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PubMed1998

A study of sports-related mandibular angle fracture: relation to the position of the third molars.

Mandibular angle fractures have been considered attributable to the presence of unerupted third molars. We examined the relationship between the incidence of sports-related mandibular angle fractures and the presence of a mandibular third molar with emphasis on the position of the third molar. The incidence of angle fracture was significantly higher in the sports-related injury group than in the group with fracture due to other causes (P < 0.05). The incidence of angle fracture in the athletes with higher impaction scores was significantly higher than that in the subjects with higher scores who did not have sports-related fractures (P < 0.05). The percentage of rugby athletes with third molars was significantly higher than that of those without third molars (P < 0.001), and a high proportion of young athletes (89.5%) was considered to belong to a potential high-risk group for angle fractures. Our findings suggest that mandibular angle fractures are influenced by the presence and characteristics of the third molar in sports-related injuries.

Accidents, Traffic↗
PubMed1996

Position of upper permanent central incisors prior to eruption in unilateral cleft lip and palate.

The position and degree of eruption of permanent central incisors within the premaxilla were measured on x-ray films obtained in 102 patients with unilateral cleft lip and palate and in 52 normal individuals aged 5 years. The patients were subdivided according to sex and to the method of surgical repair (bone grafting or periosteal flap surgery). Individuals with rotated incisors were assessed separately. The results showed that maxillary depth was not significantly reduced prior to palate surgery while the alveolar process was markedly retroclined. An unerupted central upper incisor on the side of the cleft was situated more anteriorly than in controls. Because of the distortion of the alveolar process, it was retroclined and produced a deformation of the subspinal concavity. Both this deformation and the distortion of the alveolar process interfered with the measurements of maxillary depth and rendered it inadequate. The incisor on the normal side was situated more posteriorly than in controls and was less retroclined than the incisor on the affected side. The degree of eruption of incisors on both the normal and affected sides did not differ from controls. The type of surgical repair influenced only the retroclination of the alveolar process and of the incisors within this process. The retroclination was more marked after primary bone grafting than after periosteal flap surgery. The position and degree of eruption of rotated incisors did not differ from nonrotated incisors, and the presence of rotated incisors was not related to the degree of the shortening of maxillary depth. There were no significant differences between males and females.

Bone Transplantation↗
PubMed2005

A visual analog scale for measuring dental fluorosis severity.

BACKGROUND: To date, no continuous scale exists for measuring the severity of dental fluorosis (DF). OBJECTIVES: The authors developed and validated a visual analog scale (VAS) for DF. They tested the scale in clinical (DF-endemic area) and laboratory settings. METHODS: Dentists and nondentists (23 per group) were asked to grade the DF severity in photographs of 23 anterior teeth with different DF levels (using a 100-millimeter VAS) to create a VAS for DF. Statistical analysis was performed to validate the new scale. The authors used clinical and laboratory (unerupted third molars) analyses to assess the usefulness of the VAS. RESULTS: The authors used an intraclass correlation coefficient (ICC) to assess the interexaminer (ICC = .79: good agreement) and intraexaminer (.88 < ICC < .97: excellent agreement) reliability during creation of the scale. They used the Spearman rank correlation (r(s)) to validate the VAS against the gold standards (that is, the Thylstrup-Fejerskov index [TFI] and Dean's index [DI]) (the results showed excellent or good correlation for 45 examiners). Two dentist examiners clinically tested the new VAS, and the results showed excellent (r(s) = .922, P < .001) correlation and excellent ICC between the examiners (ICC = .96), as well as good ICC between the TFI and the VAS for DF (ICC = .6). The laboratory study showed better correlation between fluoride concentration and the VAS for DF than between fluoride concentration and the TFI. CONCLUSION: Because of its simplicity, precision and utility in statistical applications, the VAS for DF can be useful in DF studies.

Adolescent↗
PubMed2006

Dynamic light scattering study of an amelogenin gel-like matrix in vitro.

