Accuracy of virtually planned mandibular distraction in a pediatric case series

A distraction assembly system with fully-customized fixation plate unit and factory-manufactured distraction unit: Overview and accuracy validation for mandibular distraction osteogenesis

A distraction assembly system (DAS), consisting of a distractor of fully individualized fixation plate unit and factory-engineered distraction unit, was recently developed to enhance the accuracy, stability, and workability of distraction osteogenesis (DO). We here wanted to evaluate the accuracy of DAS for mandibular DO, focusing on the consequences of the distractor design and manufacturing method. The bar-type distractor unit showed smaller discrepancies than did the cylinder-type one, both units showing far fewer discrepancies than those of a conventional distractor. And there were no significant differences in morphological accuracy between the plates produced by milling and 3D printing. These accuracies feature the promising application in clinical setting, and further work is anticipated to refine DAS for successful computer-aided DO.

Artificial Intelligence and Pediatric Otolaryngology

Artificial intelligence (AI) studies show how to program computers to simulate human intelligence and perform data interpretation, learning, and adaptive decision-making. Within pediatric otolaryngology, there is a growing body of evidence for the role of AI in diagnosis and triaging of acute otitis media and middle ear effusion, pediatric sleep disorders, and syndromic craniofacial anomalies. The use of automated machine learning with robotic devices intraoperatively is an evolving field of study, particularly in the realms of pediatric otologic surgery and computer-aided planning for maxillofacial reconstruction, and we will likely continue seeing novel applications of machine learning in otolaryngologic surgery.

An updated protocol for mandibular reconstruction in nongrowing patients with craniofacial microsomia with temporomandibular joint total prosthesis

The authors aim to present an updated protocol for mandibular reconstruction in nongrowing patients with Pruzansky/Kaban type IIb/III congenital craniofacial microsomia with customized temporomandibular joint (TMJ) prosthesis to reduce facial nerve (FN) damage and improve surgical accuracy. This is illustrated (using 3 cases) and is based on preoperative mapping of the FN using MRI for better virtual surgical planning of custom-made TMJ prosthesis. Intraoperative FN mapping and monitoring, as well as verification of the final result with intraoperative cone-beam computed tomography (CBCT) and 3D-reconstructed images is also achieved. All 3 patients presented mild transient postoperative facial palsy due to surgical soft tissue stretching which resolved within 2 months of surgery. All patients presented proper occlusion and mouth opening without pain, with an average incisal opening of 38.8 mm (range 35.5-42 mm) at two months of follow-up. Moreover, superposition of intraoperative and preoperative 3D reconstruction images ensured surgical accuracy and avoided the need for a potential reintervention. In conclusion, the proposed surgical protocol for mandibular reconstruction with customized alloplastic TMJ prosthesis in nongrowing patients with type IIb/III Pruzansky-Kaban congenital mandibular hypoplasia may reduce FN morbidity, improve surgical accuracy and final outcomes.

Computerized Surgical Planning for Mandibular Distraction Osteogenesis

Mandibular distraction osteogenesis is a technically challenging procedure due to complex mandibular anatomy, especially in the treatment of Pierre-Robin Sequence due to variable bone thickness in the infant mandible and the presence of tooth buds. Computerized surgical planning (CSP) simplifies the procedure by preoperatively visualizing critical structures, producing cutting guides, and planning distractor placement. This paper describes the process of using CSP to plan mandibular distraction osteogenesis, including discussion of recent advances in the use of custom distractors.

Clinical Outcomes in Orthognathic Surgery for Craniofacial Microsomia Following Mandibular Distraction Using CBCT Analysis: A Retrospective Study

OBJECTIVE

The aim of this study was to evaluate the outcomes of orthognathic surgery (OGS) in patients with craniofacial microsomia (CFM) who had previously undergone mandibular distraction osteogenesis (MDO).

DESIGN

A retrospective cohort study was performed including all patients with CFM who were treated with OGS at a single institution between 1996 and 2019. The clinical records, operative reports, and cone beam computed tomography (CBCT) scans were reviewed. CBCT data before OGS (T1), immediately after OGS (T2), and at long-term follow-up (T3) were analyzed using Dolphin three-dimensional software to measure the occlusal cant and chin point deviation.

