Association between clinical manifestations of occlusal trauma and magnetic resonance imaging findings of periodontal ligament space.

OBJECTIVES: The purpose of this study was to evaluate the association between clinical manifestations of occlusal trauma of the teeth and maximum signal intensity of periodontal ligament space on MRI. METHODS: 20 subjects (males: 9, females: 11, mean age: 35.9 ± 14.0 years, range: 22-65 years) participated in this study. Subjective symptoms of bruxism, tooth mobility, fremitus, occlusal contact area, occlusal force, widening of the periodontal ligament space, and thickening of the lamina dura were defined as clinical manifestations of occlusal trauma. The total number of clinical manifestations was used to evaluate the degree of clinical occlusal trauma, with a score of 7 indicating the highest degree of occlusal trauma. The maximum signal intensity in the periodontal ligament space was evaluated by a specific T2 weighted MRI sequence: IDEAL image. RESULTS: Spearman's rank correlation between the total clinical occlusal trauma score and maximum signal intensity in the periodontal ligament space was 0.529 for all teeth, 0.517 for anterior teeth, and 0.396 for molar teeth (p < 0.001 for all). CONCLUSIONS: A significant correlation between the degree of occlusal trauma and the signal intensity of the periodontal ligament space suggests a new potential MRI-based method for objectively determining occlusal trauma.

Lesiones cervicales no cariosas: una revisión sistemática / Non carious cervical lesions: a systematic review

Introducción: las lesiones cervicales no cariosas (NCCL, por sus siglas en inglés) son un grupo de lesiones que afectan el área cervical del órgano dental causando hipersensibilidad dentinaria y defectos estéticos. Objetivo: analizar la literatura sobre las lesiones cervicales no cariosas, su etiología, consideraciones anatómicas, características morfológicas de la lesión y tratamientos no restaurativos. Material y métodos: se realizó una búsqueda en la base de datos PubMed, utilizando las palabras clave: non-carious cervical lesions OR noncarious cervical lesions OR tooth wear OR tooth erosion OR dental abfraction OR abfraction, recopilando un total de 78 artículos. Resultados: es necesario determinar la etiología antes de seleccionar las estrategias de tratamiento para las lesiones cervicales no cariosas. Conocer los distintos tipos de tejidos que componen al órgano dentario facilita la comprensión de los factores que participan en el desarrollo de las lesiones cervicales no cariosas. Esto permite que el tratamiento se enfoque más en la causa del problema que en los síntomas. Con esto podemos modificar diversos factores de manera interceptiva, los tratamientos de terapia con láser y compuestos tópicos son una estrategia mínimamente invasiva. Conclusiones: la mejor manera de describir a las lesiones cervicales no cariosas sería como una enfermedad multifactorial. Se debe prestar especial atención en los métodos de diagnóstico, identificando cofactores que propicien el avance de la lesión, como son la fricción y la biocorrosión. Esta revisión brinda datos que asocian a los factores oclusales como una de las principales causas de una enfermedad que afecta a más de la mitad de la población adulta (AU)

Introduction: non-carious cervical lesions (NCCL) are a group of lesions that affect the cervical area of the dental organ causing dentin hypersensitivity and cosmetic defects. Objective: to know, through a systematic review, the current state of non-carious cervical lesions. Material and methods: a search was conducted in the PubMed database, using the keywords: non-carious cervical lesions OR noncarious cervical lesions OR tooth wear OR tooth erosion OR dental abfraction OR abfraction, compiling a total of 78 articles. Results: determining etiology is necessary before selecting treatment strategies for non-carious cervical lesions (NCCL). Know the different types of tissues that make up the dentary organ, facilitate the understanding of the factors involved in the development of noncarious al cervical lesions. This allows treatment to focus more on the cause of the problem than on symptoms. With this we can modify various factors in an interceptive way, laser therapy treatments and topical compounds, are a minimally invasive strategy. Conclusions: the best way to describe non-carious al cervical lesions would be as a multifactorial disease to which special attention should be paid to both diagnostic methods, identifying cofactors that promote the progression of injury, such as friction and biocorrosion. This review provides data that associates occlusal factors as one of the main causes of a disease that affects more than half of the adult population (AU)

Radiographic signs of excessive occlusal forces are associated with marginal bone loss: a retrospective clinical study.

