Fred K Spijkervet

University of Groningen | RUG · Department of Oral and Maxillofacial Surgery

Several new systems for three-dimensional (3D) surface imaging of the face have become available to assess changes following orthognathic or facial surgery. Before they can be implemented in practice, their reliability and validity must be established. Our aim, therefore, was to study the intra- and inter-system reliability and validity of 3dMD (st...

The aim of this systematic review was to assess the efficacy of arthroscopy compared to arthrocentesis and to conservative treatments for temporomandibular joint disorders. Thirteen controlled studies on various patient outcomes were included after a systematic search in seven electronic databases. Meta-analyses were conducted separately for arthro...

Introduction Several new systems of three-dimensional (3D) surface imaging of the face have become available to assess changes following orthognathic or facial surgery. Before they can be implemented into practice their reliability and validity must be established. Our aim was therefore to study 3dMD (stereophotogrammetry), Artec Eva and Artec Spac...

Objective: To perform a systematic review and meta-analysis on the efficacy and safety of sialendoscopy in the treatment of obstructive diseases of the major salivary glands. Materials and methods: We searched four databases for literature. The primary outcome assessed was the success rate. Secondary outcomes included the use of supportive devic...

Background Salivary gland biopsies play an important role in the classification and diagnosis of primary Sjögren’s syndrome (pSS). Currently, salivary gland biopsies are considered positive for pSS if the focus score (FS), calculated by the number of characteristic lymphocytic periductal infiltrates per 4 mm2, is ≥1. However, the FS has several lim...

The purpose of this study was to assess the 1-year skeletal stability of the osteotomized maxilla after Le Fort I surgery, comparing conventional osteosynthesis with patient-specific osteosynthesis. Patients were assigned to a conventional or patient-specific osteosynthesis group using prospective randomization. The primary outcome was the three-di...

Arthrocentesis for arthralgia of the temporomandibular joint (TMJ) is often only indicated when conservative, non-surgical interventions have failed. However, performing arthrocentesis as initial therapy may facilitate earlier and better recuperation of the joint. The aim of this study was to assess the efficacy of this therapy with a long-term fol...

Background Salivary glands of primary Sjögren’s syndrome (pSS) patients characteristically contain periductal lymphocytic infiltrates. Associated with these infiltrates, lymphoepithelial lesions (LELs) can be formed. LELs are composed of hyperplastic ductal epithelium with infiltrating lymphocytes and may assist in the diagnostic process of pSS ¹ ....

Background Salivary gland involvement is a hallmark of disease in primary Sjögren’s syndrome (pSS). This is reflected by the prominent role of a positive biopsy within the ACR-EULAR classification criteria, which is solely based on the focus score (FS) ¹ . In pSS all salivary glands might be involved in the disease process. For this reason, both la...

β-Adrenergic signaling blockade is a mainstay of hypertension management. One percent of patients taking β-blockers develop reduced salivary gland (SG) function. Here we investigate the role of SG progenitor cells in β-blocker-induced hyposalivation, using human SG organoid cultures (SGOs). Compared with control SGs, initial low SG progenitor cell...

Background Oral and maxillofacial surgery currently relies on virtual surgery planning based on image data (CT, MRI). Three-dimensional (3D) visualizations are typically used to plan and predict the outcome of complex surgical procedures. To translate the virtual surgical plan to the operating room, it is either converted into physical 3D-printed g...

In TMJ patients, with severe pain and TMJ destruction causing a strong limitation of function, a small group remains therapy resistant. For these patients, after failure of open joint surgery, a total joint prosthesis may be indicated to treat these mutilated TMJs. One of the challenges in replacing the TMJ is the imitation of the complex movements...

Total joint replacement (TJR) with a prosthesis can be indicated for patients with severe temporomandibular joint (TMJ) dysfunction. Surgical accuracy is necessary for correct translation of the preoperatively predicted functional outcome, wear, and biomechanical behaviour of the patient-specific TMJ-TJR prosthesis. This study describes the first c...

