiving feminizing GAHT. The results of this study will be useful for innovation of feminizing GAHT. TRIAL REGISTRATION: WHO International Clinical Trials Registry Platform: EUCTR2020-001952-16-NL; date of registration: 12 December 2020 https://trialsearch.who.int/Trial2.aspx?TrialID=EUCTR2020-001952-16-NL .

Workflow and treatment results for computer-aided design and 3D-printed conformer therapy of congenital anophthalmia and microphthalmia.

BACKGROUND/AIMS: To evaluate treatment with custom, three-dimensional (3D) printed conformers for socket expansion in congenital microphthalmia and anophthalmia (MICA). METHODS: Retrospective analysis of prospective cohort from 2016 to 2020. All children received custom-made 3D-printed conformers increasing in size. We measured height, width, thickness, surface and volume of first and consecutive conformers, as well as horizontal palpebral fissure length (HPF) at start and follow-up visits. We analysed these parameters for severely (<45%) and moderately (>45%-75%) affected children, based on affected axial length on ultrasonography. RESULTS: We included 18 cases (9 severe, 9 moderate) with a total of 174 conformers (88 severe, 86 moderate) and a mean follow-up of 2.8 years (range 1.3-4.8). The mean relative HPF increased from 77% to 93% with 16/17 cases reaching >80%, and 12/17 cases >90% symmetry. Horizontal and vertical conformer dimensions increased up to 10 months of treatment, with a steeper slope for the severe group (10.5% vs 5.5% for height and 9.0% vs 6.1% for width gain per treatment month, for severe and moderate MICA, respectively). After 10 months of treatment conformer height and width increased only slightly. No serious complications were observed. CONCLUSION: 3D-design and printing of solid conformers results in highly acceptable horizontal eyelid symmetry in the treatment of congenital MICA. The mean increase in conformer height and width in the first 10 months should be about 170% for moderate and about 200% for severe MICA. The presented conformer size formulas can aid ophthalmologists and ocularists to plan conformer treatment.

The Amsterdam UMC protocol for computer-assisted mandibular and maxillary reconstruction; A cadaveric study.

OBJECTIVES: In this cadaveric study, the accuracy of CAS guided mandibular and maxillary reconstruction including immediate dental implant placement in different Brown defect classes is assessed. MATERIALS AND METHODS: The virtual planning and surgical procedure was conducted according to a newly proposed Amsterdam UMC reconstruction protocol. Postoperative evaluation was performed according to a previously proposed evaluation guideline. RESULTS: Fourteen mandibular and 6 maxillary reconstructions were performed. Average mandibular angle deviations were 1.52°±1.32, 1.85°±1.58, 1.37°±1.09, 1.78°±1.37, 2.43°±1.52 and 2.83°±2.37, respectively for the left and right axial angles, left and right coronal angles and left and right sagittal angles. A total of 62 dental implants were placed in neomandibles with an average dXYZ values of 3.68 ± 2.21 mm and 16 in neomaxillas with an average dXYZ values of 3.24 ± 1.7 mm. CONCLUSION: Promising levels of accuracy were achieved for all mandibular angles. Dental implant positions approached the preoperative preferred positions well, within the margin to manufacture prosthetic devices.

A Novel Treatment Concept for Advanced Stage Mandibular Osteoradionecrosis Combining Isodose Curve Visualization and Nerve Preservation: A Prospective Pilot Study.

BACKGROUND: Osteoradionecrosis (ORN) of the mandible is a severe complication of radiation therapy in head and neck cancer patients. Treatment of advanced stage mandibular osteoradionecrosis may consist of segmental resection and osseous reconstruction, often sacrificing the inferior alveolar nerve (IAN). New computer-assisted surgery (CAS) techniques can be used for guided IAN preservation and 3D radiotherapy isodose curve visualization for patient specific mandibular resection margins. This study introduces a novel treatment concept combining these CAS techniques for treatment of advanced stage ORN. METHODS: Our advanced stage ORN treatment concept includes consecutively: 1) determination of the mandibular resection margins using a 3D 50 Gy isodose curve visualization, 2) segmental mandibular resection with preservation of the IAN with a two-step cutting guide, and 3) 3D planned mandibular reconstruction using a hand-bent patient specific reconstruction plate. Postoperative accuracy of the mandibular reconstruction was evaluated using a guideline. Objective and subjective IAN sensory function was tested for a period of 12 months postoperatively. RESULTS: Five patients with advanced stage ORN were treated with our ORN treatment concept using the fibula free flap. A total of seven IANs were salvaged in two men and three women. No complications occurred and all reconstructions healed properly. Neither non-union nor recurrence of ORN was observed. Sensory function of all IANs recovered after resection up to 100 percent, including the patients with a pathologic fracture due to ORN. The accuracy evaluation showed angle deviations limited to 3.78 degrees. Two deviations of 6.42° and 7.47° were found. After an average of 11,6 months all patients received dental implants to complete oral rehabilitation. CONCLUSIONS: Our novel ORN treatment concept shows promising results for implementation of 3D radiotherapy isodose curve visualization and IAN preservation. Sensory function of all IANs recovered after segmental mandibular resection.

