Publications by authors named "Jopi Mikkonen"

Radiation exposure is a major health concern due to bone involvement including mandible, causing deleterious effects on bone metabolism, and healing with an increasing risk of infection and osteoradionecrosis. This study aims to investigate the radiotherapy-induced microstructural changes in the human mandible by scanning electron microscopy (SEM). Mandibular cortical bone biopsies were obtained from control, irradiated, and patients with osteoradionecrosis (ORN).

View Article and Find Full Text PDF

It is well established that cancer cells exploit aberrant synthesis of mucin 1 (MUC1) and hyaluronan (HA) synthesis along with HA's physiological cell surface receptor CD44. However, their role in irradiated oral tissue has not been reported previously. We, therefore, aimed to study MUC1, CD44 and HA immunohistochemically in irradiated oral mucosa and their role in the long-term effects after radiotherapy.

View Article and Find Full Text PDF

Objectives: The aim of this study was to assess the MUC1 expression in the oral epithelium of normal, oral epithelial dysplasia (OED), oral squamous cell carcinoma (OSCC), and irradiated oral epithelium (IROE) and its association with smoking habits in non-smokers and smokers.

Design: Oral mucosal biopsies from controls, OED, OSCC, and IROE groups were obtained and categorized based on the smoking history as non-smokers, smoker I (25 pack-years), and smoker II (>25 pack-years). Immunohistochemical staining of MUC1 using human milk fat globule 1 (HMFG 1) antibody was performed, and the MUC1 score was calculated.

View Article and Find Full Text PDF

Understanding the biochemical changes in irradiated human mandible after radiotherapy of cancer patients is critical for oral rehabilitation. The underlying mechanism for radiation-associated changes in the bone at the molecular level could lead to implant failure and osteoradionecrosis. The study aimed to assess the chemical composition and bone quality in irradiated human mandibular bone using Raman spectroscopy.

View Article and Find Full Text PDF

Purpose: Emerging evidence shows that changes in the bone and its microenvironment following radiotherapy are associated with either an inhibition or a state of low bone formation. Ionizing radiation is damaging to the jawbone as it increases the complication rate due to the development of hypovascular, hypocellular, and hypoxic tissue. This review summarizes and correlates the current knowledge on the effects of irradiation on the bone with an emphasis on jawbone, as these have been a less extensively studied area.

View Article and Find Full Text PDF

Saliva is a complex oral fluid, and plays a major role in oral health. Primary Sjögren's syndrome (pSS), as an autoimmune disease that typically causes hyposalivation. In the present study, salivary metabolites were studied from stimulated saliva samples ( = 15) of female patients with pSS in a group treated with low-dose doxycycline (LDD), saliva samples ( = 10) of non-treated female patients with pSS, and saliva samples ( = 14) of healthy age-matched females as controls.

View Article and Find Full Text PDF

Saliva is a useful biological fluid and a valuable source of biological information. Saliva contains many of the same components that can be found in blood or serum, but the components of interest tend to be at a lower concentration in saliva, and their analysis demands more sensitive techniques. Metabolomics is starting to emerge as a viable method for assessing the salivary metabolites which are generated by the biochemical processes in elucidating the pathways underlying different oral and systemic diseases.

View Article and Find Full Text PDF

Radiation therapy may compromise the quality of bone around dental implants, and its ability to regenerate, remodel, and revascularize. This study aimed to describe the irradiation effect on the bone microstructure of the mandible using dental implants in a canine model. Five beagle dogs were exposed to 40 Gy fractionated radiation.

View Article and Find Full Text PDF

Purpose: To investigate inter- and intra-individual variation in the levels and outputs (concentration multiplied by salivary flow rate) of salivary metabolites in patients with primary Sjögren's syndrome (pSS).

Methods: A total of 56 samples of stimulated saliva were collected from 14 female pSS patients during four laboratory visits within 20 weeks and analyzed using proton nuclear magnetic resonance spectroscopy. Single saliva samples from each of 15 controls were also analyzed.

View Article and Find Full Text PDF

The purpose of the present study was to demonstrate the localization of transmembrane mucin MUC1 on the outer layer of oral mucosal cells and the involvement of apical cell surface microplicae (MPL) in bioadhesion of MUC1. Tissue samples of six healthy subjects were obtained. First, the presence of MUC1 was examined with an immunohistochemical method using a monoclonal MUC1 antigen called HFMG1.

View Article and Find Full Text PDF

Radiation exposure during the course of treatment in head and neck cancer (HNC) patients can induce both structural and biochemical anomalies. The present study is focused on utilizing infrared imaging for the identification of the minor biochemical alterations in the oral mucosa. Chemical maps generated using glycoprotein band indicates its differential distribution along the superficial layer.

