Putative cancer stem cells are present in surgical margins of oral squamous cell carcinoma.

PURPOSE: Recent evidence suggests that small subpopulations of stem-like cells are accountable for tumour initiation, progression and metastasis. Until now, studies were focused exclusively on the characterization of these cell populations within the tumour itself, while tumour margins were neglected, although it is known that the histological and molecular status of tumour margins may play a significant role in the course of the disease. Therefore, the aims of the study were to isolate cells from oral squamous cell carcinomas and their respective margins, to characterize these cells using specific markers, to assess their self-renewal potential and determine their chemoresistance. METHODS: Cell cultures were obtained from 12 tissue specimens (6 tumours and 6 margins). Total RNA was extracted and gene expression analysis was done by real-time PCR (RT-PCR). Flow cytometry, immunocytometry, sphere formation and MTT assays were also applied. RESULTS: With minor differences, cells originating from both tumours and tumour margins showed the presence of stem cell markers CD133, Nanog, Sox2, CD44, and Oct4, had the capacity to form spheroids and showed chemoresistance. CONCLUSIONS: Subpopulations of margin cells appeared to have stemness properties which might raise the question of re-evaluation of optimal surgical management.

High frequency of p16 and p14 promoter hypermethylation and marked telomere instability in salivary gland tumors.

OBJECTIVES: to investigate p16(INK4a) and p14(ARF) tumor suppressor gene methylation status, determine telomere length and assess the importance of these epigenetic and genetic parameters in the development of pleomorphic adenoma and carcinoma ex pleomorphic adenoma of the parotid salivary glands. MATERIALS AND METHODS: Genomic DNA from paraffin-embedded samples of 50 pleomorphic adenomas and 10 carcinomas ex pleomorphic adenoma was subjected to methylation specific polymerase chain reaction for hypermethylation analyses and real time polymerase chain reaction for the relative telomere length calculations. RESULTS: Promoter hypermethylation of the two genes was a very frequent event in both neoplasms - between 60% and 90% of samples were hypermethylated - but without significant difference between the groups. The mean relative telomere length in the pleomorphic adenoma group was significantly increased in comparison to the control group (P=0.00), and significantly decreased in comparison to the carcinoma group (P=0.05). Telomeres were also longer in myxoid and cellular histological subtypes of adenomas than in the classic type (P=0.044 and P=0.018, respectively). Longer telomeres were more frequent in tumors with hypermethylated p14(ARF) alleles (P=0.013). CONCLUSION: Promoter hypermethylations seems to be an important mechanism of p16(INK4a) and p14(ARF) inactivation in parotid gland tumors. Telomeric lengthening appears to be involved in the pathogenesis of both benign and malignant tumors of the parotid glands.

Analysis of polymorphism in the survivin gene promoter as a potential risk factor for head and neck cancers development.

INTRODUCTION: Association studies have shown that gene polymorphisms in various classes of genes can modulate cancer risk. The -31G/C polymorphism in the promoter of survivin gene, affects the expression of the anti-apoptotic protein survivin which in turn may predispose an individual to some types of cancer. OBJECTIVE: The aim of the study was to determine whether the survivin promoter -31G/C polymorphism could be a susceptibility factor for squamous cell carcinoma (SCC) of the oral cavity and basal cell carcinoma (BCC) of the skin. METHODS: The DNA obtained from 88 patients with SCC, 60 patients with BCC and 111 healthy individuals was subjected to polymerase chain reaction-restriction fragment length polymorphism analysis (PCR-RFLP) in order to determine genotype and allele frequencies in patients and control groups. Logistic regression was used for cancer risk assessment. RESULTS: The following distribution of genotypes was obtained: CC genotype 15% in the SCC group, 13% in the BCC group and 12% in controls; CG genotype 41% in SCCs, 35% in BCCs, 48% in controls; GG genotype 44% in SCCs, 52% in BCCs and 40% in controls. Allelic frequencies were as follows: G allele 0.65 in SCCs, 0.69 in BCCs and 0.64 in the control group; C allele 0.35 in SCCs, 0.31 in BCCs and 0.36 in the control group. There was no statistically significant difference in allele or genotype frequencies between the patients and controls (p>0.05). CONCLUSION: In Serbian population, -31G/C polymorphism in the promoter of the survivin gene cannot be considered as a risk factor for oral squamous cell carcinoma and skin basal cell carcinoma.