Objectives: In case of surgical removal of oral squamous cell carcinomas, a resection of mandibular bone is frequently part of the treatment. Nowadays, such resections frequently include the application of 3D virtual surgical planning (VSP) and guided surgery techniques. In this paper, current methods for 3D VSP leads for optimisation of the workf...

Background Abatacept (CTLA-4-Ig) targets the CD80/CD86:CD28 co-stimulatory pathway required for full T-cell activation and T-cell dependent activation of B-cells. The Abatacept Sjögren Active Patients phase III (ASAPIII) trial is a mono-center, investigator-initiated, placebo controlled study with an open-label extension phase ( NCT02067910 ), whic...

The use of finite element analysis (FEA) has increased rapidly over the last decennia and has become a popular tool to design implants, osteosynthesis plates and prostheses. With increasing computer capacity and the availability of software applications, it has become easier to employ the FEA. However, there seems to be no consensus on the input va...

Pretreatment dental screening aims to locate and eliminate oral foci of infection in order to eliminate local, loco‐regional or systemic complications during and after oncologic treatment. An oral focus of infection is a pathologic process in the oral cavity that does not cause major infectious problems in healthy individuals, but may lead to sever...

Introduction: When the application of a free vascularised flap is not possible, a segmental mandibular defect is often reconstructed using a conventional reconstruction plate. Mechanical failure of such reconstructions is mostly caused by plate fracture and screw pull-out. This study aims to develop a reliable, mechanically superior, yet slender p...

Histopathological assessment of salivary gland biopsies is an important element of the diagnostic work‐up of Sjögren’s syndrome (SS) (Fox, 2017; Kroese et al., 2018). Microscopic evaluation of salivary glands of primary SS (pSS) patients reveals characteristic periductal lymphocytic infiltrates (foci), which mainly consist of T‐ and B‐lymphocytes,...

The accuracy of orthognathic surgery has improved with three-dimensional virtual planning. The translation of the planning to the surgical result is reported to vary by >2 mm. The aim of this randomized controlled multi-centre trial was to determine whether the use of splintless patient-specific osteosynthesis can improve the accuracy of maxillary...

Head and neck radiotherapy is accompanied by deleterious effects of radiation to healthy tissues. The clinical consequences of the effects of radiotherapy on the salivary glands include a reduced salivary secretion (hyposalivation) and accompanying sensation of oral dryness (xerostomia) due to damage to the salivary glands, taste loss, and the life...

Background Primary Sjögren’s syndrome (pSS) patients who exhibit germinal centres (GCs) within salivary gland parenchyma have higher focus scores and present with more disease activity than GC negative pSS patients. Moreover, presence of GCs might be of clinical importance for stratification of treatment. However, there is considerable heterogeneit...

Purpose: Intensity-modulated radiation therapy (IMRT) has changed radiation treatment of head and neck cancer (HNC). However, it is still unclear if and how IMRT changes oral morbidity outcomes. In this prospective study, we assessed the outcome of reducing post-IMRT sequelae by means of pre-radiation dental screening and eliminating oral foci. M...

Objectives Patients suffering from osteoarthritis, ankylosis (e.g. post-trauma or tumour) in the temporomandibular joint (TMJ) can present with symptoms such as severely restricted mouth opening, pain or other dynamic restrictions of the mandible. To alleviate the symptoms, a total joint prosthesis can be indicated, such as the Groningen TMJ prosth...

Objective To assess the inter- and intraobserver reliability of ultrasound of major salivary glands in patients clinically suspected of having primary Sjögren’s syndrome (pSS) as well as to assess sources of variation in outcomes of ultrasonographic evaluation. Methods 80 consecutive outpatients with clinically suspected pSS underwent ultrasound ev...

Osteoradionecrosis is defined as bone death secondary to radiotherapy. There is a relationship between the radiation dose received and the occurrence of osteoradionecrosis of the jaws, with the risk increasing above a dose of 60Gy. In cases of class III mandibular osteoradionecrosis, a segmental resection can be indicated. Current practice is to co...