OBJECTIVES: Work in animal models has implicated excessive occlusal forces and occlusal trauma as co-destructive factors for periodontitis. The main aim of the present study was to make a radiographic assessment of the effects of excessive occlusal forces, ie occlusal/incisal tooth wear, widening of the periodontal space, and the presence of a mandibular torus, on interproximal marginal bone loss in a large series of patients. A secondary aim was to evaluate the statistical correlation between the parameters in two specific teeth and those of 12 teeth for marginal bone loss and six teeth for occlusal/incisal tooth wear within the same individual. METHOD AND MATERIALS: A total of 1,950 full-mouth radiographic surveys were analyzed retrospectively. Interproximal marginal bone loss was quantified relative to the root length (Schei ruler technique). In addition, occlusal/incisal tooth wear and periodontal ligament space widening of the periodontal space were assessed, as well as the presence of a mandibular torus. Odds ratio and logistic regression analysis were used to determine the association between occlusal trauma and marginal bone loss. RESULTS: The correlation of the measured parameters between the values for specific teeth and the whole dentition was evaluated from data from the first 400 radiographs. Teeth 41 and 33 showed the best correlation to the whole dentition: 0.85 for interproximal marginal bone loss, 0.83 for widening of the periodontal space, and 0.97 for occlusal/incisal tooth wear. The results of a logistic regression analysis with age as an independent variable, revealed a significant association between bone loss and both tooth wear (odds ratio = 2.767) and bone loss and widening of the periodontal space (odds ratio = 2.585). CONCLUSION: Tooth wear was positively correlated to both widening of the periodontal space and marginal bone loss. No correlation was found between the presence of a mandibular torus and marginal bone loss.

Malocclusions, pathologic tooth migration, and the need for orthodontic treatment in subjects with stage III-IV periodontitis. A cross-sectional study.

BACKGROUND: Literature is scarce on malocclusion prevalence and orthodontic treatment need (OTN) in subjects with stage III-IV periodontitis. Study aims were to assess prevalence of primary and secondary malocclusions in subjects with stage III-IV periodontitis and OTN based on pathologic tooth migration (PTM) and occlusal trauma of anterior teeth (AT). SUBJECTS AND METHODS: One hundred and twenty-one subjects with stage III-IV periodontitis were examined. A comprehensive periodontal-orthodontic examination was performed. Exclusion criteria: age <30 years, removable prosthetics, uncontrolled diabetes, pregnancy/lactation, and oncologic disease. RESULTS: Class II malocclusion was found in 49.6% (Class II div 1-20.7%, Class II div 2-9.9%, subdivision Class II-19.0%), Class I-31.4%, Class III-10.7%, no malocclusion-8.3% of subjects. PTM was observed in 74.4% of maxillary and 60.3% of mandibular AT. Spacing and extrusion were the main types of PTM of AT. Odds ratio for PTM of maxillary AT was 9.3 in cases with >30% of sites with clinical attachment loss ≥5 mm (P = 0.001). Spacing of maxillary AT was influenced by periodontitis, Class III malocclusion, and lost teeth. Tongue habit had impact on spacing of mandibular AT. Dental Health Component of Index of Orthodontic Treatment Need yielded that OTN was found in >50% and OTN due PTM, occlusal trauma and impaired function in 66.1% of subjects. CONCLUSIONS: The most prevalent malocclusion was Class II. Spacing and extrusion were prevalent types of PTM of AT. OTN was found in more than half of the subjects. The study highlights the need for preventive measures for PTM in subjects with stage III-IV periodontitis.

Study on the role of pyroptosis in bone resorption induced by occlusal trauma with or without periodontitis.

