The clinical meaning of external cervical resorption in maxillary canine: transoperative dental trauma

External Cervical Resorption in maxillary canines with pulp vitality is frequently associated with dental trauma resulting from surgical procedures carried out to prepare the teeth for further orthodontic traction. Preparation procedures might surgically manipulate the cementoenamel junction or cause luxation of teeth due to applying excessive force or movement tests beyond the tolerance limits of periodontal ligament and cervical tissue structures. Dentin exposure at the cementoenamel junction triggers External Cervical Resorption as a result of inflammation followed by antigen recognition of dentin proteins. External Cervical Resorption is painless, does not induce pulpitis and develops slowly. The lesion is generally associated with and covered by gingival soft tissues which disguise normal clinical aspects, thereby leading to late diagnosis when the process is near pulp threshold. Endodontic treatment is recommended only if surgical procedures are rendered necessary in the pulp space; otherwise, External Cervical Resorption should be treated by conservative means: protecting the dental pulp and restoring function and esthetics of teeth whose pulp will remain in normal conditions. Unfortunately, there is a lack of well-grounded research evincing how often External Cervical Resorption associated with canines subjected to orthodontic traction occurs.

A reabsorção cervical externa em caninos superiores com vitalidade pulpar em sua quase totalidade está associada a traumatismo dentário decorrente de procedimentos cirúrgicos associado à preparação desse dente para ser tracionado ortodonticamente. Nessa preparação pode se manipular cirurgicamente a junção amelocementária ou luxar o dente com forças excessivas ou com testes de movimentação além dos limites de tolerância estrutural do ligamento periodontal e tecidos cervicais. A exposição dentinária na junção amelocementária é o estopim para se iniciar uma reabsorção cervical externa a partir de uma inflamação induzida na região seguida de reconhecimento antigênico das proteínas dentinárias. A reabsorção cervical externa é indolor, não induz pulpites e tem uma evolução lenta. Em geral, a lesão está associada e recoberta por tecidos moles gengivais que mantêm, por longos períodos, os aspectos clínicos normais, induzindo diagnósticos tardios, quando o processo se aproxima dos limites pulpares. O tratamento endodôntico está indicado apenas em função de procedimentos operatórios que se fazem necessários no espaço pulpar; caso contrário, a reabsorção cervical externa deve ser tratada de forma conservadora, protegendo a polpa dentária e restaurando a função e estética do dente que permanecerá com sua polpa normal. Infelizmente, não sabemos, com base em pesquisas de casuísticas bem estabelecidas, qual é a frequência da reabsorção cervical externa associada a caninos ortodonticamente tracionados.

Microscopic evaluation of induced tooth movement after subluxation trauma: an experimental study in rats

OBJECTIVE: The objective of this study was to assess the histological alterations that occurred in the periodontal area of rat molars submitted to induced tooth movement (ITM) right after an intentional trauma (subluxation). METHODS: Forty adult male Wistar rats (Rattus norvegicus albinus) were selected. The animals were divided into eight groups (n = 5), according to the combination of variables: Group 1 - control (neither trauma nor ITM); Group 2 - ITM; Groups 3, 4, 5 and 6 - dentoalveolar trauma groups corresponding, respectively, to 1, 3, 8 and 10 days after trauma; Groups 7 and 8 - the animals' molars were subjected to a 900 cN impact and, one and three days after the trauma event, tooth movement was induced. The rats' maxillary first molars were mesially moved during seven days with a closed coil (50 cN). After the experimental period of each group, the animals were sacrificed by anesthetic overdose and the right maxillas were removed and processed for histological analysis under light microscopy. RESULTS: In the animals of group 3, 4, 5 and 6, the histological alterations were not very significant. Consequently, the effect of induced tooth movement right after a subluxation event (groups 7 and 8) was very similar to those described for Group 2. CONCLUSION: There was no difference in the quality of periodontal repair when ITM was applied to teeth that had suffered a subluxation trauma. .

