Mandibular Bone Mineral Density Changes Dependet on the Denture Support. A Six Month Follow up Study

Reduction in the height of the alveolar edentulous ridge in denture wearers is a well documented problem which depends on various local and systemic factors. Changes of bone mineral density (BMD) in denture wearers have not yet been documented in follow-up studies. The aim of this study was to determine the changes in BMD of the mandible in complete (CD) and removable free-end saddle denture wearers (RPD) during a six month period (both groups had complete dentures in the maxilla). Twenty RPD patients (5 male, 15 female) and 20 CD wearers (7 male, 13 female) participated. The BMD measurements were performed on digitised dental panoramic radiographs (DPR) with a 5 step copper stepwedge attached to each film cassette. Grey levels of each step of the stepwedge were transformed to optical density values and using the 3rd degree polynomial the regression formula was calculated for each digitised image to express BMD values of the measured region of interest (ROI) in the copper stepwedge thickness equivalents. The results revealed that the BMD values of the examined ROIs under the distal end of the CD decreased, and in contrast, the matching BMD values under the distal end of the RPD increased, during the six month period, although the changes did not reach a statistically significant level (p>0.05). The BMD values on gonion increased significantly in both examined groups (p<0.05), which was attributed to the increased load of the strain forces of the masseter muscle at gonion after the denture delivery. Supported by the Ministry of Science and Technology, Republic of Croatia, Project No. 065911

Evaluation of Denture Stomatitis in Croatian Adult Population

Denture stomatitis (DS) is often found under the removable partial dentures (RPDs). There are many factors influencing it, such as patient’s age and gender, smoking habits, denture age, denture material, denture wearing habits, denture hygiene habits, oral hygiene instruction, denture cleanness and denture plaque accumulation. The aim of this study was to find out the influence these factors have on the prevalence of DS under RPDs and complete dentures (CDs). A total of 200 patients took part in this study. Half of the examined patients (100) wore CD and the other half (100) RPDs. There were 63 males and 137 females, aged between 45 and 83 years. Different smoking habits, denture wearing habits, denture hygiene habits, denture cleanness and oral hygiene instructions had significant influence on the degree of DS in CD wearers (p < 0.01). In the RPD wearers, denture material and denture support had a significant influence on DS (p < 0.01). The significant correlation was found between the denture plaque accumulation and the DS in complete maxillary and mandibular ( U = 0.85; L = 0.61) and removable maxillary and mandibular partial dentures ( U = 0.45; L = 0.62)

ITI Implant-Supported Dentures: Assessment of Peri-Implant Bone Changes

Mandibular overdentures, supported by osseointegrated implants, is a well established, successful treatment of partialy edentulous patients. The aim of the study was to analyse the bone mineral density (BMD) in the implant site of the mandibles with ITI implant-supported overdentures when compared with the same site of the edentulous mandibles in complete denture wearers. Eight patients (4 males, 4 females) with 16 ITI implants and overdentures in the mandible and 8 complete denture wearers (4 males, 4 females) who had approximately the same body mass index and the same age participated. The BMD measurements were performed on digitised periapical radiographs with a 10 steps copper stepwedge attached to each film. Grey levels of each step of the stepwedge were transformed to optical density values and using the 3rd degree polynomial the regression formula was calculated for each film. The BMD values of each measured region of interest (ROI) were expressed in the copper stepwedge thickness equivalents. BMD values of the ROIs close to the implant were statistically compared to the same ROIs in the edentulous mandible using t test for independent samples. BMD values were significantly higher in ITI implant ROIs compared to the matching edentulous mandible sites (p<0.05). We concluded that an increased function after the implant-overdenture treatmentcaused a load-related bone formation which minimizes the physiologic age-related mandibular BMD loss. Supported by the Ministry of Science and Technology, Republic of Croatia, Project No. 065911

Evaluation of Denture Stomatitis in Croatian Adult Population

Denture stomatitis (DS) is often found under the removable partial dentures (RPDs). There are many factors influencing it, such as patient’s age and gender, smoking habits, denture age, denture material, denture wearing habits, denture hygiene habits, oral hygiene instruction, denture cleanness and denture plaque accumulation. The aim of this study was to find out the influence these factors have on the prevalence of DS under RPDs and complete dentures (CDs). A total of 200 patients took part in this study. Half of the examined patients (100) wore CD and the other half (100) RPDs. There were 63 males and 137 females, aged between 45 and 83 years. Different smoking habits, denture wearing habits, denture hygiene habits, denture cleanness and oral hygiene instructions had significant influence on the degree of DS in CD wearers (p < 0.01). In the RPD wearers, denture material and denture support had a significant influence on DS (p < 0.01). The significant correlation was found between the denture plaque accumulation and the DS in complete maxillary and mandibular ( U = 0.85; L = 0.61) and removable maxillary and mandibular partial dentures ( U = 0.45; L = 0.62)

Alveolar Bone Loss on Abutment and Non-Abutment Teeth as Related to Removable Partial Denture Wearing. A Six Month Follow up Study

Loss of interdental alveolar bony septum can be determined directly from a radiograph as a percentage length of the interdental bony crest of the alveolus to the distance from cemento-enamel junction of the tooth to the tooth apex. The aim of this study was to measure the height of interdental alveolar bone around the abutment and nonabutment teeth in removable partial denture wearers (RPD) on dental panoramic radiographs (DPR) through a period of six months. Twenty RPD patients (5 males, 15 females participated in the study. The alveolarbone loss measurement was performed on DPRs, using Shei index, on each mandibular abutment and non-abutment tooth on its mesial and distal side, after the RPD delivery and six months later. Recordings of plaque index (PlI) were made at the mid-buccal, mid-palatal, mesio- and disto-palatal surfaces of each abutment and non-abutment teeth after the RPD delivery and six months later. The results revealed a decrease of Shei index values on both abutment and non-abutment teeth, which reached a statistically significant level for distal Shei index values of the abutment teeth and mesial and distal Shei index values of the non-abutment teeth (p<0.05) in a 6 month period. There was no statistically significant difference in PlI values between the first and the second measurement (p>0.05). We concluded that the decrease in bone support on both abutment and non-abutment teeth was attributed to the high levels of PlI and low level of oral hygiene than to RPD loading. Supported by the Ministry of Science and Technology, Republic of Croatia, Project No. 065911