Objectives: To identify the most discussed dental articles on the Web and to assess the association between the intensity of online attention, publication characteristics and citations. Materials & methods: An Altmetric Explorer search was conducted for articles published in the 91 dental journals included in 2015 InCites(™) Journal Citation Rep...

Objectives The aim of the present study was to compare the composition of the periodontal microflora at baseline (T0) with the submucosal microflora at least 1 year after implant placement (T1) in periodontally healthy patients. Material and methodsFor all 169 consecutive patients that visited our clinic during 1 year, we determined their periodont...

Objective: We used the 28-joint Disease Activity Score (DAS28) and the European League Against Rheumatism Sjögren's Syndrome Disease Activity Index (ESSDAI) articular domain to assess the effect of rituximab (RTX) and abatacept (ABA) on articular involvement in primary Sjögren syndrome (pSS). Methods: Patients with pSS treated with RTX (n = 18)...

Objectives: Besides ocular and oral dryness, fatigue is a major symptom in patients with primary Sjögren's syndrome (pSS). Our aim was to investigate the importance of fatigue in relation to other symptoms experienced as well as to evaluate the effect of rituximab treatment on fatigue in pSS patients with active disease. Methods: This analysis w...

Objectives: The aim of this study was to assess the histopathological changes in parotid gland tissue of primary Sjögren's syndrome (pSS) patients treated with abatacept. Methods: In all 15 pSS patients included in the open-label Active Sjögren Abatacept Pilot (ASAP, 8 abatacept infusions) study parotid gland biopsies were taken before treatment...

Objectives The aims of this study were (1) to assess the effect of rituximab (RTX; anti-CD20) treatment in patients with primary Sjogren's syndrome (pSS) based on sequential parotid biopsies obtained in a placebo-controlled, randomised clinical trial, and (2) to assess the prognostic value of the histological characteristics of parotid gland tissue...

Salivary gland biopsy is a technique broadly applied for the diagnosis of Sjogren syndrome (SS), lymphoma in SS, and connective tissue disorders (sarcoidosis, amyloidosis). In SS characteristic histology findings are found, including lymphocytic infiltration surrounding the excretory ducts in combination with destruction of acinar tissue. In this a...

Background Patients with rheumatoid arthritis (RA) can develop sicca symptoms which may be related to secondary Sjögren's syndrome (sSS). Objectives To assess the prevalence and clinical characteristics of sSS in RA patients. Methods In this cross-sectional study, 96 consecutive established RA patients referred to our outpatient clinic were submi...

Background Besides ocular and oral dryness, fatigue is a prominent symptom in patients with primary Sjögren's syndrome (pSS). Objectives To investigate the importance of fatigue in relation to other symptoms and to evaluate the effect of rituximab treatment on fatigue in pSS patients with active disease. Methods The present analysis was based on...

Background B cell hyperactivity is a hallmark of primary Sjögren's syndrome (pSS) and plays a critical role in sustainment and progression of pSS.¹ Hyperactivity is reflected by the presence of germinal centers (GCs) in periductal lymphoid infiltrates in the salivary glands. Risselada et al² reviewed the presence of GCs in the salivary gland biopsi...

Background The involvement of the epithelium in the pathology of primary Sjögren's syndrome (pSS) has long been proposed. Epithelial cells have potential to transmit immune initiation signals and to serve as autoimmune targets, in addition to their function as saliva channeling/modulating agents in the salivary gland. Recently, we have demonstrated...

We have read with great interest the letter to the editor by van Roon et al 1 commenting on our paper ‘Towards personalised treatment in primary Sjogren's syndrome: baseline parotid histopathology predicts responsiveness to rituximab treatment’.2 The authors argue that there is a need for standardisation of the histopathological characteristics of...

Background: Leukaemic patients receiving intensive chemotherapy and patients undergoing autologous stem-cell transplantation (ASCT) are routinely screened for oral foci of infection to reduce infectious complications that could occur during therapy. In this prospective study we assessed the effect of leaving chronic oral foci of infection untreate...

