Primary Failure of Dental Eruption Due to Variants Parathyroid Hormone Receptor 1: Retrospective Study and Proposal of Guidelines Treatment

OBJECTIVE

Primary failure of eruption is characterized by a nonsyndromic defect in tooth eruption in the absence of mechanical obstruction. It is correlated to rare heterozygous variants in the parathyroid hormone receptor 1 gene. The management of primary failure of eruption is complex because many therapies are ineffective. The present study aimed to compare the clinical outcomes of our patients with the findings reported in the literature, and to propose a treatment guideline based on the literature and our experience.

METHODS

Retrospective study of patients affected by primary dental eruption failure in the department and analyse of the results and compare with those of the litterature.

RESULTS

Twelve patients belonging to 5 families (9 males, 3 females; 13-52 y old) diagnosed and treated in the maxillofacial surgery and stomatology department of the Lille University Hospital were included. All patients showed posterior tooth involvement, and most patients showed bilateral defects. None of the affected teeth had coronal alveolar bone, whereas 6 patients showed root resorption in the affected teeth. Genetic analyses, performed on 11 patients, identified a parathyroid hormone receptor 1 disease-causing variant in 7 of them (63%). Multidisciplinary treatment was required to rehabilitate these patients. Orthodontic interventions, even at an early age, are difficult in affected teeth, which are often blocked or have internal resorption. Moreover, retention of these affected teeth during growth leads to dentoskeletal malocclusions, requiring difficult surgical management in the long term. Therefore, early extraction of these teeth is frequently recommended once the diagnosis has been confirmed. An implant-borne prosthetic rehabilitation can then be achieved at the end of growth after correction of the jaw discrepancy. In case of a late diagnosis, other surgical or noninvasive techniques may be used depending on the clinical situation. Distraction osteogenesis or segmental osteotomy could be discussed for patients with mild phenotypes.

CONCLUSIONS

Early diagnosis of primary eruption defects is crucial to offer appropriate management as early as possible, and so to avoid late complicated treatments.

AI-based diagnosis in mandibulofacial dysostosis with microcephaly using external ear shapes

Introduction

Mandibulo-Facial Dysostosis with Microcephaly (MFDM) is a rare disease with a broad spectrum of symptoms, characterized by zygomatic and mandibular hypoplasia, microcephaly, and ear abnormalities. Here, we aimed at describing the external ear phenotype of MFDM patients, and train an Artificial Intelligence (AI)-based model to differentiate MFDM ears from non-syndromic control ears (binary classification), and from ears of the main differential diagnoses of this condition (multi-class classification): Treacher Collins (TC), Nager (NAFD) and CHARGE syndromes.

Methods

The training set contained 1,592 ear photographs, corresponding to 550 patients. We extracted 48 patients completely independent of the training set, with only one photograph per ear per patient. After a CNN-(Convolutional Neural Network) based ear detection, the images were automatically landmarked. Generalized Procrustes Analysis was then performed, along with a dimension reduction using PCA (Principal Component Analysis). The principal components were used as inputs in an eXtreme Gradient Boosting (XGBoost) model, optimized using a 5-fold cross-validation. Finally, the model was tested on an independent validation set.

Results

We trained the model on 1,592 ear photographs, corresponding to 1,296 control ears, 105 MFDM, 33 NAFD, 70 TC and 88 CHARGE syndrome ears. The model detected MFDM with an accuracy of 0.969 [0.838-0.999] (p < 0.001) and an AUC (Area Under the Curve) of 0.975 within controls (binary classification). Balanced accuracies were 0.811 [0.648-0.920] (p = 0.002) in a first multiclass design (MFDM vs. controls and differential diagnoses) and 0.813 [0.544-0.960] (p = 0.003) in a second multiclass design (MFDM vs. differential diagnoses).

Conclusion

This is the first AI-based syndrome detection model in dysmorphology based on the external ear, opening promising clinical applications both for local care and referral, and for expert centers.

Dental and maxillofacial manifestations of Steinert's myotonic dystrophy: A retrospective case series and therapeutic investigation

This retrospective study was performed to analyse the facial features and occlusal anomalies in 18 patients with Steinert's myotonic dystrophy (MD1). Medical and surgical management issues noted in this study may contribute to clinical decision-making. This series included 18 patients with MD1 who presented for maxillofacial consultations. For all patients, the following characteristics were assessed: sex, age, intellectual ability, oral condition, initial assessment of the occlusion and facial aspect. In total, 11 of 18 patients underwent surgery (10 achieved occlusion modification, whereas one did not). amongst patients who underwent surgery and achieved occlusion modification, six had stable class I results and four had unstable results or exhibited a slight degradation. Facial muscles play an important role in craniomaxillofacial development and facial aspects. A high prevalence of malocclusions is present in patients with MD1. Orthodontics and orthognathic surgery can improve the quality of life for affected patients. However, the long-term results of these treatments may be disappointing, and relapse can occur in patients with the most severe disease. Aspects of disease to consider while planning for surgery include oral health, risks of instability and relapse, and risks involving anaesthesia.

Three-dimensional printing models improves long-term retention in medical education of pathoanatomy: A randomized controlled study

INTRODUCTION

Craniosynostosis is a rare and complex pathology, and visuospatial skills are necessary for a good understanding of the condition. While the use of three-dimensional (3D) models has improved the understanding of complex craniofacial anatomy, no study has evaluated the impact of this teaching support on long-term retention.

