Leander Dubois

Academisch Medisch Centrum Universiteit van Amsterdam | AMC · Department of Oral and Maxillofacial Surgery

Objectives Temporomandibular disorders (TMD) are musculoskeletal conditions with a multifactorial aetiology. The predictive role of direct orofacial macrotrauma in the development of TMD is considered controversial. This systematic review aims to elucidate the association between direct orofacial macrotrauma and TMD, and to identify potential facto...

Panfacial fractures are complex fractures involving multiple regions of the facial skeleton and may require multiple surgeries over a relatively short period. They are often associated with polytrauma and other injuries including neurotrauma, which require either immediate (ATLS) airway management, prolonged intubation, or repeated intubations for...

After nasal bone fractures, fractures of the mandible are the most frequently encountered injuries of the facial skeleton. Accurate identification of fracture locations is critical for effectively managing these injuries. To address this need, JawFracNet, an innovative artificial intelligence method, has been developed to enable automated detection...

Management of orbital fractures has been a topic of controversy for the last 50 years. There is consensus on acute indications for orbital reconstruction and the need for surgery in large fractures with severe functional symptoms or early enophthalmos. Small fractures without complaints will generally be treated without surgery. There is a large gr...

This chapter focuses on the preparation, execution, and evaluation of orbital reconstruction, once the indication for surgery has been established. A logical order in the surgical decision-making process is created with the help of a step-wise approach, starting with timing and biomaterials considerations. The virtual treatment planning is describe...

Panfacial fractures are complex injuries involving multiple regions of the facial skele-ton simultaneously, which may necessitate multiple surgeries over a relatively short period. They are often associated with polytrauma and other injuries including brain trauma, which re-quire either immediate airway management, prolonged intubation, or repeated...

Objective As treatment options for condylar fractures have comparable outcomes, getting insight into associated costs is a first step towards implementing value-based healthcare (VBH). Therefore, we described the actual costs of the different treatment options (surgical, conservative, and expectative treatment) for condylar fractures. We expected s...

Objective: Premature dental contact on the fractured side and a contralateral open bite are signs of a unilaterally fractured condyle of the temporomandibular joint (TMJ). The lateral pterygoid muscle pulls the condyle inwards, causing angulation of the fractured part and shortening of the ramus. This imbalance after fracture might change the load...

After a fracture of the condyle, the head of the condyle is often pulled inwards, which causes the fractured part to angulate medially. This change can cause a disbalance in the masticatory system. The disbalance could lead to contact stress differences within the temporomandibular joints (TMJs) which might induce remodelling within the TMJ to rest...

Purpose: To assess the difference between preformed anatomically shaped osteosynthesis plates and patient-specific implants versus conventional flat plates for the treatment of skeletal fractures in terms of anatomical reduction, operation time, approach, patient outcomes, and complications. Material and methods: MEDLINE (1950 to February 2023),...

Objectives: After a fracture of the condyle, the fractured ramus is often shortened, which causes premature dental contact on the fractured side and a contralateral open bite. The imbalance could change the load in the temporomandibular joints (TMJs). This change could lead to remodelling of the TMJs to compensate for the imbalance in the masticat...

Background: Three-dimensional (3D) imaging allows assessment of changes in condylar volume and morphology. The association between the morphology of the condyle and post-treatment functional impairment is still unclear. Purpose: To analyse the volume of both condyles after a unilateral condylar fracture and to evaluate the relationship between cond...

Objectives This study pertains to a secondary data analysis aimed at determining differences between oral and maxillofacial surgeons (OMFSs) and dentists handling dental extractions without an evident clinical indication. Study design A survey of 18 questions was conducted among 256 OMFSs in the Netherlands and a random sample of 800 dentists Resp...

Restoration of the orbit is the first and most predictable step in the surgical treatment of orbital fractures. Orbital reconstruction is keyhole surgery performed in a confined space. A technology-supported workflow called computer-assisted surgery (CAS) has become the standard for complex orbital traumatology in many hospitals. CAS technology has...

Treatment of odontogenic infections, such as drainage of submucosal abscesses, should be carried out by the dental practitioner. However, when an odontogenic infection deteriorates into a deep neck abscess, treatment should be carried out by the oral maxillofacial surgeon. Based on two cases, this article describes the clinical presentation, course...