A Postoperative Evaluation Guideline for Computer-Assisted Reconstruction of the Mandible.

Valid comparisons of postoperative accuracy results in computer-assisted reconstruction of the mandible are difficult due to heterogeneity in imaging modalities, mandibular defect classification, and evaluation methodologies between studies. This guideline uses a step-by-step approach guiding the process of imaging, classification of mandibular defects and volume assessment of three-dimensional (3D) models, after which a legitimized quantitative accuracy evaluation method can be performed between the postoperative clinical situation and the preoperative virtual plan. The condyles and the vertical and horizontal corners of the mandible are used as bony landmarks to define virtual lines in the computer-assisted surgery (CAS) software. Between these lines the axial, coronal, and both sagittal mandibular angles are calculated on both pre- and postoperative 3D models of the (neo)mandible and subsequently the deviations are calculated. By superimposing the postoperative 3D model to the preoperative virtually planned 3D model, which is fixed to the XYZ axis, the deviation between pre- and postoperative virtually planned dental implant positions can be calculated. This protocol continues and specifies an earlier publication of this evaluation guideline.

Virtual forensic anthropology: The accuracy of osteometric analysis of 3D bone models derived from clinical computed tomography (CT) scans.

Clinical radiology is increasingly used as a source of data to test or develop forensic anthropological methods, especially in countries where contemporary skeletal collections are not available. Naturally, this requires analysis of the error that is a result of low accuracy of the modality (i.e. accuracy of the segmentation) and the error that arises due to difficulties in landmark recognition in virtual models. The cumulative effect of these errors ultimately determines whether virtual and dry bone measurements can be used interchangeably. To test the interchangeability of virtual and dry bone measurements, 13 male and 14 female intact cadavers from the body donation program of the Amsterdam UMC were CT scanned using a standard patient scanning protocol and processed to obtain the dry os coxae. These were again CT scanned using the same scanning protocol. All CT scans were segmented to create 3D virtual bone models of the os coxae ('dry' CT models and 'clinical' CT models). An Artec Spider 3D optical scanner was used to produce gold standard 'optical 3D models' of ten dry os coxae. The deviation of the surfaces of the 3D virtual bone models compared to the gold standard was used to calculate the accuracy of the CT models, both for the overall os coxae and for selected landmarks. Landmark recognition was studied by comparing the TEM and %TEM of nine traditional inter-landmark distances (ILDs). The percentage difference for the various ILDs between modalities was used to gauge the practical implications of both errors combined. Results showed that 'dry' CT models were 0.36-0.45mm larger than the 'optical 3D models' (deviations -0.27mm to 2.86mm). 'Clinical' CT models were 0.64-0.88mm larger than the 'optical 3D models' (deviations -4.99mm to 5.00mm). The accuracies of the ROIs were variable and larger for 'clinical' CT models than for 'dry' CT models. TEM and %TEM were generally in the acceptable ranges for all ILDs whilst no single modality was obviously more or less reliable than the others. For almost all ILDs, the average percentage difference between modalities was substantially larger than the average percentage difference between observers in 'dry bone' measurements only. Our results show that the combined error of segmentation- and landmark recognition error can be substantial, which may preclude the usage of 'clinical' CT scans as an alternative source for forensic anthropological reference data.

Gender-Affirming Hormone Treatment Induces Facial Feminization in Transwomen and Masculinization in Transmen: Quantification by 3D Scanning and Patient-Reported Outcome Measures.

