Comparative In Vitro Biocompatibility Study of the Two Orthodontic Bonding Materials of Different Types.

In the present study, the in vitro biocompatibility and cell response to two commonly used orthodontic bonding materials of different types, one self-curing and one light-curing, were examined and compared in indirect and direct cell culture systems. The study was conducted on fibroblasts and macrophages as in vitro models to study the biocompatibility of dental materials. Differences were found between the light- and self-curing material in cytotoxicity and effects on fibroblasts' proliferation in indirect cell culture systems as well as in macrophages response in vitro in both direct and indirect cell culture systems. Based on the obtained results, we can conclude that the self-curing material is generally more cytotoxic for fibroblasts compared to the light-curing, while macrophages' response to these materials was dependent on the macrophages' state and differed between the examined materials. This indicates that more attention should be paid when choosing and applying these materials in practice due to their toxicity to cells. Prior to their use, all aspects should be considered regarding the patient's conditions, associated problems, microenvironment in the oral cavity, etc. Further studies on in vivo models should be conducted to fully understand the potential long-term effects of the use of mentioned materials in orthodontics.

Index of orthodontic treatment need in children from the Nis region.

BACKGROUND/AIM: The Index of Orthodontic Treatment Need (IOTN) is a scoring system for malocclusion that con- sists of the two independent components: Denal Health Component (DHC) and Aesthetic-Component (AC). IOTNs are usually used in the countries with dental healthcare financed by the government through the national healthcare system or healthcare insurance. The aim of the study was to determine IOTN in primary school children from the town of Nis and to asses percent of children with any kind of orthodontic treatment. METHODS: The study involved 301 school children, 11-14 (12.4 ± 1.1) years old. The IOTN was used by the two examiners in order to evaluate the treatment need. RESULTS: The results of the study showed that 111 (37%) out of 301 examined children had orthodonic treat- ment (33.33% boys and 66.67% girls) and they were excluded from the study. Out of final sample of 190 school children, considering DHC of the IOTN, 27.4% of the children showed great (grades 4-5), 41.0% moderate (grade 3) and 31.6% slight or no treatment need (grade 1-2). Considering IOTN AC, 15.3% of the children showed great (grade 8-10), 24.3 % moderate (grade 5-7) and 60.4% slight or no treatment need (grade 1-4). CONCLUSION: The need for ortho- dontic treatment in school children in the town of Nis, Serbia, is similar to the need in most European countries, despite the fact that the number of children orthodontically treated is much higher compared to most of European countries.

Cephalometric analysis of the middle part of the face in patients with mandibular prognathism.

BACKGROUND/AIM: The middle part of the face, that is the maxilla, has always been mentioned as a possible etiologic factor of skeletal Class III. However, the importance of the relationship of maxillary retroposition towards the cranial base is still unclear, although it has been examined many times. The aim of this study was to conduct cephalometric analysis of the morphology of maxilla, including the whole middle part of the face in patients with divergent and convergent facial types of mandibular prognathism, as well as to determine differences betweeen them. METHODS: Lateral cephalometric teleradiograph images of 90 patients were analyzed at the Dental Clinic of the Military Medical Academy, Belgrade, Serbia. All the patients were male, aged 18-35 years, not previously treated orthodontically. On the basis of dentalskeletal relations of jaws and teeth, the patients were divided into three groups: the group P1 (patients with divergent facial type of mandibular prognathism), P2 (patients with convergent facial type of mandibular pragmathism) and the group E (control group or eugnathic patients). A total of 9 cephalometric parameters related to the middle face were measured and analyzed: the length of the hard palate--SnaSnp, the length of the maxillary corpus--AptmPP, the length of the soft palate, the angle between the hard and soft palate--SnaSnpUt, the angle of inclination of the maxillary alveolar process, the angle of inclination of the upper front teeth, the effective maxillary length--CoA, the posterior maxillary alveolar hyperplasia--U6PP and the angle of maxillary prognathism. RESULTS: The obtained results showed that the CoA, AptmPP and SnaSnp were significally shorter in patients with divergent facial type of mandibular prognathism compared to patients with convergent facial type of the mandibular prognathism and also in both experimental groups of patients compared to the control group. SnaSnp was significantly shorter in patients with divergent facial type of mandibular prognathism compared to the control group, whereas SnaSnp was significantly smaller in patients with convergent facial type of mandibular prognathism compared to the control group. Additionally, there was a pronounced incisor dentoalveolar compensation of skeletal discrepancy in both groups of patients with mandibular prognathism manifested in the form of a significant upper front teeth protrusion, but without significant differences among the groups, while the maxillary retrognathism was present in most patients of both experimental groups. A pronounced UGPP was found only in the patients with divergent type of mandibular prognathism. CONCLUSION: The maxilla is certainly one of the key factors which contributes to making the diagnosis, but primarily to making a plan for mandibular prognathism treatment Accurate assessment of the manifestation of abnormality, localization of skeletal problems and understanding of the biological potential are key factors of the stability of/the results of surgical-orthodontic treatment of this abnormality.

