PAX9 polymorphism and susceptibility to sporadic non-syndromic severe anodontia: a case-control study in southwest China

Our research aimed to look into the clinical traits and genetic mutations in sporadic non-syndromic anodontia and to gain insight into the role of mutations of PAX9, MSX1, AXIN2 and EDA in anodontia phenotypes, especially for the PAX9.

Material and Methods:

The female proband and her family members from the ethnic Han families underwent complete oral examinations and received a retrospective review. Venous blood samples were obtained to screen variants in the PAX9, MSX1, AXIN2, and EDA genes. A case-control study was performed on 50 subjects with sporadic tooth agenesis (cases) and 100 healthy controls, which genotyped a PAX9 gene polymorphism (rs4904210).

Results:

Intra-oral and panoramic radiographs revealed that the female proband had anodontia denoted by the complete absence of teeth in both the primary and secondary dentitions, while all her family members maintained normal dentitions. Detected in the female proband were variants of the PAX9 and AXIN2 including A240P (rs4904210) of the PAX9, c.148C>T (rs2240308), c.1365A>G (rs9915936) and c.1386C>T (rs1133683) of the AXIN2. The same variants were present in her unaffected younger brother. The PAX9 variations were in a different state in her parents. Mutations in the MSX1 and EDA genes were not identified. No significant diferences were found in the allele and genotype frequencies of the PAX9 polymorphism between the controls and the subjects with sporadic tooth agenesis.

Conclusions:

These results suggest that the association of A240P with sporadic tooth agenesis still remains obscure, especially for different populations. The genotype/phenotype correlation in congenital anodontia should be verified.     

ORAL FINDINGS IN PATIENTS WITH APERT SYNDROME

Introduction:

The Apert syndrome is a rare disorder of autosomal dominant inheritance caused by mutations in the FGFR2 gene at locus 10q26; patients with this syndrome present severe syndactyly, exophthalmia, ocular hypertelorism and hypoplastic midface with Class III malocclusion, besides systemic alterations. Most investigations available on the Apert syndrome address the genetic aspect or surgical management, with little emphasis on the oral aspects.

Objective:

to investigate the oral findings, including dental anomalies, ectopic eruption of the maxillary permanent first molars and soft tissue alterations, in subjects with Apert syndrome.

Material and methods:

clinical and radiographic examination of nine patients with Apert syndrome, aged 6 to 15 years, not previously submitted to orthodontic or orthognathic treatment.

Results:

dental anomalies were present in all patients, with one to eight anomalies per individual. The most frequent anomalies were tooth agenesis, mainly affecting maxillary canines, and enamel opacities (44.4% for both). Ectopic eruption of maxillary first molars was found in 33.3% of patients; lateral palatal swellings were observed in 88.8% of patients.

Conclusions:

The occurrence of typical lateral palatal swellings agrees with the literature. The high prevalence of dental anomalies and ectopic eruption may suggest a possible etiologic relationship with the syndrome.     

Analysis of the association between lactotransferrin (LTF) gene polymorphism and dental caries

Objective

The present study evaluated the association between lactotransferrin (LTF) gene polymorphism (exon 2, A/G, Lys/Arg) and dental caries.

Material and Methods

A convenience sample of 110 individuals, 12 years old, was divided into: group 1, 48 individuals without caries experience (DMFT=0), and group 2, 62 subjects with caries experience (DMFT≥1). DNA was obtained from a mouthwash with 3% glucose solution, followed by a scrapping of the oral mucosa. After DNA purification, polymerase chain reaction (PCR), single strand conformation polymorphism (SSCP) was performed to access the study polymorphism. The LTF A/G (Lys/Arg) polymorphism had been previously reported as located in exon 1.

Results

Allele 1 of the study polymorphism was associated with low DMFT index and showed a protective effect against caries experience (OR=0.16, IC=0.030.76, p=0.01).

Conclusion

Lactotransferrin A/G (exon 2, Lys/Arg) polymorphism was associated with susceptibility to dental caries in 12-year-old students.     

Distribution of Third Molar Impactions Among Rural and Urban Dwellers in the Age Group of 22–30?years in South India: A Comparative Study

Objectives

(1) To collect the data related to distribution of third molar impactions among rural population by clinical and radiological examinations. (2) To collect the information on distribution of third molar impactions among urban population by clinical and radiological examinations. (3) To compare the patterns of distribution of third molar impactions among rural and urban residents with respect to type of impaction, arch, gender and age.

