Comparative study of cone beam computed tomography and intraoral periapical radiographs in diagnosis of lingual-simulated external root resorptions

Background: Owing to a lack of symptoms and difficult visualization in routine intraoral radiographs, diagnosis of external root resorptions can be challenging. Aim: The goal of this study was to compare two image acquisition methods, intraoral radiographs and cone beam computed tomography (CBCT), in the diagnosis of external resorption. Material and Methods: Thirty-four maxillary and mandibular bicuspids were divided into three groups. Perforations measuring 0.3 and 0.6 mm in diameter and 0.15 and 0.3 mm in depth, respectively, were made on the lingual root surfaces in thirty teeth, and four were used as controls. Next, teeth were mounted on an apparatus and radiographed at mesial, distal, and orthoradial angulations. CBCT images were also taken. The analysis of the intraoral radiographic and tomographic images was carried out by two experts using standardized scores. Data were then compared statistically. Results: A strong agreement between the examiners was observed in both diagnosis methods, the intraoral radiographic (r = 0.93) and the tomographic analysis (r = 1.0). Tomography had higher statistically significant detection values than intraoral radiography (P < 0.05). In intraoral radiographs, the detection was significantly greater (P < 0.05) in the mandibular bicuspids, compared with their maxillary counterparts. The ability to detect 0.6-mm perforations by intraoral radiography was significantly higher than that of 0.3-mm perforations (P < 0.05). Conclusion: Cone beam computed tomography showed better diagnostic ability compared with intraoral radiography, regardless of the tooth or the dimensions of the resorption evaluated.

Ultrastructural aspects of Callithrix penicillata lingual papillae

Callithrix penicillata belongs to the family Callitrichidae, Callithrix genus. They are basically insectivorous, but they consume fruits. The mucosa of the tongue is composed of some papillary types, revealing different levels of expertise. The present study attempted to describe the morphological and ultrastructural aspects of the dorsal surface of the C. penicillata, describing the characteristics and distribution of papillae found. Five tongues of C. penicillata (two females and three males), obtained from breeding colonies of CENP-Ananindeua-PA, died from natural causes. The material was fixed partly in a buffer solution paraformaldehyde 10% and partly in modified Karnovsky solution, divided into apex, body, and root, and then the fragments were used in light microscopy and scanning electron microscopy. The average length of the tongue of the females was 22 mm and for males 20.5 mm. Three types of papillae were described: filiform (along all tissue extension with 154 mu m of diameter), fungiform (along all tissue extension with 275 mu m of diameter), and vallate (just three units in caudal (dorsal) portion with 672 mu m of diameter). Data analysis indicates that the distribution and ultrastructural morphology of the C. penicillata lingual papillae are some similar to other primates. Microsc. Res. Tech. 2011. (c) 2011 Wiley Periodicals, Inc.

Surdez pós-lingual: benefícios do implante coclear versus prótese auditiva convencional

Devido aos avanços na tecnologia dos implantes cocleares e das estratégias de processamento, indivíduos com surdez grave a profunda puderam ouvir sons e reconhecer fala em diferentes graus. A variabilidade nos resultados audiológicos em portadores de surdez pós-lingual tem sido grande e a indicação para o implante coclear tem se estendido e inclui uma população cada vez maior. OBJETIVO: Avaliar em quais pacientes portadores de surdez pós-lingual o implante coclear traz benefício auditivo superior ao da prótese auditiva convencional. MATERIAIS E MÉTODOS: consulta a artigos científicos por busca no banco de dados SciELO, Cochrane, MEDLINE e LILACS-BIREME. Foram selecionadas publicações com força de evidência A ou B até a data da investigação, que comparassem aparelhos de amplificação sonora e implante coclear na população com surdez pós-lingual. Desenho do Estudo: revisão sistemática. RESULTADOS: Entre os 2169 artigos consultados, 11 trabalhos se mostram pertinentes ao tema e apresentaram força de evidência B. Seis estudos são do tipo coorte prospectivo, quatro são estudos transversais e um ensaio clinico. CONCLUSÃO: A avaliação dos benefícios obtidos por portadores de surdez pós-lingual reabilitados com o uso de implante coclear mostra que este dispositivo é efetivo e apresenta melhores resultados quando comparado aos aparelhos de amplificação sonora individual.

