Unusual Dental Morphology in a Chimpanzee: A Case Report Utilizing Cone-Beam Computed Tomography.

This case report illustrates the teeth morphology of a chimpanzee and its anatomical variations. A well-preserved skull of a male Pan troglodytes troglodyte chimpanzee was scanned using a cone-beam computed tomography machine. Measurements included tooth and crown height, root length, root canal length and width (posterior teeth), and pulp cavity length (anterior teeth). Nonmetrical parameters included number of canals and foramina per root of every root. Interestingly, the mandibular central incisor was longer than the lateral incisor, and all the mandibular anterior teeth presented with a solitary flame-shaped or conical-calcified structure in their pulp cavity. The premolars are usually dual rooted except for the first maxillary premolar that displayed 3 roots. Other unusual discoveries were the presence of bilateral radicular dens invaginatus in the mandibular first premolars and the possibility of having 2 canals and 2 foramina in the roots of the posterior teeth. The presence of conical stone mineralizations at the pulp cavity and the presence of dens invaginatus were of particular interest.

Human Mesiodistal Tooth Width Measurements and Comparison with Dental Cast in a Bangladeshi Population.

AIM: This analysis was aimed to determine the mesiodistal tooth width of human teeth and to compare with the measurements on plaster model in a Bangladeshi population. MATERIALS AND METHODS: The samples of 2,892 teeth of Bangladeshi subjects were collected for this purpose. This article presents mesiodistal tooth width measurements made on all types of teeth and compares with the mesiodistal tooth width measurements of dental cast collected from Bangladeshi subjects between the ages of 18 and 24 years. The mesiodistal dimension was recorded, involving the maximum mesiodistal dimension of each tooth when measurement was rendered parallel to the occlusal and labial surfaces. Descriptive and comparative statistics were applied. RESULTS: The mean, standard deviation and 95% confidence interval of mesiodistal tooth width measurements were determined and have been with the mesiodistal tooth width measurements of dent al cast. Significant differences have been observed between mesiodistal tooth size of direct measurement on tooth (DMT) and measurement on plaster model (MPM) for the maxillary first molar (p < 0.001) and mandibular incisors to first premolar (p < 0.001). CONCLUSION: These data should prove to be helpful to the practitioner for performing successful orthodontic treatment in Bangladeshi population. CLINICAL SIGNIFICANCE: Direct measurement of mesiodistal tooth width and individual variation of maxillary and mandibular permanent central incisor to first molar of the Bangladeshi individuals showed some distinguishable features, which will certainly help an orthodontist for diagnosis and treatment plan of an orthodontic case.

Bolton tooth size ratio and its relation with arch widths, arch length and arch perimeter: a cone beam computed tomography (CBCT) study.

OBJECTIVE: The prime aim of the study was to measure and compare the 3D CBCT Bolton tooth size ratio in relation to the upper and lower arch widths, arch length and arch perimeter. MATERIALS AND METHODS: The data source was CBCT high volumetric data from the archives. Tooth size, arch widths, arch length and arch perimeter were measured in maxilla and mandibular arches. The independent t-test and ANOVA were used for statistical analyses. RESULTS: The female Bolton anterior ratio (BAR) (78.373) and Bolton overall ratio (BOR) (93.231) show a greater tooth size ratio in comparison to male BAR (77.162) and BOR (93.124), respectively. However, no significant difference was found in the sexual comparison of all the measurements. Tooth size ratio in arch width groups also showed no significant difference. Significant discrepancies in the arch length (p < 0.05) groups and overall ratio and in the arch perimeter groups (p < 0.05 and p < 0.01) and anterior ratio were revealed. CONCLUSIONS: Tooth size ratios during orthodontic treatment for different arch length and arch perimeter groups need to be evaluated carefully.

The application and correlation of Pont's Index to the facial framework of three main ethnic groups in Malaysia.

OBJECTIVE: To assess the applicability of Pont's Index in a Malaysian population by obtaining baseline measurements of dental arch shape based on premolar arch width, molar arch width and the combined width of the maxillary incisors. A secondary aim was to determine whether a correlation exists between arch widths, Pont's Index and the facial framework. METHODS: Ninety subjects of mixed racial backgrounds had maxillary dental casts made, measured and selected craniofacial anthropometric measurements taken. Arch widths were compared between the measured and the predicted values derived from Pont's formula. A comparative analysis was performed between interpremolar and intermolar widths and the craniofacial anthropometric measurements. Comparative statistics were applied. RESULTS: The average interincisal measurement, interpremolar and intermolar widths were 30.31 +/- 2.49 mm, 36.67 +/- 2.50 mm and 45.21 +/- 2.90 mm respectively. No significant differences were detected between the races. The interincisal measurement in males was significantly lower than for females but male intermolar width was significantly higher than for females. The average predicted interpremolar width (37.89 +/- 3.1 1 mm) and intermolar widths (47.36 +/- 3.89 mm) were higher than the actual measured means, suggesting that Pont's Index overestimated interpremolar and inteimolar widths in the majority of Malaysians. The premolar index (83.34) and molar index (67.71) of the Malaysians were higher than the original Pont's Indices. Significant correlations were noted for intermolar width with facial width, mandibular width, mandibular depth and mouth width. CONCLUSION: The findings suggest that Pont's Index should not be applied to the Malaysian population.

