Decreased tooth size in schizophrenia

Schizophrenia and Dental Health: A Systematic Review

ABSTRACT

Schizophrenia is characterized not only by psychopathological symptoms but also by medical comorbidities. Among the latter, there are limited data on dental health. We conducted a systematic review with the primary aim of clarifying the extent of the relationship between dental diseases and schizophrenia. The second aim was to delineate an intervention program based on illness-related factors that influence dental health. The preferred reporting items for systematic reviews and meta-analyses statement for reporting systematic reviews was used. Only articles published in English language peer-reviewed journals were considered; we excluded case reports, meta-analyses, and systematic reviews, as well as studies that did not clearly report statistical analysis, diagnostic criteria, or the number of patients included. Twenty-one studies comprising 13,110 patients with schizophrenia and 9025 healthy controls were included. Negative symptomatology, long duration of illness, smoking habit, drug-induced xerostomia, and neuroinflammation are the most critical areas. We suggest an intervention program for prevention and treatment of dental diseases in schizophrenia.

Nicotinic receptor Alpha7 expression during tooth morphogenesis reveals functional pleiotropy

The expression of nicotinic acetylcholine receptor (nAChR) subtype, alpha7, was investigated in the developing teeth of mice that were modified through homologous recombination to express a bi-cistronic IRES-driven tau-enhanced green fluorescent protein (GFP); alpha7GFP) or IRES-Cre (alpha7Cre). The expression of alpha7GFP was detected first in cells of the condensing mesenchyme at embryonic (E) day E13.5 where it intensifies through E14.5. This expression ends abruptly at E15.5, but was again observed in ameloblasts of incisors at E16.5 or molar ameloblasts by E17.5–E18.5. This expression remains detectable until molar enamel deposition is completed or throughout life as in the constantly erupting mouse incisors. The expression of alpha7GFP also identifies all stages of innervation of the tooth organ. Ablation of the alpha7-cell lineage using a conditional alpha7Cre×ROSA26-LoxP(diphtheria toxin A) strategy substantially reduced the mesenchyme and this corresponded with excessive epithelium overgrowth consistent with an instructive role by these cells during ectoderm patterning. However, alpha7knock-out (KO) mice exhibited normal tooth size and shape indicating that under normal conditions alpha7 expression is dispensable to this process. The function of ameloblasts in alpha7KO mice is altered relative to controls. High resolution micro-computed tomography analysis of adult mandibular incisors revealed enamel volume of the alpha7KO was significantly reduced and the organization of enamel rods was altered relative to controls. These results demonstrate distinct and varied spatiotemporal expression of alpha7 during tooth development, and they suggest that dysfunction of this receptor would have diverse impacts upon the adult organ.