Visuospatial abilities and 3D-printed based learning.

PURPOSE: The use of 3D-printing in every field of medicine is expanding, notably as an educational tool. The aim of this study was to assess how visuospatial abilities (VSA) of students may impact learning helped with 3D-printed models. METHODS: Participants were undergraduate medical school students during their clinical rotation in oral and maxillofacial surgery in two French Universities. Students were included prospectively and consecutively from September 2021 to June 2023. First, a lecture about craniosynostosis was performed with the help of 3D-printed models of craniosynostotic skulls. Then, a mental rotation test (MRT) followed by a multiple-choice questions (MCQs) form about craniosynostosis presentations were submitted to the students. RESULTS: Forty undergraduate students were finally included. Median MRT score was 15 (10.75;21) and median score to the MCQs was 13 (11.75;14). There was a significantly weak correlation between the MRT-A score and the score to the MCQs (rs = 0.364; p = 0.022). A simple linear regression was calculated to predict the result to the MCQs on MRT-A score [ (F(1,39) = 281.248; p < 0.0001), with a R2 of 0.878 ]. CONCLUSION: This study showed that VSA has an impact on the recognition of complex clinical presentations, i.e. skulls with craniosynostosis. The correlation found between VSA and complex 3D shape recognition after learning aided with 3D-printed model is emphasizing the importance of VSA when using innovative technologies. Thus, VSA training should be envisioned during the curriculum.

Simultaneous Mandibular Anterior Segmental Osteotomy and Genioplasty: A Novel Technique.

The current standard approach to treat class II malocclusion is orthodontic preparation followed by a mandibular advancement through bilateral sagittal split osteotomy associated or not with a genioplasty. However, when a malocclusion with an important incisors' axis deviation is associated with a chin malposition, an alternative technique can be considered: simultaneous mandibular anterior segmental osteotomy and genioplasty. This technique is performed without a bony bridge between osteotomies. Care must be taken not to wound the lingual mucosa. If preserved, this technique is safe. The result is stable and predictable.

Characterization of Infraorbital Nerve Sequelae After Orbital Floor or Zygomaticomaxillary Complex Fractures.

INTRODUCTION: Neurological sequelae of infraorbital nerve (ION) lesion 6 months after orbital floor or zygomaticomaxillary complex (ZMC) fractures, associated with initial ION injury, were compared according to the treatment performed and the type of fracture. The topographic and symptomatic sequelae at 6 months were described. MATERIALS AND METHODS: Patients with orbital floor or ZMC fracture associated with initial ION injury, between November 2018 and April 2020 and clinically reassessed 6 months after trauma were included. Detailed neurological symptomatology was assessed by a questionnaire. RESULTS: A total of 81 patients were included. Forty-two patients (51.8%) showed persistent neurological signs, i.e., isolated hypoesthesia in 28 patients (66.7%), isolated pain in 10 patients (23.8%) and both in 5 patients (9.5%). The most affected area was the cheek (42.8%). Thirty-eight patients (46.9%) presented associated signs, which were intermittent in 78.9% of cases. A pronounced improvement happened for 65.1% of patients and 76.7% were not or only slightly hindered in their daily activities. There were significantly more neurologic symptoms at 6 months in the surgical group than in the observational group and more in the ZMC fracture group than in the orbital floor fracture group. DISCUSSION: Neurological symptomatology was more frequent in patients treated surgically. Our results suggest the interest of a surgical decompression when orbital or ZMC fracture is associated with nerve damage but more data are needed. Neurological injury requires a careful initial clinical evaluation and regular follow-up to help patients coping, painful symptoms may benefit from specialized care.

3D printing for orbital volume anatomical measurement.