Inflammation begins as a response of the immune system to an external, harmful stimulus. This stimulus can be chemical, mechanical or bacterial in nature. The inflammatory response is necessary to create optimal conditions for healing. In case of pulpitis, a peri-apical granuloma, peri-coronitis or periodontitis, complaints arise as a result of an...

The terms inflammation and infection are often used interchangeably. Technically this is incorrect. Inflammation is defined as the body's response to a potentially damaging stimulus. Infection involves tissue invasion by microorganisms. An inflammatory reaction will be provoked when infection occurs in an otherwise healthy patient. Inflammation can...

Within 24 hours after a human bite trauma, a 34-year-old male patient became septic and ended up at an intensive care unit. The combination of a local damage of the skin or mucosa, aggressive micro-organisms, local host factors, and some bad luck resulted in necrotizing fasciitis for this patient. This is a very rapid progressive infection which ca...

Background The purpose of this study was to determine how often dental patients request extraction for nondental reasons and how dentists handle such requests. Methods The authors conducted a survey among 800 Dutch dentists from November 17, 2019, through January 5, 2020. The questionnaire contained 17 items, including a hypothetical case vingette...

Orbital reconstruction is one of the most complex procedures in maxillofacial surgery. It becomes even more complex when all references to the original anatomy are lost. The purpose of this article is to provide an overview of techniques for complex three- and four-wall orbital reconstructions. Preoperative virtual surgical planning is essential wh...

In orbital reconstruction, a patient-specific implant (PSI) may provide accurate reconstruction in complex cases, since the design can be tailored to the anatomy. Several design options may be embedded, for ease of positioning and precision of reconstruction. This study describes a cohort of 22 patients treated for secondary orbital reconstruction...

The accuracy of intra-operative navigation is largely dependent on the intra-operative registration procedure. Next to accuracy, important factors to consider for the registration procedure are invasiveness, time consumption, logistical demands, user-dependency, compatibility and radiation exposure. In this study, a workflow is presented that elimi...

Management of zygomaticomaxillary complex (ZMC) fractures can be challenging. Consequently, there is a difference in treatment amongst clinicians. In literature it remains unclear if the number of fixation points affects the quality of the anatomical reduction, stability through time, and the potential complications. Therefore, the objective was to...

In intra-operative navigation, a registration procedure is performed to register the patient’s position to the pre-operative imaging data. The registration process is the main factor that determines accuracy of the navigation feedback. In this study, a novel registration protocol for craniofacial surgery is presented, that utilizes a virtual splint...

Adequate positioning of an orbital implant during orbital reconstruction surgery is mandatory for restoration of the pre-traumatised anatomy, but visual appraisal of the implant’s position is limited by the keyhole access and protruding soft-tissues. A positioning instrument, that attaches to the implant, was designed to provide feedback outside th...

Objective Most tooth extractions are performed for dental reasons, but there are also nondental and nonmedical reasons for extractions; these include psychological, financial, religious, and cultural reasons as well as simply granting a patient's request. This systematic review was performed to examine the proportion and range of indications associ...

The accuracy of intra-operative navigation is largely dependent on the intra-operative registration procedure. Next to accuracy, important factors to consider for the registration procedure are invasiveness, time consumption, logistical demands, user-dependency, compatibility and radiation exposure. In this study, a workflow is presented that elimi...

Isolated fractures of the anterior wall of the frontal sinus are most often treated through a coronal approach. Although the coronal approach is a relatively easy procedure, the size of the incision is causing more problems related to patient morbidity and recovery time than smaller approaches. A novel, minimal invasive procedure for reconstruction...

In naso-orbito-ethmoid (NOE) fractures, a highly complex and delicate region is involved. Commonly, the focus of most clinicians goes to the esthetical disfigurations, such as the loss of nasal projection, position of the medial canthal tendon or enophthalmos/hypoglobus, or the functional problems such as diplopia. Nasal investigation is mandatory...