Long chain N-acyl homoserine lactone production by Enterobacter sp. isolated from human tongue surfaces.

We report the isolation of N-acyl homoserine lactone-producing Enterobacter sp. isolate T1-1 from the posterior dorsal surfaces of the tongue of a healthy individual. Spent supernatants extract from Enterobacter sp. isolate T1-1 activated the biosensor Agrobacterium tumefaciens NTL4(pZLR4), suggesting production of long chain AHLs by these isolates. High resolution mass spectrometry analysis of these extracts confirmed that Enterobacter sp. isolate T1-1 produced a long chain N-acyl homoserine lactone, namely N-dodecanoyl-homoserine lactone (C12-HSL). To the best of our knowledge, this is the first isolation of Enterobacter sp., strain T1-1 from the posterior dorsal surface of the human tongue and N-acyl homoserine lactones production by this bacterium.

N-acyl homoserine lactone production by Klebsiella pneumoniae isolated from human tongue surface.

Bacteria communicate by producing quorum sensing molecules called autoinducers, which include autoinducer-1, an N-hexanoyl homoserine lactone (AHL), and autoinducer-2. Bacteria present in the human oral cavity have been shown to produce autoinducer-2, but not AHL. Here, we report the isolation of two AHL-producing Klebsiella pneumoniae strains from the posterior dorsal surface of the tongue of a healthy individual. Spent culture supernatant extracts from K. pneumoniae activated the biosensors Agrobacterium tumefaciens NTL4(pZLR4) and Escherichia coli [pSB401], suggesting the presence of both long and short chain AHLs. High resolution mass spectrometry analyses of these extracts confirmed that both K. pneumoniae isolates produced N-octanoylhomoserine lactone and N-3-dodecanoyl-L-homoserine lactone. To the best of our knowledge, this is the first report of the isolation of K. pneumoniae from the posterior dorsal surface of the human tongue and the production of these AHLs by this bacterium.

Microbial contamination of orthodontic buccal tubes from manufacturers.

This study aimed to test the sterility of new unused orthodontic buccal tubes received from manufacturers. Four different types of buccal tubes were used straight from the manufactures package without any additional sterilizing step. Of these buccal tubes tested, three genera of bacteria, implicated as opportunistic pathogens, namely Micrococcus luteus, Staphylococcus haemolyticus and Acinetobacter calcoaceticus were recovered from these buccal tubes. Our data showing microbial contamination on buccal tubes highlights the need of sterilization before clinical use. We also suggest that manufacturers should list the sterility state of orthodontic buccal tubes on their packaging or instructions stating the need for sterilization.

Shear bond strengths of buccal tubes.

AIMS: To investigate the shear bond strengths of buccal tubes and to determine the sites of failure. METHOD: Four orthodontic buccal tubes were selected: A, American Orthodontics; B, 3M Unitek - small base; C, 3M Unitek--large base; D, Hangzhou Dentop. Twenty buccal tubes from each group were bonded to the buccal surfaces of lower right first molars with the same light-cured composite resin. The buccal tubes were debonded with a universal testing machine and the data analysed. The amount of adhesive remaining on the teeth after debonding was classified with the modified adhesive remnant index (ARI). RESULTS: The groups ranked from the highest to lowest bond strength (MPa) were: B, A, D and C. The bond strengths of the buccal tubes, except Groups A and B, were significantly different (p < 0.05). The majority of the buccal tubes (63 per cent) had modified ARI scores of 1 and 2 and 25 per cent of the tubes had scores of 4 and 5. After debonding, no adhesive remained on 40 per cent of the teeth in Groups B and D. CONCLUSIONS: The shear bond strengths of the buccal tubes fell below the value considered to be clinically acceptable. There were no differences between the shear bond strengths of the buccal tubes with photoetched and microetched bases. The buccal tubes with the largest base failed prematurely, possibly because the unsupported bonding pad flexed during debonding.

Mediation--the Malaysian Dental Association experience.

OBJECTIVES: To study the success and failures of the mediation process of complaints from 2004-2007 by the Complaints Bureau Steering Committee and the Public Complaints Bureau Committee of the Malaysian Dental Association (MDA). METHODS: Retrospective analysis of complaints from the records at the MDA. RESULTS: There were 41 cases during the three years, most involved surgical procedures (9), endodontics (9), miscellaneous (8), orthodontics (6), restorative problems (6) and prosthetics (2). Chinese patients made the most complaints (67%) followed by Malay patients (23%), foreigners (7%) and Indians (3%). 69% of the cases where against dentists working in the Klang Valley, 14% in Johore and the rest in various part of the country. 69% of the cases were successfully mediated, 10% unresolved and the 21% are in various stages of mediation. CONCLUSION: It is heartening to report that the MDA has successfully mediated in a sizeable number of the complaints which are increasing yearly.

Unilateral coronoid hyperplasia following trauma: a case report.