Electromyographic Evaluation of the Influence of Denture Adhesive on Retention and Stability of Complete Dentures

Improving retention and stability of complete dentures is of considerable interest in prosthetic dentistry. Approaches to this problem over the years have included overdentures, implants and denture adhesives. Although denture adhesives are widely used, there are few quantitative data on the effects of an adhesive on denture retention and stability during normal functional activities. The purpose of this investigation was to study the influence of denture adhesive on the surface EMG activity of the masticatory muscles in a sample of complete denture wearers. In this study 6 denture wearers were investigated. Surface EMG recordings were obtained from left and right anterior temporal and masseter muscle and from the sub-mandibular group in the region of the anterior belly of the digastric muscle on the left and right side. Data were recorded during standardized jaw positions that included clenching in the position of maximal intercuspation of teeth (at 100%, 50% and 25% of the maximum activity), lateral eccentric positions, maximal lateral eccentric positions, protrusion, maximal protrusion and wide opening. The results demonstrated higher digastric muscle activity in protrusion with the teeth at an edge-toedge position after the use of adhesive (p0.05). This investigation demonstrated that patients were able to produce greater levels of muscle activity in protrusive and laterotrusive positions with the use of adhesive

The Rate of Resorption of Different Regions of Residual Ridges in Complete Denture Wearers Dependent on the Region and the Period Following the Last Extraction. One Year Study.

Residual alveolar ridges (RR) show continual resorption after the loss of the natural dentition, resulting in reduction of the morphologic face height and counterclockwise rotation of the mandible, regardless of whether the dentures are worn or not. The aim of this study was to analyse residual ridge resorption (RRR) in 5 different regions of both jaws on the successive lateral cephalograms of 50 complete denture wearers and to correlate such changes with the number of years of edentia and the region where the last extraction was performed. The height of the residual ridges was measured on 5 different sites of the mandible and the maxillary RR using a calibrated grid. The results revealed that all the patients showed significant RRR in the one year period (p<0.01), which was 2.5x more in the mandible than in the maxilla. RRR was bigger in patients who had had their last extraction within a period of one year before receiving their dentures, than in patients who had extracted their teeth earlier (p<0.01). However, the rate of RRR was significantly higher (p<0.01) in the anterior regions of both jaws compared to distal regions (0.41 and 0.42 mm in the incisive/canine region: 0.2 and 0.17 mm in the premolar/ molar region for the maxilla 1.05 and 0.82 mm in the incisive/canine region : 0.27 and 0.11 in the premolar/ molar region for the mandible), even in patients where the last extraction was performed in the premolar region. It seems that the structure of the bone and strains in RR, due to loading from the dentures, may play a role, not only the period following extraction and the region of the last extraction

The Rate of Resorption of Different Regions of Residual Ridges in Complete Denture Wearers Dependent on the Region and the Period Following the Last Extraction. One Year Study.

Residual alveolar ridges (RR) show continual resorption after the loss of the natural dentition, resulting in reduction of the morphologic face height and counterclockwise rotation of the mandible, regardless of whether the dentures are worn or not. The aim of this study was to analyse residual ridge resorption (RRR) in 5 different regions of both jaws on the successive lateral cephalograms of 50 complete denture wearers and to correlate such changes with the number of years of edentia and the region where the last extraction was performed. The height of the residual ridges was measured on 5 different sites of the mandible and the maxillary RR using a calibrated grid. The results revealed that all the patients showed significant RRR in the one year period (p<0.01), which was 2.5x more in the mandible than in the maxilla. RRR was bigger in patients who had had their last extraction within a period of one year before receiving their dentures, than in patients who had extracted their teeth earlier (p<0.01). However, the rate of RRR was significantly higher (p<0.01) in the anterior regions of both jaws compared to distal regions (0.41 and 0.42 mm in the incisive/canine region: 0.2 and 0.17 mm in the premolar/ molar region for the maxilla 1.05 and 0.82 mm in the incisive/canine region : 0.27 and 0.11 in the premolar/ molar region for the mandible), even in patients where the last extraction was performed in the premolar region. It seems that the structure of the bone and strains in RR, due to loading from the dentures, may play a role, not only the period following extraction and the region of the last extraction

A Method to Evaluate and Compare Two Different Intraoral Radiographs of the Same Patient

Objective of this study was to determine the accuracy of the method of the clinical intraoral densitometry, to compare differences in the calculation with or without subtraction of the background adjacent soft-tissues from the stepwedge (SW) and to verify which regression model best fitted the experimental data in order to express the measured values in equivalents of SW thickness. Two intraoral radiographs, one after another, were made for each of 6 patients. A copper SW (6 steps, thickness 0.05–0.3 mm) was attached to each radiograph, trying to avoid the superimposition of the bony structures. Films were processed and digitized. Grey levels were measured on each step of the SW, on the background of the SW and on the same 3 randomly chosen regions of interest (ROIs) on each digitized image. The measurement with and without the subtraction of optical densities of the background around the SW from the optical densities of the SW was performed. For the calculation of the SW thickness equivalents, the regression analysis was performed by using different regression models. The best fitting regression model was the 3rd degree polynomial. The results were more precise when using the subtraction of the background overlapping the SW

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