Surdez pré-lingual: benefícios do implante coclear versus prótese auditiva convencional

INTRODUÇÃO: A maioria dos pacientes com perda auditiva, incluindo casos de perdas severas, é beneficiada com o uso de aparelho de amplificação sonora individual. Acredita-se que o implante coclear estabeleça melhores resultados na reabilitação de uma criança com perda auditiva nos casos em que a gravidade da deficiência torna os aparelhos acústicos convencionais incapazes de fornecer informação sonora adequada, já que estes necessitam de reserva coclear suficiente para que ocorra detecção acústica. OBJETIVO: Avaliar se em pacientes portadores de surdez pré-lingual o implante coclear traz benefício auditivo superior ao da prótese auditiva convencional. SÍNTESE DOS DADOS: Revisão sistemática realizada a partir de consulta a artigos científicos selecionados por busca no banco de dados SciELO, Cochrane, MEDLINE e LILACS-BIREME. Entre os 2169 artigos consultados, 12 trabalhos se mostram pertinentes ao tema e apresentaram força de evidência B. Entre os desenhos de estudos analisados na revisão, 7 são do tipo coorte prospectivo e 5 são estudos transversais. CONCLUSÃO: O implante coclear demonstrou, através de diversos estudos, ser atualmente, a melhor alternativa para os casos de perdas auditivas bilaterais severas ou profundas, atingindo resultados superiores em percepção e desenvolvimento de fala em crianças pré-linguais quando comparados aos aparelhos de amplificação sonora convencionais.

In-vitro assessment of the forces generated by lingual fixed retainers

The aim of this article was to assess the effect of wire adaptation on the lingual surfaces of mandibular anterior teeth with 3 types of lingual retainers on the development of vertical and labiolingual forces.

Long-term effectiveness of canine-to-canine bonded flexible spiral wire lingual retainers

The flexible spiral wire (FSW) canine-to-canine lingual retainer bonded to all 6 anterior teeth is a frequently used type of mandibular fixed retainer. This study aimed to assess the long-term effectiveness of FSW canine-to-canine lingual retainers in maintaining the alignment of the mandibular anterior teeth after orthodontic treatment.

Release of bisphenol-A from a light-cured adhesive bonded to lingual fixed retainers

Our aim was to quantitatively determine the bisphenol-A (BPA) released from a light-cured orthodontic adhesive used to bond lingual fixed retainers.

Evaluation of location and dimensions of lingual foramina using limited cone-beam computed tomography

To assess retrospectively the frequency and location of mandibular lingual foramina and their bony canals with limited cone-beam computed tomography.

Assessment of speech perception and communication skills in adolescents with cochlear implants for pre- and peri-lingual deafness

This study aimed to assess speech perception and communication skills in adolescents between ages 8 and 18 that received cochlear implants for pre- and peri-lingual deafness.

Severe complication of a bonded mandibular lingual retainer

Bonding a flexible spiral wire retainer to the lingual surfaces of all 6 anterior mandibular teeth is a commonly used type of retention. Complications are rare but can be serious enough to produce biologic damage. This article presents a serious complication of a lingual flexible spiral wire retainer. Four years after the orthodontic treatment, a 20-year-old man sought treatment for a broken flexible spiral wire retainer. The clinical examination showed about 35° of buccal root torque of that tooth. A cone-beam computed tomography image showed that the root and the apex of the tooth were almost completely out of the bone on its buccal side. Surprisingly, the tooth's vitality was preserved. The tooth was moved back, nearly to its original position; clinically, only a gingival recession remained. Orthodontists and dentists should be aware of possible complications of bonded retainers. Patients should be clearly informed how to detect problems at an early stage.

