Influence of diet on dental caries in diabetics.

Two groups of population consisting of 84 patients suffering from diabetes (60 type I, 24 type II) and 69 nondiabetics of the same age have been examined on: oral hygiene index (OHI), frequency of daily tooth brushing, dietary habits and incidence of dental caries by registration of the decayed, missed and filled dental surfaces (DMFS-index). OHI in type I and type II diabetes was found to bee slightly worse than in nondiabetics, but not significantly (p > 0.05). In the number of daily tooth brushing there is not significant difference between diabetics and nondiabetics. All diabetics have considerably lower daily intake of total as well as simple carbohydrates than nondiabetics. The diabetics have a significantly higher daily intake of dietary fibers, calcium and phosphorus as well as the number of meals with simple carbohydrates and also DMFS-index than the nondiabetics. A significantly higher incidence (p < 0.01) of caries location was found on the buccal and labial cervical areas among patients suffering from diabetes. Explanation for this could be more frequent daily intake of low molecular carbohydrates with an improper calcium phosphorus ratio.

Dynamic influence of food consistency on the masticatory motion.

The masticatory cycle is a complex process and it depends on many factors. In our study we wanted to prove to what extent various types of food consistency influence the masticatory motions, especially the extent of forward, downward and lateral motions of the mandible. Nineteen study subjects aged from 20 to 37 years and with intact teeth rows were asked to chew three types of food of various consistency (banana, bread and carrot). The motions of the mandible were recorded by stereo-photo-grammetric system. Study results have shown that in all 19 study subjects the increase in food consistency increases the extent of masticatory motions. The average size of forward mandibular motion in all 19 study subjects when chewing banana amounts to 2.65 mm, when chewing bread it is 2.96 mm and 3.64 mm when chewing carrot. The average size of downward mandibular motion for all 19 study subjects amounts to 6.79 mm when chewing banana, 7.17 mm when chewing bread and 8.09 mm when chewing carrot. The average size of lateral mandibular motion in all 19 study subjects amounts to 2.46 mm when chewing banana, 2.80 mm when chewing bread and 3.40 mm when chewing carrot. Although varying from subject to subject, the masticatory cycle significantly depends on food consistency. By increasing the consistency of a mouthful, the extent of mandibular motion increases in every single study subject.

Tooth morphology in function of selfprotective mechanism.

The degree of curvature of vestibular and oral tooth surfaces is determined by the shape sequence from the tooth crown to the epithelial attachment and the alveolar bone, and directly influences the health of gingiva and the entire tooth support system. The goal of this research was to determine vestibulo-oral planes of upper and lower permanent premolars and molars and the thickness of the associated alveolar osseous wall, and 2,727 measurings were processed using pertinent statistical procedures. The results have shown the degree of curvature of vestibular and oral tooth surfaces to be higher in upper teeth than in lower ones (p > 0.05); vestibular convexities higher than oral ones and especially noticeable at the junction from the meandle to the lower third of the crown. Higher vestibular curvature also entailed thicker osseous wall. All results were higher than the ones found in literature. We consider our results to be relevant for our population. The research on the relationship of teeth and the alveolar bone should be continued by using even more test points and more sophisticated research procedures.

Foramen mandibulae as an indicator of successful conduction anesthesia.

Comparative measurements were made of 144 orthopantomographs in 50 patients with successful and 94 patients with unsuccessful inferior alveolar nerve block anesthesia. The results show that the bony lingula is prominent in 28.5% of all patients, or in 56.0% of those with unsuccessful anesthesia. The variables mandibular notch vs. mandibular foramen (MN-MF) and the anterior ramus ridge vs. mandibular foramen (ARR-MF) show greater distances in the group of patients with successful anesthesia, while the variables of posterior ramus ridge vs. mandibular foramen (PRR-MF) and mandibular angle vs. mandibular foramen (MA-MF) were greater in the group of patients with unsuccessful anesthesia (p > 0.05). It is concluded that the variability in position of the mandibular foramen among others may be responsible for an occasional failure of inferior alveolar nerve block.

Model for computer simulation of bone tissue.

The paper deals with the dependence of the torsional moment on the angle of the compact bone torsion in laboratory animals and humans. Based on the data for laboratory animals obtained by measurements, the data on dependence of the torsional moment and the angle of torsion were predicted for humans. The measurements were carried out in four groups of laboratory animals. One was the control group, and the other three groups were treated by various vitamin D3 metabolites. The same measurements were performed also in only one group of humans, due to the impossibility to treat humans with vitamin D3 metabolites. The functional relationship between the angle of torsion and the torsional moment for all the groups of animal bone tissue were determined by measurements, and results were used to predict the reaction of the human compact bone tissue if treated by vitamin D3 metabolites.

Dynamic effects of food consistency on chewing motions.