PURPOSE: The aim was to develop a method for reproducible orbital volume (OV) measurement in vivo based on 3D printing. METHODS: Twelve orbits were obtained from dry skulls of the Human Anatomy Department of Lille University. Computer tomography (CT) slice images of these orbits were transformed into stereo-lithography (STL) format and 3D-printed. Bone openings were closed using either putty and cellophane after printing (3D-Orb-1) or at the printing stage in silico using MeshMixer (3D-Orb-2). The results were compared with those of the conventional water-filling method as a control group (Anat-Orb). RESULTS: The observers reported a mean orbital volume of 21.3 ± 2.1 cm3 for the open-skull method, 21.2 ± 2.4 cm3 for the non-sealed 3D-printing method, and 22.2 ± 2.0 cm3 for the closed-print method. Furthermore, the intraclass correlation coefficients (ICCs) showed excellent intra-rater agreement, i.e., an ICC of 0.994 for the first observer and 0.998 for the second, and excellent interobserver agreement (ICC: 0.969). The control and 3D-Orb-1 groups show excellent agreement (ICC: 0.972). The 3D-Orb-2 exhibits moderate agreement (ICC: 0.855) with the control and appears to overestimate orbital volume slightly. CONCLUSION: Our 3D-printing method provides a standardized and reproducible method for the measurement of orbital volume.

Orthognathic Surgery in Craniosynostosis.

INTRODUCTION: Craniosynostosis is characterized by the fusion of 1 or more sutures of the skull leading to craniofacial deformations. Our aim is to describe the dental malocclusion associated with craniosynostosis, syndromic, or nonsyndromic, and also the treatment used and its stability. MATERIAL AND METHODS: This retrospective study included all patients who presented at our Department for facial growth monitoring and occlusal management following syndromic and nonsyndromic craniosynostosis. Inclusion began in January 1996 and ended in December 2015 to ensure sufficient follow-up. Orthognathic surgery was performed after the end of growth. Dental occlusion was evaluated clinically and radiographically. RESULTS: Fifty-five patients were included with 18 syndromic cases. The majority of patients presented with class III malocclusion (69.1%), especially syndromic cases (94.7%) and brachycephalies (96.3%). Conversely, scaphocephalies are associated with class II malocclusions. Thirty-nine patients underwent orthodontic treatment associated with orthognathic surgery to correct their malocclusion. In 4 cases, optimal dental occlusion was achieved with orthodontic treatment alone. Forty patients achieved stable optimal final dental occlusion. Optimal dental occlusion was achieved in 76.9% of the nonsurgically treated craniosynostosis patients and 68.9% of the surgically treated craniosynostosis patients. DISCUSSION: Sutural fusion induces a facial growth restrictions and dental malocclusions. Several mechanisms may be responsible for these malocclusions: positional anomaly of the jaws due to the cranial deformity, associated anomaly of the facial sutures, or osteocartilagenous system diseases. Early craniosynostosis management does not avoid the occurrence of malocclusion, which will require orthodontic treatment and orthognathic surgery for their management.

Temporomandibular Joint Dysplasia in Cranio-Maxillofacial Dysplasia: A Retrospective Study. Guideline Treatment Proposal.

INTRODUCTION: Cranio-Maxillofacial Dysplasias (CMD), including Craniofacial Microsomias, syndromes (such as Treacher Collins or Williams) and isolated Condylo-Mandibulo-Dysplasia, is a controversial subject with treatments as diverse as diagnostic classifications. The authors present here a retrospective study of 85 patients, with congenital condyle dysplasia arising from these 3 main types of CMD, treated with different techniques that aimed to normalize the facial skeleton and occlusion. METHODS: The authors studied retrospectively 85 patients, aged from 3 to 53 years old, affected by different types of CMD. Treatment options included: costochondral grafts, orthognathic surgeries, distraction osteogenesis procedures, orthodontic and dentofacial orthopedic treatments, and soft tissues surgeries. Outcomes were evaluated by the surgical team. RESULTS: Seventeen patients were treated with costochondral grafting, 14 with distraction osteogenesis, 17 with orthodontic and dentofacial orthopedic, and 45 with orthognathic surgery. The authors did not perform any nerve grafting or temporomandibular joints prosthesis placement. Fifty-one patients presented an excellent result, 10 a good result, 9 a poor result, 2 a bad result, and 14 an unknown result. DISCUSSION: Several different treatments of CMD can be proposed. The authors think that major defect in children should undergo costochondral grafting because of its growth potential while in case of minor defect, orthopedic treatment should be tried in the first place. Distraction osteogenesis should be reserved for cases with poor response after orthopedic treatment or growth insufficiency with costochondral grafting. Orthognathic surgery is often necessary at the end of the growth period to obtain an excellent result. Temporomandibular joints prosthesis should be reserved for extreme cases.

