Halitosis, or bad breath, is an oral health problem characterized by an unpleasant malodor emanating from the oral cavity. This condition can have different origins and causes a negative burden in social interactions, communication and quality of life, and can in uncommon cases be indicative of underlying non-oral non-communicable diseases. Most cases of halitosis are due to inadequate oral hygiene, periodontitis and tongue coating, yet the remaining proportion of cases are due to ear–nose–throat-associated (10%) or gastrointestinal/endocrine (5%) disorders. For this reason, the diagnosis, treatment and clinical management of halitosis often require a multidisciplinary team approach. This comprehensive review revisits the etiology of halitosis as well as standard and novel treatment that may contribute to higher clinical success.

We aimed to explore the association between volatile sulfurous compounds (VSCs) and periodontal epithelial surface area (PESA) and periodontal inflamed surface area (PISA) on a cohort of periodontitis patients. Consecutive patients were assessed for periodontitis and halitosis. A full-mouth periodontal status assessment tested probing depth (PD), clinical attachment loss (CAL), gingival recession (REC), bleeding on probing (BoP), PISA and PESA. A halitosis assessment was made using a VSC detector device. Periodontal measures were regressed across VSC values using adjusted multivariate linear analysis. From a total of seventy-two patients (37 females/35 males), the PESA of posterior-lower regions was found to be significantly higher in halitosis cases than their non-halitosis counterparts (p = 0.031). Considering all patients, the PESA of the posterior-lower region (B = 1.3, 95% CI: 0.2–2.3, p = 0.026) and age (B = −1.6, 95% CI: −3.1–0.2, p = 0.026) showed significant association with VSCs. In halitosis patients, the PESA of the posterior-lower region (B = 0.1, 95% CI: 0.0–0.1, p = 0.001), PISA Total (B = −0.1, 95% CI: −0.1–0.0, p = 0.008) and the OHIP-14 domain of physical disability (B = −2.1, 95% CI:−4.1–0.1, p = 0.040) were the most significant variables in this model. The PESA from the posterior-lower region may be associated with VSCs when other causes of extra-oral halitosis are excluded. Further intervention studies are needed to confirm this association.

The purpose of this study was to characterize and compare subgingival microbiome before and after periodontal treatment to learn if any changes of the subgingival microbiome were reflected in intra-oral halitosis. We tested the hypothesis that intra-oral halitosis (Volatile sulfur compounds levels) correlates with corresponding subgingival bacterial levels before and after periodontal treatment. Twenty patients with generalized periodontitis completed the study. Subgingival plaque samples were collected at baseline and 6–8 weeks after nonsurgical periodontal therapy. Full-mouth periodontal status assessed probing depth (PD), clinical attachment loss (CAL), gingival recession (REC), bleeding on probing (BoP), PISA and PESA. Halitosis assessment was made using a volatile sulfur compounds (VSC) detector device. Periodontal measures were regressed across VSC values using adjusted multivariate linear analysis. The subgingival microbiome was characterized by sequencing on an Illumina platform. From a sample of 20 patients referred to periodontal treatment, 70% were females (n = 14), with a mean age of 56.6 (±10.3) years; full-mouth records of PD, CAL, BOP (%) allowed to classify the stage and grade of periodontitis, with 45% (n = 9) of the sample having Periodontitis Stage IV grade C and 95% (n = 19) had generalized periodontitis. The correlation of bacterial variation with VSCs measured in the periodontal diagnosis and in the reassessment after treatment were evaluated. Fusobacterium nucleatum, Capnocytophaga gingivalis and Campylobacter showaei showed correlation with the reduction of VSC after periodontal treatment (p-value = 0.044; 0.047 and 0.004, respectively). Capnocytophaga sputigena had a significant reverse correlation between VSCs variation from diagnosis (baseline) and after treatment. Microbial diversity was high in the subgingival plaque on periodontitis and intra-oral halitosis participants of the study. Furthermore, there were correlations between subgingival plaque composition and VSC counting after periodontal treatment. The subgingival microbiome can offer important clues in the investigation of the pathogenesis and treatment of halitosis.

Halitosis is an unpleasant breath odor that interferes with self-confidence and with people’s professional and social lives. The aim of this cross-sectional study was to evaluate the impact of tongue coating on intra-oral halitosis in patients with periodontitis. The Winkel Tongue Coating Index (WTCI) score was found to be positively and significantly correlated with VSC values (rho = 0.473, p < 0.001). WTCI may be associated with levels of volatile sulfur compounds (VSCs) when other causes of extra-oral halitosis are excluded.

The investigation of rigidity physiology in Parkinson’s Disease involves the examination of reflexes. Parkinsonian patients often demonstrate reduced sensitivity in polysynaptic reflexes within the leg extensor muscles, which is correlated with their postural instability. The compensatory mechanisms for impaired proprioceptive reflex function may involve alterations in intrinsic muscle stiffness. The interplay between gait and reflexes is intricately linked to the nervous system’s functioning and motor control. Certain reflexes, such as patellar reflex, play a pivotal role in maintaining walking and posture. Ensuring the integrity of these reflexes is essential for facilitating smooth and efficient walking. To analyze the behavior of patellar reflex in four Parkinson’s Disease patients undergoing an acupuncture treatment protocol. This study adopts a case series design. Reflex outcomes based on amplitude and velocity were assessed at six different time moments throughout a month-long treatment protocol using the MP 36, Biopac Systems. Over the long term, a tendency for an improvement in range of movement and velocity of the patellar reflex, was observed. Nevertheless, in specific cases, a reduction in the amplitude during acute effects was also found. Our findings suggest that the acupuncture protocol used may lead to a cumulative improvement in efficacy of patellar reflex in patients with Parkinson’s disease. However, further in-depth research, including a statistical evaluation with a larger participant pool, is necessary to validate and confirm these promising preliminary results.