[The effects of orthognathic surgery on mandibular movements in patients with mandibular prognathism].

INTRODUCTION: Mandibular prognathism, one of the most severe dentofacial deformities, affects the person's appearance, psychological health and the quality of life in the most sensitive age period. OBJECTIVE: The aim of this study was to evaluate the effects of sagittal split ramus osteotomy on the range of mandibular border movements in the early postoperative period. METHODS: The study was conducted on 20 patients, of mean age 20.8 years, with mandibular prognathism. All patients included in this study were operated on by bilateral sagittal spliting ramus osteotomy according to Obwegeser and Dal Pont followed by mandibular immobilization during eight weeks. In all patients mandibular border movements were recorded before and six months after surgery using the computerized pantograph Arcus-Digma (KaVo EWL GmbH, Leutkirch, Germany). RESULTS: The analysis of the chosen kinematic parameters revealed that sagittal split ramus osteotomy followed by eight weeks of mandibular immobilization had severe effects on the mouth opening. Six months after surgery the range of maximal mouth opening decreased for approximately 13.9 mm in relation to the preoperative stage. On the contrary, the ranges of maximal protrusion and the border of laterotrusive excursions increased significantly after surgery. CONCLUSION: In patients with mandibular prognathism where enormous mandibular growth was the main causal factor of the deformity, the sagittal split ramus osteotomy yielded good results. The rigid fixation of bone fragments and reduced period of mandibular immobilization followed by appropriate physical therapy could considerably contribute to a more rapid recovery of mandibular kinematics in the postoperative period.

[Analysis of sagittal condyle inclination in subjects with temporomandibular disorders].

BACKGROUND/AIM: Disturbances of mandibular border movements is considered to be one of the major signs of temporomandibular disorders (TMD). The purpose of this study was to evaluate the possible association between disturbances of mandibular border movements and the presence of symptoms of TMD in the young. METHODS: This study included two groups of volunteers between 18 and 26 years of age. The study group included 30 examineers with signs (symptoms) of TMD, and the control group also included 30 persons without any signs (symptoms) of TMD. The presence of TMD was confirmed according to the craniomandibular index (Helkimo). The functional analysis of mandibular movements was performed in each subject using the computer pantograph. RESULTS: The results of this study did not confirm any significant differences between the values of the condylar variables/sagittal condylar inclination, length of the sagital condylar guidance, in the control and in the study group. CONCLUSION: The study did not confirm significant differences in the length and inclination of the protrusive condylar guidance, as well as in the values of the sagittal condylar inclination between the subjects with the signs and symptoms of TMD and the normal asymptomatic subjects.

Genomic instability and tumor-specific DNA alterations in oral leukoplakias.

Leukoplakias, clinically identifiable premalignant lesions, often precede oral squamous cell carcinoma (OSCC). Identification of leukoplakias that have the potential for transformation to malignancy is a key clinical problem. The aim of this study was to assess genomic instability, and to detect tumor-specific genomic alterations, in leukoplakias. Genomic instability was analyzed by comparing the DNA fingerprints of 32 leukoplakias with those of paired normal tissue. In addition, the mutational status of the p53 gene was analyzed using polymerase chain reaction-single-stranded conformational polymorphism (PCR-SSCP) and polymerase chain reaction-heteroduplex DNA (PCR-HET), and the mutations were subsequently confirmed by DNA sequencing. Moderate-to-significant genomic instability was detected in all leukoplakias analysed. Nine unique amplicons, present in leukoplakias but not in normal tissue, were retrieved and successfully characterized. The p53 gene was mutated in 40.6% of patients. Four patients with moderate instability and mutated p53 developed OSCC. The data obtained in this study support and concretize the thesis that premalignant lesions possess many of the alterations found in cancer before the development of a malignant phenotype. Inactivation or mutation of the p53 tumor-suppressor might be an early event contributing to genomic instability and increasing the risk of malignant transformation.

[Roentgencraniometric analysis of the angular craniofacial dimensions in subjects with temporomandibular disorders].