Surgical Management of Craniomaxillofacial Features in the Otopalatodigital Spectrum Disorders.

ABSTRACT: Otopalatodigital syndrome spectrum disorders are caused by Filamin A (FLNA) gene mutations. Otopalatodigital syndrome spectrum disorders are a group of rare congenital skeletal dysplasia, with specific craniomaxillofacial features including otopalatodigital syndrome type 1 and type 2, Melnick-Needles syndrome, frontometaphyseal dysplasia, terminal osseous dysplasia with pigmentary defects. The authors describe cases of a young girl with Melnick-Needles syndrome and a young boy with frontometaphyseal dysplasia treated in the Oral and Maxillofacial Surgery Department. Both patients had FLNA gene mutation confirmed with molecular genetic analysis. The authors proposed a 4 step treatment of the malformations with good outcomes both aesthetically and functionally, without complication.

Secondary Care of Cleft Lip and Palate: Analysis of Dentofacial Orthopedic and Orthognathic Treatments.

INTRODUCTION: Orthodontic and orthognathic management of cleft lip and/or palate (CLP) is a highly controversial subject. We present herein a retrospective study of 214 secondary cases followed over 22 years in order to assess the factors of successful management. MATERIAL AND METHODS: The study focuses on the results of gingivoperiosteoplasty, and occlusal stability. Nine subgroups were identified, taking into account the age of the patients, the history of surgery on the alveolar region, and the presence or absence of skeletal discrepancy. RESULTS: Results clearly demonstrate a higher rate of poor outcomes and failures in the multioperated population. The success rate of the graft is 80.82% in the multioperated population versus 100% non-multioperated population. Periodontitis problem or orthodontic difficulties affect 19.17% of the patient in the multioperated groups versus 12% in the other groups. Relapse, particularly the transversal dimension, is also found mostly in the multi-operated population: 17.8% versus 6% in the non-multioperated population. DISCUSSION: Several factors are involved in the success of orthodontics, dentofacial orthopedics, and orthognathic surgery of CLP patients. Our study shows that previous surgeries, especially when they are multiple with repeated failures, jeopardize the chances of success of secondary treatments. This is explained by the secondary fibrosis of the tissues around the cleft. Finally, major palatal surgeries performed early, have adverse effects on maxillary growth. Many other factors play an important role in the stability of the success that are linked with orofacial functions. These data must be taken into account in the treatment of CLP patients.

Lateral Pterygoid Muscle Biometric Modifications in Pterygoid Process Fractures Associated With Mandibular Fractures.

PURPOSE: Pterygoid process fractures (PPFs) are classically associated with Lefort fractures but can also be encountered in association with other facial fractures such as mandibular fractures. The aim of this study was to estimate the frequency of PPFs associated with mandibular fractures and identify factors associated with PPF. MATERIALS AND METHODS: We conducted a retrospective cross-sectional study using computed tomography scanning of patients having a mandibular fracture between November 2018 and April 2020. PPFs were classified using the classification by An et al. Volume, length, and width of both lateral pterygoid muscles have been evaluated by using an image processing software. Study population has been divided into 2 groups: fracture of pterygoid process or the absence of PPF. To evaluate the implication of lateral pterygoid muscle in the pathophysiology of PPF, we compared lateral pterygoid muscle volume, its maximal length, and width between both groups. Patients with bilateral fractures were excluded from this analysis. RESULTS: About 304 patients with at least 1 mandibular fracture have been included in this study. About 18 patients presenting an association of mandibular fracture and PPF were finally selected. About 83.33% of the patients were concerned by a fracture of the posterior part of the mandible. The PPF was classified as type IIA by the classification of An et al for 94.4% of patients. The lateral pterygoid muscle volumes were significantly larger on the side of the PPF (P = .02). However, there were no significant differences in the maximum length (P = .49) and width (P = .1) of lateral pterygoid muscle. CONCLUSIONS: Our study showed an association between mandibular fractures (mainly ipsilateral posterior) and isolated PPF through a lateral pterygoid muscle volume increase.

