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Marfan syndrome is an autosomal dominant genetic disorder of connective tissue origin that can affect multiple organs. Various oral manifestations have been associated with this syndrome. Hypohyperdontia is a condition of mixed numeric variations that presents a combination of hypodontia with hyperdontia within a single human dentition. The purpose of this paper is to report a case of Marfan syndrome with a concomitant occurrence of hypohyperdontia. A narrative review was also included to describe the other syndromes that had been associated with concomitant hypohyperdontia.

Objectives To compare the prevalence and severity of diffuse opacities among subjects whose maxillary incisors developed during periods with different concentrations of fluoride in the Hong Kong public water supply. Methods Standardized intra-oral photographs of random samples of 12-year-old children were collected in 1983, 1991, 2001 and 2010 (n = 2658) in Hong Kong and were assessed for diffuse opacities by a calibrated and blinded examiner. The fluoride concentrations in the public water supply at the times when the enamel on their maxillary incisors developed were 1.0, 0.7, 0.5 and 0.5 ppm, respectively. Results The mouth prevalence figures for diffuse opacities of these children (based on the maxillary incisors) were 89.3%, 48.5%, 32.4% and 42.1 in the years 1983, 1991, 2001 and 2010, respectively. Variation in the mouth and tooth prevalences of diffuse opacities was apparent among the four different year groups (P

Supernumerary teeth are teeth, or tooth-like structures that have either erupted or remain unerupted in addition to the 20 primary and 32 permanent teeth. This paper attempts to (a) provide an overview of the proposed hypotheses and the current understanding of the aetiology of supernumerary teeth, and (b) review the published cases of supernumerary teeth occurring in families. No studies have been able to distinguish between different aetiologies for the different locations of supernumerary teeth, while, from a developmental or molecular perspective, the proposed hypotheses may be plausible and explains the origin of different types of supernumerary teeth. The only clearly evident feature, based on the existing published reports, is that it is logical to state that supernumerary teeth have a genetic component in their aetiology.

Background Estimation of age of an individual can be performed by evaluating the pattern of dental development. A dataset for age estimation based on the dental maturity of a French–Canadian population was published over 35 years ago and has become the most widely accepted dataset. The applicability of this dataset has been tested on different population groups. Aim To estimate the observed differences between Chronological age (CA) and Dental age (DA) when the French Canadian dataset was used to estimate the age of different population groups. Materials and methods A systematic search of literature for papers utilizing the French Canadian dataset for age estimation was performed. All language articles from PubMed, Embase and Cochrane databases were electronically searched for terms ‘Demirjian’ and ‘Dental age’ published between January 1973 and December 2011. A hand search of articles was also conducted. Results A total of 274 studies were identified from which 34 studies were included for qualitative analysis and 12 studies were included for quantitative assessment and meta-analysis. When synthesizing the estimation results from different population groups, on average, the Demirjian dataset overestimated the age of females by 0.65 years (−0.10 years to +2.82 years) and males by 0.60 years (−0.23 years to +3.04 years). Conclusion The French Canadian dataset overestimates the age of the subjects by more than six months and hence this dataset should be used only with considerable caution when estimating age of group of subjects of any global population.

Schwartz-Jampel syndrome (SJS) is a rare autosomal recessive skeletal dysplasia associated with myotonia. The manifestations of SJS include short stature, blepharophimosis, and skeletal anomalies. The combination of skeletal and muscular abnormalities may result in oro-dental manifestations such as atypical facies, with micrognathia, microstomia, pursed lips, crossbite, cleft palate, as well as mandibular hypoplasia, the risk of dentigerous cysts, and impacted teeth. The use of general anesthesia in patients with SJS is dangerous, as there is a risk of malignant hyperthermia. The purpose of this paper is to describe a 3-year-old Chinese boy diagnosed with SJS at birth. His intra-oral examination revealed significant dental findings such as dentin defects with generalized attrition and hypodontia of the permanent dentition. Comprehensive dental treatment was provided at the same time as lower right limb surgery to reduce the potential complications with general anesthesia.

Several papers have been published to illustrate the effectiveness of mineral trioxide aggregate (MTA) as a pulpotomy medicament. Most of these reports do not offer a critical assessment on the data quality. Therefore, this review evaluated whether the currently available evidence is of an appropriate quality to support the long-term effectiveness of MTA as a pulpotomy medicament in primary molars using a standardized assessment criterion. A comprehensive literature search of human clinical outcome studies, which employed MTA as a pulpotomy medicament in primary teeth, was conducted using the MEDLINE database. Two independent observers rated these articles using the standardized assessment criteria. Furthermore, based on the initial sample mentioned in the individual studies and the sample included for the final analysis, the drop-out rates were calculated. Twenty-two studies were included for quality assessment with an excellent interobserver agreement. None of the 22 studies obtained grade A, four studies attained grade B1, five were graded B2 and 13 received grade C. Based on the assessment criteria employed, there was no evidence that MTA was better than present materials and techniques as a pulpotomy medicament. Furthermore, given the low quality of data, it is highly desirable to establish standard requisites for conducting and reporting on pulp therapy studies in primary teeth so as to benefit both researchers and clinicians to produce high-quality studies that are comparable and to prevent the misuse of clinical material and resources.