INTRODUCTION: Hormone treatment induces feminization of the body in transwomen and masculinization in transmen. However, the effect of hormone treatment on facial characteristics is still unknown. AIM: We aimed to study whether hormone treatment induces facial feminization and masculinization and how this potential change affects satisfaction and self-esteem. METHODS: In this single-center cohort study, we included 27 transwomen and 15 transmen who received standardized hormone treatment in the Center of Expertise on Gender Dysphoria, VU University Medical Center Amsterdam. Facial 3-dimensional images were obtained at baseline and at 3 and 12 months. At each image, 22 facial landmarks were placed. Furthermore, the FACE-Q Satisfaction with Facial Appearance Overall and the Rosenberg self-esteem scale were obtained at the same measurement points. MAIN OUTCOME MEASURES: The main outcome measures included the relative local shift of skin in millimeters in the 22 landmarks in the transverse (x-axis), coronal (y-axis), and sagittal (z-axis) anatomic axes, the color maps, and the outcomes of the questionnaires. RESULTS: After 12 months, cheek tissue in transwomen increased, with 0.50 mm (95% CI 0.04-0.96) in the x-axis and 1.08 mm (95% CI 0.31-1.85) in the z-axis. Tissue in the jaws decreased with -0.60 mm (95% CI -1.28-0.08) in the x-axis and -0.18 mm (95% CI -0.03-0.33) in the y-axis. Cheek tissue in transmen decreased with -0.45 mm (95% CI -1.00-0.11) in the x-axis and -0.84 mm (95% CI -1.92-0.25) in the z-axis. These changes already started after 3 months. An increase in satisfaction with the facial appearance was found in both transwomen and transmen. There were no changes in reported self-esteem. CLINICAL IMPLICATION: These results could lead to more realistic expectations of facial changes. Furthermore, our results suggest that the face continues to change for at least a year, which could suggest that performing facial feminization surgery after 1 year of hormone treatment might be too early. STRENGTH & LIMITATIONS: This study is the first that provides insight into the facial changes in transgender individuals receiving hormone treatment, and it introduces an objective method to examine (small) facial changes. Our study is limited by the poor reliability of the landmarks, the difficulty of facial fixation, and the lack of gender-specific questions in the questionnaires. CONCLUSIONS: Hormone treatment in transwomen induces an increase in cheek tissue and a decrease in jaw tissue. In transmen a tendency of decrease in cheek tissue and an increase in jaw tissue was found. These changes are in the direction of the desired gender. Tebbens M, Nota NM, Liberton NPTJ, et al. Gender-Affirming Hormone Treatment Induces Facial Feminization in Transwomen and Masculinization in Transmen: Quantification by 3D Scanning and Patient-Reported Outcome Measures. J Sex Med 2019;16:746-754.

Accuracy of computer-assisted surgery in mandibular reconstruction: A postoperative evaluation guideline.

Comparing accuracy results for mandibular reconstructions using computer-assisted surgery (CAS) is limited due to heterogeneity in image acquisition, extent of mandibular resection, and evaluation methodologies between studies. We propose a practical, feasible and reproducible guideline for standardizing evaluation methods to allow valid comparisons of postoperative results and facilitate meta-analyses in the future. It offers a guide to imaging, data comparison, volume assessment of 3-dimensional models, classification of defects, and it also contains a quantitative accuracy evaluation method.

Accuracy of computer-assisted surgery in mandibular reconstruction: A systematic review.

Computer-assisted surgery (CAS) for mandibular reconstruction was developed to improve conventional treatment methods. In the past years, many different software programs have entered the market, offering numerous approaches for preoperative planning and postoperative evaluation of the CAS process of mandibular reconstruction. In this systematic review, we reviewed planning and evaluation methods in studies that quantitatively assessed accuracy of mandibular reconstruction performed with CAS. We included 42 studies describing 413 mandibular reconstructions planned and evaluated using CAS. The commonest software was Proplan/Surgicase CMF (55%). In most cases, the postoperative virtual 3-dimensional model was compared to the preoperative 3-dimensional model, revised to the virtual plan (64%). The commonest landmark for accuracy measurements was the condyle (54%). Accuracy deviations ranged between 0 mm and 12.5 mm and between 0.9° and 17.5°. Because of a lack of uniformity in planning (e.g., image acquisition, mandibular resection size) and evaluation methodologies, the ability to compare postoperative outcomes was limited; meta-analysis was not performed. A practical and simple guideline for standardizing planning and evaluation methods needs to be considered to allow valid comparisons of postoperative results and facilitate meta-analysis in the future.

MRI and Additive Manufacturing of Nasal Alar Constructs for Patient-specific Reconstruction.

Surgical reconstruction of cartilaginous defects remains a major challenge. In the current study, we aimed to identify an imaging strategy for the development of patient-specific constructs that aid in the reconstruction of nasal deformities. Magnetic Resonance Imaging (MRI) was performed on a human cadaver head to find the optimal MRI sequence for nasal cartilage. This sequence was subsequently used on a volunteer. Images of both were assessed by three independent researchers to determine measurement error and total segmentation time. Three dimensionally (3D) reconstructed alar cartilage was then additively manufactured. Validity was assessed by comparing manually segmented MR images to the gold standard (micro-CT). Manual segmentation allowed delineation of the nasal cartilages. Inter- and intra-observer agreement was acceptable in the cadaver (coefficient of variation 4.6-12.5%), but less in the volunteer (coefficient of variation 0.6-21.9%). Segmentation times did not differ between observers (cadaver P = 0.36; volunteer P = 0.6). The lateral crus of the alar cartilage was consistently identified by all observers, whereas part of the medial crus was consistently missed. This study suggests that MRI is a feasible imaging modality for the development of 3D alar constructs for patient-specific reconstruction.