Aspects of orthodontic-prosthetic rehabilitation of dentofacial anomalies.

Skeletal class III malocclusion is one of the most difficult dentofacial anomalies, characterized by deviation in the development of the mandible and maxilla in the sagittal plane, where the mandible is dominant in relation to the maxilla. In patients with class III malocclusion, anomalies in the dentoalveolar level and esthetic discrepancies are also frequent. The etiology of class III malocclusion is multifactorial due to the interaction of hereditary and environmental factors. Rehabilitation and treatment of malocclusion is one of the major goals of modern dentistry. This article presents the orthodontic-prosthetic therapy and rehabilitation of a 45-year-old patient with an abnormal occlusal vertical dimension and a skeletal class III malocclusion. The patient came to the clinic complaining about degraded esthetics and disordered functions of the orofacial region (functions of eating, swallowing, speech) and also pain in the temporomandibular joint. After the diagnosis was made, the patient was first referred to orthodontic treatment with fixed orthodontic appliances (self-ligating brackets system Rot 0.22). Upon completion of the orthodontic treatment, the patient was sent for further prosthetic treatment. Fixed prosthetic restorations were made in the upper and lower jaw, thus achieving a satisfactory result in terms of esthetics and function of the stomatognathic system.

[Analysis of interjaw ratios in relation to permanent tooth size in subjects with class I malocclusion].

INTRODUCTION: A certain ratio of maxillary to mandibular tooth size is very important for the proper occlusion formation. In regular occlusion, the teeth must be proportional to size. A discrepancy in tooth size between the mandibular and maxillary arch is usually the cause of disharmonious occlusion ratios. One of the most widespread methods in determining of discrepancy in tooth size between the upper and lower jaw is the Bolton analysis of mesiodistal width of permanent teeth. MATERIAL AND METHODS: The subjects of both sexes with the permanent dentition and occlusive ratio of Angle Class I classification had had the precise impressions taken on the basis of which the study models were obtained. 60 patients were selected for this investigation (30 males and 30 females) according to the following criteria: the presence of completely erupted teeth of permanent dentition from the first molar on one side to the first molar on the other side of the dental string; good quality of the study models; the absence of mesiodistal and occlusive abrasion, caries lesions, Class II fillings; the absence of prosthetic or composite restoration;the absence of anomalies in regard to shapes, structures and tooth development. We measured the mesiodistal width of each tooth from the first molar on one side to the first molar on the other side, from the mesial contact point to the distal contact point with the greatest interproximal distance. RESULTS: The obtained results for mesiodistal tooth width of the right and left side do not show statistically significant differences. The mean values of the Bolton anterior ratio showed neither the sexual dimorphism nor did the mean values of the Bolton total ratio show any differences in sexes. The mean values of the Bolton anterior ratio in our examinees of both sexes are significantly higher compared to the values of Bolton norms. The mean values of the Bolton total ratios in our examinees of both sexes were not statistically different compared to the values of Bolton norms. CONCLUSION: Determining of intermaxillary ratios is an important diagnostic and prognostic value in orthodontics since it offers a possibility to predict the outcome of orthodontic therapy applied on persons with tooth size discrepancy related to the upper and lower jaw.

