1
|
Pre-surgical socket analysis for immediate implant placement. Med Oral Patol Oral Cir Bucal 2024:26269. [PMID: 38368526 DOI: 10.4317/medoral.26269] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2023] [Accepted: 01/22/2024] [Indexed: 02/19/2024] Open
Abstract
BACKGROUND Traditional protocols for implant surgery suggest a healing period of 2-3 months from dental extraction to implant placement. Based on all the volumetric modifications produced by that approach, there are authors who advocate for immediate implantology. The aim of the present study was to determine the prevalence of different sockets, and the dimensions of the bone around the upper anterior incisors and canines, to determine the predictability of immediate implants in our population. MATERIAL AND METHODS This is an observational, cross-sectional study based on cone-beam computed tomography images of the anterior maxila of patients attending the Odontological Hospital of the University of Barcelona (OHUB) and requesting for implant treatment. Different measurements were performed on every analyzed tooth, and also they were categorized by using the main dental sockets classifications. RESULTS Bone attachment levels and cortical thickness are lower in women compared to men in all three types of teeth (the difference in the bone attachment levels ranges from 4.68%-8.63% and in the bone thickness goes from 0.02-0.58mm). Bone attachment level gradually reduces with age. The reductions observed in all the measurements are higher in the case of canines, compared with the other teeth. The differences from patients <45 years old and patients between 55-64 years old are 13.58±14.55mm in the case of central incisors, 10.04±5.52 in the case of lateral incisors and 22.39±13.65mm in the case of canines. CONCLUSIONS According to our results, the canines are the teeth with the greatest complexity when it comes to immediate implantology treatments. Furthermore, that kind of treatment is more complex as age increases, since we observed a gradual percentage of unfavourable sockets in older patients.
Collapse
|
2
|
Role of selected salivary inflammatory cytokines in the diagnosis and prognosis of oral squamous cell carcinoma. A Systematic Review and Meta-analysis. Med Oral Patol Oral Cir Bucal 2023; 28:e474-e486. [PMID: 37099710 PMCID: PMC10499341 DOI: 10.4317/medoral.25889] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2022] [Accepted: 03/06/2023] [Indexed: 04/28/2023] Open
Abstract
BACKGROUND Oral squamous cell carcinoma (OSCC) is gradually increasing its incidence in our society. Unfortunately, this entity is diagnosed at an advanced stage in most patients, a fact that implies greater difficulty in its treatment and a worse prognosis. This systematic review aims to assess whether the cytokines IL-6, IL-8 and TNF-α are potential salivary biomarkers that allow early diagnosis of cancer. MATERIAL AND METHODS An electronic search was performed in three databases (Pubmed, Scopus and Web of Science). We used the following keywords: "salivary cytokines", "saliva cytokines", "salivary interleukins", "biomarkers", "oral squamous cell carcinoma" and "diagnosis", combined with the Boolean operators "AND" and "OR". RESULTS 128 publications were found and finally 23 articles were included in the review and 15 in the meta-analysis. It has been observed that the majority of OSCC patients express higher salivary concentrations of IL-6, IL-8 and TNF-α compared to the control (CL) and premalignant lesion (OPML) groups. It has also been observed that the different premalignant lesions do not have statistically significant differences in the salivary concentration of the cytokines, and on the other hand, differences have been observed between the different TNM stages. The meta-analysis has shown that the difference in concentration of IL-6, IL-8 and TNF-α is statistically significant between the CL group and the OSCC, and also between the CL group and OPML. CONCLUSIONS There is sufficient evidence to affirm that IL-6, IL-8 and TNF-α are useful salivary cytokines in the early diagnosis and prognosis of OSCC. Although future studies are necessary to establish greater reliability of these biomarkers and thus be able to develop a valid diagnostic test.
