A large case-control study indicates a breed-specific predisposition to feline tooth resorption.

Tooth resorption (TR) is one of the most common dental diseases of cats. It is a painful condition leading to tooth loss. The etiology of TR remains unclear, but old age, breed, other oral and dental diseases, and environmental factors are suspected predisposing factors. In our study, we used part of the data from the extensive feline health online survey of 8115 Finnish cats. As TR is difficult to detect and as the feline health survey included diagnoses defined by both veterinarians and the owners, we limited our study to a subpopulation of cats diagnosed with oral or dental disease by a veterinarian and had dental examination or surgery under sedation (n=944). We utilized case-control study analysed by multivariable logistic regression to determine the risk factors and breed variation of feline TR. The 202 cats diagnosed with TR were defined as TR cases and the remaining 742 cats as controls. The frequency of veterinarian-diagnosed TR was 3.9% in the health survey data (316/8115) and 21% in the subpopulation (202/944). The risk of TR increased with age (14.7% in youngest and 25.3% in oldest age group). Our finding that TR was significantly associated with gingivitis or periodontitis in cats that had also calculus (OR: 2.49 and 3.70, respectively) suggests that inflammatory changes caused by calculus increase the risk of TR. We found that Cornish Rex, European, and Ragdoll are at higher risk for TR (OR: 2.44, 2.98 and 2.90, respectively). Exotic-Persians breed group had lower risk (OR: 0.28). TR was not observed in Turkish van or Devon Rex. The differences between breeds highlight a genetic contribution. In addition, female cats that had food available constantly had significantly less TR than female cats that had feeding times (OR: 0.44). The underlying reasons for this remain unexplained in our study.

Alignment efficiency and three-dimensional assessment of root resorption after alignment with conventional and copper-nickel-titanium archwires: A randomized controlled trial.

OBJECTIVE: To compare alignment efficiency and root resorption between nickel-titanium (NiTi) and copper-nickel-titanium (CuNiTi) archwires after complete alignment in mandibular anterior region. METHODS: In this two-arm parallel single-blind randomized controlled trial, forty-four patients with Class I malocclusion with mandibular anterior crowding were recruited form orthodontic clinic of All India Institute of Medical Sciences (Jodhpur, India). Patients were randomly allocated into NiTi and CuNiTi groups, with a 1:1 allocation. Alignment was performed using 0.014-in, 0.016-in, 0.018-in, 0.019x0.025-in archwire sequence in the respective groups, which terminated in 0.019 x 0.025-in stainless-steel working archwire. The primary outcome was alignment efficiency, measured on study models from baseline (T0) to the first, second, third, fourth and fifth-month (T5). Secondary outcome was root resorption, measured from CBCT scans taken at T0 and T5. Mixed-factorial ANOVA was used to compare Little's Irregularity Index (LII). For assessing the proportion of patients with complete alignment at the end of each month, Kaplan-Meier survival curve was built and time to treatment completion was compared between groups using log rank test. Paired t-test was used to assess external apical root resorption (EARR) within groups, whereas independent t-test was used to evaluate LII and EARR between the groups. RESULTS: Twenty-two patients were recruited in each group. One patient was lost to follow-up in the CuNiTi group. No statistically significant differences were observed in alignment efficiency between the groups (p>0.05). Intergroup comparison revealed that the changes in root measurement in three-dimensions were not statistically significant (p>0.05), except for mandibular right central incisor, which showed increased resorption at root apex in NiTi group (p<0.01). CONCLUSION: The two alignment archwires showed similar rate of alignment at all time points. Root resorption measurement did not differ between the NiTi and CuNiTi groups, except for the mandibular right central incisor, which showed more resorption in NiTi group.