BACKGROUND AND OBJECTIVE: Occlusal trauma is considered to be a contributing factor to bone loss associated with inflammatory periodontal disease. We hypothesized that pyroptosis, a recently discovered inflammation-induced programmed cell death pathway, plays a role in occlusal trauma. MATERIALS AND METHODS: The occlusal trauma model was established using a cemented 1-mm elevated computer-aided design and manufacturing (CAD/CAM) metal crown. The periodontitis model was established by periodontal wire ligation with lipopolysaccharide (LPS) injection. The rats were sacrificed at 1, 2, 3, and 4 weeks. Quantitative real-time polymerase chain reaction (qRT-PCR) was used to analyze the expression of pyroptosis-, inflammation-, and osteoclast-related markers. Micro-computed tomography (micro-CT) was used to determine bone morphology parameters. Tissue morphology was evaluated using hematoxylin and eosin staining (H&E). Osteoclasts were identified using tartrate-resistant acid phosphatase (TRAP) staining. The expression and distribution of factors related to pyroptosis and inflammation were evaluated by immunohistochemistry (IHC). The colocalization of dead cells and cysteinyl aspartate-specific proteinase-1 (caspase-1)-positive cells was analyzed by immunofluorescence. RESULTS: Quantitative real-time polymerase chain reaction and IHC results showed that occlusal trauma induced the expression of pyroptotic factors during the early stages, while occlusal trauma with periodontitis upregulated the expression of pyroptotic factors at the later stages. The results of qRT-PCR, TRAP staining, and micro-CT showed that occlusal trauma with periodontitis increased the production of proinflammatory cytokines, leading to severe bone loss. Glyburide, an NOD-like receptor pyrin domain containing protein 3 (NLRP3)inhibitor, reduced the expression of pyroptosis markers induced by occlusal trauma with periodontitis and reversed bone resorption. CONCLUSIONS: Pyroptosis was involved in bone loss induced by occlusal trauma with or without periodontitis, while glyburide reversed inflammation and bone resorption.

Occlusal trauma is associated with periodontitis: A retrospective case-control study.

BACKGROUND: Excessive occlusal forces and occlusal trauma have been implicated as co-destructive factors for periodontitis in animal models. The objective of this study was to assess the association between occlusal trauma and periodontitis. METHODS: A total of 167 cases and 205 controls were included for analysis. Occlusal trauma was the exposures of interest and was registered for cases and controls. Additional clinical co-variables were registered as well for further analysis. The association of the exposure and periodontitis was determined by the odds ratio and logistic regression analysis adjusted for confounders. RESULTS: Amalgam restorations, pathogenic occlusion and occlusal trauma were more frequent in cases as compared to controls (P ≤ 0.05). The distribution of pathogenic occlusion and occlusal trauma was similar according to the stage and class of periodontitis. Logistic regression analysis showed a significant association for cigarette smoking, systemic conditions, amalgam restorations, pathogenic occlusion, and occlusal trauma with periodontitis (P ≤ 0.05). After adjusting for confounding variables in the model, amalgam restorations and occlusal trauma remained strongly associated with periodontitis (P ≤ 0.05). CONCLUSIONS: Occlusal trauma is strongly associated with periodontitis. Additional long-term prospective studies are necessary to further understand the impact of the occlusal condition and periodontitis.

Inhibition of yes-associated protein dephosphorylation prevents aggravated periodontitis with occlusal trauma.