INTRODUCTION: Anomalies in growth and development of the craniofacial skeleton, particularly of vertical dysplasia, may be accompanied by distinct signs and symptoms of temporomandibular disorders. Vertical dysplasia followed by numerous occlusal disturbances alters muscular activity resulting in non-physiological strain on articular structures and their remodelling. OBJECTIVE: The purpose of this study was to evaluate a possible assocciation between certain morphologic features of the craniofacial skeleton and the presence of signs and symptoms of temporomandibular disorders in young adults with preserved natural dentition. METHOD: The investigation was carried out on 30 lateral cephalometric radiographs made of 30 subjects with signs and symptoms of temporomandibular disorders. According to the values of the ANB angle (Steiner cephalometric analysis), all subjects were classified in the skeletal class 1. The control group consisted of 50 lateral cephalometric radiographs made of subjects with the skeletal class 1 without signs and symptoms of temporomandibular disorders. The roentgencraniometric analysis of lateral cephalometric radiographs included the evaluation of 20 angular dimensions. RESULTS: The result of this study points at significant differences between the Bolton standards and the following angular dimensions in subjects with temoromandibular disorders: (S-Na)-Pg, (B-Na)-Pg, (Pns-Ans)-(Go-Gn), Occl-i, (S-Na)-i, (S-Na)-(Go-Me), (Go-Me)-i, SNB. The comparative analysis between the subjects of the experimental and the control group revealed significant differences in the values of the following angular dimensions: OccP-(Go-Po) i (S-N)-(Go-Me) at the level of p < 0.001. CONCLUSION: The values of the analysed angular dimensions in both subjects of the experimental and the control group show significant differences when related to the same angular dimensions in the Bolton standards. This can be explained by specific morphologic features of the craniofacial skeleton in subjects of our population. Small number of significant differences in the values of the examined angular variables between the subjects with signs and symptoms of temporomandibular disorders and subjects without such signs/symptoms can be explained by the fact that the study included young persons with the skeletal class 1 jaw relationships and relatively harmonious relations within the orofacial complex.

Correlation between atherosclerosis and periodontal putative pathogenic bacterial infections in coronary and internal mammary arteries.

BACKGROUND: Chronic infections, such as periodontitis, have been associated with an increased risk for atherosclerosis and coronary artery disease. The aim of this study was to investigate biopsy samples of coronary and internal mammary arteries for the presence of putative pathogenic bacteria (Porphyromonas gingivalis, Actinobacillus actinomycetemcomitans, Prevotella intermedia, and Tannerella forsythensis), Chlamydia pneumoniae, and human cytomegalovirus (CMV). METHODS: Patients with a diagnosis of coronary artery disease were included in the study. Fifteen coronary arteries with atherosclerosis and 15 internal mammary arteries without clinically assessable atherosclerotic degeneration were investigated. Both groups of specimens were obtained during coronary artery bypass grafting surgery. In all cases, the coronary and mammary artery specimens were taken from the same patient. The detection of periodontal pathogens, C. pneumoniae, and CMV was done by polymerase chain reaction analysis. RESULTS: Bacterial DNA was found in nine of 15 (60%) coronary artery biopsy samples: P. gingivalis in eight (53.33%), A. actinomycetemcomitans in four (26.67%), P. intermedia in five (33.33%), and T. forsythensis in two (13.33%) samples; CMV was detected in 10 (66.67%) samples, and C. pneumoniae was detected in five (33.33%) samples. Some of the samples contained more than one type of bacteria. Periodontal pathogens were not detected in internal mammary artery biopsies, whereas CMV was present in seven (46.67%) samples and C. pneumoniae was present in six (40%) samples. CONCLUSION: The absence of putative pathogenic bacteria in internal mammary arteries, which are known to be affected rarely by atherosclerotic changes, and their presence in a high percentage of atherosclerotic coronary arteries support the concept that periodontal organisms are associated with the development and progression of atherosclerosis.

Surgical management of squamous cell carcinoma of the lip: analysis of a 10-year experience in 223 patients.