RESULTS

The study included 12 patients with CFM who underwent OGS (6 underwent OGS without MDO and 6 underwent OGS after MDO). There was a statistically significant improvement in occlusal cant and chin point deviation in both groups postoperatively. Occlusal cant relapsed by a mean of 0.6° (standard deviation [SD] 1.1°) in the patients who had OGS alone compared with 0.7° (SD 1.2°) in the patients who had OGS after MDO (P  =  .745) between T2 and T3. There was no statistically significant difference in chin point relapse between patients who had OGS alone compared with those who had OGS after MDO (0.1 mm [SD 2.5mm] vs 0.7mm [SD 2.2mm]; P  =  .808).

CONCLUSIONS

Within the limitations of this study, these findings suggest that OGS after MDO in patients with CFM can produce stable results.

3D printing in pediatric surgery

Pediatric surgery presents a unique challenge, requiring a specialized approach due to the intricacies of compact anatomy and the presence of distinct congenital features in young patients. Surgeons are tasked with making decisions that not only address immediate concerns but also consider the evolving needs of children as they grow. The advent of three-dimensional (3D) printing has emerged as a valuable tool to facilitate a personalized medical approach. This paper starts by outlining the basics of 3D modeling and printing. We then delve into the transformative role of 3D printing in pediatric surgery, elucidating its applications, benefits, and challenges. The paper concludes by envisioning the future prospects of 3D printing, foreseeing advancements in personalized treatment approaches, improved patient outcomes, and the continued evolution of this technology as an indispensable asset in the pediatric surgical arena.

The Use and Outcomes of 3D Printing in Pediatric Craniofacial Surgery: A Systematic Review

Three-dimensional (3D) printing has demonstrated efficacy in multiple surgical specialties. As accessibility improves, its use in specific fields deserves further attention. We conducted a systematic review of the implementation and outcomes of 3D printing in pediatric craniofacial surgery, as none has been performed. A systematic review was conducted according to Cochrane and PRISMA guidelines. PubMed, Embase, Cochrane library, and Clinicaltrials.gov were queried with combinations of the terms: "3D printing," "craniofacial," "surgery," and "pediatric." Original human studies containing patients <18 years old implementing 3D printing to aid in craniofacial surgery were included. Study selection, grading, and data extraction were performed independently by multiple authors. After screening 120 articles, 7 (3 case series and 4 case reports) were included, published from 2017 to 2022. All studies addressed patients with different disease processes including craniosynostosis, cleft lip/palate, and mandibular hypoplasia. 3D printing was used to create mock surgical models in 2 studies, intraoperative cutting guides/molds (CGs) in 6 studies, and cranioplasty implants in 2 studies. Two case series determined the accuracy of the CGs was acceptable within historical comparison, while 4 articles included subjective statements on improved accuracy. Five studies noted reduced operating time, 2 noted reduced intraoperative blood loss, and 1 felt the use of 3D printed materials was responsible for shorter hospitalization duration. No adverse events were reported. Despite the limitations of the current literature, all studies concluded that the use of 3D printing in pediatric craniofacial surgery was beneficial. Definitive conclusions cannot be made until further controlled research is performed.

Condylar resorption post mandibular distraction osteogenesis in craniofacial microsomia: A retrospective study

The aim of this study was to investigate the characteristics of condylar resorption in craniofacial microsomia (CFM) patients following mandibular distraction osteogenesis (MDO). Patients with unilateral type-IIa and type-IIb CFM, who had completed MDO and mandibular distractor extraction (MDE), were recruited. The height and volume of the condyle were measured on three-dimension models created by the analysis of computed tomography (CT) data. Normality analysis was performed using the Shapiro-Wilk test. Data for the affected and unaffected sides were compared using the paired t-test or Wilcoxon signed-rank test. Data for both type-IIa and type-IIb CFM were compared using the independent-samples t-test or Mann-Whitney U test. The Pearson or Spearman correlation was used to determine the correlations of condylar resorption rate with related measurements. In total, 48 type-IIa and 48 type-IIb CFM patients were included. The condylar resorption rate in type-IIa CFM (0.35 ± 0.32) was significantly associated with the height of the condyle (r = 0.776, p < 0.001) and distraction distance (r = 0.447, p = 0.001), while the condylar resorption rate in type-IIb CFM (0.49 ± 0.46) was significantly associated with the height of the condyle (r = 0.924, p < 0.001). However, there was no significant difference in condylar resorption rate between type-IIa and type-IIb CFM (p = 0.075). In addition to occlusal changes, no other negative symptoms of the TMJ were observed with condylar resorption. Condylar resorption was evident in CFM patients following mandibular distraction osteogenesis, and the condylar resorption rate showed a relationship with distraction distance and condylar height.