Efectos antirresortivos y antimicrobianos de los antiinflamatorios no esteroideos en lesiones periapicales / Antiresorptive and antimicrobial effects of nonsteroidal anti-inflammatory drugs in periapical lesion

Los antiinflamatorios no esteroideos (AINE) son un grupo de fármacos que han sido comúnmente prescritos por sus propiedades antiinflamato- rias, antipiréticas y analgésicas, mismas que se deben a la inhibición de la formación de prostaglandinas. Este mecanismo ha sido ampliamente respaldado en la literatura; sin embargo, en la actualidad poco se co- noce sobre las propiedades adicionales de estos medicamentos como el efecto antirresortivo y antimicrobiano. La función antirresortiva se debe principalmente al bloqueo de la producción de prostaglandinas en específico la PGE2, que posee gran potencial osteoclastogénico, esencial para la aparición de lesiones periapicales; asimismo, la acción antimicrobiana de los AINE está relacionada con la afectación directa de la perpetuación de biopelícula, potencian la acción de los antibióticos, entre otros. Dichos efectos combinados podrían contribuir en la cura- ción de lesiones periapicales. El objetivo de este estudio es recopilar información actualizada sobre estas funciones agregadas de los AINE, con el fin de dar a conocer a los profesionales estos beneficios en la terapéutica de las lesiones periapicales (AU)

Non-steroidal anti-inflammatory (NSAIDs) are a group of drugs that have been commonly prescribed for their anti-inflammatory, antipyretic and analgesic properties, which are due to the inhibition of prostaglandin formation. This mechanism has been widely supported in the literature; however, currently little is known about the additional properties of these drugs such as the antiresorptive and antimicrobial effect. The antiresorptive function is mainly due to the blockage of prostaglandin production, specifically PGE2, which has great osteoclastogenic potential, and is essential for the appearance of periapical lesions; likewise, the antimicrobial action of NSAIDs is related to the fact that they directly affect the perpetuation of biofilms, enhance the action of antibiotics, among others. These combined effects could contribute to the healing of periapical lesions. The aim of this study is to gather updated information on these added functions of NSAIDs, in order to inform professionals about these benefits in the therapy of periapical lesion (AU)

Expression of Toll-like receptor and cytokine mRNAs in feline odontoclastic resorptive lesion (FORL) and feline oral health.

Feline odontoclastic resorptive lesion (FORL) is a common chronic inflammatory condition whose aetiopathogenesis remains unclear. FORL affects 20-75% of cats and causes excruciating pain and tooth loss. The purpose of this study was to evaluate chronic inflammation in FORL by assessing differences in Toll-like receptor (TLR) and cytokine transcripts in gingival tissues between diseased and healthy cats. Gingival tissue samples were collected from 14 healthy cats with no known clinical signs of oral disease and 41 cats with FORL. Levels of mRNA encoding TLR2, TLR3, TLR4, TLR7, TLR9 and the cytokines interleukin-1ß (IL-1ß), IL-4, IL-6, IL-10, IL-12, interferon-γ (IFN-γ) and tumour necrosis factor-α (TNF-α) was evaluated using quantitative real-time PCR. Statistical significance of the results was assessed using non-parametric tests. Levels of TLR and cytokine transcripts were upregulated in gingival tissue from cats with FORL as compared with healthy gingival tissue: TLR2, TLR3 and TLR9, p ≤ 0.001; TLR4 and TLR7, p ≤ 0.01; IFN-γ, IL-4, IL-6, IL-10, IL-12, IL-1ß and TNF-α, p ≤ 0.001). In conclusion, expression of TLR and both pro- and anti-inflammatory cytokines were significantly increased, confirming an ongoing chronic inflammatory response to the microbiome in FORL. It is likely that dysbiosis of the oral microbiota in cats with FORL activates the innate immune response, leading to active inflammation that results in tooth resorption.

Clinical, Diagnostic and Histological Findings Involving Cheek Teeth Hypercementosis in Nine Horses.