BACKGROUND: Occlusal trauma can aggravate periodontitis, but the mechanism remains unclear. Yes-associated protein (YAP), a mechanical stressor protein, may play an important role in this process. METHODS: Western blot and quantitative real-time polymerase chain reaction (qRT-PCR) were applied to detect the expression of YAP and inflammatory factors in patients with periodontitis accompanied with or without occlusal trauma. Through local administration of Porphyromonas gingivalis and composite resin bonding on maxillary molars in mice, we established periodontitis and occlusal trauma models. Treatment with or without XAV939, to inhibit YAP activation, was performed in these models. Micro-computed tomography, immunofluorescence (IF), and qRT-PCR were used to explore the YAP pathway in periodontitis with occlusal trauma. Cyclic stress and lipopolysaccharide (LPS) stimuli were applied to the L929 mouse fibroblast cell line with or without XAV939. Western blot, IF, and qRT-PCR were used to verify the in vivo results. RESULTS: Activated dephosphorylated YAP and increased expression of inflammatory factors were observed in patients with periodontitis accompanied with occlusal trauma. In the mouse model of periodontitis with occlusal trauma, YAP transferred into the nucleus, resulting in Jun N-terminal kinases (JNK) related pro-inflammatory pathway up-regulation. L929 cell cyclic stress and LPS stimulation results confirmed the in vivo results. Application of XAV939 inhibited YAP protein dephosphorylation and reduced JNK pro-inflammatory pathway factor expression in vivo and in vitro. CONCLUSIONS: Occlusal trauma can activate YAP nuclear transfer, resulting in the up-regulation of the JNK pro-inflammatory pathway. This can be inhibited by the XAV939 YAP inhibitor.

Does traumatic occlusal forces lead to peri-implant bone loss? A systematic review.

Observational studies have indicated that crestal bone level changes at implants are typically associated with clinical signs of inflammation, but still mechanical overload has been described as possible factor leading to hard-tissue deficiencies at implant sites without mucosal inflammation. The aim of this paper was systematically review the literature regarding the possible effect of traumatic occlusal forces on the peri-implant bone levels. Literature search was conducted using PubMed, Scielo and Lilacs, including the following terms: oral OR dental AND implant$ AND (load OR overload OR excessive load OR force$ OR bruxism) AND (bone loss OR bone resorption OR implant failure$). Databases were searched for the past 10 years of publications, including: clinical human studies, either randomized or not, cohort studies, case control studies, case series and animal research. Exclusion criteria were review articles, guidelines and in vitro and in silico (finite element analysis) research, as well as retrospective studies. The PICO questions formulated was: "does traumatic occlusal forces lead to peri-implant bone loss?" The database searches as well as additional hand searching, resulted in 807 potentially relevant titles. After inclusion/exclusion criteria assessment 2 clinical and 4 animal studies were considered relevant to the topic. The included animal studies did not reveal an association between overload and peri-implant bone loss when lower overloads were applied, whereas in the presence of excessive overload it seemed to generate peri-implant bone loss, even in the absence of inflammation. The effect of traumatic occlusal forces in peri-implant bone loss is poorly reported and provides little evidence to support a cause-and-effect relationship in humans, considering the strength of a clinically relevant traumatic occlusal force.

Does traumatic occlusal forces lead to peri-implant bone loss? A systematic review

Abstract Observational studies have indicated that crestal bone level changes at implants are typically associated with clinical signs of inflammation, but still mechanical overload has been described as possible factor leading to hard-tissue deficiencies at implant sites without mucosal inflammation. The aim of this paper was systematically review the literature regarding the possible effect of traumatic occlusal forces on the peri-implant bone levels. Literature search was conducted using PubMed, Scielo and Lilacs, including the following terms: oral OR dental AND implant$ AND (load OR overload OR excessive load OR force$ OR bruxism) AND (bone loss OR bone resorption OR implant failure$). Databases were searched for the past 10 years of publications, including: clinical human studies, either randomized or not, cohort studies, case control studies, case series and animal research. Exclusion criteria were review articles, guidelines and in vitro and in silico (finite element analysis) research, as well as retrospective studies. The PICO questions formulated was: "does traumatic occlusal forces lead to peri-implant bone loss?" The database searches as well as additional hand searching, resulted in 807 potentially relevant titles. After inclusion/exclusion criteria assessment 2 clinical and 4 animal studies were considered relevant to the topic. The included animal studies did not reveal an association between overload and peri-implant bone loss when lower overloads were applied, whereas in the presence of excessive overload it seemed to generate peri-implant bone loss, even in the absence of inflammation. The effect of traumatic occlusal forces in peri-implant bone loss is poorly reported and provides little evidence to support a cause-and-effect relationship in humans, considering the strength of a clinically relevant traumatic occlusal force.