Amelogenin self-assembly is critical for the structural organization of apatite crystals during enamel mineralization. The aim of the present study was to investigate the influence of temperature and protein concentration on the aggregation of amelogenin nanospheres at high protein concentrations (>4.4 mg ml-1) in order to obtain an insight into the mechanism of amelogenin self-assembly to form higher-order structures. Amelogenins were extracted from enamel scrapings of unerupted mandibular pig molars. The dynamics of protein solutions were measured using dynamic light scattering (DLS) as a function of temperature and at acidic pH. At pH 4-5.5, three kinds of particles were observed, ranging in size from 3 to 80 nm. At pH 6, heating the solution above approximately 30 degrees C resulted in a drastic change in the solution transparency, from clear to opaque. Low pH showed no aggregation effect, whilst solutions at a slightly acidic pH exhibited diffusion dynamics associated with the onset of aggregation. In addition, at the same temperature range, the hydrodynamic radii of the aggregates increased drastically, by almost one order of magnitude. These observations support the view that hydrophobic interactions are the primary driving force for the pH- and temperature-sensitive self-assembly of amelogenin particles in a 'gel-like' matrix. The trend of self-assembly in a 'gel-like matrix' is similar to that in solution.

Amelogenesis↗
PubMed1988

Transmission electron microscopic study of giant tubules in bovine dentin.

Giant tubules in the axiomesiodistally extended incisal dentin of unerupted permanent bovine incisors from 1/2-1 1/2-yr-old calves were studied by TEM. The pulpal portion of each giant tubule contained two capillaries forming a loop incisally. The capillaries consisted of a delicate, continuous, or fenestrated endothelium and often had a pericyte coating. Cells with a rich RER, mitochondria, and Golgi apparatus dominated along and just incisal to the vessels. Extravasated erythrocytes and occasional macrophages were also seen in the latter location. It was suggested that the pulpal retraction of the giant tubule vessels during primary dentinogenesis might be the result of an intermittent sequestration of the most incisal portion of the loop, concomitant with endothelial proliferation in the pulpal portion of the capillaries. The major portion of the giant tubules, incisal to the vessels, contained a dense matrix of more or less axially oriented unmineralized 0.07-0.1-micron-thick collagen fibrils and single cells showing gradually increasing degenerative and necrotic changes in an incisal direction. Longitudinal sections of the mineralized tubular walls revealed transversely cut collagen fibrils. The incisally located giant tubule origins were circumvented by dentinal tubules and contained 0.10-0.22-micron-thick, densely packed collagen fibrils with an electron dense perifibrillar zone.

Animals↗
PubMed1993

Dental follicular tissue: misinterpretation as odontogenic tumors.

The dental follicle is radiographically and histologically observed in association with unerupted or impacted teeth. However, this normal tissue structure is often confused with odontogenic tumors by pathologists with limited experience in evaluating jaw lesions. This study was designed to evaluate the incidence and possible reasons for incorrect interpretation of dental follicles. From 1970 to 1988, 847 dental follicles and/or dental papillas from 663 patients were submitted to the Armed Forces Institute of Pathology (AFIP) by medical pathologists seeking diagnostic consultation. Nearly 84% of patients were in the second and third decades of life. The male to female ratio was 1.4:1.0. Over 70% of specimens were obtained from around impacted third molar teeth. Fifty-three percent of specimens were correctly interpreted by the contributing pathologists. Only a descriptive interpretation was given for 17%, no diagnosis was made in 10%, and 20% were incorrectly diagnosed. In descending order, the most frequent incorrect diagnoses were odontogenic cyst, odontogenic myxoma, odontogenic fibroma, ameloblastic fibroma, odontoma, and ameloblastoma. Dental papillas were most frequently misdiagnosed as odontogenic myxomas. The histologic features and diagnostic pitfalls are discussed, as well as the need to consider the clinical, radiographic, and microscopic features in arriving at a final diagnosis.

Adolescent↗
PubMed1999

Localization of the unerupted maxillary canine: how to and when to.