Hypercementosis is infrequently reported to affect the cheek teeth of horses and presents as mineral deposits either attached (peripheral) or solitary ovoid (nodular) structures in the tooth bearing region. There is overlap between radiological and histological appearance of hypercementosis, cementoma, and equine odontoclastic tooth resorption and hypercementosis (EOTRH). The clinical presentation, imaging features, surgical management, and histological findings of nine horses that presented for dental lesions and associated hypercementosis of cheek teeth are reported. Horses were 4-15 years old and presented for either nasal discharge or facial swelling. Peripheral and nodular mineral structures were identified using radiographs or computed tomography in six and three horses, respectively. Eight of nine cases involved maxillary cheek teeth. Of six cases with peripheral hypercementosis, three had enlargement of the apical cross-sectional area that was greater than the coronal cross-sectional area thus preventing extraction along the normal eruption pathway and necessitating sectioning (two cases) and repulsion. Nodular hypercementosis lesions were extracted in three of the four cases. Post-extraction complications occurred in five cases; four cases required additional procedures. All horses returned to their intended use, ie riding or pasture. Histology of extracted dental and proliferative mineral material revealed hypercementosis characterized by large sheets of eosinophilic matrix with lacunae (usually empty; presumed artifact) and frequent, irregular, basophilic cement lines. All cases had evidence of chronic inflammation, such as caries, chronic fractures and/or pulpitis. The findings of this case series share many features with previous published descriptions of cementoma and with histological findings of hypercementosis lesions of EOTRH. Further investigation into differentiation of these entities is warranted.

Denosumab and invasive cervical root resorption: a case report.

This case report describes an adverse side effect from long-term denosumab therapy in a patient with metastatic breast cancer. The patient presented with extensive invasive cervical root resorption affecting most of her dentition. There were no other identified risk factors. As the treatment of breast cancer evolves leading to improved survival, and the number of cancer survivors increases, it is expected that dental practitioners will see a growing number of patients who are on long-term denosumab. Comprehensive dental examinations including radiographs are warranted to identify unusual or unexpected findings such as invasive cervical root resorption. © 2022 Australian Dental Association.

Chemerin/ChemR23 regulates cementoblast function and tooth resorption in mice via inflammatory factors.

BACKGROUND: Periodontitis and orthodontic treatment can lead to inflammatory root resorption (IRR) through an unclear mechanism. Chemerin, a novel chemoattractant protein, is closely associated with inflammation, affects osteoblast and osteoclast differentiation, and may play a role in IRR. We aimed to explore possible roles of the chemerin/ChemR23 interaction in cementoblast function and IRR and reveal a new IRR therapeutic target. METHODS: Cementoblast function-related gene and protein expression in the immortalized murine cementoblast cell line OCCM-30 after treatment with chemerin and siChemR23 was examined by qRT-PCR and Western blotting. The roles of the MAPK and PI3K-Akt signaling pathways were studied using specific inhibitors. Cementoblast cytokine production under different treatment conditions was measured by enzyme-linked immunosorbent assay and qRT-PCR. Additionally, we modeled IRR in wild-type and chemerin-overexpressing mice and injected transgenic mice with anti-ChemR23 antibody to block ChemR23. We then calculated the root resorption volume and examined periodontal tissue cathepsin K, Runx2, tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6) expression. RESULT: Chemerin suppressed cementoblast differentiation and mineralization and exerted a proinflammatory effect on cementoblasts. These effects were partially reversed by siChemR23 and reversed to different extents by p38, Erk1/2 and PI3K-Akt pathway inhibition, suggesting p38, Erk1/2 and PI3K-Akt pathways as signaling pathways downstream of chemerin/ChemR23. In vivo, chemerin overexpression worsened IRR. Moreover, chemerin expression was positively correlated with TNF-α, IL-6, and cathepsin K expression and negatively correlated with Runx2 expression. ChemR23 downregulation reversed these effects. CONCLUSION: Chemerin/ChemR23 induced TNF-α and IL-6 expression dependent on Erk1/2, p38 MAPK, and PI3K-Akt signaling pathway activation, thereby regulating cementoblast function and affecting IRR.

Ten reasons to not ignore the third molar

ABSTRACT Introduction: The third molars are forgotten because they are the last in the dental arch, they do not directly influence the smile and they appear only in adolescence, when they do. Objectives: 1) to provide the clinician with a "checklist" to assess and diagnose changes to be screened in the third molar region in new patients; 2) to reveal the importance of not discharging the patient submitted to any dental treatment without first analyzing the third molars region clinically and on imaging examinations, since many diseases are associated to them. Result: A list of 10 situations that cover all diagnostic possibilities involving the third molars is presented. Conclusion: Adopting this protocol is a matter of habit, since the need is fundamental. The next professional assisting your patient may ask: "Did he not request examinations for the third molars?".