MATERIALS AND METHODS

Our randomized controlled trial was designed to compare the long-term retention of information with 3D-printed models of four types of craniosynostosis versus classic 3D reconstructions displayed in two-dimensional (2D) among undergraduate students. All students benefited from the same standardized course followed by the manipulation of the learning tool associated with the group for 15 minutes. Long-term retention was assessed by the capability to properly recognize different types of craniosynostosis 3 weeks after the course.

RESULTS

Eighty-five students were enrolled. Previous educational achievements and baseline visuospatial skills were similar between the groups. The bivariate analysis showed the mean score in the 3D and 2D groups were 11.32 (2.89) and 8.08 (2.81), respectively (p < 0.0001).

CONCLUSIONS

3D-printed models of structures with spatial complexity such as various craniosynostosis patterns improve significantly medical students' long-term retention, indicating their educational efficacy.

Implant-borne rehabilitation for alveolar dental cleft: Retrospective analysis of thirty-nine cases

INTRODUCTION

Dental rehabilitation of patients with alveolar-dental cleft sequelae is a crucial issue in the final stages of functional and aesthetic management of these patients. The objectives of this study are to establish the success of implant-supported rehabilitations for patients with alveolar dental cleft sequelae followed in the Department of Maxillofacial Surgery and Stomatology of Lille University Hospital and the reasons for not using this type of rehabilitation for others.

MATERIALS AND METHOD

Patients treated between January 2009 and December 2018 with implant-supported prostheses at an alveolar dental cleft site were included. Dental implants were placed after a complementary alveolar bone graft. Clinical and radiological criteria regarding periodontal, occlusal and prosthetic status were studied.

RESULTS

A total of 12 implants in 8 patients were placed. One of these implants was lost, resulting in an implant survival rate of 91.7%. All patients were able to benefit from functional rehabilitation.

DISCUSSION

The present results demonstrate the interest and reliability of implant rehabilitation in these patients. They furthermore highlight financial factors as a barrier to using this solution among the majority of patients in care.

Anatomic study of the arterial territories of the face depending on the external carotid artery branches

AIM OF THE STUDY

Blood supply of the skin of the face is mainly provided by 3 branches of the external carotid artery: facial artery (FA), superficial temporal artery (STA) and transverse facial artery (TFA) which is a branch of the STA. The aim of the study was to describe the arterial territories of the skin of the face depending on the external carotid branches.

MATERIAL AND METHODS

After dissection of the first two centimeters of these arteries on one side, we performed an injection of India ink of different colors in the arteries in order to describe the arterial territories (angiosomes) of the face on 24 embalmed cadavers.

RESULTS

The lips and the tip of the nose were vascularized in most cases by the FA. The STA vascularizes the temporal and frontal areas and a part of the auricle. The buccal area blood supply is coming from the FA with a participation of the TFA which is variable (10/24 cases), and the zygomatic area blood supply is coming from the STA with a participation of the TFA (9/24 cases).

CONCLUSIONS

Variations in the angiosomes of the face have to be considered in reconstructive surgery, and in face transplantation.

[Surgical management of animal bites in children]

Children represent a population at risk, because of their short size, their naivety and their attraction to animals. The face and hands are the most specific locations in young children. Wounds are often multiple. In more than half the cases, the child knows the animal, which are dogs and cats by frequency argument. The bite episode occurs mostly when the child is alone with the pet without direct supervision, while playing or stroking the animal. As in all bites, pediatric lesions are infectious, functional and aesthetic emergencies, but the goal of this work was primarily to make a point on principles of surgical management of animal bites in children, highlighting pediatric specificities. Animal bites require psychological, anesthetic and surgical treatment, adapted to the child, in a specialized structure. Hospitalization and general anesthesia are more frequent in children. Any suspicion of mistreatment (and/or abuse) should lead to the child's hospitalization, even if wounds do not justify monitoring in a surgical environment. Emergency surgery is essential to limit functional and aesthetic consequences. The healing capacities of the child and the frequent lack of co-morbidity allow a conservative surgical treatment with suture, repositioning skin flaps and controlled healing in the first place. Immobilization, drainage, and antibiotics will complete the surgery. The healing process, however, leads to a specific management during scar remodeling phase and growth. Psychological care of the child and parents should not be forgotten, and has to start at the same time as surgical treatment at in acute phase.

Retrospective evaluation of 211 patients with maxillofacial reconstruction using parietal bone graft for implants insertion

PURPOSE

For a century, autologous bone grafts have been used in maxillofacial reconstruction. The ideal bone harvest site and grafting procedure remains a point of contention in regards to obtaining optimal long-term results with sufficient bone quantity and density without serious complications. More recently, confronted with growing patient requests and biomaterials development, maxillofacial surgeons and dentists have been considering these issues as they relate to pre-implant surgery. This study sought to evaluate implant success rate and complications following pre-implant surgery with parietal bone grafting.

MATERIALS AND METHODS

A retrospective study was carried out on patients who underwent maxillofacial reconstruction of different sites (symphysis, mandibular corpus, maxillary sinus and premaxilla) for the purpose of implant insertion.

RESULTS

311 procedures in 211 patients were included. The implant osseointegration rate was around 95%. Clinical follow-up ranged from 10 months to 11 years. A secondary procedure was performed in 6.1% of cases and we noted no serious complications at the harvest site.

DISCUSSION

With good revascularization and osseointegration of the graft, the use of parietal bone leads to an implant success rate similar to that seen in the literature. Moreover, the use of this material results in few infections and low bone resorption provided there is strict immobilization of the graft and no tension on the soft tissue sutures.

CONCLUSION

Parietal bone grafts technique possess the required qualities for the success of implant surgery, offering results at least as interesting as others using autogenous bone and with no serious complications on donor site.