BackgroundThe aim of this study was to record the frequency of dilaceration in patients attending our institution and to analyze the possible associated factors.Material and MethodsOrthopantomograms from all patients attended in our institution were reviewed and those cases of dilaceration were selected. Documented data were age, gender, diagnosis, location and involved teeth. Data on possible etiological factors was also recorded.Results125 dilacerated teeth in 99 patients were found. Dilacerations were more commonly detected in females and in maxillary teeth. Maxillary 2nd bicuspids and lateral incisors were the more commonly affected teeth and were more common in teeth with predecessors (anterior teeth and bicuspids). Traumatic episodes and caries of the predecessor teeth was mentioned but never were related with affected teeth.ConclusionsData from the studied population are different compared to previously published studies. Our results support the point of view that the occurrence of dilacerated teeth could be related to limited availability of space to allocate the erupting teeth in the dental arch and perhaps to the possibility of the tooth to rotate, preventing eruption. Key words:Developmental alterations, dental developmental alterations, root dilaceration.

BackgroundThe aim of this study was to record and analyze all DDAs associated to dilacerated teeth in patients attending the clinics of the Postgraduate Division, Facultad de Odontología, UNAM in Mexico City.Material and MethodsOrthopantomograms from all patients seeking for stomatological attention in our institution were reviewed and those cases of dilaceration were separated. Age, gender, diagnosis, location, involved teeth and associated DDAs were recorded and analyzed.ResultsFrom 6,340 patients, 99 (1.6%) harbored 125 dilacerated teeth. Of them, 45 (45.5%) showed one or more DDAs. The most frequently detected DDAs were hypodontia, enamel pearls, taurodontism and microdontia.Conclusions45.5% is a very high proportion of DDAs in patients with dilacerated roots. Findings from this study strongly suggest that patients with dilacerated teeth should be carefully screened since many of them could present other DDAs. Simultaneous occurrence of dilaceration and DDAs suggests synchronic developmental defects during dental growth. Key words:Developmental alterations; dental developmental alterations; root dilaceration.

Background Oral melanomas have some histopathological resemblance with its cutaneous counterpart; however, an aggressive behavior is more common in tumors that occur in the oral cavity. Several markers have been suggested as indicative of tumoral progression and aggressiveness, such as cyclooxygenase 2 (COX-2) and Ki67. Material and Methods In this study, we have compared the expression of COX-2 and Ki67 in a series of amelanotic (n=7) and melanotic oral melanomas (n=22). The cases were selected from 4 pathology laboratories and submitted to the immunohistochemical (IHC) reactions. We analyzed the IHC staining based on a qualitative – using visual scores; and a computer-assisted method (quantitative) using scanned slides and software for digital analysis. Results COX-2 was expressed in all oral melanomas; however, its intensity was significantly higher in the amelanotic ones ( P <0.001). Similarly, a high Ki67-positivity index was observed in the amelanotic than melanotic ones ( P <0.001). Conclusions Based on these results, we suggest that amelanotic oral melanomas have marked pro-inflammatory and high-proliferative phenotype, justifying their more aggressive behavior compared with the melanotic ones. Key words: Oral melanoma, amelanotic tumor, cyclooxygenase 2, Ki67.

Aim: To retrieve and analyze the published information on the prevalence of Oral Squamous Cell Carcinoma (OSCC) in Mexico.