BACKGROUND: The most common type of lip carcinoma is squamous cell carcinoma (SCC), accounting for approximately 90% of all oral malignancies. Currently, surgery and/or radiotherapy are considered the standards of care for SCC of the lip. MATERIALS AND METHODS: We retrospectively analyzed medical records of patients diagnosed with SCC of the lip at the Clinic for Maxillofacial surgery at University of Belgrade (Belgrade, Serbia) during a period between 1991 and 2000. RESULTS: A total of 223 patients with SCC of the lip were diagnosed and treated during a 10-year period. The overall male-to-female ratio was 5 to 0. The most frequently affected site was the lower lip (92.8%). Mean diameter of the tumor was 30.1 mm (range, 5 to 80 mm). Neck lymph node metastases at presentation was detected in 26.5% of patients, who subsequently underwent neck dissection. We observed a linear trend in the association between the size of the tumor and the clinical stage of the neck (chi2 = 15.1; df = 1; P < .0001). Different surgical techniques were used for reconstruction of the lip defect after tumor removal. After a median follow-up of 56 months (range, 15 to 78 months), local recurrence occurred in 10.8% of patients while regional metastases developed in 4.5% of patients. Mortality from SCC of the lip was only 2.2%. CONCLUSION: SCC of the lip generally has a favorable outcome. Recently, there have been no major advances in lip reconstruction but rather continued improvement on accepted techniques. Early detection is essential for the successful treatment of SCC of the lip, which requires a multidisciplinary approach.

[Roentgencraniometric evaluation of the craniofacial dimensions in subjects with symptoms of temporomandibular disorders].

BACKGROUND/AIM: The aim of this study was to evaluate the possible association between certain morphologic features of the craniofacial skeleton and the presence of symptoms of temporomandibular disorders in young subjects with natural dentitions. METHODS: The investigation was carried out on 80 lateral cephalometric radiographs of two groups of male and female subjects between 18 and 25 years of age with natural dentitions. The analysed group consisted of 30 subjects with symptoms of temporomandibular disorders, and the control group of 50 subjects without such symptoms. According to the values of the ANB angle (position of the maxilla with the mandible-Steiner cephalometric analysis) all subjects were classified in the skeletal class 1. The roentgencraniometric analysis of cephalometric radiographs included the evaluation of 25 linear dimensions which values were compared between the examined groups and with the values of the same dimensions in the Bolton standards for 18 years of age. RESULTS: The results of this study confirmed the presence of significant differences between the examined linear dimensions in the Bolton standards and the same dimensions measured in the subjects of the analysed and the control group. The comparative analysis of these values between the groups confirmed the presence of significant differences in following linear dimensions at the level of p < 0.00: S - Cs(Go), Mol - PP, Mol - MP and Ar - Go. CONCLUSION: Significant differences between the examined linear dimensions measured in the subjects included in this study and the same dimensions in the Bolton standards can be explained by specific morphologic features of the craniofacial skeleton in people of our population. Within the limitation of this study, the minor differences in the values of the examined linear variables between the subjects of the experimental and the control group can not be accepted as indicators of disturbed function of the orofacial system.

[Use of the modified Fries technique in the reconstruction of the lower lip after the removal of a malignant tumor].

BACKGROUND/AIM: Lip carcinoma makes about 1/4 of all oral carcinomas. Primary treatment of the lower lip carcinoma means radical excision of the full thickness of the lower lip tissue together with the tumor. The reconstruction of the defect accomplished after the removal of the lower lip tumor is a challenge for the surgeon and requires a detailed preoperative planning, the right choice of the method for reconstruction and the knowledge of the adequate surgical techniques needed. The aim of this study was to presenta ten-year clinical results and experience concerning the reconstruction of lower lip defects longer than 4 cm by means of the modified Fries method in patients treated for the lower lip carcinoma. METHODS: The reconstruction of the lower lip by means of the modified Fries method was performed in 37 patients. The following parameters were analyzed: sex, age, the time elapsed from the occurrence of the first symptoms until the first consultation with the doctor, the size of tumors, the size of the postexcision defect, TNM classification, the application of side diagnostic procedures, pathohistological diagnosis of postoperative complications. The sensibility of the lower lip region was monitored, as well as the obtained esthetic effects. RESULTS: The results classified according to the mentioned parameters were processed, analyzed and displayed in detail. Clinical experience concerning the application of this reconstruction technique was presented and analyzed. CONCLUSION: The modified Fries technique can successfully be applied in the reconstruction of the lower lip defects longer than 4 cm because its application leads to satisfactory functional and acceptable esthetic results.

[The prevalence of craniomandibular disorders in the military population of the Republic of Serbia].