A 15-year-old girl was brought to the emergency department of a hospital by ambulance with extensive facial trauma following a horse's kick. The considerable impact resulted in a combination of injuries to the bone, teeth and soft tissue. Following the transfer from the ambulance, the AE physician immediately consulted an oral and maxillofacial sur...

In dental trauma, the first thought is often: 'Where is that tooth?' And, of course, it is certainly true that fast repositioning is beneficial for the prognosis of the tooth. Nevertheless, it is extremely important to focus on the condition of the patient before focussing on the treatment. A structured approach is mandatory for optimal diagnosis a...

It is estimated that, in the Netherlands, 20-30% of 18-year-olds have suffered some form of dental trauma. A third of them must bear the consequences for the rest of their lives. Adequate care and treatment can make a difference and considerably improve the prognosis of a traumatised tooth. Knowledge about the various types of injuries, forms the b...

Intraoperative imaging enables the surgeon to control the position of the implant during orbital reconstruction. Although it might improve surgical outcome and avoid the need for revision surgery, it may also increase the duration of the operation and the exposure to radiation. The goal of this study was to find out whether intraoperative imaging i...

A 68-year-old man presented at the emergency room with acute difficulty breathing. On account of recent subarachnoidal haemorrhage the patient was a resident of a care facility, and was also being treated for acute bronchitis there. Radiographic imaging of the lungs revealed a tooth with crown and pontic to have been inhaled. The tooth was surgical...

Objective This study presents the results of an updated clinical protocol for orbital blow-out fractures, with a special emphasis on nonsurgical treatment and orthoptic evaluation of functional improvement. Methods A two-centre multidisciplinary prospective cohort study was designed to monitor the results of a clinical protocol by assessing ductio...

In orbital reconstruction, the acquired position of an orbital implant can be evaluated with the aid of intraoperative navigation. Feedback of the navigation system is only obtained after positioning of the implant: the implant's position is not tracked in real time during positioning. The surgeon has to interpret the navigation feedback and transl...

Purpose: Cranioplasty is customary after decompressive craniectomy. Many different materials have been developed and used for this procedure. The ideal material does not yet exist, while complication rates in cranioplasties remain high. This study aimed to determine factors related to autologous bone flap failure. Materials and methods: In this...

A 58-year-old patient with a history of intravenous use of denosumab was referred to the department of oral and maxillofacial surgery with inadequate recovery after a series of extractions. During physical and radiological examination, several sites of exposed necrotic bone with purulent discharge were seen, and the maxilla appeared fractured at th...

Two patients were referred to a maxillofacial surgeon in connection with the occurrence of needle breakage during local anaesthesia. In the first case, of a 67-year-old woman, it concerned a needle breakage after giving mandibular block anaesthesia. The needle could be removed quite easily under local anaesthesia. The second case concerned a less c...

Purpose: The aim of this study was to evaluate the accuracy of resection templates in cranioplasties in order to facilitate a one-stage resection and cranial reconstruction. Patients and methods: In three cases, cranial resections were combined with direct reconstructions using the principles of computer-aided design, manufacturing, and surgery....

The treatment of mandibular condyle fractures has been the subject of considerable discussion, especially whether open or closed treatment should be used. There is a need for practical,evidence-based guidelines, and both objective and subjective parameters should be measured. To date, fewstudies have considered clinically relevant subjective parame...

Background: There is considerable controversy about whether condylar fractures should be treated open or closed. Even when there is a clear indication for open treatment, the appropriate approach opens another debate. Purpose: To provide a clear overview on the complications of extraoral approaches to condylar fractures. Methods: Systematic li...

Post-traumatic malocclusion is one of the most common complications following closed treatment of condylar fractures. Depending on the severity of the malocclusion, most clinicians choose an orthodontic and/or surgical treatment plan. In this technical note, an alternative non-surgical procedure for managing malocclusion complications associated wi...

Objective: Advanced three-dimensional (3D) diagnostics and preoperative planning are the first steps in computer-assisted surgery (CAS). They are an integral part of the workflow, and allow the surgeon to adequately assess the fracture and to perform virtual surgery to find the optimal implant position. The goal of this study was to evaluate the a...