This study evaluated the effect of chlorhexidine (CHX) incorporation into experimental dentin adhesives with different hydrophilicities on the microtensile bond strength (µTBS) to dentin.Flat, deep dentin surfaces were prepared from 60 extracted human third molars. Three ethanol-solvated (50 wt% ethanol/50 wt% comonomers) experimental adhesives with varying degrees of hydrophilicity were prepared for the CHX-free groups. For the CHX-containing groups, chlorhexidine diacetate was further added to the ethanol-solvated adhesives to form a concentration of 2.0 wt% CHX. Dentin surfaces were etched with 37% phosphoric acid for 15 s, rinsed and blot dried before bonding. The adhesives were generously applied to dentin with a microbrush for 15 s. A second application of fresh adhesive was made and light cured for 20 s (600 mW/cm2) after solvent evaporation. Composite buildups were made using Filtek Z250 (3M ESPE). The bonded teeth were sectioned into 0.9 mm x 0.9 mm beams and stressed to failure at a crosshead speed of 1 mm/min. Testing was performed 24 h after specimen preparation and 12 months after storage in artificial saliva. The µTBS data were analyzed using three-way ANOVA and Tukey's multiple comparison tests. Fractographic analysis was performed by SEM.Significant differences were observed for the three factors "adhesive hydrophilicity" (p0.001), "CHX incorporation" (p = 0.001), and "storage time" (p0.001). Interaction among these three factors was also significant (p0.001). Incorporation of CHX had no effect on the immediate bond strength of the three experimental adhesives (p0.05). After storage in artificial saliva, significant reduction in bond strength was observed in all adhesive groups, except for CHX-containing adhesive I (p0.001). The µTBS of the CHX-containing experimental adhesive III was significantly higher than the corresponding CHX-free adhesive (p0.001) after aging.When incorporated into hydrophilic dental adhesives, chlorhexidine can partially reduce the degradation of the resin-dentin bonds.

Objective This study evaluated the caries experience in the primary teeth of children with and without cleft lip and palate (CLP). Design Observational study. Setting Dental hospital clinic. Patients The sample consisted of 132 pairs of Chinese children with and without CLP matched by gender, age, ethnicity, and socioeconomic status. Their ages were between 2 and 7 years. Methods The children were dichotomized into 2- to 4-year-old (n = 71) and 5- to 7-year-old groups (n = 61). The oral examination was performed by one trained and calibrated dentist, and the caries experience was determined using the dmft (decay missing filled teeth) index. Results For the 2- to 4-year-old group, the dmft values were 1.5 for the cleft group and 1.6 for the non-CLP group, but the difference was not statistically significant. For the 5- to 7-year-old group, the dmft indices were 5.2 for the cleft group compared with 2.9 for the control group; this difference was statistically significant ( p = .0006). The caries rate for the various tooth types in the 5- to 7-year-old group was higher in the CLP group than in the non-CLP group; the most marked difference was for the lateral incisors, mandibular molars, and maxillary left first molars ( p = .0001). Conclusions The 5- to 7-year-old children with CLP had a higher caries experience in the primary dentition than the children without CLP.

Background: The prevalence of dental anomalies in children with cleft lip and palate (CLP) has been said to be higher than in the normal children; however, such findings have not been expressed for different racial groups. Aim: To determine the prevalence of anomalies in children with CLP and to ascertain if there were any differences between the prevalence figures for CLP and non-CLP children. Design: This is a retrospective study looking at previously collected clinical records. The sample consisted of 231 pairs of age and gender matched CLP and non-CLP southern Chinese aged between 12 and 16 years. The dental records of the subjects were examined to gather data on anomalies of tooth number, size and shape. Results: It was found that 57.6% of the CLP children had hypodontia, 10.0% hyperdontia, 8.7% taurodontism, 0.8% a double tooth, 1.30% dens evaginatus, and 42.4% had microdontia in the permanent dentition. The CLP subjects had a statistically higher prevalence of hypodontia (p

Publisher Summary This chapter discusses use of nanoindentation technique in nanomechanical characterization of mineralized tissues in the oral cavity. Nanoindentation is a proven technique for characterizing the mechanical properties of materials at the nano/microscale. One of the concerns when working with oral mineralized tissues is their small sizes. To overcome this problem, the tissues are sometimes embedded in resins such as polymethyl methacrylate to facilitate handling during processing, as well as to provide mechanical support during indentation. Although infiltration of the embedding material could be prevented by a careful choice of the resin, nanoindentation should only be conducted in areas of the tissues away from the resin–tissue interfaces, since the presence of the resin may alter the mechanical properties of the tissues. This chapter begins with discussing basic data analysis protocol for nanoindentation. Different steps, such as sample preparation, hydration, indepter tips, load function and data analysis, etc., for nanoindentation of oral mineralized tissues are also discussed. It is concluded that accurate nanoindentation measurements on the oral mineralized tissues cannot be achieved using the conventional technique developed for hard, synthetic materials.

Treatment of impacted maxillary canines frequently requires surgical intervention, which can involve substantial complications. Thus, it is desirable to identify a reliable method for the early diagnosis of canine displacement. In this study, we sought to determine whether impaction of a maxillary canine can be predicted using measurements made on a panoramic radiograph.This retrospective study was conducted at a dental hospital in Hong Kong with panoramic radiographs. Geometric measurements were made on 384 panoramic radiographs of patients with a unilaterally impacted maxillary canine (group I) to characterize its presentation and compare them with the unaffected antimere (group II).There was a clinically discernible difference of 4 mm at the age of 8 years and beyond between the mean distance of the tip of the impacted canine (group I) and that of the antimere (group II) from the occlusal plane (P0.05). Furthermore, there was a statistically significant difference at the age of 9 years and beyond between the 2 groups according to the position in different sectors and according to the mean angle made with the midline (P0.05).Diagnosis of maxillary canine impaction is possible at 8 years of age by using geometric measurements on panoramic radiographs.