Resveratrol suppresses the alveolar bone resorption induced by artificial trauma from occlusion in mice.

OBJECTIVE: Besides inflammatory bone loss, trauma from occlusion (TO)-induced alveolar bone loss increases the risk of future tooth loss. We have shown that resveratrol, a polyphenol, possesses anti-inflammatory characteristics and a suppressive effect on osteoclastogenesis. Therefore, we investigated the effects of resveratrol on TO-induced bone loss in mice. MATERIAL AND METHODS: Trauma from occlusion was induced by overlaying composite resin onto the maxillary first molar of C57BL/6 mice. TO-induced mice were administered either resveratrol or vehicle for 15 days from 5 days before TO induction. The mice administered vehicle only served as controls. The effect of resveratrol on bone resorption was assessed histologically. Gene expression in gingival and periodontal ligament tissues was analyzed. In vitro effect of resveratrol on the differentiation of RAW 264.7 cells and bone marrow-derived macrophages into osteoclastic cells was analyzed. RESULTS: Resveratrol administration significantly decreased the bone loss and suppressed the elevated expression of osteoclastogenesis-related gene in periodontal ligament tissue by TO. Resveratrol treatment also suppressed the differentiation of both RAW 264.7 cells and bone marrow-derived macrophages into osteoclastic cells. CONCLUSION: Resveratrol administration suppressed the TO-induced alveolar bone loss by suppressing osteoclast differentiation, suggesting that resveratrol is effective in preventing both inflammation and mechanical stress-induced alveolar bone resorption.

Micro-computed tomography for evaluating alveolar bone resorption induced by hyperocclusion.

PURPOSE: Occlusal trauma, resulting in the destruction of alveolar bone, is a form of periodontal disease caused by excessive mechanical stress (MS) during hyperocclusion. Previously, we showed that CC chemokine ligand (CCL) 2/CCR2 receptor axis plays a crucial role in MS-dependent osteoclastogenesis. However, in the previous work, we were unable to precisely measure changes in alveolar bone profiles. In the present study, we sought to establish a precise method for evaluating alveolar bone resorption induced by hyperocclusion using micro-computed tomography. METHODS: Under anesthesia, a stainless steel wire was attached to the molars of 5-week-old C57/BL6 wild-type (WT) mice, CCL2-/- mice, and CCR2-/-mice to induce occlusal force overload. At days 0 and 7, hard tissue samples were harvested and analyzed by micro-computed tomography. RESULTS: In the WT mice, bone mineral density of the alveolar bone was significantly decreased at day 7 as compared with day 0, with marked alveolar bone resorption observed. Similarly, significant alveolar bone resorption was observed in the CCL2-/- and CCR2-/- mice at day 7 as compared with day 0. CONCLUSIONS: Micro-computed tomographic images can be used to measure changes in bone mineral density in a mouse model of hyperocclusion. This method may be useful for further investigating bone changes in other periodontal disease research fields.

The influence of primary occlusal trauma on the development of gingival recession / La influencia del trauma oclusal primario en el desarrollo de la recesión gingival

This study aimed to histometrically evaluate the presence of gingival recession in the mesial surface of the teeth of rats experimentally subjected to primary occlusal trauma. This evaluation verified the distance from the cement-enamel junction (CEJ) to the free marginal gingiva (FMG) and to the height of the alveolar bone crest (CEJ-crest bone distance). There were 10 animals, randomly divided into 2 groups: occlusal trauma (OT) (n = 5) - creation of an occlusal interference by fixing an orthodontic wire segment on the mandibular first molar occlusal face, which was randomly chosen, and a Control Group (CG) (n = 5) - five animals with no exposure to the OT variable were euthanised after 14 days to obtain the initial parameters. The inter-group evaluation showed there was no significant difference between OT × CG when the CEJ-FGM distance (P = 0.192) was evaluated after 14 days, but there was a significant difference between the two groups as regards the CEJ-alveolar crest bone distance (P = 0.0142). Thus, it can be concluded that the OT induction model, after 14 days of experiment, promoted bone resorption. This was observed by the increase in the CEJ-alveolar crest bone distance. It also did not promote gingival recession, which was evaluated by the CEJ-FGM distance.