Reasons for localizing impacted maxillary canines are outlined and methods of localization described. The favored method of radiographic localization is the parallax method (image/tube shift method). Tube shifts can be carried out in both the horizontal and the vertical planes. For a horizontal tube shift, two occlusal radiographs are recommended; for a vertical tube shift, a rotational panoramic radiograph and an occlusal radiograph are recommended. This latter combination is usually the combination of choice because the panoramic radiograph, which provides information about all the teeth in both arches, the two jaws, and the surrounding structures, is often taken as an initial radiograph and this combination only requires one additional exposure, the occlusal radiograph. To facilitate the interpretation of a vertical tube shift, the angle of the tube in the occlusal radiograph should be increased from the customary 60 degrees to 65 degrees to 70 degrees to 75 degrees. Less accurate methods of radiographic localization are to use (1) image magnification of the impacted maxillary canines and (2) image superimposition of the impacted maxillary canines on the central or lateral incisor. Reasons why periapical radiographs are not recommended to be used for a horizontal tube shift or for a vertical tube shift in combination with a panoramic radiograph are explained. Indications to suspect palatal impaction may occur in the future if the patient is less than 10 years of age, and indications to suspect impaction may have occurred if the patient is more than 10 years of age are discussed. Patient questionnaires are advocated to aid the clinician in anticipating palatal impaction, the most frequent impaction.

Child↗
PubMedDate not supplied

[Assessment of effectiveness of the Tanaka-Johnston method for prediction of the mesiodistal diameter of unerupted canines and premolars].

In the present study, the authors evaluated the Tanaka-Johnston method of prediction, with the objective of verifying its effectiveness for the right and left sides, for both genders and for the white, light mulatto, medium mulatto, dark mulatto and black races in the city of Salvador, Bahia. The mesiodistal diameter of the inferior permanent incisors, canines and premolars that had already erupted was measured with the aid of a digital caliper rule in the oral cavity of 98 individuals (45 males and 53 females), aging from 13 to 29 years. The results obtained with the application of the Tanaka-Johnston formulas were compared with the real values through statistical tests. After the analysis of the results, it was observed that the correlation between the estimated values and the real values was greater for females than it was for males. As to race, the coefficients of correlation were satisfactory. They were greater in the superior arch for the dark mulatto race (0.67), and in the inferior arch for the light mulatto race (0.74). Considering the sides, the findings revealed a greater coefficient of correlation for the inferior arch on the left side (0.61). It was concluded that the Tanaka-Johnston method, in spite of originating from a sample of European descendants, is indicated for the prediction of the mesiodistal diameter of canines and premolars in the different races evaluated in this research. The effectiveness of the referred method was also checked for both genders and sides in the studied sample.

Adolescent↗
PubMed1994

Effects of the Nd:YAG laser and combined treatments on in vitro fibroblast attachment to root surfaces.

The purpose of this in vitro study was to evaluate the effects of the Nd:YAG laser either alone or in combination with root planning or air-powder abrasive treatment on fibroblast attachment to non-diseased root surfaces. 28, 4 x 4 mm root specimens and four disc-shaped root specimens 6 mm in diameter were obtained from unerupted 3rd molars. The root segments were randomly assigned to 4 treatment groups: (1) control; (2) laser-only treated; (3) laser treated followed by root planning; (4) laser treated followed by air-powder abrasive treatment. Laser-treated root specimens were exposed for 1 min with the Nd:YAG laser calibrated at an energy setting of 75 mJ at 20 pulses/s using a 320 microns contact fiber. The contact fiber was held parallel to the root segments and the root segments were kept moist with distilled water. Following the prescribed treatments, the root specimens were incubated with fibroblast cultures and then prepared for SEM examination. Results of cell counts of fibroblasts attached to specimens within each treatment group yielded the following means and standard deviations: control groups, 181.64 +/- 44.74; lased only, 78.57 +/- 21.35; lased and root planed 125.35 +/- 26.13; and lased followed by an air-powder abrasive, 177.28 +/- 55.71. Application of ANOVA followed by the Dunn Multiple Comparison test revealed significant differences (p < 0.01) in the number of attached cells between the control and laser-only treated groups; and between the laser-only and laser/air-powder abrasive treated groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Air↗
PubMed2006

A longitudinal study of early childhood caries in 9- to 18-month-old Thai infants.

