Soft-Tissue Volumetric Changes Following Monobloc Distraction Procedure: Analysis Using Digital Three-Dimensional Photogrammetry System (3dMD)

Volumetric Analyses of Dysmorphic Maxillofacial Structures Using 3D Surface-Based Approaches: A Scoping Review

Background/Objectives: Three-dimensional (3D) analysis of maxillofacial structures in dysmorphic patients offers clinical advantages over 2D analysis due to its high accuracy and precision in measuring many morphological parameters. Currently, no reliable gold standard exists for calculating 3D volumetric measurements of maxillofacial structures when captured by 3D surface imaging techniques. The aim of this scoping review is to provide an overview of the scientific literature related to 3D surface imaging methods used for volumetric analysis of the dysmorphic maxillofacial structures of patients affected by CL/P or other syndromes and to provide an update on the existing protocols, methods, and, when available, reference data. Methods: A total of 17 papers selected according to strict inclusion and exclusion criteria were reviewed for the qualitative analysis out of more than 4500 articles published between 2002 and 2024 that were retrieved from the main electronic scientific databases according to the PRISMA-ScR guidelines. A qualitative synthesis of the protocols used for the selection of the anatomical areas of interest and details on the methods used for the calculation of their volume was completed. Results: The results suggest a great degree of heterogeneity between the reviewed studies in all the aspects analysed (patient population, anatomical structure, area selection, and volume calculation), which prevents any chance of direct comparison between the reported volumetric data. Conclusions: Our qualitative analysis revealed dissimilarities in the procedures specified in the studies, highlighting the need to develop uniform methods and protocols and the need for comparative studies to verify the validity of methods in order to achieve high levels of scientific evidence, homogeneity of volumetric data, and clinical consensus on the methods to use for 3D volumetric surface-based analysis.

Three-dimensional quantification of soft tissue changes and its relationship to skeletal changes after Le Fort III, monobloc, and facial bipartition in syndromic craniosynostosis

To determine the effect of midface surgery on soft tissue changes and their relationship to hard tissue changes in patients with syndromic craniosynostosis. A retrospective analysis of patients who had undergone Le Fort III (LFIII), monobloc (MB), or facial bipartition (FB) was conducted. A 3D soft tissue mesh was generated from the preoperative scan and registered to the postoperative scan, after which the advancement was visualised. A total of 68 patients were included: 28 had undergone LFIII, 27 MB, and 13 FB. The included diagnoses were Apert (n = 23), Crouzon (n = 34), and craniofrontonasal syndrome (n = 11). After LFIII, most soft tissue advancement was seen around subnasale and pronasale (mean 15.1 ± 5.9 mm and 14.7 ± 5.7 mm, at age 7-12 years). After MB, a greater hard tissue than soft tissue advancement was seen for most landmarks, showing a high positive correlation. In patients undergoing FB without distraction (n = 10), mean preoperative inter-canthal distance was 48.9 mm, this reduced by 6.9 mm postoperatively. This study provides a comprehensive overview of the outcomes after midface surgery using 3D quantification for a better understanding of the soft tissue changes and their relationship to hard tissue changes.

LeFort III Versus Monobloc Frontofacial Advancement: A Comparative Analysis of Soft Tissue Changes

INTRODUCTION

The LeFort III and monobloc are commonly used midface advancement procedures for patients with syndromic craniosynostosis with well characterized postoperative skeletal changes. However, the differential effects of these procedures on facial soft tissues are less understood. The purpose of this study was to critically analyze and compare the effects of these 2 procedures on the overlying soft tissues of the face.

METHODS

Frontal and lateral preoperative and postoperative photographs of patients undergoing monobloc or LeFort III were retrospectively analyzed using ImageJ to measure soft tissue landmarks. Measurements included height of facial thirds, nasal length and width, intercanthal distance, and palpebral fissure height and width. Facial convexity was quantified by calculating the angle between sellion (radix), subnasale, and pogonion on lateral photographs.

RESULTS

Twenty-five patients with an average age of 6.7 years (range 4.8-14.5) undergoing monobloc (n=12) and LeFort III (n=13) were identified retrospectively and analyzed preoperatively and 6.4±3.6 months postoperatively. Patients undergoing LeFort III had a greater average postoperative increase in facial convexity angle acuity (28.2°) than patients undergoing monobloc (17.8°, P =0.021). Patients in both groups experience postoperative increases in nasal width ( P <0.001) and decreases in palpebral fissure height ( P <0.001).

