RESUMEN
Environmental stressors can disrupt the gut-brain relationship and alter the gut microbial composition, potentially leading to chronic pain, including neuropathic pain (NP). To understand this complex relationship, we conducted a systematic scoping review to examine the gut microbial-neuroimmune connection to NP and the potential therapeutic targets. The review includes English-language manuscripts in databases such as MEDLINE, Cochrane, and DOAJ between January 2000 and April 2022. Out of the 48 full texts examined, only 15 articles met the inclusion criteria. These included a randomised controlled trial involving 327 individuals, an in vitro, and 13 animal model studies. The findings suggest that the gut flora plays a role in the immunological, neurological, and metabolic signalling pathways associated with NP. Animal studies have been the primary focus in this area, indicating that an imbalanced-gut microbiome and subsequent activation of biochemical and neuro-immunologic pathways may influence the development of NP. This review provides a comprehensive summary of the gut microbiome-immune-NP axis and identifies potential therapeutic targets. However, since most of the evidence comes from animal studies, future research should include clinical trials to gain a better understanding of the role of gut microbiota in NP and discover new therapeutic strategies.
RESUMEN
Cementoenamel junction is an anatomical landmark which indicates the meeting point of enamel of the crown and the cementum of the root. It is an important reference point in clinical dentistry as well as in dental radiography. The present study is done to describe the distribution of the mineralized tissue at the cementoenamel junction in relation to various surfaces of the premolars. The study sample consisted of 89 permanent maxillary and mandibular premolars from both males and females extracted for orthodontic reasons. They were stained with carbol fuchsin and observed under a dissecting microscope to identify the following tissue interrelationships at the cementoenamel junction: cementum overlapping the enamel; edge-to-edge relationship between enamel and cementum; gap between the enamel and cementum and enamel overlapping the cementum. The cementum overlapping the enamel interrelationship was predominant in the buccal and lingual surfaces of both first and second maxillary premolars, while the edge-to-edge relationship and the presence of a gap between the enamel and the cementum relationship were abundant in distal and mesial sides. Enamel overlapping the cementum was recorded only in a very small proportion of the sample. A good understanding about the morphological variations at the cementoenamel junction area is very important and this area should be handled carefully during routine dental procedures such as dental bleaching, orthodontic treatment, placement of rubber dam and placement of dental materials.