OBJECTIVE: To examine the rate and pattern of early childhood caries (ECC) development and to investigate the transitional changes of the carious lesions during a follow-up period of 3-9 months. METHODS: A longitudinal observational community-based survey of 599 children, 9-18 months old. The children's dental examinations were first carried out at the age of 9 months with re-examination at 12 and 18 months by five dentists using standardized methods. The affected rates of dental caries were determined for prevalence, incidence density for risk of caries per person (IDp) and risk by surface (IDs). Changes in dental status over time were explored from unerupted (U) to sound (S), including enamel caries (D1), dentine caries (D2) and caries involving pulp (D3) by computing transitional probabilities. RESULTS: The prevalence of caries was 2.0%, 22.8% and 68.1% among 9-, 12- and 18-month olds, respectively. The IDp observed for newly affected children 9-12 and 12-18 months old was 10.32 and 15.70 persons/100 person-months, respectively. The IDs for children 9-12 months old was 2.17 newly affected surfaces/100 surface-months whereas it was 2.22 surfaces/100 surface-months for children 12-18 months old. The buccal surface of maxillary incisors was the most affected (44.9%) followed by lingual, mesial and distal surfaces, respectively. The transitional probability of caries progression ranged between 1.79% and 15.38% during the follow-up period from 9 to 12 months old. It was 3.43-39.60% from 12 to 18 months old. CONCLUSIONS: An extremely high caries-affected rate was found among the study children even before the age of 18 months. The buccal surface of the maxillary incisors was the most affected. The teeth acquired caries at 3-6 months after initial eruption and carious lesions developed continuously over time.

Cohort Studies↗
PubMedDate not supplied

A contribution to the diagnosis of the small dentigerous cyst or the paradental cyst.

The aim of this study was to verify the relationship between the radiographically measured width of the pericoronal space (PS) and the microscopic features of the follicle in order to contribute to the diagnosis of small dentigerous cysts and paradental cysts. One hundred and thirty unerupted teeth (UT) and thirty-five partially erupted teeth (PET) were radiographed and extracted. The radiographic analysis consisted of measuring the width of the PS. The results of the radiographic analysis were compared with those of the histopathologic examination of the dental follicle. The width of the PS ranged from 0.1 to 5.6 mm. The most frequently observed lining of the follicles was a reduced enamel epithelium (REE) (68.4%) in UT and a hyperplastic stratified squamous epithelium (HSSE) (68.5%) in PET. Inflammation was present in 36.1% of the UT and in 82.8% of the PET. There was a statistically significant association between the presence of stratified squamous epithelium (SSE) and PS enlargement for UT (p < 0.05). There was a tendency of association between inflammation and PS enlargements in PET and, possibly, in UT, despite the absence of statistical significance. Surgically, we did not detect bone cavitation or luminal cystic contents in pericoronal spaces smaller than 5.6 mm. We suggest that the first radiographic diagnosis for a PS enlargement, in most of the routine clinical cases, should be of "inflammation of the follicle". The hypothesis of "dentigerous cyst" or "paradental cyst" is suggested as a second diagnosis. The final differential diagnosis between a small dentigerous or a paradental cyst and a pericoronal follicle depends on clinical and/or surgical findings, such as the presence of bone cavitation and cystic content.

Adult↗
PubMed1984

Purification and characterization of bovine dental pulp collagenase inhibitor.

Root pulps from bovine unerupted wisdom teeth produce a potent collagenase inhibitor together with latent collagenase when cultured in Eagle's minimal essential medium (Biochem. Int. 5, 763, 1982). The inhibitor was purified more than 700-fold from the explant medium using Con A-Sepharose, Ultrogel AcA 44 and DE-52 cellulose columns. It showed a single band (MW = 36,000) on sodium dodecyl sulfate-polyacrylamide gel electrophoresis, but showed multiple bands on basic (pH 8.3) polyacrylamide gel electrophoresis and electrofocusing. The inhibitor is a sialo-glycoprotein containing approx. 20% carbohydrate by weight and its composition suggests that it contains complex-type oligosaccharides. The electrophoretic heterogeneity of the inhibitor was proved to be due to the attachment of different numbers of sialic acid residues. All the SH groups were demonstrated to exist as six disulfide linkages which might be involved in the inhibitory activity. The bovine pulp inhibitor does not combine with collagen. The addition of the inhibitor to activated collagenase resulted in dose-dependent inhibition of the enzyme activity, but the interaction between the inhibitor and activated collagenase is not tight enough for the complex to remain intact during gel filtration column chromatography. A rabbit antiserum was prepared against the inhibitor, and immunoglobulin purified from the antiserum can completely abolish the inhibitory activity of the inhibitor.