Prediction of Post-Traumatic Enophthalmos Based on Orbital Volume Measurements: A Systematic Review.

PURPOSE: Enophthalmos greater than 2 mm should be considered clinically relevant and can be responsible for esthetic and functional morbidity. The difficulty has always been the best method to use to accurately determine when the orbital wall displacement will lead to clinically relevant enophthalmos. None of the currently used techniques is able to accurately predict for post-traumatic enophthalmos (PE). The aim of the present study was to systematically review the use of orbital volumetric tools in the prediction of PE after orbital fracture. MATERIALS AND METHODS: The terms searched in each database were "(orbital volumetry) and enophthalmos," "volumetry and enophthalmos," "volume and enophthalmos," and "volumetric and enophthalmos." The relationship between PE and the orbital volume (OV) was assessed. RESULTS: The initial search yielded 346 results. Of the 346 studies, 14 were included and analyzed. Every study reported a different numerical relationship between the OV and PE, with a mean enophthalmos of 0.80 mm after a 1-cm3 increase in the OV. CONCLUSIONS: The present review found that most studies concluded that a direct relationship exists between the OV and PE and defined the degree of PE in relation to the OV expansion. Enophthalmos assessment using radiologic evaluation provides increased accuracy and reproducibility compared with clinical measurement using an exophthalmometer. It has been notoriously difficult to determine when orbital wall displacement will lead to clinically relevant enophthalmos. Measurement of the OV could have a role in the decision for surgical or conservative treatment.

Three-Dimensional Printing of Prenatal Ultrasonographic Diagnosis of Cleft Lip and Palate: Presenting the Needed "Know-How" and Discussing Its Use in Parental Education.

Parental prenatal counseling is of paramount significance since parents often experience an emotional crisis with feelings of disappointment and helplessness. Three-dimensional (3D) printed model of the unborn child's face presenting with cleft lip and palate, based on ultrasonographic information, could be used to provide visual 3D information, further enhancing the prospective parent's comprehension of their unborn child's pathology and morphology, helping them to be psychologically prepared and improving the communication with the caretaking team. Prospective parents appreciate if prenatal counseling is available with the most detailed information as well as additional resources. The technique necessary to create 3D models after ultrasonographic information is explained, and the related costs are evaluated. The use of such models in parental education is then discussed.

A New Orbito-Zygomatic Complex Reconstruction Technique Using Computer-Aided Design and Manufacturing-Assisted Harvest of Autologous Calvarial Bone in Cases of Orbito-Zygomatic Benign Tumor.

The orbito-zygomatic complex (OZC) includes several key structures, and its destruction leads to the impairment of functional activities such as nutrition, communication, nasal support, and vision. Management of benign tumors of the OZC is therefore a surgical challenge because of the necessity for reconstruction of these elements. Autogenous bone is considered the gold standard for reconstruction. Nevertheless, there is difficulty related to the complex anatomy and distorted skeletal anatomic landmarks, which require precise work in the case of bone grafts. The aim of this report is to propose a new reconstruction technique consisting of OZC reconstruction with computer-aided design and manufacturing of autologous calvarial bone. Three cases are presented. After performing tumor resection using computer-aided design and manufacturing cutting guides, we used a piezotome to perform osteotomies and preserve the periosteum and sinus mucosa. The SinpliciTi system (Materialise, Châtillon, France) allowed us to make cutting guides and a 3-dimensional surgical plan of the shapes and ideal positions of the calvarial bony plates for the OZC reconstruction. Calvarial osteotomies were performed using a piezotome through the polyamide calvarial cutting guide to obtain the shapes designed beforehand. Once the samples were collected, the shapes could be assembled ex vivo and then put in place through a minimally invasive approach. We discuss the advantages and limitations of our reconstruction method and its place in the management of OZC reconstruction.

Dental and Maxillofacial Signs in Leri-Weill Dyschondrosteosis.