El objetivo de este estudio fue evaluar histométricamente en ratas la presencia de recesión gingival en la superficie mesial de los dientes sometidos experimentalmente a trauma oclusal primario a partir de la evaluación de la distancia desde la unión esmalte cemento (CEJ) a la encía marginal libre y la altura de la cresta ósea restante (distancia de la CEJ-cresta ósea) Con este fin, 10 animales fueron divididos al azar en 2 grupos: trauma oclusal (TO) (n = 5) - creación de una interferencia oclusal mediante la fijación de un segmento de alambre de ortodoncia en la superficie oclusal del primer molar elegido al azar; y un grupo control (CO) (n = 5) -5 animales sin la introducción de la variable TO fueron sometidos a eutanasia después de 14 días para obtener los parámetros iniciales. La evaluación intergrupo no mostró diferencias significativas entre los grupos TO × CO al evaluar después de 14 días la distancia de la CEJ-encía marginal libre (p = 0,192) pero mostró una diferencia significativa entre los grupos TO × CO en cuanto a distancia de la CEJ-cresta ósea alveolar (p = 0,0142). Por lo tanto, se concluye que el modelo de inducción del TO después de 14 días del experimento promueve reabsorción ósea siendo observado por el aumento en la distancia de la CEJ-cresta ósea alveolar y no promueve la recesión gingival evaluada a partir de la distancia de la CEJ-encía marginal.

Goldenhar Syndrome and Pain-Related Temporomandibular Disorders. A Case Report.

Goldenhar syndrome (GS) is a development syndrome, characterized by incomplete development of the craniofacial region. The involvement is mainly unilateral; it varies from being mild to severe; and it can range from malocclusion and facial asymmetry to a more complex phenotype with complete absence of the mandibular ramus and temporomandibular joint. However, orthopedic symptoms of orofacial pain and dysfunction have not generally been considered as part of the symptom complex in GS cases. The case presented here is of a 15-year-old Caucasian patient, who was referred for evaluation because of bilateral pain in the masticatory muscles and temporomandibular joints.

Efeito das forças oclusais excessivas sobre os dentes e o periodonto de inserção / Effect of excessive occlusal forces on teeth and the supporting periodontium

Os dentes e o periodonto respondem com alterações funcionais adaptativas às forças mastigatórias. Porém, estudos clínicos têm mostrado que forças oclusais excessivas podem causar injúria aos tecidos de suporte do dente, com alterações clínicas como mobilidade e migração dental, trincas de esmalte, sensibilidade térmica e frêmito. Estudos pré-clínicos em animais também têm mostrado alterações histológicas frente às forças oclusais excessivas, como espessamento do ligamento periodontal, radioluscência no ápice de dentes vitais, reabsorção óssea e radicular. Tais alterações, conhecidas como trauma oclusal, são reversíveis quando não há inflamação instalada e as forças excessivas são removidas. Por outro lado, a literatura é controversa no que se refere à relação entre o trauma oclusal e o início e progressão da doença periodontal. O presente estudo teve como objetivo revisar a literatura a respeito do efeito das forças oclusais excessivas incidentes sobre os dentes e o periodonto de inserção, em condições saudáveis ou quando o suporte encontra-se inadequado ou reduzido.

Teeth and periodontium answer with adaptive alterations to the masticatory forces. However, clinical studies have shown that excessive occlusal forces may cause an injury in the supporting tissues of the tooth, causing clinical alterations such as tooth mobility and migration, enamel cracks, thermal sensitivity and fremitus. Pre-clinical studies in animals have shown histological alterations such as widening of the periodontal ligament, radiolucency at the apex of vital teeth, bone and root resorption. These alterations, known as occlusal trauma, are reversible when there is no inflammation and the excessive forces are removed. On the other hand, literature is controversial regarding the association between the occlusal trauma and the beginning and progression of the periodontal disease. This study aimed to review the literature regarding the effect of the excessive occlusal forces on the teeth and on the insertion periodontium, under healthy conditions and inadequate or reduced support.