OBJECTIVES. To evaluate the reliability of panoramic radiographs (PRs) for identifying supernumerary teeth (ST) and to determine whether the level of dental training of the observer influenced the identification of ST. METHODS. Seventy-five PRs were randomly selected from the patient records and 18 examiners independently rated 25 radiographs each, for specific risk factors as well as for a measure of adequacy. Subsequently, the results were paired with those of the other examiners who assessed the same set of PRs. Descriptive statistics were computed using Fisher's exact test, and kappa statistics were used to assess the inter- and intra-observer reliability. RESULTS. Four hundred and fifty PRs were available for analysis. The overall sensitivity and specificity figures were 50% and 98.3%, whereas the positive and negative predictive values were 90.6% and 83.6%, respectively. The sensitivity figures for Junior House Dental Officers and Postgraduate Paediatric Dental Trainees were 39.2% and 60.8%, whereas the specificity figures were 99.4% and 95% with slight inter-examiner and moderate intra-examiner reliability. CONCLUSIONS. Panoramic radiographs are unreliable for identifying ST, and higher level of dental training is essential for identifying ST.

The early childhood oral health impact scale (ECOHIS), a proxy measure to assess the impact of oral health problems and on the quality of life of preschool children and their families, has been translated into Chinese and validated employing the classical test theory. However, some invariable problems are related to this theory. The objective of this study was to assess the metric properties of the ECOHIS by applying the item response theory.A random sample of 1296 Chinese preschool children in Hong Kong participated in the study and were subjected to an oral examination for their caries status. Their parents were asked to respond to the ECOHIS and an extra set of questions concerning their socio-demographic backgrounds. The collected data were analysed using Rasch model.The obtained results support the interpretation of adequate total fit of persons and items, because the mean infit MNSQ (1.08) and outfit MNSQ (0.94) for persons, and the mean infit MNSQ (0.99) and outfit MNSQ (0.94) for items, are within the acceptable ranges (0.6-1.4). The difficulty spread of the items was between -0.81 and 1.96 logits, and the levels of respondents spanned from -5.56 to 6.72 logits on the person-item map. The spread of respondents was skewed and mistargeting, between the items and respondents, was confirmed. Combination of responses of 'often' and 'very often' was suggested because of their flat probability showing on the characteristic curves.Rasch model has been shown to be a feasible and practicable way of assessing the metric properties of the ECOHIS. The results allow the use of ECOHIS to be recommended for clinical research in oral health-related quality of life in young children with minor modifications.

This study aimed to investigate the sensitivity and responsiveness of the Chinese version of the Early Childhood Oral Health Impact Scale (ECOHIS) to dental treatment under general anaesthesia (GA).A consecutive sample of primary caregivers of children (aged 5 and younger) with early childhood caries (ECC) attending a university hospital dental clinic for dental treatment under GA was recruited over a 12-month period. Caregivers self-completed the ECOHIS prior to and 3 months following their child dental treatment under GA. In addition, caregivers rated the change in their child's overall health condition compared to before treatment on a global transition scale. Sensitivity of the measure was assessed by determining distribution changes in ECOHIS scores; responsiveness was assessed by investigating whether the observed changes took the form of a gradient according to the global transition judgement, in terms of the observed change in scores and effect size.Following treatment under GA, there was significant changes in ECOHIS scores (P0.01) and many of its sub-domains. The magnitude of change (effect size) of the total ECOHIS following treatment was 0.89 and among sub-domains ranged from -0.29 to 1.33. There was an observed gradient in the changes of ECOHIS scores (and effect sizes) in relation to global transition judgement of oral change following treatment, supporting the responsiveness of the measure. The Chinese version of ECOHIS is sensitive and responsive to dental treatment of ECC under GA.

The occurrence of supernumerary teeth in the premolar regions of three patients is reported. Of the 20 supernumerary teeth identified, 16 had crowns which resembled premolars and may thus be considered to be supplemental premolars, while the remainder were conical in shape. The delayed development of the supernumerary teeth in the premolar region supports the hypothesis that these teeth were part of a post-permanent dentition. The eruption of six of the eight supernumerary teeth in the 30-year-old patient demonstrated that given time some of these teeth can erupt into the dental arch.

This study examined the effects of using two different burs for dentin surface preparation on the microtensile bond strength (microTBS) of three resin luting cements. Flat, deep dentin surfaces from 45 extracted human third molars were divided into three groups (n = 15) according to bur type: (i) diamond bur and (ii) tungsten carbide bur. The controls were abraded with #600-grit SiC paper. Both burs operated in a high-speed handpiece under water-cooling. Composite blocks were luted onto the dentin using one of three cements: RelyX ARC (ARC, 3M ESPE), Panavia F2.0 (PF, Kuraray) and RelyX Unicem (UN, 3M ESPE) following the manufacturers' instructions. For ARC, the dentin surface was treated with 32% phosphoric acid. The bonded specimens were stored at 37 degrees C for 24 hours and sectioned into 0.9 x 0.9 mm beams for microTBS testing. The data were analyzed using the two-way ANOVA and Student-Newman-Keuls tests. Representative fractured beams from each group were prepared for fractographic analysis under SEM. Two-way ANOVA revealed that the effects of "dentin surface preparation" and "luting cement" were statistically significant (p0.001); however, the interaction of these two factors was not significant (p0.05). ARC showed no significant difference in microTBS among the three differently prepared dentin surfaces. The microTBS of PF and UN was significantly lower when bonding to dentin prepared with a diamond bur (p0.05), compared to the control. For Panavia F2.0, higher bond strengths were achieved on the dentin surface prepared with a tungsten carbide bur. Proper bur selection is essential to optimizing the dentin adhesion of self-etch resin luting cements.