In the Netherlands the general public can legally use fireworks on New Year's Eve. Despite the fact that the public is well aware of the dangers of fireworks, fireworks accidents occur in which the victims suffer a variety of injuries. In addition to burns, injuries to fingers and/or hands are most common. However, injuries to the eye, which can al...

Dubois L, Bahalou Hore M, Tjiook RP, Mourits MP, Kloos R, Brons R. De impact van vuurwerk: achtergronden van het aangezichtsletsel [The impact of fireworks: the context of facial trauma]. Ned Tijdschr Tandheelkd. 2017;124(12):619-623. doi:10.5177/ntvt.2017.12.17188

Intraoperative navigation is frequently used to assess the position of the implant in orbital reconstruction. Interpretation of the feedback from the navigation system to a three-dimensional position of the implant needs to be done by the surgeon, and feedback is only gathered after the implant has been positioned. An implant-oriented navigation ap...

Purpose: Mirroring has been used as a diagnostic tool in orbital wall fractures for many years, but limited research is available proving the assumed symmetry of orbits. The purpose of this study was to evaluate volume and contour differences between orbital cavities in healthy humans. Materials and methods: In this cross-sectional study, the le...

Objective: The study aim was to investigate variations in the symmetry of the zygomaticomaxillary complex (ZMC) in normal individuals. Method: Computed tomography datasets of 200 individuals without facial fractures were analyzed using a validated three-dimensional analysis technique. The absolute average distance (AD) and 90th percentile distan...

Since the introduction of rigid internal fixation devices, more and more surgeons favour an open approach to treating condylar fractures of the mandible in adult patients. Different indications for open treatment have been published. Open treatment is associated with surgical complications because of the technique employed. The aim of this systemat...

Purpose: This study determined the average distances and angles between anatomic landmarks within the orbit, with an emphasis on localization of the orbital process of the palatine bone. This information will help the surgeon with treatment planning and surgical procedures. Patients and methods: Four anatomic landmarks were identified retrospect...

A novel surgical treatment sequence for secondary orbitozygomatic complex (OZC) reconstruction is described. Orbital reconstruction is performed before OZC repositioning. A surgical plan is made: the affected OZC is virtually osteotomized and aligned with a mirrored model of the unaffected OZC. A patient-specific implant (PSI) is designed for orbit...

An estimated 1 in 1,000 maxillary or mandibulary local anesthetic injections lead to unwanted effects on the ipsilateral eye. A literature review of reports on this type of complication resulted in a total of 144 cases published between 1936 and 2016. Frequently reported symptoms included diplopia (72%), partial or full ophthalmoplegia (26%), ptosi...

Background: Approximately one quarter of polytrauma patients has facial injuries, which usually lead to loss of form and function. Several specialties are involved in the acute and reconstructive phases of facial injuries, such as oral and maxillofacial surgery, otorhinolaryngology, plastic surgery, ophthalmology and dentistry. Case description:...

Of all mandibular fractures, 25–35% are condylar. Many studies have focused on whether to treat such fractures via open or closed modalities. A uniform protocol for closed treatment is lacking, but such a protocol could ensure good clinical practice. The aims of this systematic review were to provide an overview of the published studies exclusively...

Objective: The study aim was to validate a new method for measuring zygomaticomaxillary complex (ZMC) symmetry, which can be helpful in analyzing ZMC fractures. Methods: Three-dimensional virtual hard-tissue models were reconstructed from computed tomography (CT) datasets of 26 healthy individuals. Models were mirrored and superimposed. Absolute...

Purpose: The aim of this study was to evaluate the usefulness of intra-operative visualisation, endoscopic assistance, and CT measurements for estimating the orbital fracture size and complexity. Methods: Ten human cadaver heads were subjected to thin-slice computed tomography (CT). Standardised fractures were created using piezoelectric surgery...

Introduction In orbital reconstruction, the optimal location of a predefined implant can be planned preoperatively. Surgical results can be assessed intraoperatively or postoperatively. A novel method for quantifying orbital implant position is introduced. The method measures predictability of implant placement: transformation parameters between pl...

Resulting implant position analyzed with Orbital Implant Positioning Frame. The rotational parameters (in degrees) and translational parameters (in mm) are given for every specimen. (XLSX)