The effect of traumatic dental occlusion on the degradation of periodontal bone in rats.

CONTEXT: A better understanding of the relation between traumatic dental occlusion and periodontal changes is needed. AIMS: This study aimed to evaluate the pattern of osteoclastic activity in the periodontal bone in front of the traumatic dental occlusion in rat molars. PATIENTS AND METHODS: Traumatic dental occlusion (TO) was induced in twenty rats, which were sacrificed after periods of 2, 5, 7, and 14 days. Transversal histological sections of both jaws were stained with tartrate-resistant acid phosphatase and hematoxylin and eosin. Mann-Whitney U-test was used for group comparison, and Pearson's correlation test was applied for the number of osteoclasts and bone area (BA). RESULTS: Traumatic dental occlusion caused an increase in the number of osteoclasts in the bone of the upper and lower right first molar from days 2-5 to 2-14, respectively. In the TO groups, the number of osteoclasts on the lamina dura and in the center of the alveolar bone septum, respectively, increased almost 4-fold and 9-fold in the lower jaw; and 3-fold and 5-fold in the upper jaw, during all periods. In the TO groups, the BA of the alveolar bone septum was substantially reduced. There was a negative correlation between the number of osteoclasts and BA in both jaws during all experimental periods. CONCLUSIONS: Traumatic dental occlusion increases osteoclast activity in the alveolar lamina dura and in the center of alveolar bone and stimulates a higher degradation in the center of the alveolar bone septum.

Oral parafunctions, piercing and signs and symptoms of temporomandibular disorders in high school students.

OBJECTIVE: The use of chewing-gum and piercing has become common among adolescents and might result in increased oral muscle activity and overloading. Aim To investigate the frequency of oral piercing and parafunctions in relation to symptoms of temporomandibular disorders (TMD) among adolescents. MATERIALS AND METHODS: One hundred and twenty-four third level high school students, living either in a city or in a small town, enrolled in either science or media programmes, were included. The students completed a questionnaire regarding different parafunctions and symptoms of TMD. A clinical examination of the temporomandibular system and estimation of the tooth wear was performed in 116 students. RESULTS: Chewing-gum was used by 86% of the students (25% with a daily use) and 14% had an oral piercing. The science students used more chewing gum than the media students (p = 0.008), while the media students had more piercings (p < 0.001). Symptoms once a week or more were reported with 39% for headache, 18% for clicking, 7% for facial pain and 6% for difficulty to open wide. Girls reported more headaches (p = 0.007) and more severe symptoms (p = 0.003), had more medical consultations and used more analgesics (both p < 0.05) and had more clinical signs (p = 0.01) than boys. Girls had more oral piercings and used more chewing gum than boys (both p < 0.05). The media students had more sick leave (p < 0.01) than the science students. Chewing-gum use was associated with headache (p < 0.01), with difficulty to open wide (p < 0.05) and with tenderness of the temporomandibular joints and muscles (both p < 0.05). Oral piercing was associated with headache and muscle tenderness (both p < 0.05) and daily nail biting with headache (p < 0.05) and tooth wear (p = 0.004). CONCLUSIONS: There is an association between use of chewing gum, nail biting, oral piercing, and symptoms of TMD.