Dental age assessment is one the most accurate methods for estimating the age of an unknown person. Demirjian's dataset on a French-Canadian population has been widely tested for its applicability on various ethnic groups including southern Chinese. Following inaccurate results from these studies, investigators are now confronted with using alternate datasets for comparison. Testing the applicability of other reliable datasets which result in accurate findings might limit the need to develop population specific standards. Recently, a Reference Data Set (RDS) similar to the Demirjian was prepared in the United Kingdom (UK) and has been subsequently validated. The advantages of the UK Caucasian RDS includes versatility from including both the maxillary and mandibular dentitions, involvement of a wide age group of subjects for evaluation and the possibility of precise age estimation with the mathematical technique of meta-analysis. The aim of this study was to evaluate the applicability of the United Kingdom Caucasian RDS on southern Chinese subjects. Dental panoramic tomographs (DPT) of 266 subjects (133 males and 133 females) aged 2-21 years that were previously taken for clinical diagnostic purposes were selected and scored by a single calibrated examiner based on Demirjian's classification of tooth developmental stages (A-H). The ages corresponding to each stage of tooth developmental stage were obtained from the UK dataset. Intra-examiner reproducibility was tested and the Cohen kappa (0.88) showed that the level of agreement was 'almost perfect'. The estimated dental age was then compared with the chronological age using a paired t-test, with statistical significance set at p

This investigation sought to identify the common manifestations of KBG syndrome in the literature and to determine the major oral abnormalities in a 12-year-old Chinese boy.PUBMED search, using the keyword phrase "KBG syndrome," produced 20 articles. Due to the disparities in the quality of evaluations in the reports, any physical feature that was not discussed was assumed to be absent.Of the 54 cases, including the present case, 36 (67%) were males. Mental retardation or global developmental delay was reported in 42 (78%) cases, while 46 (85%) exhibited shortness of stature. Oral features occurred in 53 (98%) cases; macrodontia was present in 49 (96%) cases; the present case was the only one with hyperdontia and a talon cusp. Other features were craniofacial anomalies, followed by abnormalities of the nose, hand, mouth, eyes, eyebrows, philtrum, costovertebrae, ears, and, less frequently, low hairline and lower extremity abnormalities.Cardinal features of KBG syndrome include facial dysmorphism, short stature, skeletal anomalies, and mild developmental delay; intraorally, macrodontia of the maxillary central incisors occurs in most cases. This is the first known report of KBG syndrome in a Chinese subject and the only case with hyperdontia and a talon cusp.

Larsen syndrome is a rare genetic disorder characterized by multiple dislocations of the large joints and characteristic craniofacial abnormalities. It exists in both a severe autosomal recessive form and a mild autosomal dominant variety. To date, only three authors have reported oral findings for this syndrome. This paper describes an 8-year-old Chinese boy with Larsen syndrome who had advanced periodontitis. The need for periodontal therapy and regular monitoring of such patients has been highlighted.

International Journal of Paediatric Dentistry 2010; 20: 330-335 Objectives. To assess and compare the oral health status of preschool children with and without cerebral palsy (CP). Methods. Preschool children with CP (72) were recruited from 23 Special Child Care Centers in Hong Kong. An age (+/-3 months) and gender matched sample of preschool children from mainstream preschools were recruited as the control group. Dental caries status, gingival health status, tooth wear, developmental defect of enamel, malocclusion, dental trauma and oral mucosal health were assessed and compared between the two groups. Results. Significant differences in gingival health status were found between children with and without CP (mean plaque index scores, P = 0.001 and mean gingival index scores, P0.05). Tooth wear involving dentine was more prevalent among CP children (P0.001), as were evidence of anterior open-bite (P0.001) and oral mucosal lesions (P0.05). Children with and without CP had similar caries experiences (P0.05), prevalence of enamel defects (P0.05) and dental trauma (P0.05). Conclusions. Differences of oral health status exist among preschool children with and without CP. Preschool children fare worse in terms of gingival health, tooth wear, oral mucosal health and malocclusion.

This article is an observational-descriptive type case study with references to recent literature on ceramic fracture. The case selected was an unusual incidence of a veneer-to-core fracture of a Procera AllCeram crown after 18 months of service. This unusual case represents a significant concern to general dentists, because the highly dense alumina core is supposed to show comparable fracture resistance to the metal cores of conventional metal-ceramic crowns. Clinical evidence shows that bruxism, manufacturing defects, pre-cementation occlusal adjustment by the laboratory technician or dentist, and the cement used are factors that contribute to the fracture of ceramic cores.

Oral lesions commonly diagnosed in newborns and infants include Epstein's pearls, Bohn's nodules, dental lamina cysts and congenital epulis. Nevertheless, intriguing cases which have rarely been reported in the literature are encountered by clinicians. This paper reports a case of an unusual white lesion in a 10-month-old child which resolved spontaneously. However, histological examination proved it to be a foreign body.Infants tend to explore things with their mouths; hence they put anything they can hold into it to determine the size and texture. This case serves to illustrate that the unexpected can occur and that, in children, the differential diagnosis should include a foreign body.