The purpose of the study was to find evidence of how different types of food consistency affect chewing motions, especially the forward, downward and sidewise extents of motion of the lower jaw. Nineteen individuals with intact tooth sequence, aged from 20 to 37 years, were asked to chew three types of food of different consistency (banana, bread, carrot). The motions of the lower jaw were recorded by ELITE system, i.e. the measurement instrument that by stereo-photo-grametric procedures calculates space co-ordinates of markers on faces of the study subjects. The system enables continuous recording of lower jaw motions in three dimensions, without any possibility of the study subjects' influencing the operation of the instrument, which significantly decreases the possibility of error. Study results have shown that in all 19 subjects a greater food consistency increases the extent of chewing motion. In each individual study subject different average values were found for equal shifts of lower jaw when chewing the same type of food. Although varying from subject to subject, the chewing cycle depends to a great extent on food consistency. By increasing the consistency of a bite, the extent of lower jaw motion has increased in every single study subject.

Hereditary and environmental dental findings in identification of human remains.

The paper presents the results on hereditary and environmental dental findings in identification of human remains exhumed from mass graves in the Republic of Croatia. The total of 17,880 teeth from all the categories (incisors, canines, premolars and molars) was examined. Hereditary findings of the teeth such as shape, size, position, as well as age were used in all of the cases confirming and completing the identification. In only 15% of the cases they were the starting points for the identification that would be later confirmed with another 3-5 traditional identification procedures. Disturbances in tooth eruption were recorded in 22% of the cases, impaction of teeth in 10%, and retarded eruption of teeth in 12%. Disturbances of tooth position were recorded in 65% of the cases. Tooth rotation in 26% and diastema mediana in maxilla or mandible in 39%. Disorders of tooth number in the form of unilateral and bilateral missing of lateral maxillary incisors were recorded only in 2% of the monitored cases. Abnormalities of the tooth shape were found in 11% of the cases. The majority of them were found on the tooth crowns 6%, and less on the tooth roots 5%. Environmental dental findings that were the most significant for the identifications were prosthetic appliances in 30% of cases. Prostheses were helpful in the identification of 3% of the cases, while crowns and bridges were helpful in 27% of the cases. Ante mortem teeth extractions were helpful in 25% of the cases. Teeth restorations were recorded in 20% of the identified cases, amalgams in 19% and aesthetic filings in 1%. Dental caries was helpful in only 10% of the cases, superficial caries in 3% and caries of dentin in 7% of cases.

Measurement of magnetic field in dentistry.

The principal objective was to measure the magnetic fields occurring in dental surgeries at simultaneous subtraction of direct ground component of the magnetic field. A specifically designed instrument with the Hall probe was used for the measurement. It consisted of two amplifiers and a low frequency filter. Its task was to measure mean square values of the field (RMS) dependent on the position in space. Qualitative and quantitative analyses of the investigated variables enabled making conclusions about the magnetic fields in dental surgeries. A number of studies have shown that many dental instruments produce radiation with magnetic field higher than 40 G, at a significant decrease in power of the magnetic field with increasing distance from the source. It has also been reported that instruments of older generations produce stronger magnetic fields than do the new ones.

Vomer as relevant factor in the mastication forces transmission system.

In the region of the posterior segment of bony palate and nasal cavities in both sides, the following three bones come together: the upper jaw, the palatal and the sphenoid bones. The perpendicular upper palate lamina laterally leans on the corpus of the upper jaw and on the wing process of the sphenoid bone. It is the posterior bony transmission system that has been selected as a separate study entity, which is otherwise a functionally inseparable part of the overall system of trajectories of mastication forces. It is a supporting element that begins at the dental alveolus of the wisdom tooth, ascends along the tuber maxillae and by the wing process of the sphenoid bone transmits the mastication load to the body of the sphenoid bone, i.e. into the mid-portion of the neurocranial base. By observing the characteristics of the vomer and measurement of distances between its morphological markings, or craniometric landmarks, together with its fitting into the harmonic analysis of face and head, the essential role of vomer has been established in regard to the trajectory system of mastication forces which has enabled us to create the basis for further biomechanical research of this phenomenon using photoelasticimetric procedures.

Morphometric characteristics of toothless lower jaw ridge as a bed for total lower jaw prosthesis.

Analysis was made of 44 solid casts of toothless lower jaws. Stereophotogrammetry, a measurement procedure in photogrammetry, was used as a method in the measurement of solid casts. Adequate instruments and method of measurement made it possible to objectify anatomical and morphological structures of toothless lower jaws. The anterior width of the ridge in the region of canines was 22.70-35.50 mm. The posterior width in the first molars region was 43.30-59.10 mm, with statistically significant difference between the genders. The width at the level of posterior ridge of mandibular tubercle was 52.10-70.00 mm, with statistically significant difference between the genders. The length of the alveolar ridge between the symphysis and the tangent line of posterior ridge of mandibular tubercle in the medial line was 34.70-49.00 mm, without statistically significant difference between the genders. The surface of the toothless ridge is at the same time the surface of the total lower prosthesis bed. The size of the surface depended on the resorption and relation between the alveolar ridge and the surrounding active structures; it ranged between 103.21-205.50 mm2. The mean value being 145.99 mm2. The values obtained in our study are in approximate accordance with the reference literature data. They are the results of accurate measurements of solid casts.