Relación entre la recesión ósea y atrición en cráneos secos contemporáneos / Relationship between bone recession and attrition in contemporary dry skulls

Objetivos: El objetivo de éste estudio és observar la posible influencia de las fuerzas oclusales según el grado de atrición de las piezas dentarias sobre la altura de la cresta alveolar. Material y métodos: Se estudiaron dientes de cráneos secos de la época actual y secomparó el desgaste oclusal ó atrición (A) con la pérdida de altura de la cresta alveolar (CA) ó recesión ósea (RO) y ambos registros se relacionaron estadísticamente. Resultados: De todos los dientes estudiados 2 tuvieron grado de atrición (GA) 0, 170 grado 1, 96 grado 2 y 15 grado 3. Registrando la recesión ósea (RO) las medidas extremas promedio estuvieron entre 2,80mm y 5,30mm; la mayor RO promedio se encontró en la parte media de las caras libres (pieza 23) y la menor en distal (pieza 11). Conclusión: No hay correlación entre la recesión ósea y el desgaste oclusal ó atrición.

Aim: The aim of these work is to know the relaciònship between the bonerecessiòn and the attritiòn.Materials and methods: We taken 228 teeth belonging to 25 dry skullsof actual edge and we compare the bone recession (BR) with the occlusalwaer or attrition (A) and both to be related with a statistical analyses.Results: Of all the teeth studied, 2 had attrition degree 0, 170 degree 1,96 degree 2 y 15 degree 3. Regarding the BR the measures differ between2,80 to 5,30mm. The BR major average was in the middle of the free aspect(tooth 23) and the minor in distal (tooth 11).Conclusion: There are not correlation between bone recession andocclusal wear or attrition.

Fixed prosthodontic treatment outcomes in the long-term management of patients with periodontal disease: a 20-year follow-up report.

PURPOSE: The aim of this long-term cohort study was to evaluate the efficacy and complications of fixed partial dentures in a convenience sample of 100 patients with periodontal disease who were treated and maintained periodontal patients after 20 years. MATERIALS AND METHODS: After active treatment, including periodontal surgery and endodontic and prosthetic treatment, patients were enrolled in a supportive periodontal care (SPC) program with 3- to 6-month recalls. All patients showed clinical data recorded at (1) the original consultation (T0), (2) the first SPC visit following the completion of prosthetic treatment (T1), and (3) at the latest SPC clinical session 20 years after T1 (T2). Multivariate analyses were performed to investigate the influence of clinical variables on the risk of prosthetic abutment (PA) loss after 20 years' visits. RESULTS: The final sample comprised 100 patients. At T1, a total of 948 PAs represented the original sample of experimental teeth. At the 20-year follow-up, a total of 854 PAs (90.1%) were still in function, while 94 (9.9%) PAs in 41 patients (41%) were lost during SPC; 98% of lost PA were endodontically treated. Vertical root fracture (48%) was the major cause of PA loss, while progression of periodontitis caused 31% of PA loss. Age (P = .002), Full-Mouth Plaque Score (P < .0001), Full-Mouth Bleeding Score (P = .0002), and oral parafunctions (P = .0083) were associated with increased probability of PA failure. Among clinical-related factors, endodontic treatment (P = .0082), root resection/ amputation (P < .0001), multi-rooted teeth (P = .0005), and abutment associated with parafunction (P < .0001) were associated with increased risk of abutment loss after 20 years. CONCLUSIONS: Perioprosthetic treatment in compliant patients is highly successful after 20 years of SPC.

The effect of dental occlusal disturbances on the curvature of the vertebral spine in rats.

OBJECTIVE: To determine whether a unilateral increase or decrease in the bite affects the curvatures of the vertebral spine in rats. METHODS: 25 male Sprague Dawley rats were included. Five animals received no alteration on their bite. Bite was increased on 10 animals and molar teeth were extracted on 10 other animals. Frontal and lateral radiographs were taken on days 0, 7, 14 and 21. Distances from landmarks to a true vertical line were measured on both radiographs. RESULTS: Repeated measures analysis showed statistically significant differences between the amount of the curvature at the cervical and thoracic spines on frontal and lateral radiographs over time (P<0.05 and P<0.0001). One-way ANOVA computed significant differences (P<0.05) at D14 at the cervical and thoracic spines on both, increased and decreased vertical dimension. CONCLUSION: Alterations in the dental occlusion affects the normal curvatures of the vertebral spine in rats.