Method

A cross-sectional study was conducted in Dharwad district of Karnataka state located in South India involving 630 rural and 270 urban subjects as per demographic profile of India. A two stage sampling procedure was adopted in the selection of the sample.

Statistical Analysis

Data was analyzed using STATISTICA-6.0. χ² test was used to explore the association between different variables and third molar impactions. A P ≤ 0.05 was considered statistically significant.

Results

14.92% of rural subjects and 27.40% urban subjects were reported to be suffering from third molar impactions.

Conclusions

The overall prevalence of third molar impactions among the study subjects was found to be 18.67%. A significant association was noticed between the ‘different arches’ and distribution of third molar impactions in both rural and urban population. Subjects with vertical impactions were found to be most common in both the groups.     

Mandibular Third Molar Position Influencing the Condylar and Angular Fracture Patterns

Purpose

The aim of this study was to assess the influence of position of mandibular 3rd molar on angle and condylar fractures.

Materials and Methods

Panoramic radiographs were used to determine the mandibular fracture patterns based on the presence or absence of the third molar.

Results

Of the 64 patients with mandibular fractures, condyle and angle fractures were found to be 67 and 33 % respectively. The greatest percentage (75 %) of condylar fractures were associated with erupted third molar teeth, and 25 % had impacted teeth. Subcondylar region was found to be the most common site that predisposes to fracture. Moderate force lead to condylar fracture when third molar is erupted or absent and mild force showed angle fracture when third molar is impacted. Increased incidence of angle fracture was observed when tooth is in mesioangular and distoangular position.

Conclusion

Impacted mandibular 3rd molar leads to an increased risk of angle fracture and decreased risk of condylar fracture especially when they are more deeply seated.     

Anesthetic technique for inferior alveolar nerve block: a new approach

Background

Effective pain control in Dentistry may be achieved by local anesthetic techniques. The success of the anesthetic technique in mandibular structures depends on the proximity of the needle tip to the mandibular foramen at the moment of anesthetic injection into the pterygomandibular region. Two techniques are available to reach the inferior alveolar nerve where it enters the mandibular canal, namely indirect and direct; these techniques differ in the number of movements required. Data demonstrate that the indirect technique is considered ineffective in 15% of cases and the direct technique in 1329% of cases.

Objective

Objective: The aim of this study was to describe an alternative technique for inferior alveolar nerve block using several anatomical points for reference, simplifying the procedure and enabling greater success and a more rapid learning curve.

Materials and Methods

A total of 193 mandibles (146 with permanent dentition and 47 with primary dentition) from dry skulls were used to establish a relationship between the teeth and the mandibular foramen. By using two wires, the first passing through the mesiobuccal groove and middle point of the mesial slope of the distolingual cusp of the primary second molar or permanent first molar (right side), and the second following the oclusal plane (left side), a line can be achieved whose projection coincides with the left mandibular foramen.

Results

The obtained data showed correlation in 82.88% of cases using the permanent first molar, and in 93.62% of cases using the primary second molar.

Conclusion

This method is potentially effective for inferior alveolar nerve block, especially in Pediatric Dentistry.     

IMPACT OF THE BITEWING RADIOGRAPHY EXAM INCLUSION ON THE PREVALENCE OF DENTAL CARIES IN 12-YEAR-OLD STUDENTS IN THE CITY OF FRANCA,S?O PAULO,BRAZIL

Introduction:

The pattern of development of carious lesions has changed. The carious lesion has been progressive and reaches the dentin without showing alterations in the clinical aspects.

Objectives:

To determine the prevalence of caries in 12-year-old students in the city of Franca – São Paulo, Brazil, during the year of 2003, and to evaluate the additional value of bitewing radiograph to detect hidden carious lesions in permanent molar dentin.

Materials and Methods:

A probabilistic sample composed of two hundred and fifty six (256) students, from public and private schools, was submitted to a cross-sectional study through examination by a calibrated examiner, in order to detect the caries prevalence, using the methodology recommended by the World Health Organization (WHO). For 66% of the sample, bitewing radiographs of the permanent molar region were obtained. The images were analyzed by a calibrated examiner, who established the presence of hidden caries in teeth with radiolucency in dentin, yet considered healthy in the epidemiological survey.