One of the most common causes of short stature is a defect of the short stature homeobox-containing (SHOX) gene, which is located in pseudoautosomal region 1 on the distal end of the short arm of chromosomes Xp22.33 and Yp11.32. More than 300 different mutations in the SHOX gene responsible for short stature syndrome have been described. The phenotypic expression of SHOX haploinsufficiency is remarkably varied. The 3 typical clinical presentations, from least to most severe, are idiopathic short stature without skeletal malformations, Leri-Weill dyschondrosteosis (LWD), and Langer mesomelic dysplasia, which is believed to represent the homozygous form of LWD. Despite a higher prevalence in women, suggesting the potentiating action of high estrogen levels on the effects of SHOX deficiency, the syndrome was initially believed to have an autosomal pattern of inheritance. In reality, heterozygous SHOX mutations can be transferred from the Y to the X chromosome and vice versa. This phenomenon is called "the jumping SHOX gene" and corresponds to a pseudoautosomal dominant inheritance. LWD is characterized by mesomelic short stature and Madelung deformity defined by an upward and medial displacement of the radial joint surface, which restricts range of motion. Less specific dysmorphic signs associated with LWD, such as short hands and feet, scoliosis, or muscular hypertrophy, have been described. When reviewing the dental and maxillofacial signs, only limited and summary data (micrognathia and high arched palate) have been published in the literature. This report presents a case of LWD that highlights many other noteworthy dental and maxillofacial signs that are important to clearly identify and appropriately treat.

Postoperative morbidity of free flaps in head and neck cancer reconstruction: a report regarding 215 cases.

OBJECTIVES: The aim of this study was to identify the factors responsible for free flap failure, the surgical complications, and the non-oral feeding period in patients treated for an oral squamous cell carcinoma. MATERIALS AND METHODS: This multicentric study included 215 patients treated by tumour resection with immediate free flap reconstruction for an OSCC between 2010 and 2016. All of the patient medical files were reviewed and the data regarding the patient medical history, the tumour-related features, the surgical procedure, and the postoperative recovery were compiled. A statistical analysis with univariate and multivariate logistic regression was carried out. RESULTS: The free flap success rate was 94.4% in our series. A postoperative complication occurred in 101 patients (41%). Minor surgical complications were shown to increase the free flap failure rate (OR 3.32; p = 0.04). A major surgical complication was encountered in 48 patients (22.3%), and these were linked to minor surgical complications (OR 2.89; p = 0.004) and the use of a tracheostomy (OR 5.76, p = 0.002). Conversely, a medical history of high blood pressure had a protective effect (p = 0.04). The non-oral feeding rate at the end of the hospital stay was 28.4%, and it correlated with the tracheostomy (p = 0.002), as well as the major and the minor surgical complications (p = 0.04). CONCLUSION-CLINICAL RELEVANCE: Free flap reconstruction is a safe and reliable technique with head and neck cancer reconstruction. Postoperative care favouring early and safe oral-feeding, and avoiding a tracheostomy can reduce the incidence of surgical complications after OSCC reconstruction.

Reconstruction of a Large Posttraumatic Mandibular Defect Using Bone Tissue Engineering With Fresh-Frozen Humeral Allograft Seeded With Autologous Bone Marrow Aspirate and Vascularized With a Radial Forearm Flap.

INTRODUCTION: Currently, vascularized autologous bone transplantation is considered the gold standard for large mandibular continuity defect reconstruction. Donor site morbidity is a major concern. Therefore, bone tissue engineering (BTE) seems to be the ideal solution. Fresh-frozen bone allograft is the closest material to autologous bone. The purpose of this clinical report is to show a new technique of large mandibular continuity defect reconstruction using a fresh-frozen humeral allograft seeded with autologous iliac bone marrow aspirate and vascularized with a radial forearm flap. METHODS: A 33-year-old man presented with severe cranio-facial trauma resulting in several fractures of the facial skeleton including a comminuted mandibular fracture from left parasymphysis to left angle, which caused a large continuity defect. RESULTS: Result at 6 months was aesthetically and functionally satisfactory with osseointegration of the bone graft. DISCUSSION: The authors chose to use iliac bone marrow aspirate to seed the allograft scaffold since hematopoietic stem cells and mesenchymal stem cell are able to differentiate into osteoblasts, ease of harvest of the iliac crest and its low rate of morbidity. Contemporary biomaterials used for BTE are bioceramic but bone is still the better scaffold to engineer bone and only allografting avoids donor site morbidity. Vascularization is one of the main challenges of BTE; insertion of autologous vascular bundles from pedicle or free flaps is 1 solution. The authors chose the radial forearm flap since the pedicle is long and the authors did not need a great amount of soft tissue.