Collapse
|
3
|
Role of thyroid hormones in burning mouth syndrome. Systematic review. Med Oral Patol Oral Cir Bucal 2023; 28:e81-e86. [PMID: 36173716 PMCID: PMC9805331 DOI: 10.4317/medoral.25596] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Accepted: 08/31/2022] [Indexed: 01/13/2023] Open
Abstract
BACKGROUND Burning mouth syndrome is an idiopathic condition characterized by burning pain in a normal-appearing oral mucosa lasting at least four to six months. In the case of secondary burning mouth syndrome is associated with local or systemic factors (such as thyroid disorders) that can cause these symptoms. The aim of this review was to study the relationship between thyroid disorders and burning mouth syndrome. MATERIAL AND METHODS The present study followed the PRISMA guidelines. An electronic search strategy was developed for PubMed/Medline, Scopus and Cochrane. The following combination of keywords and Boolean operators were used: Thyroid AND burning mouth; Thyroid AND burning mouth syndrome; Hypothyroidism AND burning mouth; Hypothyroidism AND burning mouth syndrome; Hyperthyroidism AND burning mouth; Hyperthyroidism AND burning mouth syndrome. The results were processed by existing free software in https://www.graphpad.com/. To evaluate the association of the categorical variables we used the Fisher test at a level of significance of p-value ≤ 0,05. As a primary summary measure the Odds Ratio (OR) has been used. To analyze the risk of bias the guidelines of the GRADE guide were used and the grade of evidence was analyzed by the guide of Joanna Briggs Institute: Levels of Evidence and Grades of Recommendations. RESULTS After applying the inclusion and exclusion criteria, 5 studies were selected for review. The Chi-square was 10.92 and the Odds Ratio was 3.31 with respect to TSH values with p <0.0001 (Fisher's test). The population of patients with TSH alterations is increased in 80.49% and decreased in 19.51%. CONCLUSIONS It can be concluded that thyroid hormone abnormalities are a factor in secondary burning mouth syndrome; specially in patients with hypothyroidism.
Collapse
|
4
|
Antibiotics prescription habits of Spanish endodontists: Impact of the ESE awareness campaign and position statement. J Clin Exp Dent 2022; 14:e48-e54. [PMID: 35070124 PMCID: PMC8760970 DOI: 10.4317/jced.59053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2021] [Accepted: 10/24/2021] [Indexed: 11/05/2022] Open
|
5
|
[Pain and Achilles tendon shortening in patients with idiopathic toe walking]. Rev Neurol 2021; 73:307-314. [PMID: 34676528 DOI: 10.33588/rn.7309.2021228] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
INTRODUCTION Idiopathic toe walking (ITW) is a heterogeneous disorder, which is associated with muscle shortening in lower limbs, pain and neurodevelopmental disorders. We try to study the frequency of clinical features in patients with ITW. PATIENTS AND METHODS Out of 100 patients evaluated with toe walking in a pediatric rehabilitation clinic, 77 (24,7% women) patients were diagnosed with ITW by means of TWT questionnaire. Achilles' tendon shortening with Silfverskiold manoeuvre, pain and attention deficit hyperactivity disorder (ADHD) were studied. In the group of patients with pain (n = 30), we studied pain evolution by means of a telephonic interview which assessed intensity, location, school absenteeism and used therapies. RESULTS Out of 77 patients, 44.2% had family history of toe walking. 37.7% and 9.1% showed Achilles' tendon shortening and Knee flexor shortening, respectively. Confirmed diagnosed of ADHD was present in 9.1% and was suspected in 20.8%. The older the patient was, the higher frequency of pain and the lower passive ankle dorsiflexion. Pain has a moderate-severe intensity, was related with school absenteeism in 42.3% of the patients with pain. Pain was located mainly on the calf, the ankle and the foot. It was treated with physiotherapy, oral pain relievers, orthosis and botulinum toxin type A (BTxA). CONCLUSIONS Pain in ITW is frequent, have a moderate-severe intensity, interferes in normal life and is referred in older children with lower ankle dorsiflexion. We found a common association between ITW and ADHD which points out ITW as alarm sign of learning problems.
