Cambios morfofuncionales en el periodoncio asociados al movimiento dentario por tratamiento ortodóncico / Morfofunctional changes in the periodontium associated to the teeth movement due to orthodontic treatment

Los cambios morfofuncionales que se producen en las estructuras de soporte dentario durante el movimiento ortodóncico involucran procesos bioquímicos, histológicos y fisiológicos. Desde hace más de un siglo, existen disímiles teorías que tratan de explicarlos; sin embargo, todavía se siguen realizando estudios a fin de comprenderlos más a fondo. En la presente comunicación se ofrece una actualización secuencial y resumida de dichos episodios, con el propósito de incrementar el nivel de conocimientos sobre el tema y mejorar la calidad en la atención ortodóncica.

Morfofunctional changes which take place in the supporting structures during the orthodontic movement involve biochemical, histological and physiologic processes. For more than one century, dissimilar theories exist that try to explain to them; however, studies are still being carried out in order to understand them thoroughly. In the present communication a sequential and summarized updating of these episodes, with the purpose of increasing the knowledge on the topic and improving the quality in the orthodontic care.

Changes in masticatory performance and quality of life in individuals with chronic periodontitis.

BACKGROUND: This study evaluates the effect of periodontitis on masticatory performance and quality of life index. METHODS: Patients (n = 24; 23 to 76 years of age) with periodontal conditions ranging from healthy to generalized disease categorized by the alveolar bone height-to-tooth length (AB/T) ratio were separated into the following two groups: control (AB/T >50%) and test (AB/T <50%). The masticatory performance was evaluated through continuous mastication of a special device called a biocapsule. The Brazilian Oral Health Impact Profile (OHIP-14Br) questionnaire was used to assess the oral health-related quality of life. The Student t test was applied for independent samples (P <0.05) to evaluate the masticatory performance, and the Mann-Whitney U test was used to determine quality of life (P <0.05). RESULTS: There was a statistically significant difference in masticatory efficiency between groups (P = 0.006). Statistically significant differences were also observed in the following parameters: 1) physical pain (P = 0.003); 2) psychologic discomfort (P = 0.008); 3) physical disability (P = 0.033); and 4) OHIP-14Br total score (P = 0.001). The control group achieved the best indicators. Both the masticatory performance and quality of life indicators showed significant correlation with the alveolar bone height. CONCLUSION: The loss of periodontal supporting structures has negative effects on the masticatory performance and quality of life.

Compensatory canine angulation in angle Class II and III patients.

The aim of this study was to evaluate the occurence of compensation in mesiodistal axial inclinations of canines in skeletal malocclusions patients. The sample consisted of 25 Angle Class II, division 1 malocclusion (group 1) and 19 Angle Class III malocclusion patients (group 2). After measurement of dental angulations through a method that associates plaster model photography and AutoCad software, comparisons between the groups were performed by T-test for independent samples. Results showed that there was no statistically significant difference (p < 0.05) between groups, when maxillary canine angulations were compared. Regarding the mandibular canines, there was a statistically significant difference in dental angulation, expressed by 3.2 degrees for group 1 and 0.15 degrees for group 2. An upright position tendency for mandibular canines was observed in the Angle Class III sample. This configures a pattern of compensatory coronary positioning, since the angulation of these teeth makes them occupy less space in the dental arch and consequently mandibular incisors can be in a more retracted position in the sagittal plane.

Compensatory canine angulation in angle Class II and III patients

The aim of this study was to evaluate the occurence of compensation in mesiodistal axial inclinations of canines in skeletal malocclusions patients. The sample consisted of 25 Angle Class II, division 1 malocclusion (group 1) and 19 Angle Class III malocclusion patients (group 2). After measurement of dental angulations through a method that associates plaster model photography and AutoCad software, comparisons between the groups were performed by T-test for independent samples. Results showed that there was no statistically significant difference (p < 0.05) between groups, when maxillary canine angulations were compared. Regarding the mandibular canines, there was a statistically significant difference in dental angulation, expressed by 3.2° for group 1 and 0.15° for group 2. An upright position tendency for mandibular canines was observed in the Angle Class III sample. This configures a pattern of compensatory coronary positioning, since the angulation of these teeth makes them occupy less space in the dental arch and consequently mandibular incisors can be in a more retracted position in the sagittal plane.

Clinical evaluation of abutment teeth of removable partial denture by means of the Periotest method.

Prosthodontics should be one of the means of establishing conditions for the maintenance of periodontal health. The forces applied to the abutment teeth and their effects are very important considerations in the design and construction of the removable partial dentures. This 6-month follow-up clinical study evaluated the degree of mobility of abutment teeth of distal extension and tooth supported removable partial dentures by using Periotest. Two types of clasp design were selected for evaluation. In cases with unilateral and bilateral distal-extension, a clasp design including a T clasp of Roach retentive arm, a rigid reciprocal arm and a mesial rest were used. For the abutments of tooth-supported removable partial dentures, a second clasp design with a cast circumferential buccal retentive arm, a rigid reciprocal clasp arm and a rest adjacent to the edentulous ridges was selected. A total of 68 abutment teeth was analysed. Periotest values were made at the time of denture placement (control) and at 1, 3 and 6 months after the denture placement. The statistical analysis was performed using Friedman test. All analysis was performed at a 0.05 level of significance. The results revelled that no significant changes in tooth mobility were observed during the 6-months follow-up (P > 0.05). In conclusion, our findings suggest that adequate oral hygiene instructions, careful prosthetic treatment planning and regular recall appointments play an important role in preventing changes in abutment tooth mobility caused by removable partial denture placement.

Consideraciones periodontales en el diseño de prótesis parciales removibles. Parte 1 / Periodontal considerations in the design of removable partial dentures. Part 1

Se presenta una revisión de la literatura referente a la prótesis parcial removible sobre los tejidos periodontales y las consideraciones en el diseño de cad uno de los elementos constituyentes. Se concluye que el control de la placa y los programas de mantenimiento son los factores fundamentales para la conservación de los tejidos remanentes, objetivo principal de toda restauración protésica; en tal sentido, también es importante considerar el control de la cobertura del tejido periodontal por alguna parte de la P.P.R. y la fuerza oculsal transmitida a las estructuras de soporte

Evaluación clínica y radiográfica de autotrasplantes y reposiciones dentales / Clinical and radiographic evaluation of autotransplantations and dental repositions

Se realizó un estudio prospectivo de 8 autotrasplantes y 2 reposiciones dentales en 8 pacientes que consultaron entre agosto de 1994 y abril de 1996, los que se controlaron en el período de un año. Se evaluaron parámetros clínicos como dolor, cambio de color, sangrado, movilidad e índice de Russell, también se evaluaron parámetros radiográficos como espacio del ligamento periodontal, reabsorción radicular interna y externa, obliteración de la cámara pulpar y estadio de desarrollo radicular. Todos los casos se realizaron de diferentes dientes donantes a diferentes sitios receptores, notándose que los autotrasplantes más frecuentemente realizados son del tercer molar al primer molar y las reposiciones en zona de premolares. La tasa de supervivencia fue del 100 por ciento a los seis meses y del 75 por ciento a los 12 meses, teniendo en cuenta que no todos los casos han completado los períodos de control. Uno de los autotrasplantes no sobrevivió aunque se le intentó realizar tratamiento pulpar con hidróxido de calcio. Los resultados iniciales de este estudio piloto demuestran que los autotrasplantes y las reposiciones dentales son alternativas de tratamiento con altos porcentajes de éxito en caso de pérdida dentaria o alteración en la erupción por malposición