CONCLUSIONS

Both subcranial LeFort III advancements and monobloc frontofacial advancements resulted in significant changes in the soft tissues. Patients undergoing LeFort III procedures achieved greater acuity of the facial convexity angle, likely because the nasion is not advanced with the LeFort III segment.

Surgical Correction of Metopic Craniosynostosis: A 3-D Photogrammetric Analysis of Cranial Vault Outcomes

OBJECTIVE

To evaluate 3-dimensional (3-D) photogrammetry as a tool for assessing the postoperative head shape of patients who had undergone cranial vault remodeling for metopic synostosis.

DESIGN

We prospectively analyzed images of patients with metopic craniosynostosis who had undergone anterior cranial vault remodeling and age-matched controls. To ensure standardized facial orientation, each 3-D image was positioned to "best fit" the preoperative face by aligning 6 soft tissue landmarks. Forehead measurements were taken from a standardized position behind the surface of the face to landmarks placed in a ray configuration across the forehead.

SETTING

Academic teaching hospital.

PATIENTS, PARTICIPANTS

Thirteen pediatric patients with metopic craniosynostosis who had undergone anterior cranial vault remodeling and age-matched controls.

INTERVENTIONS

Images were taken preoperatively, immediately postoperatively, and over 1-year postoperatively.

MAIN OUTCOME MEASURES

Forehead contours preoperatively and postoperatively, with statistics performed using a multivariate analysis of variance shape analysis.

RESULTS

Mean postoperative follow-up was 1.8 (0.6) years. The average distance from the origin to forehead landmarks was 55.1 (3.4) mm preoperatively, 59.3 (0.7) mm immediate postoperatively, 59.1 (1.0) mm 1-year postoperatively, and 59.4 (0.6) mm in controls. Postoperative metopic forehead contours varied significantly from preoperative contours ( P < .01), while there was no statistical difference between the 2 postoperative time points ( P = .70). One-year postoperative patients were not significantly different from their age-matched controls ( P > .99).

CONCLUSIONS

Preoperative metopic forehead contours varied significantly from postoperative contours. Cranial reconstructions approximated the foreheads of normal controls, and reconstructions were stable at more than 1-year follow-up.

Retrospective study on midfacial advancement in syndromic craniosynostosis: case series

AIMS

The aim of this study was to evaluate elastic distraction surgical procedures performed on patients with syndromic craniosynostosis using cephalometric analyses.

METHODS

Eleven patients who underwent surgical midfacial advancement were divided into three groups: G1 - monobloc frontofacial; G2 - Le Fort III; and G3 - high-level Le Fort I. The cephalometric analyses were manually created through cephalometric radiographs of each patient: T1 - preoperative; T2 - 6 months postoperatively; and T3 - 12 months postoperatively. The cephalometric landmark points were A and O. The distances between preoperative and postoperative tracings were measured.

RESULTS

Point A advanced with no significant relapse 12 months after surgery. Point O advanced with a significant relapse rate of 28.5% postoperatively (p = 0.019). The vertical movement of points A and O increased by 40.6% (p = 0.033) and 38.8% (p = 0.032), respectively. There were no significant statistical differences between the assessed surgical techniques and syndromes with regard to midfacial advancement.

CONCLUSION

Point O has presented statistically significant relapse only in horizontal movement after 12 months. The cephalometric analysis performed in the present study only suggested no differences between the studied surgical techniques and syndromes with regard to midfacial advancement in syndromic craniosynostosis.

Three-dimensional imaging of soft and hard facial tissues in patients with craniofacial syndromes: a systematic review of methodological quality

OBJECTIVES

To systematically review the methodological quality of three-dimensional imaging studies of patients with craniofacial syndromes and to propose recommendations for future research.

METHODS

PubMed, Embase and Cochrane databases as well as Grey literature were electronically searched. Inclusion criteria were patients with genetic syndromes with craniofacial manifestations and three-dimensional imaging of facial soft and/or hard tissues. Exclusion criteria consisted of non-syndromic conditions or conditions owing to environmental causes, injury or trauma, facial soft and hard tissues not included in the image analysis, case reports, reviews, opinion articles. No restrictions were made for patients' ethnicity nor age, publication language or publication date. Study quality was evaluated using the Methodological Index for Non-Randomized Studies (MINORS).