RESUMO Introdução: Os terceiros molares são esquecidos por serem os últimos dentes na arcada dentária, por não influenciarem diretamente no sorriso e por aparecerem apenas na adolescência - quando aparecem. Objetivos: 1) Fornecer ao clínico um checklist de conferência e diagnóstico de alterações a serem checadas na região dos terceiros molares em novos pacientes; e 2) Destacar a importância de não dar alta ao paciente submetido a qualquer tratamento odontológico sem antes analisar, clínica e imagiologicamente, a região dos terceiros molares, pois muitas doenças estão a eles associadas. Resultado: Criou-se uma lista de 10 situações que englobam todas as possibilidades diagnósticas envolvendo os terceiros molares. Conclusão: Adotar esse protocolo é uma questão de hábito, pois a necessidade é imperiosa. O próximo profissional a atender o seu paciente vai perguntar: "Ele não solicitou exames para os terceiros molares?".

Negligible tooth resorptions after anterior open bite treatment using skeletal anchorage with miniplates

ABSTRACT Introduction: When miniplates are used as anchoring for orthodontic mechanics for anterior open bite correction by retraction of anterior teeth and posterior teeth intrusion and retraction, orthodontically induced inflammatory external apical root resorption is clinically negligible. Methods: A homogeneous sample of 32 patients was used, and the roots of the teeth were compared on CT scans performed before and after orthodontic treatment. Results: The observed root resorption was minimal, and this can be explained by the uniform distribution of forces in several teeth, simultaneously, in the set of the dental arch and in the bone that supports the teeth. Conclusion: The most important thing to prevent root resorption in orthodontic practice, besides being concerned with the intensity of the applied forces, is to be careful with its distribution along the roots of each tooth, in the dental arch and in the bone that supports the teeth.

RESUMO Introdução: Quando são utilizadas miniplacas como ancoragem para a mecânica ortodôntica de correção da mordida aberta anterior por meio da retração dos dentes anteriores e intrusão e retração dos dentes posteriores, as reabsorções radiculares apicais externas inflamatórias induzidas ortodonticamente são clinicamente irrelevantes. Métodos: Usou-se uma amostra homogênea de 32 pacientes, e comparou-se as raízes dos dentes em tomografias realizadas antes e depois do tratamento ortodôntico. Resultados: As reabsorções radiculares observadas foram mínimas, e isso pode ser explicado pela distribuição uniforme das forças em vários dentes, simultaneamente, no conjunto da arcada dentária e no osso que suporta os dentes. Conclusão: O mais importante para se prevenir as reabsorções radiculares na prática ortodôntica, além de se preocupar com a intensidade das forças aplicadas, é tomar cuidado com a sua distribuição ao longo das raízes de cada dente, na arcada dentária e no osso que suporta os dentes.

Reabsorción cervical externa por filtración de un material aclarante / External cervical resorption by filtration of a ciarifying materia

La reabsorción cervical externa es un proceso patológico con una etiología no comprendida en su totalidad. Los posibles factores predisponentes son el tratamiento de ortodoncia, los traumatismos, el blanqueamiento interno, el bruxismo, entre otros. El blanqueamiento interno es una forma efectiva y mínimamente invasiva de blanquear dientes no vitales, con un riesgo asociado con reabsorción, que al no ser tratado podría provocar incluso la pérdida dentaria. Este reporte de caso describe el manejo de dos incisivos superiores con reabsorciones cervicales externas, que tienen como antecedente tratamiento de conducto y blanqueamiento interno. (AU)

External cervical resorption is a pathological process, with an etiology that is not completely understood. Possible predisposing factors are orthodontic treatment, trauma, internal whitening, bruxism, etc. Internal whitening is an effective and minimally invasive method for the whitening non-vital teeth. This method is associated with a risk of resorption, which if not treated, can lead to tooth loss. This case report describes the management of two upper incisors with external cervical resorption, with a previous history of root canal treatment and internal whitening. (AU)