The aim of this study was to compare the performance of a generic health-related quality-of-life measure, the Pediatric Quality of Life Inventory Version 4.0 (PedsQL 4.0) and an oral health-specific quality-of-life measure, the Early Childhood Oral Health Impact Scale (ECOHIS) in assessing the impact of severe early childhood caries (S-ECC) on the children's quality of life.A trained and calibrated examiner conducted a clinical oral assessment of 111 children (mean age: 49 +/- 12 months): 64 of whom were categorized as having S-ECC and 47 as being caries-free. Primary caregivers completed a Chinese version of the PedsQL 4.0 and the ECOHIS. Clinical examinations were conducted blind of the parental assessments.The ECOHIS scores were significantly higher for the S-ECC group than for the caries-free group (Por = 0.001). No significant difference was found between the PedsQL 4.0 scores in relation to caries status, except for the subscale of physical functioning (P = 0.04). Correlation of caries status with the ECOHIS scores was strong (r = 0.66; P0.01). No significant correlation was found between PedsQL 4.0 scores and caries status (r = 0.02; P0.05).The oral health-specific measure, ECOHIS, shows better discriminant property between children with S-ECC and caries-free children than the generic measure, PedsQL 4.0. The ECOHIS appears more sensitive than PedsQL 4.0 in assessing the impact of dental caries on the life quality of preschool children.

Bilateral bi-rooted primary canines are a rare dental anomaly and the occurrence with a syndrome is even rarer. This dental anomaly has mostly occurred in African populations. This article reports a case of bi-rooted primary canines bilaterally located in both jaws of a 15-year-old Chinese boy who also suffered from cleidocranial dysostosis (CCD).

The purpose of this study was to determine the optimum time for surgical removal of unerupted maxillary anterior supernumerary teeth.The study population consisted of 126 children. Stages C to H of the Demirjian classification were used to classify the dental development of the adjacent incisors. Associations were sought between the complications and the developmental stage of the adjacent maxillary incisors at the time of surgical removal. Tests of association were carried out using Fisher's exact test with a probability level of P=.05 for statistical significance.Significant differences were evident: for mature maxillary central incisors (N=170); between all the proportions for root resorption, with the greatest difference being between stages E and H (P.001); for arrested root development between stages D and E (P=.013), and D and H (P=.02); and for persistent malocclusion between stages E and G (P=.004), E and H (P=.02), F and G (P=.005), and F and H (P=.01).Early removal of unerupted maxillary supernumerary teeth seems to be advantageous with a cutoff point of approximately 6 to 7 years old, after which more complications are expected.

Introduction This study investigated the use of 3.8% silver diamine fluoride (Ag[NH 3 ] 2 F) as an antibacterial agent against Enterococcus faecalis biofilms and its ability to penetrate dentinal tubules by the formation of silver salts. Methods Biofims were generated on membrane filter discs and subjected to 15-minute and 60-minute exposure times with 3.8% Ag(NH 3 ) 2 F, saturated Ca(OH) 2 , 5.25% NaOCl (negative control), and 0.9% NaCl (positive control). Cleaned and shaped radicular dentin were applied with Ag(NH 3 ) 2 F for 24, 48, and 72 hours. The presence of silver salts on the dentin surface was examined using low-pressure scanning electron microscopy. Results Both NaOCl and Ag(NH 3 ) 2 F were effective against E. faecalis biofilms, with no significant difference in reduction of microorganisms for both exposure times. Silver deposits were present on 66.5% of the radicular dentin surfaces after 72-hour application of Ag(NH 3 ) 2 F as simulated interappointment dressings. Penetration of the silver deposits was observed at most 40 μm into dentinal tubules after smear layer removal. Conclusion Ag(NH 3 ) 2 F has potential to be used as an antimicrobial root canal irrigant or interappointment dressing, especially in locations in which potential browning/blackening of dentin by metallic silver is not a major concern.

Objective. This study aimed to adapt the Early Childhood Oral Health Impact Scale (ECOHIS) for pre-school children in a Chinese speaking community and to investigate its psychometric properties (validity and reliability). Methods. A Chinese language version of the ECOHIS was derived through a forward–backward translation and tested for face and content validity among a focus group. A convenient sample of pre-school children (n = 111) was recruited (including a sub-sample with early childhood caries and caries-free children). Parents of the children self-completed the derived Chinese-ECOHIS measure. Validity of the measure was assessed by investigating the relationship between dental caries status and Chinese-ECOHIS scores (construct and criterion validity). A sub-sample of the parents repeated the ratings of the measure to enable reliability assessments. Both internal and test–retest reliability were determined. Results. A Chinese version of ECOHIS was derived with minor modification to the original version. Chinese-ECOHIS scores were associated with children’s caries experience (dmft) (r = 0.66, P < 0.05) supporting convergent validity. In addition, variations in ECOHIS scores were apparent with respect to caries and caries-free groups (P

Objectives Failure of the enamel adjacent to the defects in teeth with molar incisor hypomineralization (MIH) limits the success rate of the restorations placed in these teeth and this frequently leads to their ultimate extraction. To understand the cause, a state-of-the-art combination of focused ion beam (FIB) and nanoindentation techniques was used to evaluate the fracture properties and microstructure of enamel from specific regions of two MIH teeth. Methods Nanoindentation, bend tests on micro-cantilevers and transmission electron microscopy (TEM) were employed to compare the microstructure and mechanical properties of the unaffected, opaque and transitional region in two MIH teeth. Special attention was paid to the transitional region in all the experiments in an attempt to identify its role in affecting the overall integrity of the MIH teeth. Results The enamel in the transitional region, despite its translucent appearance under the naked eye, was found, under TEM, to have prism sheaths that were significantly less mineralized than unaffected enamel and were proved to be weaker in holding the prisms together when measured using bend tests on micro-cantilever samples machined from the region. Conclusion The enamel in the transitional region adjacent to the demarcated defects in MIH has notable alterations in their prism sheaths which likely contribute to their lowered mechanical properties.