The human microbiome consists of all microorganisms occupying the skin, mucous membranes and intestinal tract of the human body. The contact of the mucosal immune system with the human microbiome is a balanced interplay between defence mechanisms of the immune system and symbiotic or pathogenic microbial factors, such as microbial antigens and meta...

Objectives: To quantitatively and qualitatively assess the characteristics of YouTube videos dealing with Sjögren's syndrome. Materials & methods: A comprehensive electronic search was performed for ''Sjögren's syndrome'' in YouTube. After excluding duplicates, irrelevant videos and non-English language domains, 70 videos were included for analy...

Objectives: The aims of this study were (1) to assess the effect of rituximab (RTX; anti-CD20) treatment in patients with primary Sjögren's syndrome (pSS) based on sequential parotid biopsies obtained in a placebo-controlled, randomised clinical trial, and (2) to assess the prognostic value of the histological characteristics of parotid gland tiss...

Background: With the advents of new processing techniques and new graft survival theories in fat grafting, the question is: Which processing technique is of preference? This study systematically reviewed literature regarding current techniques for processing fat grafts. Methods: PubMed, Embase, Cinahl, and Cochrane databases were searched until...

Background: With the advents of new processing techniques and new graft survival theories in fat grafting, the question is: Which processing technique is of preference? This study systematically reviewed literature regarding current techniques for processing fat grafts. Methods: PubMed, Embase, Cinahl, and Cochrane databases were searched until Aug...

Sicca complaints (sensation of dry mouth and/or eyes) are present in about a quarter of the individuals above the age of 65 years old and are mainly due to medication. However, physiological changes that occur during aging might also lead to a diminished glandular function. These age-related changes are, at least in part, to be the consequence of d...

Background Arthralgia and arthritis are common features of disease activity in patients with primary Sjögren's syndrome (pSS) with prevalence rates of 45-50% and 15-35%, respectively. Disease Activity Score including 28 joints (DAS-28) has been developed and validated to monitor disease activity in patients with rheumatoid arthritis, but it is also...

To perform a systematic review and meta-analysis on studies examining the properties of ultrasonography of major salivary glands for diagnosing Sjögren's Syndrome. We searched for literature on eight databases. The quality of included articles was assessed with the QUADAS-2 tool. Publication bias, pooled sensitivity, specificity, diagnostic odds ra...

Van parodontitis, een ontsteking van de weefsels rondom de tand, is bekend dat het de mondgezondheid en de algehele gezondheid negatief kan beïnvloeden. Parodontitis veroorzaakt een ulcererend wondoppervlak: hoe groter dat wondoppervlak is, hoe groter de kans dat mondbacteriën en ontstekingsmediatoren via het wondoppervlak in de bloedbaan terechtko...

Een groot aantal afwijkingen kan op of in de slijmvliezen van de mond ontstaan. Deze afwijkingen kunnen zich op vele verschillende manieren presenteren. Aan eenzelfde klinische verschijningsvorm kunnen verschillende ziekteprocessen ten grondslag liggen. Een slijmvliesafwijking kan het gevolg zijn van een lokaal proces of een uiting zijn van een geg...

Bijwerkingen en interacties van geneesmiddelen kunnen het orofaciale gebied betreffen en variëren van gering tot invaliderend. Een aantal van deze bijwerkingen en interacties wordt in deze bijdrage beschreven, in voorkomende gevallen wordt ook kort het oorzakelijk mechanisme beschreven. Deze opsomming geeft een indruk van de mogelijke bijwerkingen...

Pre-radiation dental screening of head-neck cancer patients aims to identify and eliminate oral foci of infection to prevent post-radiation oral problems. The evidence for the efficacy of dental screening is unclear. In this systematic review, we analyzed available evidence on the efficacy of pre-radiation elimination of oral foci of infection in p...