OBJETIVO: avaliar as alterações histológicas ocorridas na área periodontal de molares de ratos submetidos à movimentação dentária induzida (MDI), logo após um trauma intencional (subluxação). MÉTODOS: quarenta ratos Wistar machos adultos (Rattus norvegicus albinus) foram selecionados. Os animais foram divididos em oito grupos (n = 5), de acordo com a combinação das variáveis: Grupo 1 - controle (sem trauma e sem MDI); Grupo 2 - MDI; Grupos 3, 4, 5 e 6 - grupos de trauma dentoalveolar correspondendo, respectivamente, para 1, 3, 8 e 10 dias após o trauma; Grupos 7 e 8 - os molares murinos foram submetidos a um impacto de 900cN e, de um e três dias após o evento trauma, o movimento do dente foi induzido. Os primeiros molares superiores dos animais foram movidos mesialmente durante sete dias, com uma mola fechada (50cN). Após período experimental de cada grupo, os animais foram sacrificados por overdose anestésica e as maxilas direitas foram removidas e processadas para análise histológica qualitativa. RESULTADOS: nos animais dos grupos 3, 4, 5 e 6, as alterações histológicas não foram muito significativas. Consequentemente, o efeito do movimento dentário induzido logo após um evento de subluxação (grupos 7 e 8) foi muito semelhante ao descrito para o grupo 2. CONCLUSÃO: não houve diferença na qualidade do reparo periodontal quando a MDI foi aplicada aos dentes que sofreram um trauma de subluxação. .

Dentists' level of knowledge of the treatment plans for periodontal ligament injuries after dentoalveolar trauma

This study investigated the level of knowledge held by dentists about the possible treatment plan procedures for periodontal ligament injuries after dentoalveolar trauma. A 5-item self-applied questionnaire was prepared with questions referring to the professional profile of the interviewees and to the treatment plan they would propose for periodontal ligament injuries secondary to dentoalveolar trauma. The questionnaires were filled out by 693 dentists attending the 23rd Annual Meeting of the Brazilian Society for Dental Research, and the data obtained were subjected to descriptive analysis. Either the chi-square test or Fisher's exact test was applied to assess associations among variables, at a 5 percent level of significance. The results revealed that dentists experienced difficulty in establishing a treatment plan for subluxation, and for extrusive, lateral and intrusive luxations. In general, holding a dental specialty degree had no influence on the knowledge about treatment plan procedures for the most severe injuries. It could be concluded that the dentists participating in this study, whether specialists or not, did not have sufficient knowledge to treat most of the periodontal ligament injuries resulting from dentoalveolar trauma adequately.

Dental trauma involving root fracture and periodontal ligament injury: a 10-year retrospective study

The purpose of this retrospective study was to analyze the cases of traumatic dental injuries involving root fracture and/or periodontal ligament injury (except avulsion) treated at the Discipline of Integrated Clinic, School of Dentistry of Araçatuba, São Paulo State University (UNESP), Brazil, from January 1992 to December 2002. Clinical and radiographic records from 161 patients with 287 traumatized teeth that had sustained root fracture and/or injuries to the periodontal ligament were examined. The results of this survey revealed that subluxation (25.09 percent) was the most common type of periodontal ligament injury, followed by extrusive luxation (19.86 percent). There was a predominance of young male patients and most of them did not present systemic alterations. Among the etiologic factors, the most frequent causes were falls and bicycle accidents. Injuries on extraoral soft tissues were mostly laceration and abrasion, while gingival and lip mucosa lacerations prevailed on intraoral soft tissues injuries. Radiographically, the most common finding was an increase of the periodontal ligament space. The most commonly performed treatment was root canal therapy. Within the limits of this study, it can be concluded that traumatic dental injuries occur more frequently in young male individuals, due to falls and bicycle accidents. Subluxation was the most common type of periodontal ligament injury. Root canal therapy was the type of treatment most commonly planned and performed.

Modificaciones periodontales en molares de rata provocadas por fuerzas ortodóncicas traumáticas / Periodontal changes in rat molars due to traumatic orthodontic forces

Para determinar los cambios tisulares que provocan las fuerzas ortodóncicas de alta magnitud se utilizaron 25 ratas Sprague Dowley, a las cuales se les instaló durante 10 días un resorte comprimido que ejercía 150 grs/pond sobre el primer molar superior, de componente mesial y extrusivo. El molar contralateral fue utilizado como control. Obtenidas las muestras fueron procesadas y sometidas a 3 tinciones: hematoxilina-eosina, tricrómico de Masson y picrosirius. Los resultados observados muestran una respuesta de tipo patológico en los tejidos del periodonto de inserción del molar experimental, en los cuales se apreció una gran reabsorción del hueso alveolar, presencia de osteoclastos, células gigantes multinucleadas y reabsorción radicular, sin distinguirse aposición ósea en las áreas de tensión. La respuesta a la fuerza aplicada se extendió a los tejidos de inserción de la pieza vecina, observándose la presencia de reabsorción ósea endóstica y parietal y vasodilatación en la zona cercana al molar experimental

Biología del movimiento dentario. 1§ Parte: respuesta tisular a los estímulos artificiales (una revisión de la literatura para el ortodoncista clínico) / Biology of the tooth movement. 1st. part: tissue response to the artificial stimuli (a review of the literature for the clinical orthodontist)