This study examined the effect of saliva contamination on the microtensile bond strength (microTBS) of resin luting cements to dentin.For RelyX ARC (ARC, 3M ESPE), dentin surfaces were etched with 32% phosphoric acid. The subgroups were: ARC-control (uncontaminated), ARC-I (saliva contamination, blot-dried), ARC-II (saliva contamination, rinse, blot-dried) and ARC-III (saliva contamination, rinse, re-etch, rinse, blot-dried). For Panavia F 2.0 (PF, Kuraray), the subgroups were: PF-control (uncontaminated), PF-I (saliva contamination, dried), PF-II (saliva contamination, rinse, dried), PF-III (primer, saliva contamination, dried), PF-IV (primer, saliva contamination, dried, primer re-applied) and PF-V (primer, saliva contamination, rinse, dried, primer re-applied). Composite blocks were luted onto dentin using the two cements. Bonded specimens were sectioned into 0.9 mm x 0.9 mm beams for muTBS testing. Representative fractured beams were prepared for fractographic analysis.For ARC, salivary contamination of etched dentin (ARC-I) significantly lowered bond strength (p=0.001). Rinsing saliva off with water (ARC-II) restored bond strength to control level. Re-etching dentin surface after rinsing (ARC-III) resulted in the lowest bond strength (p0.001). For PF, salivary contamination of dentin before (PF-I) and after application of primer (PF-III and PF-IV) significantly lowered bond strength (p0.001). Rinsing saliva off with water and re-application of primer (PF-II and PF-V) improved bond strength.Saliva contamination during luting deteriorated the bond quality of resin cements. Decontamination by rinsing with water was most effective in restoring the bond strength of RelyX ARC. Decontamination by water-rinsing and primer re-application after rinsing improved the bond strength of Panavia F 2.0.

This study examined the effects of cutting dentin with different burs at various speeds on the microtensile bond strength (muTBS) of two self-etching adhesive systems.Flat deep dentin surfaces from 50 extracted human third molars were divided into 5 groups (n = 10) according to bur type and speed of rotation: (I) high-speed diamond bur, (II) low-speed diamond bur, (III) high-speed tungsten carbide bur, (IV) low-speed tungsten carbide bur. Controls were abraded with 600-grit SiC paper. A two-step self-etching adhesive, Clearfil SE Bond (SE, Kuraray) and a one-step self-etching adhesive, Clearfil S3 Bond (S3, Kuraray) were applied to dentin surfaces and light cured. Composite buildups were performed using Filtek Z250 (3M ESPE). For lTBS evaluation, composite-dentin beams of 0.8 mm2 were stressed to failure at a crosshead speed of 1 mm/min. The muTBS data were analyzed using two-way ANOVA and Tukey's multiple comparison tests. Representative fractured beams from each group were prepared for fractographic analysis under SEM.Two-way ANOVA showed that the effects of dentin surface preparations, adhesive systems, and their interaction were statistically significant (p0.001). The muTBS was the highest when bonding SE to dentin surface prepared with 600-grit SiC abrasive paper (47.3 +/- 7.4 MPa), followed by high-speed tungsten carbide burs (40.8 +/- 6.1 MPa), and the lowest when bonding S3 to dentin surfaces prepared with a high-speed diamond bur (15.2 +/- 6.2 MPa). SEM observation of the fractured surfaces revealed mixed and adhesive failures for SE groups, while in the S3 groups, adhesive failures predominated with numerous inclusion droplets.Higher bond strengths are achieved with SE bond when applied on dentin surfaces prepared with tungsten carbide burs. Proper bur and adhesive selection are essential to optimize dentin adhesion of self-etching adhesives.

To examine whether Resilon, a polycaprolactone-based thermoplastic root filling material was susceptible to biodegradation by cholesterol esterase using agar-well diffusion assay of serially-diluted aqueous Resilon emulsions that were dispersed in agar.Emulsions of Resilon and polycaprolactone were prepared and dispersed in agar on culture plates. Two different concentrations of a cholesterol esterase (0.3 and 1.2 U/mL) were prepared and fed to wells prepared in the agar plates using an agar-well diffusion assay for examination of the degradation of polymeric materials.Degradation of the emulsified Resilon was manifested as the formation of clear zones of different sizes around the agar wells. No clear zones were observed in agar wells that contain sterile distilled water as the negative control.

This study aims to translate and evaluate the performance of a Chinese version of the Child Oral Health-related Quality of Life (COHQoL) measure composed of the Child Perception Questionnaire (CPQ), Parental Perception Questionnaire (PPQ), and Family Impact Scale (FIS).Chinese versions of the measures were derived through a forward-backward translation. A consecutive sample of 168 children attending paediatric dental and orthodontic clinics in Hong Kong were recruited along with their attending primary caregiver. Children self-completed the 37-item CPQ and their attending primary caregiver self-completed the 31-item PPQ and 14-item FIS consecutively and independently. Reassessments were conducted prior to their next appointment.CPQ, PPQ, and FIS scores were associated with children's global rating of oral health (P0.05) and oral well-being (P0.05) supporting their construct validity. In addition, variations in CPQ, PPQ, and FIS were apparent with respect to patient group (P0.05) supporting their ability to distinguish between patient groups. Cronbach alpha values (internal reliability) and intraclass correlation coefficient values (test-retest reliability) for the three measures were0.80.A Chinese version of the three components of the COHQoL measure was developed with minor modifications. In psychometric testing, the validity of the three components was supported and they demonstrated acceptable reliability.

Most of the cases of talon cusp in the primary dentition affected the maxillary central incisors, but have no effect on the permanent successors. Among the 5 cases of a talon cusp in primary maxillary lateral incisors reported in the dental literature, however, one was associated with a supernumerary tooth and 3 with supplemental permanent successors. The purpose of this report was to describe 3 cases of a talon cusp on the primary maxillary lateral incisors of Chinese children, all of which were associated with talon teeth or the permanent successors. A conservative approach was used to manage these supplemental permanent lateral incisors, and the advantages of such an approach are discussed.