Uso do sistema xp-endo para limpeza do sistema de canais radiculares em dente com reabsorção radicular interna e necrose pulpar: relato de caso / Use of XP-Endo system to clean the root canal system of a tooth with internal resorption and pulp necrosis: case report

Objetivo: este estudo reporta um caso clínico de reabsorção radicular interna em um dente com necrose pulpar que foi submetido ao tratamento endodôntico no qual, na fase de preparo químico-mecânico, foi utilizada uma técnica suplementar de irrigação com o instrumento XP-Endo Finisher. Métodos: após radiografia para diagnóstico e realização dos testes semiotécnicos, fez-se a instrumentação com sistema Protaper Universal, ativação da substância irrigadora utilizada (digluconato de clorexidina a 2%), com o sistema XP-Endo Finisher, remoção da smear layer, com EDTA a 17% ativada com o mesmo sistema, inserção de medicação intracanal Calen, com paramonoclorofenol, e selamento provisório da coroa dentária, com coltosol. Na segunda sessão, realizou-se a obturação utilizando a técnica de Schilder associada à técnica híbrida de Tagger. Conclusão: o sistema XP-Endo Finisher se mostrou eficaz como técnica suplementar de irrigação, capaz de favorecer a limpeza do sistema de canais radiculares (AU)..

Objective: This study presented a case of internal root resorption in a tooth with pulp necrosis that was submitted to endodontic treatment. In this treatment, an additional irrigation technique with a XP-Endo Finisher instrument was used during the chemical-mechanical preparation. Methods: After radiographic diagnostics and semi-technique tests, instrumentation was performed with Protaper universal system, activation of irrigation solutions, 2% chlorhexidine digluconate with the XP-Endo Finisher file, removal of the smear layer with EDTA 17% activated with the same system, intracanal medication Calen with paramonochlorophenol, temporary sealing of the tooth crown with Coltosol. In the second session, an obturation procedure was performed using the Schilder technique associated with the Tagger hybrid technique. Conclusions: The XP-Endo Finisher system was effective as supplementary irrigation technique and it facilitated the cleaning of the root canal system (AU).

Relação entre reabsorções dentárias e enxerto alveolar em dentes adjacentes à área da fissura / Relationship between root resorption and alveolar graft in teeth adjacent to the cleft lip and palate area

Objetivo: avaliar, radiograficamente, a prevalência, extensão e severidade da reabsorção dentária em dentes adjacentes à área de fissura após enxerto ósseo alveolar. Métodos: radiografias de 200 indivíduos com fissura unilateral e bilateral, alveolar e palatina, foram analisadas para se investigar a presença de reabsorção dentária relacionada com o enxerto ósseo. No total, 1.315 radiografias foram analisadas (periapical, oclusal e radiografias panorâmicas), obtidas a partir de 200 indivíduos com fissura labiopalatina unilateral e bilateral completa ubmetidos a cirurgia de enxerto, disponíveis a partir dos arquivos da Seção de Radiologia do HRAC-USP. Resultados: entre os 200 indivíduos, 33 tinham reabsorções dentárias externas. Dessas, 15 estavam presentes nas radiografias pré-operatórias e 18 só depois do enxerto ósseo. No geral, 30 reabsorções localizaram- se no terço apical da raiz e 3 no terço cervical; o incisivo central esquerdo foi o mais afetado. Não foram observadas reabsorções dentárias no terço médio da raiz e nenhuma reabsorção afetou mais de um terço. Não existiu diferença estatisticamente significativa entre a idade do paciente durante a cirurgia de enxerto ósseo e a presença de reabsorção dentária externa. Conclusões: a prevalência da reabsorção dentária em dentes adjacentes à área da fissura em indivíduos submetidos a enxerto ósseo foi baixa (16,5%). O terço apical da raiz foi o local mais frequente de reabsorção radicular externa, e não houve reabsorções afetando mais de um terço da raiz. (AU)