A modo de resumen y deduciendo una suerte de conclusión, podemos decir que, hoy por hoy, los investigadores ponen en duda el esquema clásico que describía procesos de reabsorción ante la presión y neoformación ante la tensión ortodóncicamente inducida y en zonas claramente diferenciadas del periodonto de inserción. La seguidilla de reabsorción y neoformación parecía tener un "timing" muy particular en esta zona del organismo. El "stress" ortodóncico que sufrirían los tejidos vecinos al diente pareciera tener fuerte incidencia sobre estos tiempos químicos. Si la duda histológica era, y sigue siendo, determinar la célula guía de todo el mecanismo que permite el movimiento dentario o entender la diferenciación que hacen los osteoclastos a la hora de reabsorber, la duda en el campo clínico-ortodóncico podría ser tal vez: ¿se podrá aplicar fuerzas con una frecuencia distinta a la habitual? ¿Es más saludable o biológico si se quiere decir, esperar los veintiocho o treinta días usuales? ¿Habrá que esperar menos, o tal vez más tiempo antes de una nueva activación? En el campo de la investigación pura, muchos de los autores presentados coincidieron en que, las fuerzas más fuertes no producían las reacciones que ellos mismos esperaban (y temían, en cierto modo). Todos comprobaron la presencia de una zona de hialinización ante cualquier tipo de fuerza ortodóncica, pero algunos vieron restos celulares donde esperaban ausencia total de células y hasta necrosis tisular. En el campo de la clínica ortodóncica, muchos de ellos coincidieron en que los movimientos en sentido vestíbulolingual de las piezas dentarias serían potencialmente más peligrosos que otros a la hora de evaluar posibles reabsorciones radiculares. Los movimientos de "ida y vuelta" (round-tripping) serían en estos casos más peligrosos que en otros desplazamientos dentarios. En un marco clínico, también coinciden en destacar a las fibras periodontales transeptales, que unen los dientes entre sí, como las más importantes a la hora de buscar una explicación a las recidivas. La reorganización de las mismas en la nueva posición de la pieza dentaria exigiría más tiempo que otras (el cierre espontáneo del diastema interincisivo luego de una disyunción rápida de los maxilares o el desplazamiento de un segundo premolar "siguiendo" los movimientos del primer molar-anclaje corroborarían este hipótesis). Transportando al campo clínico otras referencias de la investigación, podemos concluir que sería contraproducente inhibir la reacción química propia de toda inflamación a la hora de someter las piezas dentarias a la movilización terapéutica, ya que algunos de los componentes propios de toda respuesta inflamatoria, serían imprescindibles para la reabsorción ósea. Muchas serían las aplicaciones clínicas para usufructuar los modelos propuestos por la investigación en los últimos años. Creo, en síntesis, que todos deberíamos hacernos eco de un denominador común a todos los autores presentados: "es imperioso desarrollar una mayor investigación en el área para cotejar los datos obtenidos, la especialidad lo está demandando"

Aspectos clínicos da anquilose / Clinical aspects of dental ankylosis

O propósito do estudo foi o de avaliar a presença e o desenvolvimento da anquilose em dentes submetidos à agressão traumática. Notou-se que a anquilose esta presente sempre que existe uma lesão na região do ligamento periodontal e que este processo é passível de reversão quando a região agredida apresenta uma pequena extensão. Ainda com relação ao aparecimento da anquilose pode-se observar que, quando células exógenas ao ligamento participam de sua cicatrização, ocorrerá a anquilose dento-alveolar

Histometric study of periodontal trauma in dental germs to be transplanted - scanning electron microscopy

Dental transplants are of great interest in modern dentistry. Research has been directed toward the study of different techniques and observations of the results. Scientific basis is also to be observed and the aim of this paper is to associate technical with scientific data. Dental germs in different stages of development were carefully removed from their alveolar cavities together with the dental sac. Trauma was observed in some areas resulting from the movements of extraction or of the removal of the dental sac by dissection. It should be noticed that by the trauma produced by removal of the dental sac is very uncommon, since the operation is performed at a mesoscopic level. The material showed that the periodontal collagen net is complex in form and the meshes are wider in the surface. Smaller meshes could be seen closer to the cementum surface. Measures could be taken in order to have a basis of the distribution of collagen material around the dental root in different levels. The results showed that extraction should be performed in a most conservative manner and the movements for extraction should be applied to the crown of the dental germ. The maintenance of the periodontal integrity is very important in order to preserve the vascular barrier created by the dental cementum