Jan Michaél Hirsch

• Professor em. DDS, PhD
• Professor Emeritus at Uppsala University and Public Dental Services Region Stockholm

Oral cancer is a global health challenge. It is treatable if detected early, but it is often fatal in late stages. There is a shift from the invasive and time-consuming tissue sampling and histological examination, toward non-invasive brush biopsies and cytological examination. Reliable computer-assisted methods are essential for cost-effective and...

Background Oral squamous cell carcinoma (OSCC) is a widespread disease with only 50%–60% 5‐year survival. Individuals with potentially malignant precursor lesions are at high risk. Methods Survival could be increased by effective, affordable, and simple screening methods, along with a shift from incisional tissue biopsies to non‐invasive brush bio...

Background: Oral cancer is a severe and potentially fatal disease usually starting in the squamous epithelium lining the oral cavity. Together with oropharyngeal carcinoma, it is the fifth to sixth most common malignancy worldwide. To limit the increase in the global oral cancer incidence over the past two decades, the World Health Assembly adopte...

A known complication for mechanically loaded bone implants is the instability due to screw loosening, resulting in infection and the non-union of fractures. To investigate and eventually prevent such bone degradation, it is useful to know the stress state in the bone around the screw. Considering only in-plane loadings and simplifying the mandibula...

Oral cancer is a cancer type that is widely prevalent in low-and middle-income countries with a high mortality rate, and poor quality of life for patients after treatment. Early treatment of cancer increases patient survival , improves quality of life and results in less morbidity and a better prognosis. To reach this goal, early detection of malig...

Objective Oral leukoplakia (OL) presents as a white lesion of the oral mucosa and is not typically associated with the sensation of pain. OL should be surgically removed when possible because it is considered a potentially malignant oral disorder (PMOD). This study assessed the pain sensations experienced by patients in association with the occurre...

Aim: To investigate the level of agreement between three non-invasive methods for hrHPV diagnosis in oral and oropharyngeal squamous cell carcinoma (OSCC, OPSCC) and in oral mucosal lesions. Materials and methods: For hrHPV DNA FTA Elute card™ and Anyplex II HPV28™ were used and for hrHPV mRNA PreTect SEE™ in tumour patients (n=60), non-tumour l...

Individual cutting guides for the reconstruction of lower jaw defects with fibular grafts are often used. However, the application of these osteotomy tools is costly and time intensive. The aim of this study was to compare the precision of osteotomies using a 3D-printed guide with those using a universal, reusable, and more cost-efficient Multi-Use...

The presence of non-sufficient bone height and width requires an increase in the amount of bone available to insert an implant. Different materials are described in the literature, and the “custom-made bone graft approach” is a modern option which currently requires a preoperative stage of studying the bone defect and designing the implant. SmartBo...

Forskning Denture Guided Epithelial Regeneration-metod för att skapa keratiniserad gingiva i anslutning till implantat Referentgranskad-accepterad för publicering 5 augusti 2020. Författare Vinay V Kumar (bild), dr med dent, dr rer hum, Inst för kirurgiska vetenska-per, Uppsala universitet. E-post: vinay.vijayakumar@ akademiska.se Jan-Michaél Hirsc...

Objectives Although causal associations between oral leukoplakia (OL), oral squamous cell carcinoma (OSCC), and high‐risk human papillomavirus (HR‐HPV) have been speculated upon in several reports, conclusive evidence has not been presented. This study investigates whether the number of cases of HR‐HPV in OL has increased over time and whether the...

Oral cancer incidence is rapidly increasing worldwide. The most important determinant factor in cancer survival is early diagnosis. To facilitate large scale screening, we propose a fully automated pipeline for oral cancer detection on whole slide cytology images. The pipeline consists of fully convolutional regression-based nucleus detection, foll...

This chapter discusses recent applications and findings in additive manufacturing (AM), or 3D printing, applied in oral and maxillofacial surgery. The reader will get an introduction to the basics of AM technology followed by oral and maxillofacial applications like printing of anatomical models and the design and manufacturing of customised implan...