Evolution of Medical Modeling and 3D Printing in Microvascular Midface Reconstruction: Literature Review and Experience at MD Anderson Cancer Center

Reconstruction of the midface represents a challenge for reconstructive microsurgeons given the formidable task of restoring both aesthetics and functionality. In particular, preservation of proper globe positioning and maintaining normal vision are as important as restoring the proper projection of the midface and enabling a patient to speak and eat as normally as possible. The introduction of virtual surgical planning (VSP) and medical modeling has revolutionized bony reconstruction of the craniofacial skeleton; however, the overwhelming majority of studies have focused on mandibular reconstruction. Here, we introduce some novel advances in utilizing VSP for bony reconstruction of the midface. The present review aims (1) to provide a review of the literature on the use of VSP in midface reconstruction and (2) to provide some insights from the authors' early experience.

Accuracy and safety of robotic navigation-assisted distraction osteogenesis for hemifacial microsomia

Introduction

This study aimed to verify the accuracy and safety of distraction osteogenesis for hemifacial microsomia assisted by a robotic navigation system based on artificial intelligence.

Methods

The small sample early-phase single-arm clinical study, available at http://www.chictr.org.cn/index.aspx, included children aged three years and older diagnosed with unilateral hemifacial microsomia (Pruzansky-Kaban type II). A preoperative design was performed, and an intelligent robotic navigation system assisted in the intraoperative osteotomy. The primary outcome was the accuracy of distraction osteogenesis, including the positional and angular errors of the osteotomy plane and the distractor, by comparing the preoperative design plan with the actual images one week postoperatively. Perioperative indicators, pain scales, satisfaction scales, and complications at one week were also analyzed.

Results

Four cases (mean 6.5 years, 3 type IIa and 1 type IIb deformity) were included. According to the craniofacial images one week after surgery, the osteotomy plane positional error was 1.77 ± 0.12 mm, and the angular error was 8.94 ± 4.13°. The positional error of the distractor was 3.67 ± 0.23 mm, and the angular error was 8.13 ± 2.73°. Postoperative patient satisfaction was high, and no adverse events occurred.

Discussion

The robotic navigation-assisted distraction osteogenesis in hemifacial microsomia is safe, and the operational precision meets clinical requirements. Its clinical application potential is to be further explored and validated.

How accurate is computer-assisted mandible gunshot wound management by patient-specific distraction device? Preoperative planning versus postoperative outcomes

Gunshot wounds of the lower face are a challenge for the surgeon. Customized distraction osteogenesis (DO) is a well-established procedure for managing facial gunshot wounds. However, differences between the preoperative planning and postoperative outcomes are often noted. This multi-centre, retrospective study was performed to analyse the differences between the planning and outcomes for the lower third of the face, in patients undergoing the computer-assisted repair of mandible gunshot wounds using patient-specific distraction devices. Different planes and points were defined, and two distances (anteroposterior and intercondylar lengths) and an angle (inter-mandible body angle) were measured on the preoperative planning models and the postoperative models obtained from the computed tomography data. Twelve patient cases that met the study eligibility criteria were included. A significant difference between the planning and postoperative outcome was found for the anteroposterior length (6.6 mm shorter than the preoperative planning; P = 0.003). The differences in intercondylar length (P = 0.116) and inter-mandible body angle (P = 0.121) were not significant. This study revealed a difference between the planning and outcomes. Various factors such as scar tissue and muscle forces limit distraction and therefore lead to under-correction with insufficient projection.

Quantitative structural analysis of hemifacial microsomia mandibles in different age groups

Introduction

This study aims to quantitively analyze mandibular ramus and body deformities, assessing the asymmetry and progression in different components.

Methods

This is a retrospective study on hemifacial microsomia children. They were divided into mild/severe groups by Pruzansky-Kaban classification and into three age groups (<1 year,1-5 years, 6-12 years old). Linear and volumetric measurements of the ramus and the body were collected via their preoperative imaging data to compare between the different sides and severities, using independent and paired tests, respectively. The progression of asymmetry was assessed by changes in affected/contralateral ratios with age using multi-group comparisons.

Results

Two hundred and ten unilateral cases were studied. Generally, the affected ramus and body were significantly smaller than those on the contralateral side. Linear measurements on the affected side were shorter in the severe group. Regarding affected/contralateral ratios, the body was less affected than the ramus. Progressively decreased affected/contralateral ratios of body length, dentate segment volume, and hemimandible volume were found.

Discussion

There were asymmetries in mandibular ramus and body regions, which involved the ramus more. A significant contribution to progressive asymmetry from the body suggests treatment focus in this region.