[Effect of soft tissue thickness on profile appearance in persons with class III malocclusion].

The aim of the research was to determine the characteristics of soft tissue in persons with class III malocclusion, through the analysis of profile X-rays. The research was carried out on fifty profile X-rays of people with class III malocclusion (eighteen males and thirty two females, from the age of fifteen to twenty five). Linear and angular parameters were analyzed by Burston's and Steiners method. The increased soft tissue thickness in subspinal region in both genders had a partial compensatory effect. The reduced upper and lower lip thickness in females created more harmonious profile in relation to males, in whom lip thickness shows great individual variations. The increased soft tissue thickness in supramental region in males emphasized the abnormality in relation to females.

[The influence of size and structure of metal orthodontic bracket base on bond strength on tooth enamel].

INTRODUCTION: The factors which may influence the bond strength of the applied orthodontic brackets on the tooth surface are the size and structure of the bracket base. OBJECTIVE: The aim of the paper was to investigate the influence of size and shape of different types of brackets on bond strength on the enamel and analyze the remaining quality of adhesive material on the tooth surface after debonding of orthodontic brackets (adhesive remnant index - ARI). METHODS: In this study, three types of metal brackets of different sizes and shapes of Dentaurum manufacturer were used (Utratrimm, Equilibrium 2, Discovery, Dentaurum, Inspringen, Germany). The brackets were applied onto the middle part of the anatomic crowns of buccal surfaces of 30 premolars extracted for orthodontic reasons. In addition, the pre-treatment of teeth by 37% orthophosphoric acid and adhesive material System1+ (Dentaurum, Germany) were used. RESULTS: The mean value of the bonded brackets bond strength of Discovery type after debonding was 8.67 +/- 0.32 MPa, while the value of the bonded brackets bond strength of Equilibrium 2 type amounted to 8.62 +/- 0.22 MPa. The value of the bonded brackets bond strength of Ultratrimm type after debonding was 8.22 +/- 0.49 MPa. There were no statistical differences in the values of bond strength regarding all three groups of the investigated orthodontic brackets (F = 4.56; p < 0.05). CONCLUSION: The base size and design of metal orthodontic brackets did not play a significant role in bond strength, while the values of ARI index were identical in all three investigated groups.

[Correlation of dental age and anthropometric parametres of the overall growth and development in children].

INTRODUCTION/AIM: Anthropometric methods of measuring the whole body and body parts are the most commonly applied methods of analysing the growth and development of children. Anthropometric measures are interconnected, so that with growth and development the change of one of the parameters causes the change of the other. The aim of the paper was to analyse whether dental development follows the overall growth and development and what the ratio of this interdependence is. METHODS: The research involved a sample of 134 participants, aged between 6 and 8 years. Dental age was determined as the average of the sum of existing permanent teeth from the participants aged 6, 7 and 8. With the aim of analysing physical growth and development, commonly accepted anthropometric indexes were applied: height, weight, circumference of the head, the chest cavity at its widest point, the upper arm, the abdomen, the thigh and thickness of the epidermis. The dimensions were measured according to the methodology of the International Biological Programme. The influence of the pertinent variables' related size on the analysed variable was deter mined by the statistical method of multivariable regression. RESULTS: The middle values of all the anthropometric parametres, except for the thickness of the epidermis, were slightly bigger with male participants, and the circumference of the chest cavity was statistically considerably bigger (p < 0.05). The results of anthropometric measurement showed in general a distinct homogeneity not only of the sample group but also within gender, in relation to all the dimensions, excyt for the thickness of the epidermis. The average of the dental age of the participants was 10.36, (10.42 and 10.31 for females and males respectively). Considerable correlation (R = 0.59) with high statistical significance (p < 0.001) was determined between dental age and the set of anthropometric parameters of general growth and development. CONCLUSION: There is a considerable positive correlation (R = 0.59) between dental age and anthropometric parameters of general growth and development, which confirms that dental development follows the overall growth and development of children, aged between 6 and 8 years.