Implante transalveolar inmediato ante reabsorción dentinaria interna / Immediate transalveolar implant as an effective solution for internal tooth resorption

Introducción: Dentro del marco de su actividad profesional el estomatólogo se enfrenta a diversas afecciones como la reabsorción radicular interna, cuyos casos avanzados pueden complicar el pronóstico del tratamiento endodóntico, debido al debilitamiento de la estructura dental remanente y las posibles afectaciones periodontales. Debido a que la boca está localizada en uno de los puntos focales de la cara, cualquier alteración en la apariencia estética puede provocar implicaciones psicológicas que pueden ir desde una simple forma de esconder el defecto hasta la más grande introversión. Objetivo: Presentar un caso clínico de reabsorción dentaria interna resuelto con implante postextractivo de carga inmediata. Presentación de caso: Paciente femenina de 31 años con reabsorción dental interna de incisivo central superior. Se llevó a cabo un adecuado diagnóstico y plan de tratamiento del caso, colocándose un implante transalveolar cargado de forma inmediata y la rehabilitación definitiva metalcerámica una vez concluida la fase de osteointegración. Conclusiones: Se consiguió una rehabilitación estética, funcional y biomecánicamente estable a largo plazo, que coincide con las expectativas del paciente, lo cual demuestra que cuando se cumplan los requisitos adecuados y la planificación sea exhaustiva, la implantología ofrece el tratamiento más avanzado en casos en que es inminente la extracción dental(AU)

Introduction: In their daily professional practice dentists are faced with a variety of conditions. An example is internal root resorption, the advanced stage of which may complicate the prognosis of dental treatment, due to the weakening of the remnant dental structure and the potential appearance of periodontal disease. Because the mouth is located in one of the focal points of the face, any alteration of its esthetic appearance may result in psychological disorders ranging from a simple attempt to mask the defect to the greatest introversion. Objective: Present a clinical case of internal tooth resorption solved with a post-extraction immediate load implant. Case presentation: A female 31-year-old patient presents with internal tooth resorption of the maxillary central incisor. Appropriate diagnosis was performed and a treatment plan devised, consisting in immediate placement of a transalveolar implant and definitive metal-ceramic rehabilitation upon completion of the osseointegration stage. Conclusions: Stable long-term esthetic, functional and biomechanical rehabilitation was achieved which met the patient's expectations. This result shows that when the established requirements are complied with and exhaustive planning is performed, implantology offers the most advanced treatment when dental extraction is imminent(AU)

Marginal bone loss and resorption of second molars related to maxillary third molars in panoramic images compared with CBCT.

OBJECTIVES: Compare findings among observers in panoramic images (PAN) and cone beam CT (CBCT); and assess findings in PAN as indicators for marginal bone loss and resorption observed in CBCT. METHODS: 120 impacted maxillary third molars with PAN and CBCT were included. Four observers assessed morphological features: (1) tooth angulation; (2) number of roots; (3) bony impaction (yes/no) and pathology; (4) marginal bone level at the second molar (normal/>3 mm = bone loss); (5) resorption in the second molar (no/superficial/< half way through the dentin/≥ half way through the dentin/involving the pulp); (6) size of follicular space (normal/> 4 mm(cyst)). Percentage accordance and κ statistics described observer variation in PAN and CBCT. Logistic regression analyses tested findings in PAN as indicators for marginal bone loss or resorption observed in CBCT. RESULTS: κ values were fair and interobserver accordance was marginally higher in CBCT than PAN. Agreement between PAN and CBCT was 81-88% for marginal bone loss and 68-81% for resorption. Severe resorption was more often observed in CBCT. Mesio-angulated third molars and marginal bone loss interpreted in PAN significantly indicated marginal bone loss observed in CBCT (odds ration 17-34; p < 0.012; 8.8-52.8; p < 0.02). In contrast, findings in PAN were not significant indicators for resorption observed in CBCT (p > 0.05). CONCLUSION: In general, there was a fair agreement for marginal bone loss between PAN and CBCT, and PAN could significantly predict bone loss observed in CBCT. However, presence of resorption observed in CBCT could not be determined from PAN, and more severe resorption was observed in CBCT. CBCT is indicated if resorption in the second molar needs to be assessed.