View Article and Find Full Text PDF

The analysis of the salivary metabolomic profile may offer an early phase approach to assess the changes associated with a wide range of diseases including head and neck cancer. The aim of the present study was to investigate the potential of nuclear magnetic resonance (NMR) spectroscopy for detecting the salivary metabolic changes associated with head and neck squamous cell carcinoma (HNSCC). Unstimulated whole-mouth saliva samples collected from HNSCC patients (primary tumour was located either in the larynx or in the oral cavity) and healthy controls were analysed by H-NMR spectroscopy.

View Article and Find Full Text PDF

Objectives: The aim of the present study is to investigate the morphological and cellular changes in dental extraction socket that has been irradiated after the tooth extraction and to describe morphological characteristics of the osteocytes and osteocyte-lacunar-canalicular network (LCN) by scanning electron microscopy (SEM).

Material And Methods: Five beagle dogs aged 1-2 years were used in this study. One side of each mandible was irradiated in two sessions and the other side of mandible (non-irradiated) served as a control.

View Article and Find Full Text PDF

The aim of this study was to define the acid-etching technique for bone samples embedded in polymethyl metacrylate (PMMA) in order to visualize the osteocyte lacuno-canalicular network (LCN) for scanning electron microscopy (SEM). Human jaw bone tissue samples (N = 18) were collected from the study population consisting of patients having received dental implant surgery. After collection, the bone samples were fixed in 70% ethanol and non-decalcified samples embedded routinely into polymethyl metacrylate (PMMA).

View Article and Find Full Text PDF

Objectives: The microplicae is a typical structure of the epithelial cell surface of the oral mucosa. The cell surface is potentially of great significance, as it provides the underlying basis for the protective function of the salivary pellicle. The aim of this study was to investigate whether radiation therapy affects the surface morphology of the superficial cells of the human oral mucosa in patients who have received radiotherapy for oral cancer.

View Article and Find Full Text PDF

Objective: The presence of a stable salivary pellicle (SP) is essential to provide a wet surface for the oral mucosal epithelia. The oral mucosa is covered by the SP which is suggested to be a mixed film of both salivary and epithelial components. Our aim was to analyse the presence of membrane-anchored mucin MUC1 in the oral mucosal epithelia.

View Article and Find Full Text PDF

Saliva provides a valuable tool for assessing oral and systemic diseases, but concentrations of salivary components are very small, calling the need for precise analysis methods. In this work, Fourier transform infrared (FT-IR) spectroscopy using transmission and photoacoustic (PA) modes were compared for quantitative analysis of saliva. The performance of these techniques was compared with a calibration series.

View Article and Find Full Text PDF

Optical diagnosis techniques offer several advantages over traditional approaches, including objectivity, speed, and cost, and these label-free, noninvasive methods have the potential to change the future workflow of cancer management. The oral cavity is particularly accessible and, thus, such methods may serve as alternate/adjunct tools to traditional methods. Recently, in vivo human clinical studies have been initiated with a view to clinical translation of such technologies.

View Article and Find Full Text PDF

Background: Salivary mucosal pellicle forms the structural basis of the local innate immune defense mechanism of the oral mucosa. At the surface of the oral mucosa, the apical cell membrane adjacent to the saliva interface contains short membrane folds, termed microplicae (MPL). This MPL structure of oral epithelial cells and its function as a basis to the salivary mucosal pellicle is unclear.

View Article and Find Full Text PDF

Fissured tongue (FT) is a condition frequently seen in the general population. Clinically, FT is characterized by grooves that vary in depth and are noted along the dorsal and/or dorsolateral aspects of the tongue. Furthermore, FT presents many enlarged, smooth filiform papillae and subepithelial inflammatory infiltration.

View Article and Find Full Text PDF

Objectives: The aim of the present study is to investigate if radiation induces changes in the superficial cells of the oral mucosa and secondly to describe morphological characteristics of the cell surface structure by scanning electron microscopy (SEM).

Materials And Methods: Ten beagle dogs aged 1-2 years were used in this study. One side of each mandible was irradiated in two sessions, each lasting 1 week.

View Article and Find Full Text PDF

Background: The apical cell membrane of the oral mucosa adjacent to the saliva interface is thrown into membrane folds, termed microplicae (MPL) with variation in morphology. The present study classifies morphological changes undergone by MPL into qualitative and quantitative categories.

Material And Methods: Oral mucosal specimens were obtained from 32 healthy patients.

View Article and Find Full Text PDF