Injuries to the Stomatognathic System in Tae-Kwon-Do

Martial arts are high-risk sports for injuries to the stomatognathic system, according to the FDI classification. The aim of this investigation was to determine frequency, type and severity of injuries to the stomatognathic system, during Tae-Kwon-Do, and the use of protection devices during training and competitions. This investigation included 43 examinees, 15 female and 28 male, among which were members of the national representatives of the Republic of Croatia. They were required to complete a questionnaire. The result revealed a very low number of injuries, in fact, lack of injuries in the female and male junior categories. In the male junior and both senior categories 134 injuries were reported, 118 or 88% of them were laceration of the lips, cheeks and tongue. Other injuries to the stomatognathic system represent only 16 injuries or 12% of all injuries. The majority of injuries occurred during training (68%), and 32% during competition. Protection devices (helmets) were used during training only by 5 examinees (11.63%), and during competition (100%). Mouthguards of any type were not used by any examinee. Helmets used are obligatory during competition and prevent the occurrence of injuries to the stomatognathic system, and decrease the severity of injury

Frequency of Temporomandibular Disorders in Asymptomatic Removable Partial and Complete Denture Wearers

A dogmatic view on occlusion as the main aetiological factor for temporomandibular disorder (TMD) has been present in the literature for a long time, but a direct scientific correlation between occlusal disorders and TMD has never been proven. The purpose of this study was to determine the frequency of TMD signs and tissue-specific diagnoses in a population of 164 asymptomatic participants, 70 removable partial denture wearers and 94 complete denture wearers of an average age of 61.3 years, by means of clinical manual functional analysis. TMD was found in 42.1% of the participants. No statistically significant difference in the occurrence of TMD was found between removable partial and complete denture wearers and between genders (P > 0.05). The most frequent tissue-specific diagnoses were osteoarthrosis (11%), total anterior disc displacement (9.1%) and partial anterolateral disc displacement (8.5%). The frequency of tissue-specific diagnoses was also not influenced by the type of prosthetic replacements

Terminal Hinge Axis – Hobo Point – Frankfurt Horizontal Relations

Aim of this investigation was to determine the spatial relations of the terminal hinge axis of the temporomandibular joints toward Frankfurt horizontal. The sample consisted of 50 examinees. Terminal hinge axis was located, using Lauritzen’s technique, on the left side of face for each examinee. Arbitrary point, as proposed by Sumiya Hobo, was measured and point Orbital was defined by palpation. On designated points steel pellets 0.25 mm in diameter were stocked. Lathero – latheral cephalogram was obtained for each examinee. Cephalograms were traced down on a transparent foil and points Orbital, THA – terminal hinge axis, Hobo and Porion – as the uppermost point of the metal ear rod of the cephalostat, were designated. Connecting points Orbital and Porion, Frankfurt horizontal was defined, and shortest distance toward points THA and Hobo, as well as between them were measured. Lines parallel and perpendicular to Frankfurt horizontal were drawn through point THA. In a co-ordinate system defined in such a way, upper left quadrant was first, upper right second, lower right third, and lower left was fourth. Observation was made in which quadrant Hobo point was located. Measured values were statistically evaluated. Results revealed that Hobo point is located in first quadrant in 5 cases, in second in 7, third quadrant in 18, and in fourth in 20 cases. That means that Hobo point is located lower to the THA point in majority of our population. Points THA and Hobo were not identical in any case. Mean values of variables showed that investigated points were inferior to the FH. Measures of variability revealed great variability of both points toward FH, as well as for their mutual distance. It could be pointed out that THA point should be defined kinematically during prosthodontic procedures, and that orientation in articulator’s space should not be according to the FH

The Effect of Tooth Loss on the TM-joint Articular Eminence Inclination

The inclination between the posterior wall of the articular eminence and the referential plane (Frankfurt line) was measured on 137 dry skull specimens (78 with complete dental arches and 59 edentulous). Both left and right joints were measured using direct craniometric method. The results were compared with respect to the loss of teeth, side and sex. A large range of measured values of the eminence inclination shows great individual differences, so that the mean values can have only orientational significance. The mean value of eminence inclination for all measured specimens was 61.9 angular degree. The difference between the two groups established upon dental status is very small and without any statistical significance (P > 0.05). The right joint shows a slightly steeper eminence inclination compared to the left one, but without any statistical significance (P > 0.05). Asymmetry between the right and left joint appears almost as a rule, while maximum measured differences reach up to 33°, with mean absolute difference of 6.9°. The group of edentulous specimens shows a greater symmetry and less differences between the left and right joint, which indicates that different bimechanical conditions in the joint, due to tooth loss might lead to remodellation of the articular eminence.The eminence inclination was significantly steeper in male specimens in all subgroups (P < 0.001), which confirms sexual dimorphism

The Patient’s and the Therapist’s Evaluation of Bridges of Different Materials and Age