Amino Acids↗
PubMedDate not supplied

Comparison of two methods of space prediction in the mixed dentition.

PURPOSE: This study compares the accuracy of space prediction for the unerupted permanent canines and premolars by a recognized method of mixed dentition space analysis (Moyers technique) vs estimation by simple visual observation (SVO). METHODS: Twenty clinicians with varying levels of dental experience and training blindly assessed study models of 4 intact arches (2 maxillary and 2 mandibular) from 3 patients in the mixed dentition using both Moyers and SVO space prediction methods. Corresponding full-mouth panoramic radiographs were available for each case. Follow-up records of the eventual outcome in the permanent dentition for each case available (ie, study models prior to any form of orthodontic intervention) served as the standard for further comparison of the space predictions made. Predictions by both methods were compared with each other as well as with the eventual space situation in the permanent dentition. RESULTS: The differences in overall mean space prediction between the Moyers technique (excluding molar shift) and SVO ranged between 3.67 mm to 6.9 mm (lower arches) and 4.3 mm to 4.8 mm (upper arches). Diagnostic consistency between both methods' predictions was highly variable, with correlation ranging from moderate (r = 0.53, P = .01) to very weak (r = -0.1). Generally, more crowding was estimated with the SVO method's predictions. However, the inclusion of molar shift in the Moyers analysis resulted in the prediction of more crowding in the mandible compared to SVO and eventual outcome in the permanent dentition. The range and variability in predictions were always smaller with the Moyers technique compared to SVO. Neither technique's mean space prediction more closely resembled the eventual space situation in the permanent dentition. CONCLUSIONS: This study demonstrated that although the Moyers technique demonstrated less variation and more reproducibility than SVO in its space predictions, neither of the techniques was any more accurate in predicting the final space outcome in the permanent dentition.

Analysis of Variance↗
PubMed2004

Effectiveness of strategies to disseminate and implement clinical guidelines for the management of impacted and unerupted third molars in primary dental care, a cluster randomised controlled trial.

OBJECTIVE: To investigate the effectiveness and cost-effectiveness of different guideline implementation strategies, using the Scottish Intercollegiate Guidelines Network (SIGN) Guideline 42 "Management of unerupted and impacted third molar teeth" (published 2000) as a model. DESIGN: A pragmatic, cluster RCT (2x2 factorial design). SUBJECTS: Sixty-three dental practices across Scotland. Clinical records of all 16-24-year-old patients over two, four-month periods in 1999 (pre-intervention) and 2000 (post-intervention) were searched by a clinical researcher blind to the intervention group. Data were also gathered on the costs of the interventions. INTERVENTIONS: Group 1 received a copy of SIGN 42 Guideline and had an opportunity to attend a postgraduate education course (PGEC). In addition to this, group 2 received audit and feedback (A and F). Group 3 received a computer aided learning (CAL) package. Group 4 received A and F and CAL. PRINCIPAL OUTCOME MEASUREMENT: The proportion of patients whose treatment complied with the guideline. RESULTS: The weighted t-test for A and F versus no A and F (P=0.62) and CAL versus no CAL (P=0.76) were not statistically significant. Given the effectiveness results (no difference) the cost effectiveness calculation became a cost-minimisation calculation. The minimum cost intervention in the trial consisted of providing general dental practitioners (GDPs) with guidelines and the option of attending PGEC courses. Routine data which subsequently became available showed a Scotland-wide fall in extractions prior to data collection. CONCLUSION: In an environment in which pre-intervention compliance was unexpectedly high, neither CAL nor A and F increased the dentists' compliance with the SIGN guideline compared with mailing of the guideline and the opportunity to attend a postgraduate course. The cost of the CAL arm of the trial was greater than the A and F arm. Further work is required to understand dental professionals' behaviour in response to guideline implementation strategies.