Three-dimensional assessment of external apical root resorption after maxillary posterior teeth intrusion with miniscrews in anterior open bite patients

ABSTRACT Objective: The objective of this study was to assess the external apical root resorption (EARR) of the maxillary posterior teeth after intrusion with miniscrews. Methods: Fifteen patients (13 females and 2 males) with age ranging from 14.5 to 22 years (mean 18.1 ±2.03 years) were selected to participate in this study. All patients presented with anterior open bite of 3 mm or more. An intrusion force of 300 g was applied on each side to intrude the maxillary posterior teeth. Cone beam computed tomography (CBCT) scans were taken pretreatment and post-intrusion and were analyzed to evaluate the EARR. Results: The maxillary posterior teeth were intruded in average 2.79 ± 0.46 mm (p< 0.001) in 5.1 ± 1.3 months, and all examined roots showed statistically significant EARR (p< 0.05) with an average of 0.55 mm, except the distobuccal root of the left first permanent molars and both the palatal and buccal roots of left first premolars, which showed no statistically significant changes. Conclusions: The evaluated teeth presented statistically significant EARR, but clinically, due to the small magnitude, it was not considered significant. Moreover, the CBCT provided a good visualization of all roots in all three planes, and it was effective in detecting minimal degrees of EARR.

RESUMO Objetivo: o objetivo desse estudo foi verificar a existência de reabsorção radicular apical externa (RRAE) em dentes posterossuperiores após intrusão ancorada em mini-implantes. Métodos: quinze pacientes (13 mulheres e 2 homens) com a idade variando entre 14,5 e 22 anos (média de 18,1 ± 2,03 anos) foram selecionados para participar desse estudo. Todos os pacientes possuíam mordida aberta anterior de 3mm ou mais. Uma força de 300 gramas foi aplicada em cada lado para intruir os dentes posterossuperiores. Tomografias computadorizadas de feixe cônico (TCFC), adquiridas antes do tratamento e após a intrusão, foram comparadas para se avaliar a RRAE. Resultados: os dentes posterossuperiores foram intruídos em média 2,70 ± 0,46 mm (p< 0,001) em 5,1 ± 1,3 meses, e todas as raízes examinadas mostraram RRAE estatisticamente significativa (p< 0,05), com média de 0,55 mm, exceto pela raiz distovestibular dos primeiros molares permanentes esquerdos, e pelas raízes palatina e vestibular dos primeiros pré-molares esquerdos, que não apresentaram mudanças estatisticamente significativas. Conclusões: os dentes avaliados apresentaram RRAE estatisticamente significativa, a qual, porém, não foi considerada clinicamente significativa, devido à sua reduzida magnitude. Além disso, a TCFC possibilitou uma boa visualização de todas as raízes nos três planos espaciais, e foi eficaz para detecção de níveis mínimos de RRAE.

Dental Pathology of the Iberian Lynx ( Lynx pardinus), Part II: Periodontal Disease, Tooth Resorption, and Oral Neoplasia.

The Iberian lynx is an endangered felid that has been subject to an intensive, ongoing conservation program to save it from extinction. Identification of dental pathologies could play an important role in the survival of this endangered species. The prevalence of periodontal bone loss, tooth resorption, and oral neoplasia was evaluated in this species. Skulls of 88 adult specimens of the Iberian lynx ( Lynx pardinus) from the Doñana Biological Station (EBD-CSIC), Seville, Spain, were examined macroscopically and full-mouth dental radiographs of all specimens were performed. Different stages of periodontal disease were identified in 81.3% of teeth. Approximately two-thirds (64.8%) of the specimens examined had at least 1 tooth affected by stage 3 or 4 periodontal disease. Maxillary and mandibular incisor teeth accounted for a majority (59.4%) of teeth affected by stage 3 or 4 periodontal disease. Tooth resorption affected 12 teeth (0.63% of evaluated teeth) in 6 skull specimens (6.8% of skulls evaluated). Five of the teeth with resorptive lesions were detected on 1 skull specimen. Six teeth (50%) of those affected by tooth resorption were incisor teeth. Only 1 (1.1%) adult specimen showed signs of oral neoplasia. Our study concluded that there is a high prevalence of periodontal disease that could lead to impaired hunting ability, as well as may represent a threat to overall health and subsequent survival of this endangered species. The extremely low prevalence of tooth resorption in L pardinus could open new pathways in the discovery on the pathogenesis of tooth resorption in felids.