Survival of bonded lingual retainers with chemical or photo polymerization over a 2-year period: a single-center, randomized controlled clinical trial

INTRODUCTION The objective of this trial was to compare the survival rates of mandibular lingual retainers bonded with either chemically cured or light-cured adhesive after orthodontic treatment. METHODS Patients having undergone orthodontic treatment at a private orthodontic office were randomly allocated to fixed retainers placed with chemically cured composite or light-cured composite. Eligibility criteria included no active caries, restorations, or fractures on the mandibular anterior teeth, and adequate oral hygiene. The main outcome was any type of first-time lingual retainer breakage; pattern of failure (adapted adhesive remnant index scores) was a secondary outcome. Randomization was accomplished with random permuted blocks of 20 patients with allocation concealed in sequentially numbered, opaque, sealed envelopes. Blinding was applicable for outcome assessment only. Patients were reviewed at 1, 3, and 6 months and then every 6 months after placement of the retainer until completion of the study. Data were analyzed using survival analysis including Cox regression; sensitivity analysis was carried out after data imputation for subjects lost to follow-up. RESULTS Two hundred twenty patients (median age, 16 years; interquartile range, 2; range, 12-47 years) were randomized in a 1:1 ratio to either chemical or light curing. Baseline characteristics were similar between groups, the median follow-up period was 2.19 years (range, 0.003-3.64 years), and 16 patients were lost to follow-up. At a minimum follow-up of 2 years, 47 of 110 (42.7%) and 55 of 110 (50.0%) retainers had some type of failure with chemically cured and light-cured adhesive, respectively (log-rank test, P = 0.35). Data were analyzed on an intention-to-treat basis, and the hazard ratio (HR) was 1.15 (95% confidence interval [CI], 0.88-1.70; P = 0.47). There was weak evidence that age is a significant predictor for lingual retainer failures (HR, 0.96; 95% CI, 0.93-1.00; P = 0.08). Adhesive remnant index scoring was possible for only 66 of the 102 (64.7%) failures and did not differ between composites (Fisher exact test, P = 0.16). No serious harm was observed other than gingivitis associated with plaque accumulation. CONCLUSIONS The results of this study indicated no evidence that survival of mandibular lingual retainers differs between chemically and light-cured adhesives. The overall failure rate was 46.4%; however, this included any type of failure, which may have exaggerated the overall failure rate.

Facts and myths regarding the maxillary midline frenum and its treatment: a systematic review of the literature

OBJECTIVE To systematically review the current literature on the maxillary midline frenum and associated conditions and complications, as well as the recommended treatment options. METHOD AND MATERIALS A detailed MEDLINE database search was carried out to provide evidence about the epidemiology, associated pathologies, and treatment options regarding the maxillary frenum. Of the 206 initially identified articles, 48 met the inclusion criteria. RESULTS The maxillary frenum is highly associated with a number of syndromes and developmental abnormalities. A hypertrophic frenum may be involved in the etiology of the midline diastema. There is also a tendency by orthodontists to suggest posttreatment removal of the frenum (frenectomy). Studies on the cause of gingival recession due to the maxillary frenum are inconclusive. An injured frenum in combination with other traumas and doubtful history might point to child abuse. The involvement of hyperplastic frena in the pathogenesis of peri-implant diseases remains uncertain. There seems to be a clinical interest regarding lasers for surgery for treatment of maxillary frena. The superiority of laser treatment in relation to conventional surgical methods has not yet been demonstrated in the literature. CONCLUSION A maxillary frenum is a clinical symptom in numerous syndromic conditions and plays a role in the development of the median midline diastema. Nevertheless, the contribution to gingival recession and peri-implant diseases in the region of the maxillary incisors is rather controversial. Laser techniques are reported as the method of choice for the surgical removal of frena; however, this needs to be substantiated by appropriate prospective controlled studies.