Results:

The prevalence of dental caries in epidemiological exam without (WHO) and with (WHO/R) the inclusion of hidden caries lesion was 54% and 64%, and the DMFT index was 1.73 and 1.92 respectively.

Conclusion:

Utilization of the method of bitewing radiographic diagnosis significantly increased (p<0.001) the prevalence of caries in the studied population.     

A Fast Method for DEFB1 - 44C/G SNP Genotyping in Brazilian Patients with Periodontitis

Aim

Defensins are cationic antimicrobial peptides expressed in epithelial cells. Such peptides exhibit antibacterial, antifungal and antiviral properties, and are a component of the innate immune response. It has been suggested that they have a protective role in the oral cavity. This study evaluated the DEFB1 polymorphism in diabetic patients with or without periodontitis in comparison to healthy controls.

Material and Methods

We used Hairpin-Shaped Primer (HP) assay to study the distribution of the -44 C/G SNP (rs1800972) in 119 human DNAs obtained from diabetic patients and healthy control patients.

Results

The results indicate that there are no differences in distribution between groups and that in diabetic periodontitis patients the homozygous mutant could be found more frequently.

Conclusion

Further studies are necessary in order to investigate the role of DEFB1 polymorphisms in diabetic periodontitis patients and the influence of the peptide in periodontal pathogens.Key words: Defensins, Antimicrobial Cationic Peptides, DEFB1 Protein, Humans, Epithelial Cells, Diabetes Complications, Periodontitis     

Importance of Clinical and Radiological Parameters in Assessment of Surgical Difficulty in Removal of Impacted Mandibular 3rd Molars: A New Index

Objective

The aim of the study is to assess the clinical and radiological factors that increase the surgical difficulty in removal of mandibular impacted 3rd molar and design a new difficulty predictive index.

Methods

The data was collected from 100 patients with impacted mandibular 3rd molar who presented to Department of Oral and Maxillofacial Surgery, K.L.E’s Institute of Dental Sciences. Clinical and radiological parameters included in the New Index were noted. The tooth was then removed under local anesthesia and time taken for the removal was noted. The Pederson Index, New Index and time taken were co-related using kappa statistical analysis.

Results

The kappa agreement between Pederson Index and time taken was 66.50 % (0.2231) whereas between New Index and time was 89 % (0.7177) indicating that New Index is a better predictor of the difficulty.

Conclusion

The New Index is a reliable tool in predicting the difficulty in the removal of mandibular impacted third molar.     

ANKH Polymorphisms and Clicking of the Temporomandibular Joint in Dental Residents

Aim

This study aimed to carry out a case-control research study to assess occurrence of clicking of the temporomandibular joint (TMJ) in order to establish the relationship between TMJ clicking and the genotype of “ANKH inorganic pyrophosphate transport regulator” (ANKH) polymorphisms.

Materials and Method

A sample of 41 first-year dental residents was selected. Each was examined using standard clinical procedures and genotyping techniques.

Results

The participation rate was 91.8 %. The prevalence of TMJ clicking was 51.2 % (95 % CI: 35.7–66.7 %). Occurrence of TMJ clicking was not related to age, gender and genotypes of ANKH-OR as well as ANKH-TR polymorphisms (p ≥ 0.165).

Conclusion

A similar distribution of ANKH genotypes in TMJ clicking and asymptomatic individuals has been demonstrated by this study. A high percentage of TMJ clicking has been confirmed. Future investigations are indicated.     

A FIELD-TRIAL OF TWO RESTORATIVE MATERIALS USED WITH ATRAUMATIC RESTORATIVE TREATMENT IN RURAL TURKEY: 24-MONTH RESULTS

Objective:

The purpose of this study was to investigate the clinical performance of high-strength glass ionomer cement (HSGIC) and resin-modified glass ionomer (RMGIC) in single and multiple surface carious cavities in the field conditions.

Material and Methods:

A split-mouth design, including ninety-one fillings placed on contra lateral molar pairs of 37 children, was used in permanent dentition. As filling materials, a HSGIC (Ketac Molar/3M ESPE) and a RMGIC (Vitremer/ 3M ESPE) were used with the Atraumatic Restorative Treatment (ART). Baseline and 6, 12 and 24-month evaluations of the fillings were made with standard-ART and USPHS criteria by two examiners with kappa values of 0.92 and 0.87 for both criteria.