Oral leukoplakia (OL) is a potentially malignant oral disorder. The Gold Standard treatment is to remove surgically the OL. Despite optimal surgery, the recurrence rates are estimated to be 30%. The reason for this is unknown. The aim of this study was to investigate the clinical factors that correlate with recurrence after surgical removal of OL....

Oral cancer incidence is rapidly increasing worldwide. The most important determinant factor in cancer survival is early diagnosis. To facilitate large scale screening, we propose a fully automated end-to-end pipeline for oral cancer screening on whole slide cytology images. The pipeline consists of regression based nucleus detection, followed by p...

Background: Precise, expensive individual saw guides are used with increasing frequency for the reconstruction of mandibular defects with fibular grafts. In this report, an alternative is presented - the Multiuse Cutting Jig (MUC-Jig, proprietary development). It is reusable, suitable for all patients, requires simple planning based on conventiona...

Background: Oral leukoplakia (OL) is a potentially malignant oral mucosal disorder. A casual association between OL, oral squamous cell carcinoma (OSCC) and human papillomavirus (HPV) infection has been suggested, but no conclusive evidence has been presented. p16, a tumour-suppressor protein, is used as a surrogate marker for HPV infection. The a...

There is limited information on the biological status of bone regenerated with microvascular fibula flap combined with biomaterials. This paper describes the clinical, histological, ultrastructural, and molecular picture of bone regenerated with patient-customized plate, used for mandibular reconstruction in combination with microvascular osteomyoc...

Cranio-maxillofacial surgery to restore normal skeletal anatomy in patients with serious facial conditions is both complex and time consuming. There is, however, ample evidence that careful pre-operative planning leads to a better outcome with a higher degree of function and reduced morbidity and at the same time reduced time in the operating room....

Background: It has been estimated that 15%-20% of human tumours are driven by infection and inflammation, and viral infections play an important role in malignant transformation. The evidence that herpes simplex virus type 1 (HSV-1) could be involved in the aetiology of oral cancer varies from weak to persuasive. This study aimed to investigate by...

Unlabelled: Virtual surgery planning has proven useful for reconstructing head and neck defects by fibula osteocutaneous free flaps (FOFF). Benefits include improved healing, function, and aesthetics, as well as cost savings. But available virtual surgery planning systems incorporating fibula in craniomaxillofacial reconstruction simulate only bon...

In order to reconstruct a patient with a bone defect in the mandible, a porous scaffold attached to a plate, both in a titanium alloy, was designed and manufactured using additive manufacturing. Regrettably, the implant fractured in vivo several months after surgery. The aim of this study was to investigate the failure of the implant and show a way...

Background: Infection with human papilloma virus (HPV) has been implicated as one of the risk factors for the development of oropharyngeal cancer. Many different HPV tests exist, and information regarding their specific technical, analytical, and clinical properties is increasing. Aim: This study aimed to compare the level of detection of HPV using...

Fracture of the mandible is one of the most common fractures of the maxillofacial skeleton. However, the etiology, gender, and age distribution vary between different regions and countries, and the purpose of this study was to evaluate the current trend of patients with mandibular fractures at the Department of Oral and Maxillofacial Surgery, in Up...

Abstract The free fibula osteoseptocutaneous flap is the standard for reconstruction of extensive mandibular defects. The procedure must be precise to achieve the required functional and aesthetic results. The aim of the present study was to calculate retrospectively the exact differences in surgical outcome based on preoperative and postoperative...

Oral Squamous Cell Carcinoma (OSCC) is the most common epithelial malignancy in the oral cavity. OSCCs and their variants constitute over 90% of oral malignancies, and the disease is associated with poor prognosis. OSCC is a complex malignancy where environmental factors, viral infections, and genetic alterations most likely interact, and thus give...

Snus (Swedish moist snuff) causes lesions in the oral mucosa at the location where pinches are regularly placed. In addition, some patients develop irreversible local gingival recession and sometimes ulcers with perforations to the roots. Such injuries lead to denuded roots that are at risk for caries and periodontal disease, with subsequent esthet...