Adolescent↗
PubMed2000

The effectiveness and cost-effectiveness of prophylactic removal of wisdom teeth.

BACKGROUND: Removal of wisdom teeth is one of the most common surgical procedures performed in the UK. Little controversy surrounds the removal of impacted third molars when they are associated with pathological changes such as infection, non-restorable carious lesions, cysts, tumours, and destruction of adjacent teeth and bone. However, the justification for prophylactic removal of impacted third molars is less certain and has been debated for many years. OBJECTIVES: To provide a summary of existing evidence on prophylactic removal of impacted wisdom teeth, in terms of the incidence of surgical complications associated with prophylactic removal, and the morbidity associated with retention. METHODS: A systematic review of the research literature was undertaken. METHODS - DATA SOURCES: An existing review formed the basis of this report, and additional literature searches were undertaken, including searches of electronic databases (MEDLINE, 1984-99; EMBASE, 1984-99; Science Citation Index, Cochrane Controlled Trials Register, National Research Register; Database of Abstracts of Reviews of Effectiveness), paper sources (including Clinical Evidence), and web-based resources. Relevant organisations and professional bodies were contacted for further information. METHODS - STUDY SELECTION: Studies were selected for inclusion if they met the following criteria: (1) design - randomised controlled trials (RCTs), literature reviews, or decision analyses; (2) participants - people with unerupted or impacted third molars, or those undergoing surgical removal of third molars either as prophylaxis or due to associated pathological changes; (3) reported outcomes - either the pathological changes associated with retention of third molars, or post-operative complications following extraction. There were no language restrictions on study selection. METHODS - DATA EXTRACTION AND SYNTHESIS: Data from included studies were extracted into structured tables and individual study validity was assessed against methodological checklists. Data were summarised descriptively. Decisions relating to study selection, data extraction and validity assessment were made by two independent reviewers, and disagreements were resolved by discussion. For non-English papers, translators were recruited to assist with study selection and data extraction. RESULTS: Forty studies were included in the review: two RCTs, 34 literature reviews, and four decision analysis studies. One RCT in the UK focused on the effects of retained third molars on incisor crowding (predominantly a cosmetic problem) in patients who had previously undergone orthodontic treatment. The results of this trial suggested that the removal of third molars to prevent late incisor crowding cannot be justified. Another on-going RCT in Denmark compares the effects and costs of prophylactic removal of third molars with removal according to morbidity. So far, this trial has recruited 200 participants, and preliminary results indicate that watchful waiting may be a promising strategy. However, more data and longer follow-up of patients are needed to conclude which treatment strategy is the most cost-effective. It is also known that a trial is on-going in the USA but no results are available so far. The methodological quality of the literature reviews was generally poor, and none of the reviews was systematic. Conclusions from nine reviews on anterior crowding suggested that there was only a weak association between retention of third molars and crowding. Six out of 21 reviews with a more general scope also concluded that the prophylactic removal of third molars was unjustified. Twelve general reviews did not conclude with a clear message about the management of third molars. Three reviews suggested that prophylactic removal of third molars is appropriate, but these reviews were of poorer methodological quality than the majority of other reviews. Three out of four papers focusing on surgical management expressed

Cost-Benefit Analysis↗
PubMed1993

GAPO syndrome in three relatives in a Turkish kindred.

GAPO syndrome in 2 sibs (brother and sister) and in a first cousin presented slight variations in the clinical picture. These include presence of some body hair, white eyelashes, deep furrows on sternum and back, disproportional body build, and minor skeletal abnormalities. It has been suggested that the athletic appearance of affected individuals is most likely due to the excessive amount of connective tissue.

Abnormalities, Multiple↗
PubMed1994

GAPO syndrome in a child without dermal hyaline deposit.

A 5-year-old girl with GAPO syndrome from India lacked PAS-positive hyaline material in the skin biopsy from thigh and scalp. The role of this pathological change, earlier reported by Wajntal et al. [1990] in the pathogenesis of GAPO syndrome, needs to be reexamined.

Abnormalities, Multiple↗