The influence of tooth wear on root canal dimensions.

The objective was to investigate the relations between tooth wear and root canal dimensions. The experimental group comprised 100 cuspids (canines), 50 of which had advanced abrasion and 50 were without it The dimensions of root canal were investigated at the light microscope level in order to define their vestibulo-oral and mesio-distal diameters in all three thirds. In the groups of teeth without abrasion the MD diameters of root canaliculi in their cervical thirds were greater than in the teeth with advanced abrasion. In the apical third the MD diameters of canaliculi were highly variable in teeth with no signs of abrasion. In the group of teeth with abrasion the MD and VO diameter values of the cervical thirds were significantly smaller than in the group of teeth without abrasion. In the mid-thirds the values of MD diameters were highly variable in the group of teeth with abrasion, whereas the VO diameter values were much greater than in the teeth without abrasion. As regards to the apical thirds, the VO diameter values were greater than in the control teeth. The data presented herewith contribute to better knowledge about tooth wear and are highly useful in restorative and reconstructive dental procedures.

Psychophysiological parameters and children's behavior during dental treatment.

Uncooperative children represent one of the leading problems in clinical pedodontics. The hypothesis of this study was that extraverted children reveal greater pain tolerance, lower stress levels and anxiety in general in comparison to introverted ones. A total of 130 children aged 11 to 15 years were studied, 55 boys and 75 girls. In the research, psychological tests were performed along with the measurements of some physiological parameters and children's own assessment of pain intensity. The results revealed the connection between extraverted personality and children's behavior at the dentist's clinic. Pain tolerance, levels of anxiety and general pattern of behavior were significantly dependent on psychological control mechanisms.

Assessment of position of foramen mandibulae in recent adult population.

Accurate knowledge about the morphology and topography of foramen mandibulae is of great practical importance in anaesthesia of inferior alveolar nerve. A certain number of skeletotopical relations may be used as valuable orientation points. Because of the controversies about these marking points it has been decided to perform measurements on a large sample of macerated mandibulae that are significant to location and shape of foramen mandibulae (FM) and lingula in relation to the surrounding orientation points. The measurements were taken in antero-posterior and infra-superior directions. In AP direction the distance between PRR and FM was measured; the obtained sample average was 15.03 at variability of Qv 12.18%; ARR-FM distance had the average value of 17.52 at Qv of 50%; the CT-FM distance had the average of 14.81 at Qv of 8.17%. In infra-superior direction the following measurements were made: AM-FM with the average of 21.10 at Qv of 13.98%; IM-IF with the average of 25.19 at Qv of 16.18%; PCO-FM with the average of 44.17 at Qv of 10.48%; and PCR-FM with the average of 42.79 at Qv of 10.87%. Extreme heterogeneity was noticed in the measurements of lingula. In the antero-posterior plane the FM is located in the middle of the CT-PRR distance, i.e., in measurements in which the external oblique line was used as anterior point, FM was located at the juncture of two anterior thirds and the posterior third of ramus mandibulae. In infra-superior direction the lowest FM point was closer to AM than to IM, indicating a somewhat lower position of FM. The mean value of FM depth was 4.31 and the most commonly found shape of the foramen was that of the elongated type (45%). The lingula was prominent, although unevenly, in 51% of study samples.

A biomechanical analysis of deformation and strain on lower jaw model.

Forces, occurring as result of orthodontic appliances, present a guiding system which controls force activity during the growth and development of lower jaw. By qualitative photoelasticimetric analysis author decided to evaluate the influence of extension apparatus to the lower jaw. The concentration and stress distribution, intensity and force direction on contacts with insert (extensor device) were analysed on araldyte lower jaw models. Three different loadings 41.0, 57.4 and 73.8 N under four different loading conditions with and without the correction appliance were used. The results of investigation indicated that the force created by the orthodontic appliance is correct at the beginning. The change from surface contact to linear and punctual contact increased the static moment and local stress, resulting in new regional conditions.

Heterotopia of the mandibular third molar: a case report.

A rare finding of unilateral heterotopia of a mandibular third molar was most probably caused by primary and total dislocation of the tooth base. Other possible causative factors, such as a lack of space between the mandibular second molar and the mandibular ramus or a disproportion between the base and the direction of growth of the third molar, have been considered in similar cases reported in the literature.