Intentional cranial deformations (ICD) have been observed worldwide but are especially prevalent in preColombian cultures. The purpose of this study was to assess the consequences of ICD on three cranial cavities (intracranial cavity, orbits, and maxillary sinuses) and on cranial vault thickness, in order to screen for morphological changes due to...

Purpose Cranio-maxillofacial (CMF) surgery to restore normal skeletal anatomy in patients with serious trauma to the face can be both complex and time-consuming. But it is generally accepted that careful pre-operative planning leads to a better outcome with a higher degree of function and reduced morbidity in addition to reduced time in the operati...

Virtual assembly of complex objects has application in domains ranging from surgery planning to archaeology. In these domains the objective is to plan the restoration of skeletal anatomy or archaeological artifacts to achieve an optimal reconstruction without causing further damage. While graphical modeling plays a central role in virtual assembly,...

Squamous cell carcinoma (SCC) is the most common epithelial malignancy in the oral cavity. SCCs and their variants constitute over 90% of oral malignancies, and the disease is associated with poor prognosis. OSCC is a complex malignancy where environmental factors, virus infections, and genetic alterations most likely interact, and thus give rise t...

Purpose: To improve the reconstructive surgical outcome of a discontinuous mandibular defect, we used reverse engineering (RE), computer-aided design (CAD), and rapid prototyping (RP) technique to fabricate customized mandibular trays to precisely restore the mandibular defects. Autogenous bone grafting was also used to restore the bony continuity...

Obstructive sleep apnoea (OSA) may cause considerable disturbances, including the development of health problems. This study was performed in order to evaluate the results of treating OAS with a mandibular advancement splint (MAS), and to evaluate the effects of this treatment. This was a prospective open longitudinal study. Ninety patients were ra...

Over recent decades there has been debate over whether or not Swedish snuff is carcinogenic in humans. Animal studies and molecular biological and experimental studies have shown the carcinogenic potential of Swedish snuff, but this has not been proved in prospective randomized studies. We present a case series of patients with oral squamous cell c...

Introduction: Introducing telemedicine into clinical practice has not been without difficulties. Within the framework of the European Union project "Health Optimum," telemedicine consultations with specialists at the Department of Oral & Maxillofacial Surgery at Uppsala University Hospital (Uppsala, Sweden) have been offered to dentists in the pub...

Nicotine replacement therapy (NRT) is now widely used in various forms of administration to aid cessation of tobacco use. In this smoking cessation programme, a new tablet formulation has been compared to and found bioequivalent to the existing one. The present trial was performed in order to investigate the local tolerance of the new sublingual ta...

Previously we used microarray genomic hybridization technology to explore genome-wide profiles of chromosomal aberrations in samples of oral squamous cell carcinomas (OSCCs) and paired normal controls. Based on these findings, 9 genes related to apoptosis, cell cycle regulation and intermediate filament proteins were selected and their differential...

Virtual surgical planning and computer-aided surgery were used to treat a mono-ostotic fibrous dysplasia of the right zygoma. Mirroring of the contralateral zygoma sets the target for the contouring of the affected zygomatic bone. An optical system for computer-guided surgery was used. Instruments were calibrated and visualized in real time on scre...

Smokeless tobacco (Swedish moist 'snus') users are often strongly addicted to nicotine. Compared to the large number of smoking-cessation studies, there have been few evaluated clinical cessation programs in conjunction with nicotine replacement therapy (NRT). The aim of this study was to evaluate a cessation program for snus users with a weekly us...

J Oral Pathol Med (2010) 39: 599–604 Using PCR/DNA sequencing, we investigated the prevalence of human papillomavirus (HPV), herpes simplex virus (HSV) and Epstein–Barr virus (EBV) DNA in brush biopsies obtained from 150 users of Sudanese snuff (toombak) and 25 non-users of toombak in formalin-fixed paraffin-embedded tissue samples obtained from 31...

There is a high prevalence of human papilloma viruses (HPV) in oral submucous fibrosis (OSMF) and the etiologic implication of this finding warrants further studies. The prevalence of oral squamous cell carcinoma (OSCC) and OSMF is high in India, and the diseases are partly attributed to high consumption of betel quid containing areca nut and tobac...