The aim of this study was to find out patients\u27 satisfaction with their bridges made of different materials (metal-ceramics, Au/resin, Ag-Pd/resin). One hundred and sixty four patients were examined at the Dental School, University of Zagreb, Croatia. They assessed their bridges – the overall quality, aesthetics, speech, chewing and the health of the gingiva by the scale from 1–5. The same categories were also assessed by a trained prosthodontist. The majority of the patients was really satisfied and gave the highest grades (quality, aesthetics, speech, etc.) and therefore the results were skewed and asymmetrical towards the biggest scores (biggest grades). The best gingival health was evaluated by the group of patients with ceramic crowns and bridges (p < 0.05) and the worst by the patients with Ag-Pd bridges. Speech was scored higher for the lateral than for the frontal bridges. Patients evaluated the health of the tissue surrounding their bridges, overall quality of fixed prosthodontic appliance and aesthetics with significantly higher scores than the prosthodontist (p < 0.01). The results point at a difference between the patient’s and the therapist\u27s evaluations and to the patient\u27s insufficient care about the gingiva around the bridge abutments

Implanto-Prosthetic Rehabilitation of the Mandible by Means of Two Implants

Edentulousness is a considerable problem in Croatia. So far prevention has not become the most important part of the dental profession. On the other hand,poor medical knowledge, reduced rights concerning health insurance costs as well as an increasing number of impoverished people in Croatia has resulted in postponed prosthetic rehabilitation. For the above mentioned reasons the Croatian people suffer from premature loss of their teeth. Also lower jaw atrophy occurs, which makes prosthetic rehabilitation even more difficult to achieve. In spite of some disadvantages, the double-implant borne prosthetic suprastructure has proved to be a simple and good solution to the patient\u27s problem, mainly because it is cost-effective. This particularly applies to Croatia patients. Over the last five years we have placed double -implants in 26 patients, in the anterior region of the mandible. The implants were placed in the region of the lower canine or slightly more mesially. Severe atrophy was determined in 13 patients (50%) which impeded their complete denture wearing even before the implant placement started. However, we made up for the loss in two patients by placing the implants again. This time we placed them slightly more mesially. We made one borne implant complete denture for one patient because the examination revealed severe atrophy in one segment of his mandible. In addition since the osseointegration prognosis for this patient was questionable we decided against any additional surgical treatment. Since the belts of the attached gingiva in our patients were wide enough and the diameters of the implants were not very long, no vestibuloplasty was necessary. We installed ITI, IMZ, ASTRA and Ankylos implants. All systems proved to be equally functional

Relationship Between the Face and the Tooth Form

The aim of this study was to re-examine Leon Williams geometric theory and to find the degree of correspondence between the face and the tooth form in the population of Zenica, Bosnia and Herzegovina. Two thousand individuals with intact frontal teeth, in age between 17 and 24 years, were measured for 3 horizontal distances on the face: temporal width (Ft-Ft), zygomatic width (Zyg-Zyg) and gonial width (Go-Go) and for 3 horizontal distances on the both upper incisors: cervical width (CW), contact point width (CPW) and incisal width (IW). The length of the face (Tr-Gn) as well as the length of the central maxillary incisors were also measured. The results revealed: 1. Men had significantly larger dimensions for all facial and tooth dimensions (p < 0.05) than women, except for the cervical tooth width (p > 0.05); the left and the right central incisors were of identical dimensions and forms (p > 0.05). 2. The width of upper central incisors were smaller approximately 1.5 mm than in west Europeans. 3. Upon the relation between the 3 horizontal dimensions measured on the face and upper maxillary incisor, 11 facial forms and 10 upper central tooth forms could be recognised in the study population, but 98% of the population had only 3 tooth and face forms. Face shapes: oval face – 83.3%, square-tapered face – 9.2% and tapered face – 7%; tooth forms: tapered-square incisor – 53%, oval incisor – 30%, tappered incisor – 16%. 4. Reversed and enlarged tooth form was in line associated with the facial form in only 30%, while the most common combination was of the oval face form and the tapered-square central incisor (45%). 5. These results disapprove William’s theory and may be helpful for the choice of artificial teeth in complete denture construction and the dental industry

Bite Force in Subjects with Complete Dentition

Bite force is the condition, expression and measure of the masticatory function. The purpose of this study was to examine, by means of a newly constructed electronic gnathodynamometer, the values of maximal bite forces in subjects with complete dentition, the time in which they express 50% and 75% respectively of the total forces value, and the shape of the bite curve during testing. The obtained data was statistically analyzed with respect to gender and age. Analysis of the variance confirmed the finding that there was no statistically significant correlation between the values of forces and subjects\u27 age, but there was a statistically significant difference between males and females in the values of the bite forces in the front segment, as well as between the values of the force on anterior and posterior teeth. The correlation between the time T1 posterior right and T1 posterior left, and between T1 and T2 for anterior teeth are statistically significant. Analysis of the bite curves suggests that males »bite« shorter than females with a sharper peak of the curve. Numerical values and bite curves should be a diagnostic factor in the further follow-up of subjects or in the choice of prosthodontic therapy