Race in public health dentistry: a critical review of the literature.

OBJECTIVE: To carry out a critical review of the literature on the use of race, color, and ethnicity in the field of public health dentistry. METHODS: A literature search was conducted in MEDLINE via PubMed for articles published between 2014 and 2019. Using a data extraction form, we collected information on (1) bibliographic characteristics of the selected papers; (2) race, color, and ethnicity of the study participants and their sociodemographic profiles; and (3) the extent to which the original publications followed the recommendations by Kaplan and Bennett (2003) on the use of race, color, or ethnicity in biomedical research. RESULTS: Our initial search identified 2,032 articles, 53 of which were selected for full-text examination and assessment following pre-established eligibility criteria. Around 60% (n = 32) of the included studies did not justify the use of race, color, or ethnicity in their analyses, and 9% (n = 5) took these variables as indicators of the participants' genetic makeup. On the other hand, 68% (n = 36) of the reviewed papers considered race, color, and ethnicity as risk markers - not risk factors - for adverse oral health outcomes, whereas 80% (n = 42) adjusted racial/ethnic inequities for a range of socioeconomic and demographic factors in statistical models. Only one study (2%) explicitly took race, color, or ethnicity as a contextually dependent dimension of the participants' identities. CONCLUSION: Our findings indicate that research on oral health inequities is often based on reductionist and stigmatizing conceptions of race, color, or ethnicity. Such harmful misconceptions should be replaced with anti-racist narratives in order to effectively address racial oral health inequities.

Transcriptional regulation of MSX1 natural antisense transcript.

Msx homeogenes play an important role in the epithelial-mesenchymal interactions leading development. Msx1 is relevant for dental and craniofacial morphogenesis, as suggested by phenotypes of Msx1 mutations in human and Msx1 KO mice. Our group showed that Msx1 gene expression can be regulated by a bidirectional transcription generating long noncoding antisense (AS) RNA the expression which is linked to the Msx1 sense (S) RNA level. Thus, the aim of the present study was to analyze the synthesis of Msx1 (AS) RNA. In vivo Msx1 AS expression analysis showed that (i) the putative promoter sequence but not the transcribed sequence was important and necessary for its expression, (ii) 2 different areas of alveolar bone can be distinguished depending on Msx1 S and AS expression, and (iii) Msx1 presence was necessary for Msx1 AS RNA full expression. In silico analysis of the Msx1 AS putative promoter region showed the presence of 4 Msx response elements possibly involved in Msx1 regulation. Msx1 constitutes an example of a bidirectionally transcribed gene giving rise to an S/AS RNA pair included in the big and growing family of AS noncoding RNAs. Our results contribute to defining a link between Msx1 S and AS RNAs resulting in a fine-tuned regulatory loop of Msx1 expression. The significance of this finding is that disturbance of the balance between Msx1 S and AS RNA status may be associated with tooth agenesis and bone loss.

Autoregulatory loop of Msx1 expression involving its antisense transcripts.

The Msx1 homeogene plays an important role in epithelial-mesenchymal interactions leading organogenesis. Msx1 gene is submitted to bidirectional transcription generating a long non-coding antisense (AS) RNA potentially involved in Msx1 expression regulation. RT-Q-PCR and RNA-FISH studies indicated that transient overexpression of the Msx1 AS transcript in 705IC5 mouse odontoblasts decreased the abundance of endogenous Msx1 S mRNA at the post-transcriptional level. Conversely, Msx1 overexpression increased the AS RNA level probably by activating AS transcription. In vivo mapping by RT-PCR evidenced both Msx1 RNAs in all adult mouse tissues tested raising the issue of Msx1 function during adulthood. The expression patterns of the two RNAs were similar, confirming the tight S/AS relationship. In particular, both Msx1 mRNAs and Msx1 protein were similarly distributed in eyes, and were found in regions with a common ectodermic origin and in cells potentially involved in regeneration. In conclusion, we report that Msx1 S RNA is negatively controlled by its AS RNA at a post-transcriptional level, and that the AS RNA is retrocontrolled positively by Msx1. The tight link between Msx1 S and AS RNAs constitutes a regulatory loop resulting in a fine-tuned expression of Msx1 which appears to be significant for adult homeostasis.

Msx1 expression regulation by its own antisense RNA: consequence on tooth development and bone regeneration.

Msx homeogenes play an important role in epithelial-mesenchymal interactions leading development. Msx1 is relevant for dental and craniofacial morphogenesis, as suggested by phenotypes of Msx1 mutations in human and Msx1 KO mice. During adulthood, Msx1 is still expressed in the skeleton where its role is largely unknown. Our group showed that the Msx1 gene is submitted to bidirectional transcription generating a long noncoding antisense (AS) RNA. During tooth development, Msx1 sense (S) and AS RNAs showed specific patterns of expression. Thus, the aim of the present study was to analyze the relation between Msx1 S and AS RNAs. In vivo mapping in adult mice showed that both Msx1 RNAs were detected in tested tissues such as bone. In vitro, Msx1 AS RNA decreased endogenous Msx1 S expression and modified Msx1 protein cell distribution. Regulations of Dlx5 and Bmp4 expression involving Msx1 S and AS RNAs showed that Msx1 AS RNA could modulate Msx1 function. The study of Msx1 S and AS RNA status is interesting in the case of tooth agenesis and bone loss to see if a disturbance of this balance could be associated with a disturbance of bone homeostasis. In that sense, our current results suggest a clear involvement of Msx1 in alveolar bone.

Race in public health dentistry: a critical review of the literature

ABSTRACT OBJECTIVE To carry out a critical review of the literature on the use of race, color, and ethnicity in the field of public health dentistry. METHODS A literature search was conducted in MEDLINE via PubMed for articles published between 2014 and 2019. Using a data extraction form, we collected information on (1) bibliographic characteristics of the selected papers; (2) race, color, and ethnicity of the study participants and their sociodemographic profiles; and (3) the extent to which the original publications followed the recommendations by Kaplan and Bennett (2003) on the use of race, color, or ethnicity in biomedical research. RESULTS Our initial search identified 2,032 articles, 53 of which were selected for full-text examination and assessment following pre-established eligibility criteria. Around 60% (n = 32) of the included studies did not justify the use of race, color, or ethnicity in their analyses, and 9% (n = 5) took these variables as indicators of the participants' genetic makeup. On the other hand, 68% (n = 36) of the reviewed papers considered race, color, and ethnicity as risk markers - not risk factors - for adverse oral health outcomes, whereas 80% (n = 42) adjusted racial/ethnic inequities for a range of socioeconomic and demographic factors in statistical models. Only one study (2%) explicitly took race, color, or ethnicity as a contextually dependent dimension of the participants' identities. CONCLUSION Our findings indicate that research on oral health inequities is often based on reductionist and stigmatizing conceptions of race, color, or ethnicity. Such harmful misconceptions should be replaced with anti-racist narratives in order to effectively address racial oral health inequities.

[Msx1 and its influence on craniofacial growth]. / Msxl et son influence sur la croissance cranio-faciale.

Many genes that interact in a complex and interdependent manner participate in the development of the craniofacial complex. One of them, the Msxl homeobox gene, a transcription factor, is expressed from early developmental stages to adulthood in accordance with specific spatio-temporal patterns. When it is suppressed, transgenic mice exhibit craniofacial abnormalities that demonstrate what is its function in normal growth, just as it has been shown that certain Msxl mutations in humans are commonly associated with tooth agenesis.