Results:

According to the USPHS criteria, the retention rates of RMGIC and HSGIC restorations were 100% and 80.9% for single surface, and 100% and 41.2% for multiple surface restorations after 24 months, respectively. Irrespective of surface number, RMGIC was significantly superior to HSGIC (p= 0.004), according to both standard-ART and USPHS criteria.

Conclusion:

The results indicate that RMGIC may be an alternative restorative technique in comparison to high-strength GIC applications in ART-field-trials. However, further clinical and field trials are needed to support this conclusion.     

Eruption Status of Third Molar and Its Possible Influence on the Location of Mandibular Angle Fracture: A Retrospective Analysis

Introduction

This study was designed to evaluate the influence of eruption status of mandibular third molars on the location of mandibular angle fracture. We also aimed to evaluate the incidence of damage to mandibular third molar teeth (M3) and its roots.

Materials and Methods

Medical records and panoramic radiographs of 142 patient cohorts with mandibular angle fractures with third molars present were retrospectively reviewed.

Results

Revealed that incidence of angle fracture were high in patients with fully erupted M3 when compared to unerupted group. Out of 142 patients, 108 fractures were found involving the M3 socket and 14.1 % had damage to M3.

Conclusion

The presence of erupted mandibular third molar increases the chances of angle fracture when compared to impacted M3. Involvement of the M3 socket often resulted in increased operative time and complexity of the surgical procedure with possible removal of the damaged M3.     

Clinical significance of interleukin-1 genotype in smoking patients as a predictor of peri-implantitis: A case-control study

Background

Interleukin-1 (IL-1) is a proinflammatory cytokine that plays an important role in the pathogenesis of periodontitis, and so it might be useful to detect high-risk cases of peri-implantitis. It has been reported that IL-1 polymorphisms and smoking habit have a synergic effect, increasing the incidence of peri-implantitis. The aim of the present study was to evaluate the relationship between IL-1 gene polymorphisms and peri-implantitis in smoking patients.

Material and Methods

A case-control study was performed in 27 patients with peri-implantitis and 27 patients with healthy implants. All patients included were smokers. IL-1A-C889T, IL-1B+C3953T and IL-1RN+T2018C were identified by polymerase chain reaction (PCR) amplification in order to establish a relation between these variables and the presence of peri-implantitis. A bivariate analysis was performed and odds-ratio (OR) were calculated.

Results

The incidence of peri-implantitis was significantly higher in patients with previous history of periodontitis (p=0.024; OR=10.9). Both groups were similar regarding IL-1A-C889T, IL-1B+C3953T and IL-1RN+T2018C genotypes. No increased risk in heavy smokers with IL-1 polymorphism was found.

Conclusions

IL-1 genotypes do not seem to be good predictors of peri-implantitis in the great majority of smoking patients. Furthermore, no synergic effect was found between IL-1 genotypes and heavy smokers. Patients with a previous history of periodontitis were more prone to peri-implantitis. Key words:Peri-implantitis, interleukin-1 genotype positive, case-control study, smoking.     

Shaping ability of Reciproc and TF Adaptive systems in severely curved canals of rapid microCT-based prototyping molar replicas

Objective:

To evaluate the shaping ability of Reciproc and Twisted-File Adaptive systems in rapid prototyping replicas.

Material and Methods:

Two mandibular molars showing S-shaped and 62-degree curvatures in the mesial root were scanned by using a microcomputed tomography (μCT) system. The data were exported in the stereolitograhic format and 20 samples of each molar were printed at 16 µm resolution. The mesial canals of 10 replicas of each specimen were prepared with each system. Transportation was measured by overlapping radiographs taken before and after preparation and resin thickness after instrumentation was measured by μCT.

Results:

Both systems maintained the original shape of the apical third in both anatomies (P>0.05). Overall, considering the resin thickness in the 62-degree replicas, no statistical difference was found between the systems (P>0.05). In the S-shaped curvature replica, Reciproc significantly decreased the thickness of the resin walls in comparison with TF Adaptive.

Conclusions:

The evaluated systems were able to maintain the original shape at the apical third of severely curved mesial canals of molar replicas.     

Importance of a distal proximal contact on load transfer by implant-supported single adjacent crowns in posterior region of the mandible: a photoelastic study

Objective

This study aimed to evaluate the importance of a distal proximal contact on the load transfer to the posterior region of the mandible by non-splinted adjacent implant-supported crowns using photoelastic stress analysis.