A comparative assessment of torque generated by lingual and conventional brackets

The aim of this study was to assess the effect of bracket type on the labiopalatal moments generated by lingual and conventional brackets. Incognito™ lingual brackets (3M Unitek), STb™ lingual brackets (Light Lingual System; ORMCO), In-Ovation L lingual brackets (DENTSPLY GAC), and conventional 0.018 inch slot brackets (Gemini; 3M Unitek) were bonded on identical maxillary acrylic resin models with levelled and aligned teeth. Each model was mounted on the orthodontic measurement and simulation system and 10 0.0175 × 0.0175 TMA wires were used for each bracket type. The wire was ligated with elastomerics into the Incognito, STb, and conventional brackets and each measurement was repeated once after religation. A 15 degrees buccal root torque (+15 degrees) and then a 15 degrees palatal root torque (-15 degrees) were gradually applied to the right central incisor bracket. After each activation, the bracket returned to its initial position and the moments in the sagittal plane were recorded during these rotations of the bracket. One-way analysis of variance with post hoc multiple comparisons (Tukey test at 0.05 error rate) was conducted to assess the effect on bracket type on the generated moments. The magnitude of maximum moment at +15 degrees ranged 8.8, 8.2, 7.1, and 5.8 Nmm for the Incognito, STb, conventional Gemini, and the In-Ovation L brackets, respectively; similar values were recorded at -15 degrees: 8.6, 8.1, 7.0, and 5.7 Nmm, respectively. The recorded differences of maximum moments were statistically significant, except between the Incognito and STb brackets. Additionally, the torque angles were evaluated at which the crown torque fell well below the minimum levels of 5.0 Nmm, as well as the moment/torque ratio at the last part of the activation/deactivation curve, between 10 and 15 degrees. The lowest torque expression was observed at the self-ligating lingual brackets, followed by the conventional brackets. The Incognito and STb lingual brackets generated the highest moments.

A comparative assessment of forces and moments generated by lingual and conventional brackets

The aim of this study was to assess the effect of bracket type on the labiopalatal forces and moments generated in the sagittal plane. Incognito™ lingual brackets (3M Unitek), STb™ lingual brackets (Light Lingual System; ORMCO), and conventional 0.018 inch slot brackets (Gemini; 3M Unitek) were bonded on three identical maxillary acrylic resin models, with a palatally displaced right lateral incisor. The transfer trays for the indirect bonding of the lingual brackets were constructed in certified laboratories. Each model was mounted on the orthodontic measurement and simulation system and ten 0.013 inch CuNiTi wires were used for each bracket type. The wire was ligated with elastomerics and each measurement was repeated once after re-ligation. The labiopalatal forces and the moments in the sagittal plane were recorded on the right lateral incisor. One-way analysis of variance and post hoc Scheffe pairwise comparisons were used to assess the effect on bracket type on the generated forces and moments. The magnitude of forces ranged from 1.62, 1.27, and 1.81 N for the STb, conventional, and Incognito brackets, respectively; the corresponding moments were 2.01, 1.45, and 2.19 N mm, respectively. Bracket type was a significant predictor of the generated forces (P < 0.001) and moments (P < 0.001). The produced forces were different among all three bracket types, whereas the generated moments differed between conventional and lingual brackets but not between lingual brackets.

Prevalence of tooth wear on buccal and lingual surfaces and possible risk factors in young European adults

To assess the prevalence of tooth wear on buccal/facial and lingual/palatal tooth surfaces and identify related risk factors in a sample of young European adults, aged 18-35 years. Calibrated and trained examiners measured tooth wear, using the basic erosive wear examination (BEWE) on in 3187 patients in seven European countries and assessed the impact of risk factors with a previously validated questionnaire. Each individual was characterized by the highest BEWE score recorded for any scoreable surface. Bivariate analyses examined the proportion of participants who scored 2 or 3 in relation to a range of demographic, dietary and oral care variables. The highest tooth wear BEWE score was 0 for 1368 patients (42.9%), 1 for 883 (27.7%), 2 for 831 (26.1%) and 3 for 105 (3.3%). There were large differences between different countries with the highest levels of tooth wear observed in the UK. Important risk factors for tooth wear included heartburn or acid reflux, repeated vomiting, residence in rural areas, electric tooth brushing and snoring. We found no evidence that waiting after breakfast before tooth brushing has any effect on the degree of tooth wear (p=0.088). Fresh fruit and juice intake was positively associated with tooth wear. In this adult sample 29% had signs of tooth wear making it a common presenting feature in European adults.