Objective: To compare the dental development and rate of tooth development between children with and without cleft lip and palate. Patients: Age- and gender-matched pairs (231 in all) of southern Chinese children ages 3 to 12 years, with and without cleft lip and palate. Methods: Dental histories and radiographs were studied. From these, dental development was determined. Results: Of 2946 tooth pairs in the children with cleft lip and palate, 252 (8.6%) were found to be asymmetric, significantly (p < .001) more than the 63 of 3179 (2.0%) tooth pairs observed in the children without cleft lip and palate. The teeth with the highest frequency of asymmetry were the maxillary lateral incisors (38.1%). Differences in dental development on the cleft versus noncleft sides of children with unilateral cleft lip and palate were significant for both maxillary and mandibular teeth (p < .001 and p = .039, respectively). The mean delay in tooth formation of the children with cleft lip and palate was 4.4 months relative to the children without cleft lip and palate. The majority of the teeth in the cleft lip and palate group were delayed by one developmental stage. This happened in 40.0% of the maxillary teeth and 30.1% of the mandibular teeth. The delay in tooth formation increased as the number of missing teeth increased in the children with cleft lip and palate, although not significantly. Conclusions: This group of southern Chinese children with cleft lip and palate demonstrated a higher prevalence of asymmetric and delayed dental development than did their counterparts who did not have cleft lip and palate.

Background: The aims of this study were to investigate the efficacy of CPP-ACP containing Tooth Mousse on the remineralization of enamel lesions and to compare its efficacy to that of a fluoride-containing toothpaste. Methods: Permanent teeth were placed in demineralizing solution for 96 hours to produce artificial caries-like lesions 120–200 μm in depth. They were sectioned into 100–150 μm thick samples and randomly assigned to five groups: for Group A, a fluoridated toothpaste (1100 ppm) was used as a positive control and in Group B, a non-fluoridated toothpaste was used as a negative control. Tooth Mousse containing CPP-ACP was tested by three different means: as a toothpaste (Group C); as a topical coating (Group D); and (Group E) as a topical coating after treating the sections with the same fluoridated toothpaste as in Group A. Results: The lesion depth decreased significantly by 7 per cent in Group A, 10.1 per cent in Groups C and D, and 13.1 per cent in Group E (Paired t- test, p

To examine if Resilon, a polycaprolactone-based root filling material, was susceptible to microbial biodegradation by using a simulated field test that consisted of incubating the material in wet dental sludge under mesophilic and aerobic conditions.Pressed disks prepared from Resilon, polycaprolactone (positive control) and gutta-percha (negative control) were incubated in wet dental sludge for up to 4 months and examined for topographical changes using scanning electron microscopy.Gutta-percha exhibited minimal changes in surface integrity, while polycaprolactone and Resilon exhibited severe surface pitting and erosion. In the latter, disappearance of the polymer matrix was accompanied by exposure of mineral and bioactive glass fillers. Bacteria and hyphae-like structures were present on the disk surfaces.

Hypodontia in combination with hyperdontia (hypohyperdontia) is a condition of mixed numeric variation in the human dentition. A comprehensive review on the hypohyperdontia literatures reported prevalence ranges from 0.002% to 3.1%. Our seven cases of hypohyperdontia involved both the maxillary and the mandibular arches. A traditional narrative review is included to describe the prevalence, etiology, and previously reported cases on hypohyperdontia. Furthermore, we opine that comprehensive clinical and radiographic examinations are essential for recognizing such rare dental anomalies. Judicious use of radiographs not only enhances the detection of hypohyperdontia, but also leads to changes in the course of management.

A 15 year and 1 month old Chinese female with palatally impacted upper left canine was successfully treated with an upper removable appliance with a magnet incorporated to provide orthodontic traction force. This case report indicates the possibility of using magnetic force as a safe, effective and comfortable way for orthodontic traction., published_or_final_version

Objectives This was a retrospective study to determine the characteristics and distribution of supernumerary teeth in southern Chinese children. Methods The study population consisted of 208 children aged from 2 to 16 years. Results Males were more frequently affected than females in the ratio 3.1:1. Of the 283 supernumerary teeth, 95.0% were located in the premaxilla, 71.5% were conical, 70.7% were unilateral, 29.3% were bilateral, 47.7% were inverted, and 16.9% were erupted. The mean age at the time of diagnosis and removal of the supernumerary teeth was 7.3 ± 2.7 years (the minimum age was 2.1 years) and 8.1± 2.7 years (the minimum age was 4.1 years), respectively. Seventy percent of the children were in the mixed dentition and 81.3% of the supernumeraries were removed under general anesthesia. Conclusion In accordance with previous studies, the majority of the supernumerary teeth were located in the premaxillary region, were conical shaped, and remained unerupted.

Double teeth and talon cusps are rare developmental dental anomalies affecting both primary and permanent dentitions. Talon cusps normally occur on the palatal surface of permanent maxillary incisors, although double teeth are more common in the primary anterior dentition. This paper describes a rare case of fusion of the mandibular permanent incisors with labial and lingual talon cusps. An understanding of these dental anomalies and their associated problems are important to provide prophylactic measures, thereby preventing or minimizing possible complications.