The aim of this investigation was to evaluate the clinical outcome of two different surgical protocols in the edentulous mandible: submerged and nonsubmerged. Further, the Paragon dental implant with a titanium plasma-sprayed surface was evaluated. Twenty-nine consecutively treated patients with 168 implants supporting fixed prostheses were include...

In this work, gene expression profile was examined in 19 cases of oral cancer (OC) obtained from patients from Sweden (n=8) and UK (n=11) and the findings were tested for correlation to patient's clinicopathological data. Following total RNA extraction, cDNA synthesis, labeling with fluorescent dyes and hybridization to the 21 k human oligonucleoti...

We have reported a case of triple mental foramina at the right side of the premolar region, which was discovered during reposition and ostheosynthesis of a mandible fracture. A review of the literature, was performed which disclosed no previous clinical cases reported but an incidence of 1.2% of triple foramina after investigating dry skulls or rad...

The purpose of this study was to investigate the possibility of virtually designing and manufacturing a template for reconstruction plate bending, to be used during treatment of congenital or acquired bony entities. The outcome was compared with plates bent by the freehand approach in a stereolithographic skull model. From a computed tomography exa...

When the mouth is affected by cancer, difficulties in satisfying basic human needs such as eating, tasting, swallowing, and speaking might arise, and the existential significance of the mouth might become obvious. How does it feel to live with these difficulties? What does it mean to be a human being living with the consequences of oral cancer? Fiv...

A comprehensive classification based on high resolution computed tomography (CT) of the whole craniofacial region was correlated with clinical findings of combined skull base and maxillofacial fractures. In a study of two clinical centres, 70 patients with such injuries were admitted at the Universities of Basel (n=29) and Uppsala (n=41). Clinical...

The free fibular flap is the standard procedure for reconstructing mandibular defects. The graft has to be contoured to fit the defect so preoperative planning is required. The systems used previously do not allow transfer of the surgical plan to the operation room in an optimal way. The authors present a method to bring the virtual plan to real ti...

By preserving the temporomandibular joint (TMJ) disc in the glenoid fossa at the time of resection, correctly securing the vascularised fibular end in the fossa, and by reattaching the lateral pterygoid muscle, it is possible to maintain normal rotation, translatation, and protrusion in the TMJ and the function of the jaw can be totally restored. W...

This study evaluates a comprehensive classification system for mandibular fractures based on imaging analysis. The AO/ASIF scheme, defining three fracture types (A, B, C), three groups within each type (e.g. A1, A2, A3) and three subgroups within each group (e.g. A1.1, A1.2, A1.3) with increasing severity from A1.1 (lowest) to C3.3 (highest) was us...

Oral cancer is a mutilating disease. Because of the expanding application of computer technology in medicine, new methods are constantly evolving. This project leads into a new technology in maxillofacial reconstructive therapy using a redesigned zygoma fixture. Previous development experiences showed that the procedure was time-consuming and painf...

The consequences of oral cancer may affect not only the patient, but also their spouses, as the mouth is vital for communication, social interaction and nutrition. Treatment is complex, lengthy and involves a large number of medical and dental professionals. During the treatment of oral cancer spouses are often present when the patients meet the tr...

The purpose of this clinical investigation was to evaluate the treatment outcome with zygoma implants with regard to implant survival, patient satisfaction, and function of prosthesis replacement after 3 years. The treatment outcome of 76 patients treated with 145 zygoma fixtures at 16 centers was evaluated with regard to implant survival. Status o...

The aim of this retrospective qualitative study was to describe how patients with oral cancer experience their sickness and treatment. A purposeful sample of seven patients with oral cancer was interviewed. Data were analysed using a phenomenological approach outlined by van Manen. The essence of the patients' experiences can be described as embodi...

Restoration of lost dentition in the severely artrophic posterior maxilla has for the last 2 decades been successfully treated with various sinus augmentation techniques and installation of dental implants. The use of graft material is anticipated to be necessary; however, recent studies have demonstrated that the mere lifting of the sinus mucosal...