This case describes surgical correction of unilateral coronoid hyperplasia in a 13-year-old boy due to trauma. Treatment included coronoidectomy by intraoral approach after the diagnosis was confirmed. Computed tomography scan and occipitomental view radiograph were utilized for investigation. The resected coronoid process was sent for histopathological study. The histopathological examination revealed decalcified sections showing osteochondroid hyperplasia at the expanded end. On clinical and radiographic review at 2 years postoperation, the patient was well, completely symptom free and had improved mouth opening. This case report demonstrates the management of sports injury related unilateral coronoid hyperplasia. Emphasis was also placed on postoperational rehabilitation to prevent any relapse.

Cone-beam computed tomography evaluation of Pont's index predictability for Malay population in orthodontics.

INTRODUCTION: In orthodontic treatment, three-dimensional (3D) dental casts has a significant role in diagnosis and treatment planning. The aim of this study was to evaluate Pont's index predictability in orthodontics. MATERIALS AND METHODS: Premolar arch width, molar arch width and mesiodistal width of the maxillary incisors were measured three-dimensionally to assess shape of dental arches. The data source was cone beam computed tomography (CBCT) high volumetric data acquisitions from Malay ethnic background. Arch widths were measured and recorded from 53 subjects (32 male and 21 female with the mean age, 25.81), both the maxillary and mandibular arches, to obtain CBCT high volumetric data. All measurements were obtained through CBCT Planmeca Romexis TM Software 2.3.1.R (Helsinki, Finland). RESULTS: Pont's formula overestimated the upper and lower interpremolar distance, with mean differences of 8.35 ± 3 mm and 12.02 ± 3.20 mm, respectively. Furthermore, the formula overestimated the upper and lower intermolar distance, with mean differences of 7.87 ± 3 mm and 16.14 ± 5.86 mm, respectively. CONCLUSIONS: The results indicate that Pont's index is not practical for use with the Malaysian population since the index overestimated interpremolar and intermolar widths. This raises questions whether the index is a true predictor of arch width measurements.

Shear bond strength of orthodontic buccal tubes to porcelain.

BACKGROUND: Bonding of molar tubes is becoming more popular in orthodontics. Occasionally, these bonding are done on posterior porcelain crowns or bridges. The purpose of this study was to evaluate the shear bond strength of buccal tubes on feldspathic porcelain crowns with two different methods. MATERIALS AND METHODS: Forty porcelain right molar crowns were fabricated for this study. The crowns were randomly divided into two groups. In group 1, the crowns were etched with 9.6% hydrofluoric acid, silane coupling agent applied, coated with bonding primer and bonded with Transbond XT (3M Unitek, Monrovia, Calif). In group 2, the crowns were etched with phosphoric acid 37%, silane coupling agent applied, coated with bonding primer and bonded with Transbond XT. All the crowns were stored for 24 hours at 37°C and thermo-cycled before the shear bond test. The analysis of variance (ANOVA) was used to determine whether significant difference were present between the groups. RESULTS: The results of the analysis of variance (F = 0.23) indicated the shear bond strength of group 1 (3.57 ± 0.87 MPa) was not significantly different (P > 0.05) from group 2 (3.46 ± 0.65 Mpa). Fisher's exact test for the adhesive remnant index (ARI) revealed significant difference between both groups (P < 0.05). Eighty percent of group 1 buccal tubes failed at buccal tube/resin interface and eighty percent of group 2 mostly failed at porcelain/resin interface. CONCLUSION: Etching with phosphoric acid with the use of silane coupling agent would be safer and should make it easier for clinicians to clean the adhesive on the porcelain surface after debonding.

3D mapping of safe and danger zones in the maxilla and mandible for the placement of intermaxillary fixation screws.

Intermaxillary (IMF) screws feature several advantages over other devices used for intermaxillary fixation, but using cone beam computed tomography (CBCT) scans to determine the safe and danger zones to place these devices for all patients can be expensive. This study aimed to determine the optimal interradicular and buccopalatal/buccolingual spaces for IMF screw placement in the maxilla and mandible. The CBCT volumetric data of 193 patients was used to generate transaxial slices between the second molar on the right to the second molar on the left in both arches. The mean interradicular and buccopalatal/buccolingual distances and standard deviation values were obtained at heights of 2, 5, 8 and 11 mm from the alveolar bone crest. An IMF screw with a diameter of 1.0 mm and length of 7 mm can be placed distal to the canines (2 - 11 mm from the alveolar crest) and less than 8 mm between the molars in the maxilla. In the mandible, the safest position is distal to the first premolar (more than 5 mm) and distal to the second premolar (more than 2 mm). There was a significant difference (p<0.05) between the right and left quadrants. The colour coding 3D template showed the safe and danger zones based on the mesiodistal, buccopalatal and buccolingual distances in the maxilla and mandible.The safest sites for IMF screw insertion in the maxilla were between the canines and first premolars and between the first and second molars. In the mandible, the safest sites were between the first and second premolars and between the second premolar and first molar. However, the IMF screw should not exceed 1.0 mm in diameter and 7 mm in length.