Material and Methods

A rectangular model (68x30x15 mm) was made of polymethylmethacrylate resin to simulate half of the mandibular arch. One model was completed with resin replicas representing the first premolar and second molar and with two 3.75 mm dia.x11 mm internal hexagon threaded implants replacing the second premolar and first molar. The other model was manufactured in the same way but without the second molar. Both models were duplicated using photoelastic resin. The roots of the teeth replicas were covered with a layer of polyether impression material to simulate the periodontal ligament. Two different vertical loads were applied to the crowns as follows: 1 - single static point load alternately applied to the crowns replacing the second premolar and first molar (50 N); 2 - simultaneous static point loads applied to both of the crowns replacing the second premolar and first molar (100 N). The resulting isochromatic fringe pattern in the photoelastic model was monitored and photographed.

Results

All loading conditions studied showed that the presence of the second molar has changed the load transmission and the pattern of stresses.

Conclusion

Results showed that the presence of a second molar proximal contact can help minimize the stresses around the implants.     

EFFECT OF PONTIC FRAMEWORK DESIGN ON THE FRACTURE RESISTANCE OF IMPLANT-SUPPORTED ALL-CERAMIC FIXED PARTIAL DENTURES

Objective:

The purpose of this study was to compare the fracture resistance of implant-supported all-ceramic fixed partial dentures, which have three different pontic designs.

Material and Methods:

Two implants were placed in a metal model simulating mandibular left second premolar and mandibular left second molar. Thirty standardized 3-unit all-ceramic fixed partial dentures with biconvex, convex or concave pontic designs were fabricated using IPS e.max system (n=10). Afterwards, specimens were centrally loaded on the pontics until failure with a universal testing machine. Results were analyzed by Kruskal-Wallis and Mann-Whitney U tests at 5% significance level.

Results:

The fracture resistance values of all-ceramic fixed partial dentures designed with biconvex, convex or concave pontics were 349.71, 438.20 and 300.78 N, respectively. There were no statistically significant differences between the fracture resistances of the groups (p>0.05), except for convex and concave groups (p<0.05 and p=0.009, respectively).

Conclusions:

Convex design showed the best mechanical properties as demonstrated by the high values of fracture resistance.     

In vitro evaluation of an alternative method to bond molar tubes

Despite the advances in bonding materials, many clinicians today still prefer to place bands on molar teeth. Molar bonding procedures need improvement to be widely accepted clinically.

Objective

The purpose of this study was to evaluate the shear bond strength when an additional adhesive layer was applied on the occlusal tooth/tube interface to provide reinforcement to molar tubes.

Material and methods

Sixty third molars were selected and allocated to the 3 groups: group 1 received a conventional direct bond followed by the application of an additional layer of adhesive on the occlusal tooth/tube interface, group 2 received a conventional direct bond, and group 3 received a conventional direct bond and an additional cure time of 10 s. The specimens were debonded in a universal testing machine. The results were analyzed statistically by ANOVA and Tukey’s test (α=0.05).

Results

Group 1 had a significantly higher (p<0.05) shear bond strength compared to groups 2 and 3. No difference was detected between groups 2 and 3 (p>0.05).

Conclusions

The present in vitro findings indicate that the application of an additional layer of adhesive on the tooth/tube interface increased the shear bond strength of the bonded molar tubes.     

Mandibular Third Molar Extraction Wound Healing With and Without Platelet Rich Plasma: A Comparative Prospective Study

Aims

To evaluate the efficacy of autologous platelet rich plasma (PRP) in regeneration of bone and to assess clinical compatibility of the material in mandibular third molar extraction socket.

Objective of the Study

To compare the healing of mandibular third molar extraction wounds with and without PRP.

Materials and Methods

Group A consists of the 30 patients where PRP will be placed in the extraction socket before closure of the socket. Group B consists of 30 patients who will be the control group where the extraction sockets will be closed without any intra socket medicaments. The patients would be allocated to the groups randomly.

Results

Soft tissue healing was better in study site compared to control site. The result of the study shows rapid bone regeneration in the extraction socket treated with PRP when compared with the socket without PRP. Evaluation for bone blending and trabecular bone formation started earlier in PRP site compared to control, non PRP site. Also there was less postoperative discomfort on the PRP treated side.

Conclusion

Autologous PRP is biocompatible and has significant improved soft tissue healing, bone regeneration and increase in bone density in extraction sockets.