The aim of this survey was to study the oral health status of Hong Kong Chinese adults with Down syndrome (DS). Sixty-five community-dwelling adults with DS (aged 17 to 42 years, 26.8+/-6.4) and age- and gender-matched controls attending a dental hospital were included in a cross-sectional survey. The subjects with DS had fewer filled (2.4+/-4.6 vs. 2.7+/-3.1, p=0.017) and fewer decayed (1.1 2.5 vs. 1.7+/-2.4, p=0.007) teeth than the control subjects. Significantly more peg-shaped maxillary lateral incisors and retained primary teeth (p0.001) were observed in subjects with DS, compared to the control subjects. Adults who had DS had a significantly higher percentage of surfaces with detectable plaque (81.5+/-19.1 vs. 61.9+/-16.0, p0.001) and a higher percentage of sites with bleeding on probing (76.3+/-25.8 vs. 55.6+/-21.4, p0.001). A higher proportion of subjects with DS showed one or more occurrences where probing pocket depth wasor =6mm than control subjects (49% vs. 24.5%, p0.021). In conclusion, while having fewer caries, Hong Kong Chinese adults with DS had poorer periodontal health than age- and gender-matched control subjects.

Polycaprolactone is susceptible to enzymatic biodegradation via ester bond cleavage. This study examined the susceptibility of Resilon, a polycaprolactone-based root filling material to enzymatic hydrolysis. Resilon, gutta-percha, and polycaprolactone disks, prepared by compression molding, were incubated in phosphate-buffered saline, lipase PS or cholesterol esterase at 37°C for 96 h. They were retrieved at different time intervals for gravimetric analysis and scanning electron microscopy. The materials exhibited slight weight gains when incubated in phosphate-buffered saline that can be attributed to water sorption. Gutta-percha showed similar weight gains in the two enzymes. Conversely, Resilon and polycaprolactone exhibited extensive surface thinning and weight losses after incubation in lipase PS and cholesterol esterase. Glass filler particles in Resilon were exposed following surface dissolution of the polymer matrix, creating rough surface topography. Biodegradation of Resilon by bacterial and salivary enzymes warrants further investigation of their activities using cultures of endodontically relevant microbes and human saliva extracts.

Background. Most reported cases of talon cusps in the primary dentition have been on the maxillary central incisors and the permanent successors have remained unaffected. Four of the five reported cases on a maxillary lateral incisor, however, have been associated with a supernumerary permanent successor. Aim. This paper describes the relationship between the presence of talon cusps on a primary maxillary incisor, and the morphology and number of the permanent successors in a population of Chinese children. Design. The dental records of children diagnosed with a talon cusp on a primary incisor were retrieved for review. The diagnoses took place in a regional school dental clinic in Hong Kong between April 2002 and August 2005. Results. Fifty-eight primary maxillary incisors with talon cusps were found. When the central incisors were involved, 32 of the 35 (91.4%) underlying permanent successors were not found to be associated with any odontogenic abnormalities. When the lateral incisors were involved, however, 18 of the 23 cases (78.3%) showed odontogenic abnormalities, 14 of which were associated with supernumerary teeth. Conclusions. The present study shows that, when there is a talon cusp on a primary maxillary lateral incisor, a high proportion of the underlying permanent successors can be expected to exhibit odontogenic abnormalities.

Objectives: To assess dental practitioners' views on the need to treat developmental defects of enamel (DDE). In addition, to identify factors associated with practitioners’ treatment decision (tooth factors and dentist-related). Methods: A random sample of 300 Hong Kong dentists were sent a booklet containing computer-generated images of various forms of DDE and asked to rate the treatment need. In addition, some dentist-related information was collected. Results: The response rate was 79% (237/300). The majority of the dental practitioners considered that aesthetic treatment was indicated for people with DDE subtypes of brown demarcated opacities (51.0%), confluent/patchy plus staining and/or loss of enamel (80.2%), missing enamel (67.1%) and the combination of discolouration and diffuse opacities (83.1%); their decisions were in relation to the type (P

This paper reviews the nomenclature, prevalence, definition, etiology, association with other dental anomalies, diagnosis and treatment planning of talon cusp in the primary anterior teeth. Most of the reported cases have involved the primary maxillary central incisors. However, talon cusps on the primary maxillary lateral incisors are associated with high percentages of anomalies in the permanent successors. This paper reported three such rare cases and dentists should be aware of such additional anomalies.

Autism is defined as a rare and severe psychiatric disorder of childhood. It is marked by severe difficulties in communicating, and forming relationships with other people, in developing language, repetitive and limited patterns of behaviour and obsessive resistance to small changes in familiar surroundings. Hence, affected children offer a special challenge to the practising dentist. To meet this challenge, it is necessary to understand the condition and how to manage its varying presentations in different individuals. The purpose of this article is to review the literature on the topic of autism with an emphasis on the dental perspective.A better understanding of the effects of autism on the behaviour of an affected individual provides the dental practitioner with the opportunity to deliver oral healthcare in an empathetic and appropriate manner.

Dubowitz syndrome is a rare condition in which the affected individual presents with dysmorphic facial features and manifests growth retardation. Although the condition is well reported in the medical literature, the dental manifestations have not been discussed in great detail. Some of the dental features reported include macrodontia, hypodontia, delayed eruption, and midline diastema. The purpose of this case report was to describe a young Chinese patient with Dubowitz syndrome with specific oral features.

Due to the significant increase in the incidence and prevalence of the fetal alcohol syndrome (FAS) in developing and developed nations, it is important that dental professionals recognize this condition. Patients with FAS have orofacial characteristics and various psychological and physical symptoms that may affect a dental treatment plan. This article reviews the prevalence, incidence, alcohol dose response and metabolism, and clinical characteristics of FAS. A case demonstrating moderate signs of the condition is included to illustrate some of the characteristics.