Understanding of the thrombotic response (activation of the intrinsic coagulation system followed by platelet activation) from blood components upon contact with a titanium dental implant is important and not fully understood. The aims of this study were to evaluate: (1) the thrombogenic response of whole blood, platelet-rich plasma (PRP) and plate...

Introduction: Head and neck cancer is the sixth most common malignancy in the world. Fifty percent of the patients can be cured by surgery, radiotherapy or a combination approach. Head and neck cancer is life-threatening, and treatment may leave the patient with visible facial disfigurements and impairment of functions such as speech and eating. T...

To evaluate treatment outcome with Zygoma fixtures (Nobel Biocare, Göteborg, Sweden) with regard to fixture survival, patient satisfaction, and function of prosthesis replacement. The treatment outcome of 76 patients treated with 145 Zygoma fixtures at 16 centers was evaluated. Patient's and dentist's evaluations of the functional and aesthetic out...

Whereas the smoking habit has declined significantly in Sweden in recent decades, there has been a marked increase in the consumption of 'snus' (oral moist snuff). The use of this smokeless tobacco, exposing the user locally to carcinogenic nitrosamines, raises the question - will the increasing use of snuff eventually lead to a greater incidence o...

Bone grafts are frequently used to enable the placement of dental implants in atrophied jaws. The biomechanical properties of bone grafts used in one- or two-stage implant procedures (in comparison with the use of nongrafted bone) are not well known. The purpose of this study was (1) to measure cutting torques during the placement of self-tapping d...

The role of oral subepithelial mast cells in the defence against tumours is a matter of controversy. The effect of established and suggested carcinogens, such as the carcinogen 4-nitroquinoline-N-oxide (4-NQO) and Herpes simplex virus type 1 (HSV-1), in combination with oral snuff on lower lip subepithelial mast cells (MC) was studied in rats. The...

The Epstein-Barr virus (EBV) is associated with both malignant and benign diseases in the head and neck region. In several studies it has also been associated with oral squamous cell carcinoma (OSCC). Oral lichen planus (OLP) is a disease with unknown origin, and viral antigens have been proposed as etiologic agents. Smoking and alcohol habits are...

A prospective study of one-stage surgery with intrasinus bone transplant and implants has been performed in 26 patients (13 males and 13 females). The aim of the study was to evaluate the success rate with the one-stage sinus lifting procedure in patients with a need for bony augmentation of the alveolar process. Fifteen patients were partially den...

A prospective study of one-stage surgery with intrasinus bone transplant and implants has been performed in 26 patients (13 males and 13 females). The aim of the study was to evaluate the success rate with the one-stage sinus lifting procedure in patients with a need for bony augmentation of the alveolar process. Fifteen patients were partially den...

To determine the precision of CT for calculating the volume of bone grafts to the maxilla. Plaster of Paris was used to simulate bone as onlay and inlay grafts to the maxillary alveolus and sinus in a dry skull. Two mm thick axial CT scans were obtained. The area of the graft on each slice was measured and volumes calculated according to the formul...

To evaluate the volumetric changes in bone grafts to the severely atrophic edentulous maxilla over 6 months. Ten edentulous patients received autogenous bone as buccal onlay grafts to the maxilla and bilaterally particulate bone grafts to the maxillary sinus. Two mm contiguous axial CT scans were obtained 1 to 2 weeks and 6 to 7 months postoperativ...

Epstein-Barr virus (EBV) and human papillomavirus (HPV) have been associated with benign as well as malignant oral lesions. We examined 43 patients with snuff-induced lesions and 22 control patients with clinically healthy oral mucosa for the presence of HPV and EBV. Polymerase chain reaction was performed on fresh frozen oral biopsies with degener...

This study investigated the possibility that human papilloma virus (HPV) is a possible etiologic agent in the development of ameloblastoma. DNA was extracted from 18 formalin-fixed, paraffin-embedded biopsy specimens and assayed for the presence of HPV DNA by PCR using the L1 consensus primer and specific primers for HPV types 6/11, 16 and 18. Eigh...

