Resumo Os achados clinico-patológicos que caracterizam de forma precisa o líquen plano oral (LPO) e as lesões liquenoides orais (LLO) ainda representam um desafio. O objetivo do presente estudo foi analisar, pela perspectiva do patologista oral, os achados clínicos do LPO e das LLO. Espécimes preenchendo os critérios histológicos para o diagnóstico de LPO e LLO, e também aqueles compatíveis com LPO (LPO-C), foram selecionados e as informações clínicas foram obtidas a partir das requisições laboratoriais. A amostra final foi composta de 221 casos, incluindo 119 LPO (53.8%), 65 LPO-C (29.4%) e 37 LLO (16.7%). As mulheres foram mais acometidas nos três grupos, mas o número de homens acometidos foi maior nas LLO. A média de idade foi menor no LPO (52.3 anos) em comparação com as LLO (57.9 anos) (p=0.020). O envolvimento da mucosa jugal e da língua foi mais frequente no LPO; o envolvimento gingival foi incomum nas LLO. O padrão reticular foi mais frequentemente encontrado no LPO, enquanto a associação dos padrões reticular e atrófico/erosivo/ulcerado foi mais comum no LPO-C e nas LLO (p=0.025). Em conclusão, o gênero e a média de idade dos pacientes, assim como a localização anatômica e a manifestação clínica das LLO são diferentes do LPO, e podem ajudar a melhor caracterizar este grupo de condições. Espécimes diagnosticados como LPO-C mostraram parâmetros clínicos mais próximos ao LPO.

Abstract The clinicopathological features that precisely characterize oral lichen planus (OLP) and oral lichenoid lesions (OLL) still represent a challenge. The aim of the present study was to analyze, from an oral pathologist perspective, the clinical features from OLP and OLL. Specimens fullfilling the histological criteria for OLP and OLL, and also compatible with OLP (OLP-C), were selected and clinical information was retrieved from the laboratory forms. The final sample was composed by 221 cases, including 119 OLP (53.8%), 65 OLP-C (29.4%) and 37 OLL (16.7%). Females were more affected in the three groups, but the number of males was higher in OLL. Mean age was lower in OLP (52.3 years) in comparison with OLL (57.9 years) (p=0.020). Buccal mucosa and tongue involvement was more frequent in OLP; gingival involvement was uncommon in OLL. The reticular pattern was more frequently found in OLP, while the association of reticular and atrophic/erosive/ulcerated patterns was more common in OLP-C and OLL (p=0.025). In conclusion, gender and mean age of the patients, and anatomical location and clinical manifestation of OLL are different from OLP, and could help to better characterize this group of conditions. Specimens diagnosed as OLP-C showed clinical parameters close to OLP.

Orthodontic tooth movement (OTM) is a dynamic process of bone modeling involving osteoclast-driven resorption on the compression side. Consequently, to estimate the influence of various situations on tooth movement, experimental studies need to analyze this cell. Objectives The aim of this study was to test and validate a new method for evaluating osteoclastic activity stimulated by mechanical loading based on the fractal analysis of the periodontal ligament (PDL)-bone interface. Material and Methods The mandibular right first molars of 14 rabbits were tipped mesially by a coil spring exerting a constant force of 85 cN. To evaluate the actual influence of osteoclasts on fractal dimension of bone surface, alendronate (3 mg/Kg) was injected weekly in seven of those rabbits. After 21 days, the animals were killed and their jaws were processed for histological evaluation. Osteoclast counts and fractal analysis (by the box counting method) of the PDL-bone interface were performed in histological sections of the right and left sides of the mandible. Results An increase in the number of osteoclasts and in fractal dimension after OTM only happened when alendronate was not administered. Strong correlation was found between the number of osteoclasts and fractal dimension. Conclusions Our results suggest that osteoclastic activity leads to an increase in bone surface irregularity, which can be quantified by its fractal dimension. This makes fractal analysis by the box counting method a potential tool for the assessment of osteoclastic activity on bone surfaces in microscopic examination.