In this study, we sought to understand the selective pressures shaping the Ig-producing cell repertoire in the parotid glands of primary Sjögren's syndrome (pSS) patients before and after rituximab treatment (RTX). In particular, we evaluated the role of potential N-glycosylation motifs acquired by somatic hypermutation (ac-Nglycs) within Ig H chai...

Welk geneesmiddel bij welke aandoening in en rond de mond te gebruiken is een niet altijd even eenvoudig te beantwoorden vraag. Zoals in een recent artikel in het Geneesmiddelenbulletin is beschreven, is het bewijs van de effectiviteit van een groot aantal binnen de tandheelkunde gebruikte geneesmiddelen beperkt of (nog) niet op juiste wetenschappe...

Xerostomia is the subjective feeling of oral dryness. The major causes are Sjögren's syndrome (SS), medication and radiotherapy to the head and neck. SS is a chronic systemic autoimmune disease characterized by infiltration of the exocrine glands, the salivary and lacrimal ones in particular. The pathogenesis involves systemic B cell hyperactivity...

The three most frequently diagnosed salivary gland diseases are salivary gland infections, sialolithiasis and mucoceles. Salivary gland infections are usually of bacterial or viral etiology and can be divided into acute and chronic types. Occasionally they can result from obstruction of the salivary duct, an autoimmmune disease or cancer therapy. I...

Salivary gland biopsy is a technique broadly applied for the diagnosis of Sjögren's syndrome (SS), lymphoma accompanying SS, sarcoidosis, amyloidosis, and other connective tissue disorders. SS has characteristic microscopic findings involving lymphocytic infiltration surrounding the excretory ducts in combination with destruction of acinar tissue....

To assess the efficacy and safety of abatacept in patients with early and active primary Sjögren's syndrome (pSS). All 15 patients (12 women, three men) included in the open-label Active Sjögren Abatacept Pilot study met the revised American-European Consensus Group criteria for pSS and were biological disease-modifying antirheumatic drug-naive. Pa...

Background Abatacept, a selective co-stimulation modulator of T lymphocytes, could be a new treatment option for primary Sjögren’s syndrome (pSS). Objectives To assess short-term efficacy and safety of abatacept treatment in early pSS patients. Methods 15 pSS patients (12 female, 3 male) were included in the open-label ASAP (Active Sjögren Abatacep...

The objective of this study was to assess the value of cone-beam computed tomographic (CT) images in the primary diagnosis and management of 128 outpatients with disorders of the temporomandibular joint (TMJ). Before a diagnosis was made and treatment planned, the history was taken, physical examination made, and the orthopantomogram studied. After...

To assess the qualitative standards of the information distributed via the Internet regarding xerostomia. A computerized electronic search was performed for 'xerostomia' and 'dry mouth' separately using four search engines. The first 30 results from each search term-engine combination were pooled for analysis. After excluding promotional product si...

Rituximab therapy is a promising treatment for primary Sjogren's syndrome (pSS).1 ,2 So far, treatment studies performed in patients with pSS lacked the use of a uniform outcome measure to monitor disease activity. Recently, the European League Against Rheumatism (EULAR) developed the EULAR Sjogren's Syndrome Disease Activity Index (ESSDAI).3 ESSD...

Chemosensory disorders may result in loss of body weight and sometimes in gain of body weight. Therefore, dietary advice is an essential part of the counselling and treatment ofpatients with a chemosensory disorder. In cases involving a chemosensory disorder, a distinction has to be made between general dietary advice and advice during and after a...

Taste and smell perception are closely related. Many chemosensory disorders which result in faulty taste are in fact smell disorders. Causes ofchemosensory disorders which call for attention are ageing, medication, natural proteins, burning mouth syndrome, nerve injuries, aerate disorders in the neighbourhood of the sense ofsmell, damage to the sme...

Taste and smell perception are closely related. The taste perception is performed by taste buds which can distinguish salt, sour, sweet, bitter, and umami. Moreover, 2,000-4,000 smells can be recognized. Many taste disorders are in fact smell disorders. Saliva affects taste perception because it serves as a solvent for taste substances and as a pro...