Augmented reality hologram combined with pre-bent distractor enhanced the accuracy of distraction vector transfer in maxillary distraction osteogenesis, a study based on 3D printed phantoms

BACKGROUND

Vector control is a significant concern in maxillary distraction osteogenesis (DO). Distraction vector planning on the patient's 3D-printed skull phantom is more intuitive for surgeons and cost-efficient than virtual surgical planning. However, the accuracy of transferring the planned vector to intraoperative (vector transfer) according to the shape of the pre-bent footplate alone is relatively limited. The application of augmented reality (AR) in surgical navigation has been studied for years. However, few studies have focused on its role in maxillary DO vector transfer. This study aimed to evaluate the accuracy of AR surgical navigation combined with the pre-bent distractor in vector transfer by comparing it with the pre-bent distractor alone.

METHODS

Ten patients with maxillary hypoplasia were enrolled with consent, and three identical 3D-printed skull phantoms were manufactured based on per patient's corresponding pre-operative CT data. Among these, one phantom was for pre-operative planning (n = 10), while and the other two were for the AR+Pre-bending group (n = 10) and the Pre-bending group (n = 10) for the experimental surgery, respectively. In the Pre-bending group, the distraction vector was solely determined by matching the shape of footplates and maxillary surface. In the AR+Pre-bending group, the distractors were first confirmed to have no deformation. Then AR surgical navigation was applied to check and adjust the vector in addition to the steps as in the Pre-bending Group.

RESULTS

For the angular deviation of the distraction vector, the AR+Pre-bending group was significantly smaller than the Pre-bending group in spatial (p < 0.001), x-y plane (p = 0.002), and y-z plane (p < 0.001), and there were no significant differences in the x-z plane (p = 0.221). The AR+Pre-bending group was more accurate in deviations of the Euclidean distance (p = 0.004) and the y-axis (p = 0.011). In addition, the AR+Pre-bending group was more accurate for the distraction result.

CONCLUSIONS

In this study based on 3D printed skull phantoms, the AR surgical navigation combined with the pre-bent distractor enhanced the accuracy of vector transfer in maxillary DO, compared with the pre-bending technique alone.

The Role of 3D Printing in Planning Complex Medical Procedures and Training of Medical Professionals-Cross-Sectional Multispecialty Review

Medicine is a rapidly-evolving discipline, with progress picking up pace with each passing decade. This constant evolution results in the introduction of new tools and methods, which in turn occasionally leads to paradigm shifts across the affected medical fields. The following review attempts to showcase how 3D printing has begun to reshape and improve processes across various medical specialties and where it has the potential to make a significant impact. The current state-of-the-art, as well as real-life clinical applications of 3D printing, are reflected in the perspectives of specialists practicing in the selected disciplines, with a focus on pre-procedural planning, simulation (rehearsal) of non-routine procedures, and on medical education and training. A review of the latest multidisciplinary literature on the subject offers a general summary of the advances enabled by 3D printing. Numerous advantages and applications were found, such as gaining better insight into patient-specific anatomy, better pre-operative planning, mock simulated surgeries, simulation-based training and education, development of surgical guides and other tools, patient-specific implants, bioprinted organs or structures, and counseling of patients. It was evident that pre-procedural planning and rehearsing of unusual or difficult procedures and training of medical professionals in these procedures are extremely useful and transformative.

Digitally designed, personalized bone cement spacer for staged TMJ and mandibular reconstruction - Introduction of a new technique

The aim of this paper is to introduce an innovative workflow for staged reconstruction of the mandible, including the temporomandibular joint (TMJ), using a temporary, patient-specific spacer. In cases of partial mandibular resection including disarticulation, sometimes needed to treat inflammatory bone disease, the spacer is intended to retain symmetry of the hard tissues, to preserve the soft tissues, and to act as a bactericidal agent. When complete healing of the affected surrounding tissues has occurred, final reconstruction using a patient-matched total TMJ endoprosthesis, in combination with an autogenous free bone flap, can be performed as a second-stage procedure. The crucial steps of the workflow are virtual surgical planning, manufacturing of a two-part silicone mold, and chairside manufacturing of the spacer using an established bone cement with gentamycin. The method was first introduced in two patients suffering from therapy-resistant chronic osteomyelitis. The presented protocol of staged surgery allows a much safer and predictable reconstruction compared with immediate reconstruction. The workflow also minimizes the potential risk of endoprosthesis infection - one of the major risks of implant failure.