Modified Mandibular Sagittal Split Osteotomy.

INTRODUCTION: Mandibular osteotomies aim to displace the dental arch to the necessary position, ideally without limitation, while preserving inferior alveolar nerve (IAN) function. Supraforaminal osteotomies offer nerve safety but limit the extent of advancement, whereas Epker and Obwegeser-Dal Pont osteotomies enable unchallenged mandibular advancement but are associated with an inferior border notch. Here, we describe a new technique to avoid such disadvantages. TECHNICAL NOTE: The beginning of the procedure was similar to Epker's technique, with sectioning of the lingual cortex up to the level of the lingula. Sectioning of the buccal cortex was stopped 3 to 4 mm above the inferior border and then performed horizontally up to the gonial angle in total thickness. The inferior border periosteum and muscles attachments were conserved and hence, appropriately vascularized. DISCUSSION: This technique offers 4 advantages: absence of the inferior border notch, lower risk of damage to the IAN than with Epker's technique, sufficiently large bony surface to obtain bone healing as in Epker's technique, and no limitation to setback movement in contrast to Obwegeser-Dal Pont's or the supraforaminal osteotomy techniques.

Assessing Quality of Life After Orthognathic Surgery in Disabled Patients.

INTRODUCTION: Orthognathic surgery is a common procedure in facial deformities treatment but requires a high level of compliance from the patient. Performing this treatment for mentally disabled patients is a subject of discussion. The aim of this study was to evaluate the quality of life (QOL) after orthognathic surgery in disabled patients. MATERIAL AND METHODS: Eight patients with mental disability who underwent orthognathic surgery between 2007 and 2017 participated in this study. Their family or guardian completed a questionnaire to assess modification in aesthetic, functional, and social abilities after orthognathic surgery. Complications, difficulties in maintaining postoperative cares were also recorded. RESULTS: All patients had improvement in global facial aesthetic. 62.5% of the patients had improvement in self-esteem and confidence in social events. Regarding functional aspect, the main improvement was found in chewing (75%) and ability to move the jaw (75%). Two patients (25%) found that jaw noises and pain were worse after surgery. No major complication occurred. Postoperative care was hard to follow but no patient had to stop maxillomandibular fixation. CONCLUSION: On well selected cases, orthognathic surgery is a safe procedure which provides improvement in QOL in disabled patients.

Cranio-Maxillofacial and Dental Findings in Albright's Hereditary Osteodystrophy and Pseudohypoparathyroidism.

INTRODUCTION: The clinical phenotype of pseudohypoparathyroidism (PHP) is caused by Albright's Hereditary Osteodystrophy (AHO). Often, "round face" the only facial clinical sign reported in the literature. The aim of this study was to highlight various cranio-maxillofacial clinical findings associated with AHO. RESULTS: Four patients presented with PHP type 1a. Only one patient exhibited the classical round face. All patients exhibited dental anomalies, class III malocclusion with maxillary retrusion, and a copper beaten appearance of the skull. One suffered from craniosynostosis. CONCLUSION: The frequency of craniofacial and dental features associated with malocclusion should prompt careful follow-up, particularly during facial growth, in patients with AHO.

Use of 3D printed models in student education of craniofacial traumas.

A low-cost 3D printed model has been introduced into the oral and maxillofacial surgery teaching program of undergraduate students to improve education and mechanical comprehension of craniofacial trauma. Steps of the 3D printed haptic model building process are listed. 3D printed models of facial fractures were obtained from Data Imaging and Communications in Medicine (DICOM) data. Computed Aided Design and Manufacturing (CAD-CAM) freeware was used to create new fractures on the standard tessellation language (STL) file. 3D printed haptic model appears to be an efficient low-cost support for craniofacial trauma education of undergraduate students.