RESULTS

The search yielded 2228 citations of which 116 were assessed in detail and 60 were eventually included in this review. Studies showed a large heterogeneity in study design, sample size and patient age. An increase was observed in the amount of studies with time, and the imaging method most often used was CT. The most studied craniofacial syndromes were Treacher Collins, Crouzon and Apert syndrome. The articles could be divided into three main groups: diagnostic studies (34/60, 57%), evaluation of surgical outcomes (21/60, 35%) and evaluation of imaging techniques (5/60, 8%). For comparative studies, the median MINORS score was 13 (12-15, 25-75th percentile), and for non-comparative studies, the median MINORS score was 8 (7-9, 25-75th percentile).

CONCLUSIONS

The median MINORS scores were only 50 and 54% of the maximum scores and there was a lack of prospective, controlled trials with sufficiently large study groups. To improve the quality of future studies in this domain and given the low incidence of craniofacial syndromes, more prospective multicentre controlled trials should be set up.

Treating Parry-Romberg Syndrome Using Three-Dimensional Scanning and Printing and the Anterolateral Thigh Dermal Adipofascial Flap

BACKGROUND

As three-dimensional technology becomes more ubiquitous, many plastic surgical applications have emerged. The authors investigate a three-dimensional scanning and printing system for facial soft tissue reconstruction in conjunction with an anterolateral thigh dermal adipofascial flap for the treatment of Parry-Romberg syndrome.

METHODS

Seven patients with facial atrophy of the zygomatic, buccal, and mandibular areas were included. Three-dimensional scanning of each patient's face in conjunction was analyzed with computer-aided design (CAD) to quantify areas of facial asymmetry. Models were then created using three-dimensional printing to map areas of soft tissue deficiency. Free anterolateral thigh (ALT) dermal adipofascial flaps were designed based on the three-dimensional models of soft tissue deficiency.

RESULTS

All flaps survived. One case had a postoperative hematoma. Six patients had restored facial symmetry. One patient required fat injections to obtain symmetry. No patients required revision surgery of their healed flaps for contouring.

CONCLUSIONS

Three-dimensional laser scanning and three-dimensional printing in combination with a free ALT dermal adipofascial flap offer surgeons a precise means to reconstruct facial contour deformities.

Advances in the Treatment of Syndromic Midface Hypoplasia Using Monobloc and Facial Bipartition Distraction Osteogenesis

Midface hypoplasia or retrusion remains a persistent feature of syndromic craniosynostosis years after successful treatment of the cranium. Although expansion of the cranial vault in infancy by traditional fronto-orbital advancement, posterior expansion, or both, can treat the immediate intracranial constriction, midface hypoplasia and its stigmata of exorbitism, sleep apnea, central face concavity, and malocclusion remain suboptimally treated. Initial enthusiasm for the procedures was tempered due to a high rate of infectious complications; timing and indications for surgery continue to stir controversy. During the last decade renewed interest with the monobloc and facial bipartition procedure using distraction osteogenesis with either an internal or external distraction system has decreased morbidity significantly. These procedures have re-emerged as powerful and comprehensive tools in the treatment of syndromic midface hypoplasia.

Methods to quantify soft tissue-based cranial growth and treatment outcomes in children: a systematic review

Context

Longitudinal assessment of cranial dimensions of growing children provides healthcare professionals with information about normal and deviating growth as well as treatment outcome.

Objective

To give an overview of soft tissue–based methods for quantitative longitudinal assessment of cranial dimensions in children until age 6 years and to assess the reliability of these methods in studies with good methodological quality.

Data source

PubMed, EMBASE, Cochrane Library, Web of Science, Scopus, and CINAHL were searched. A manual search was performed to check for additional relevant studies.

Study selection

Primary publications on facial growth and treatment outcomes in children younger than age 6 years were included.

Data extraction

Independent data extraction was performed by two observers. A quality assessment instrument was used to determine methodological quality. Methods used in studies with good methodological quality were assessed for reliability expressed as the magnitude of the measurement error and the correlation coefficient between repeated measurements.

Results

In total, 165 studies were included, forming three groups of methods: head circumference anthropometry, direct anthropometry, and 2D photography and 3D imaging techniques (surface laser scanning and stereophotogrammetry). In general, the measurement error was below 2 mm, and correlation coefficients were very good.

Conclusion

Various methods for measuring cranial dimensions have shown to be reliable. Stereophotogrammetry is the most versatile method for quantitative longitudinal assessment of cranial dimensions and shapes in children. However, direct anthropometry continues to be the best method for routine clinical assessments of linear cranial dimensions in growing children until age 6 years.