[Dental complications during orthodontic preparation and orthognathic surgery]. / Complications dentaires de la préparation orthodontique et de la chirurgie orthognathique.

INTRODUCTION: Orthodontic-surgical treatment can present risks to the dental organ and the periodontium. Despite the low incidence of such cases, these complications can compromise a treatment plan. Practitioners should be aware of these potential complications, take them into account during treatment in order to reduce their negative impact and, if necessary, manage them by orthodontic-surgical collaboration. MATERIALS AND METHODS: In this article, the authors present several potential complications that can occur during treatment. CONCLUSION: The information given to the patient about the risks inherent in the implementation of an orthodontic-surgical protocol must necessarily include the risks of lesion to the dental organ and the periodontium.

Aspectos biológicos e tratamentos da reabsorção radicular externa por substituição: revisão da literatura / Biological aspects and treatment of external replacement resorption: literature review

A Reabsorção Radicular Externa por Substituição (RRES) consiste na substituição da estrutura dentária por tecido ósseo. O atual consenso é de que não há terapia pertinente para tal processo. Uma revisão de literatura com enfoque em protocolos terapêuticos utilizados em dentes traumatizados e seus efeitos sobre a RRES será apresentada. Para tal, artigos científicos na língua inglesa foram reunidos por meio das bases de dados Pubmed Central, Scopus, Embase Medline, Ovid e Cochrane, utilizando as seguintes palavras chaves: Tooth Resorption, Root Resorption, Tooth Injuries, Root Canal Therapy, Ankylosis. Estudos demonstraram que anquilose e RRES se desenvolveram nas superfícies dentárias independentemente do medicamento utilizado no interior do canal. Dentes tratados com hidróxido de cálcio e guta-percha apresentaram maior predominância de deposição óssea. Corticoides demonstraram resultados promissores, observando-se reparo favorável e menor taxa de RRES. Não foram encontrados artigos relatando tentativas interceptativas frente ao processo de reabsorção por substituição. Apesar de sua ocorrência ter se demonstrado frequente, tentativas de controle do processo instalado são relevantes, considerando- se que a ausência de tratamento resulta na pior consequência possível: a perda dentária.

Resorptive potential of impacted mandibular third molars: 3D simulation by finite element analysis.

OBJECTIVES: Previous studies have suggested a relationship between resorption in second molars and pressure from the eruptive force of the third molar. The aim of this study was to simulate functional forces in a mandible model by means of finite element analysis and then assess the biomechanical response produced by impacted third molars on the roots of the second molar. MATERIALS AND METHODS: A cone beam computed tomography scan presenting an impacted mandibular third molar was segmented (Mimics V17 software). The modeling process was performed using the reverse engineering technique provided by the Rhinoceros 3D 5.0 software. The third molar position was changed in order to produce different inclinations of the impacted tooth. Bite forces were simulated to evaluate total deformation, the equivalent von Mises stress, minimum principal stress on hard tissue, and equivalent elastic strain on soft tissue. RESULTS: Areas of high energy dissipation and compression stress were detected in the second molar root, independently of the inclination of the impacted third molar. In general, the horizontal position was the situation in which major stress and the amount of deformation occurred in the second and third molar regions. CONCLUSION: Impacted third molars in close proximity with the adjacent tooth can generate areas of compression concentrated at the site of contact, which suggests an involvement of mechanical factors in the triggering of resorption lesions. CLINICAL RELEVANCE: The results of these computational experiments contribute to the understanding of the triggering and progression of resorptive lesions in the adjacent second molar.