INTRODUCTION: The aim of this study was to determine the prevalence of craniomandibular dysfunction (CMD) in the military personnel of the Republic of Serbia, as well as the distribution of sings and symptoms of CMD in this population group. MATERIAL AND METHODS: The epidemiological investigation included 284 male persons between 18 - 25 years of age. The sample consisted of Military Academy students, and soldiers from different regions of the Republic of Serbia. A questionnaire was designed using Helkimo's clinical dysfunction index and sings and symptoms of CMD were evaluated, namely the anamnestic index (Ai) and the dysfunction index (Di). RESULTS: According to the anamnestic dysfunction index (Ai), 85% of persons among the examined group presented without any symptoms of CMD (Ai = 0), 14% had mild symptoms (Ai =1) and 1% had severe symptoms of CMD (Ai = 5). Functional analysis of the orofacial system in the examined group (evaluation of dysfunction index - Di) revealed, however, that 70% of solders had at least one sign of CMD, precisely a dysfunction index Di > 0. The analysis of signs and symptoms of CMD revealed that disturbances in mandibular kinematics were the most prevalent sign of CMD in this population group, which was confirmed in 56% of examined persons. Disturbed functions of temporomandibular (TM) joints (click, and reciprocal click, deviation and deflection during mandibular opening) were established in 31% of examined persons, and sensitivity of TM joints and masticatory muscles during palpation in 4% of examined persons. Pain during mandibular movements was established only in 1% of examined persons. CONCLUSION: The results of this investigation point to significant prevalence of craniomandibular disorders in the examined population group. The incidence of TMJ and masticatory muscle pain in 4% of examined persons and of pain during mandibular movements only in 1% of examined persons, points to presence of mild or initial types of CMD in this population group.

[Positional changes of the lower and upper anterior teeth after surgical correction of mandibular prognathism].

BACKGROUND/AIM: To establish the influence of surgical corrections of mandibular prognathism upon the position of the lower and upper anterior teeth (incisors). METHODS: The changes in position of the lower and upper anterior teeth (incisors) after the surgical correction of mandibular prognathism were analyzed by means of x-ray craniometry in 183 patients (female: n = 110, male: n = 73) in which the correction had been made in accordance with the principles of sagital osteotomy of the mandibular ramus. There were 4 angular and 2 linear parameters determined in the pre- and postoperative tele-x-ray-pictures. The changes of these parameters were tested by means of the parametric statistic tests. RESULTS: The performed surgical procedures did not cause statistically significant changes in the angular parameters. The changes of both linear parameters were thought highly statistically significant. CONCLUSION: Under the influence of the performed surgical procedures no changes were found in the position of anterior teeth (incisors) in relation to SN and the mandibular plane. They were actually moved along with the medium fragment of the lower jaw and that fragment was moved linearly backwards along the occlusal plane with a practically insignificant rotation in the cranial direction.

[The relationship of occlusal disharmonies and symptoms of temporomandibular disorders].

INTRODUCTION: The influence of occlusal condition on the onset of temporomandibular disorder (TMD) has been strongly debated for many years and is still the source of controversy. Until 1980s, the occlusal factors such as the presence of uncured malocclusions, discrepancies between intercuspal position (ICP) and retruded contact position (RCP) greater than two millimeters, occlusal abnormality, particularly mediotrusion and retrusion, and loss of posterior teeth were considered the primary causes ofTMD. OBJECTIVE: The objective of our study was to find correlation of occlusion disharmonies (difference between ICP and RCP) and present sings and symptoms of TMD. METHOD: The study involved 60 subjects between 18 and 26 years of age who were divided in two groups. The study group consisted of 30 subjects between 18 and 26 years of age with sings and symptoms of temporomandibular disorders (TMD). TMD was confirmed according to Helkimo index. An average value of Helkimo index in this group was 1. The control group included 30 subjects between 20 and 25 years of age without TMD sings and symptoms. An average value of Helkimo index in this group was 0. The function analysis of cinematic centers position in RCP and ICP was performed in each subject using the computer pantograph Arcus-Digma (KaVo EWL GmbH, Leutkirch, Germany). RESULTS: The results of our study showed that the translation tracing of cinematic points from RCP to ICP was significantly different in TMD subjects and asymptomatic group (p > 0.16). In addition, the study revealed that 53.4% of subjects with sings and symptoms of temporomandibular disorders had marked translation in the lower temporomandibular joint (0.61-1.2 mm) what directed to intracapsular disorders. CONCLUSION: The results of our study suggested significant difference of RCP and ICP between subjects with sings and symptoms of the temporomandibular disorders and subjects without sings and symptoms.