Evaluation of the clinical efficacy and safety of a nicotine 2-mg sublingual tablet in smoking cessation. A randomized, double-blind, placebo-controlled study of smokers using the 2-mg tablet for 3-6 months with follow-up to 12 months. Dosing was established according to baseline nicotine dependence, scored on the Fagerström Tolerance Questionnaire...

Aims: Evaluation of the clinical efficacy and safety of a nicotine 2-mg sublingual tablet in smoking cessation. Design: A randomized, double-blind, placebo-controlled study of smokers using the 2-mg tablet for 3-6 months with follow-up to 12 months. Dosing was established according to baseline nicotine dependence, scored on the Fagerström Tolera...

Oral mucosa biopsies from 53 patients with different oral diseases, and from 12 healthy control patients, were examined by the PCR-technique using the L1 consensus primers and type-specific primers for HPV 6/11, 16 and 18. Three out of 24 (12.5%) oral cancer biopsies were HPV positive, 1 for HPV 18, 1 for HPV 16 and 6/11 and 1 for none of the speci...

A great deal of interest has been focused on finding substitutes for autogenous bone grafts. Among the most interesting materials are different calcium phosphate compositions (e.g., hydroxyapatite [HA]), due to their biocompatible properties in hard and soft tissue. The bone response to porous ceramic HA granules in combination with two lipid and o...

This 3-year follow-up study compares implant treatment in 39 1-stage sinus-inlay block-grafted patients (study group) with 37 patients treated without bone grafting (reference group), all of whom were edentulous in the maxilla and were treated over the same time period. The cumulative success rate (CSR) of implant stability after 3 years in the stu...

We have developed a rapid and reliable microporous spin-column-based method for high-throughput extraction of DNA from old paraffin-embedded biopsies. The method was developed specifically for PCRs and molecular genetic studies. De-waxing and DNA extraction from tissues is performed in only one vessel, minimizing pipetting steps and eliminating sup...

Although nicotine replacement therapy (NRT) has been used to aid smoking cessation for the last 20 years, little information exists on the effect of nicotine products on the oral mucosa, particularly with regard to the direct effect at the site of application. This study aimed to assess the oral safety of a new sublingual tablet containing 2 mg nic...

The aim of the present study was to investigate the surface topography, composition, and oxide thickness of consecutively failed, oral Brånemark implants in order to determine possible causes for failure. The failure criterion was lack of osseointegration manifested as implant mobility. Ten implants were retrieved before loading (early failures) an...

In Sweden, snuff (locally known as snus), was introduced since the year 1637. Presently, Sweden has the highest per capita consumption and sale figures of snuff in the world, and the habit is becoming increasingly popular. Snus is manufactured into a dry form used in the nasal cavity and a moist form used in the oral cavity. Snus manufactured for o...

The aim of this article was to review the literature on differential diagnosis and treatment of biologic complications and failing implants. All types of publications, with the exception of abstracts, published in English up to December 1998, were included. A multi-layered search strategy was used. Controlled clinical trials (CCTs) were searched in...

This 3-year follow-up study compares implant treatment in 39 1-stage sinus-inlay block-grafted patients (study group) with 37 patients treated without bone grafting (reference group), all of whom were edentulous in the maxilla and were treated over the same time period. The cumulative success rate (CSR) of implant stability after 3 years in the stu...

An insufficient quality and amount of bone often necessitate the clinical use of implants together with bone transplants. The present study describes an experimental animal model for the study of implants in bone grafts. Circular defects were made bilaterally in the tibia of 36 rabbits. The defects received either autologous cortical bone (control)...

The aim of the present review is to evaluate the English language literature regarding factors associated with the loss of oral implants. An evidence-based format in conjunction, when possible, with a meta-analytic approach is used. The review identifies the following factors to be associated with biological failures of oral implants: medical statu...

The aim of this review was to offer a critical evaluation of the literature and to provide the clinician with scientifically-based diagnostic criteria for monitoring the implant condition. The review presents the current opinions on definitions of osseointegration and implant failure. Further, distinctions between failed and failing implants are di...