Collapse
|
6
|
Incidence rate of metastases in the oral cavity: a review of all metastatic lesions in the oral cavity. Med Oral Patol Oral Cir Bucal 2021; 26:e619-e625. [PMID: 34023842 PMCID: PMC8412448 DOI: 10.4317/medoral.24625] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Accepted: 04/26/2021] [Indexed: 01/16/2023] Open
Abstract
Background Metastases in the oral cavity are rare and account for only 1 to 3% of all malignant lesions in this area. The primary location from which most metastases have been described in the oral cavity in adult patients include lungs, breasts, kidneys and colon. Material and Methods A systematic search of the literature was carried out following the PRISMA statement in PubMed database. Clinical trials and case series published in the last 10 years [2010-2020] were eligible to be selected. The headings and keywords used in the searches were “cancer” AND “oral metastases”, “incidence” AND “oral metastases”, “oral metastases” AND “jaw bone”, “oral metastases” AND “soft tissue”. Results For the study of the incidence of metastases in the oral cavity, 9 reports of clinical trials and 7 retrospective studies of case series have been included in this article. The primary locations from which more metastases have been described in the oral cavity are lungs (30.6% or 183 cases), breasts (22.2% or 133 cases), liver (15.5% or 93 cases), prostate (9 % or 54 cases), thyroid glands (8.1% or 49 cases), kidneys (7.3% or 44 cases), skin (2.3% or 14 cases), soft tissues (2% or 12 cases), colon (2% or 12 cases) and gastrointestinal (0.6% or 4 cases). These metastases have a predilection for hard tissues. The clinical presentation of these lesions varies from painless granulomatous lesions to lytic areas in the jaws. Conclusions Although metastases in the oral cavity is an uncommon pathology, early diagnosis is needed so that in the event that it is the first manifestation, it allows the primary tumor to be diagnosed as soon as possible. Key words:Cancer, oral metastases, incidence, jaw bone, soft tissue.
Collapse
|
7
|
Transoral robotic surgery vs open surgery in head and neck cancer. A systematic review of the literature. Med Oral Patol Oral Cir Bucal 2020; 25:e599-e607. [PMID: 32683380 PMCID: PMC7473442 DOI: 10.4317/medoral.23632] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2019] [Accepted: 07/02/2020] [Indexed: 12/16/2022] Open
Abstract
Background TORS has become one of the latest surgical alternatives in the treatment of oropharynx squamous cell carcinomas (OPSCC) and has become increasingly accepted by surgeons as a treatment option. Surgical robots were designed for various purposes, such as allowing remote telesurgery, and eliminating human factors like trembling. The study aimed to compare systematic review of the available literature in order to evaluate the safety and efficacy of Transoral Robotic Surgery (TORS) compared with open surgery.
Material and Methods We performed a systematic review of the available literature in order to evaluate the safety and effectiveness of TORS compared with open surgery. We compared TORS and open surgery based on 16 outcomes divided in to 3 groups: intra-operative complications, post-operative complications, and functional and oncologic outcomes. An electronic search of observational studies was carried out using the following databases: MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, Cochrane Oral Health Group Trials Register, and Scielo. Data analysis was carried out in accordance to Preferred Reporting Items for Systematic Reviews and Metanalysis (PRISMA) and the quality of the studies were evaluated using the Newcastle-Ottawa Scale. No language restrictions were imposed.
Results From the 4 studies identified (Newcastle-Ottawa Scale mean score 6.5), 371 patients were revised (186 patients were treated with TORS and 185 with conventional surgery). Overall, TORS, when compared with open surgery, appears to have better functional results (less hospital time, decannulation) and fewer intraoperative and post-operative complications. There is no significant difference when assessing the oncological outcomes (positive margins, survival rate) when comparing both techniques.
Conclusions TORS has an overall better functional outcome, and less intraoperative and postoperative complications with no difference in positive margins and survival rate when compared with conventional therapy. Key words:Transoral Robotic Surgery, TORS, open surgery, conventional surgery, head and neck cancer, oral cancer.
Collapse
|
8
|
Finite element analysis of narrow dental implants. Dent Mater 2020; 36:927-935. [PMID: 32466868 DOI: 10.1016/j.dental.2020.04.013] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2019] [Revised: 01/21/2020] [Accepted: 04/28/2020] [Indexed: 12/30/2022]
Abstract
Narrow-diameter implants (NDIs) traditionally have been associated to higher rates of failure in comparison with regular-diameter implants (RDIs) and wide-diameter implants (WDIs), since they generate a more unfavorable stress distribution in peri-implant bone. However, it is well known that the load sharing effect associated with prostheses supported by multiple implants (also called splinted prostheses) affords mechanical benefits. The present study involves finite element analysis (FEA) to determine whether the risks linked to NDIs could be mitigated by the mechanical advantages afforded by the splinting concept. For this purpose, a three-dimensional (3D) model of a real maxilla was reconstructed from computed tomography (CT) images, and different implants (NDIs, RDIs and WDIs) and prostheses were created using computer-aided design (CAD) tools. Biting forces were simulated on the prostheses corresponding to three different rehabilitation solutions: single-implant restoration, three-unit bridge and all-on-four treatment. Stress distribution around the implants was calculated, and overloading in bone was quantified within peri-implant volumes enclosed by cylinders with a diameter 0.1mm greater than that of each implant. The mechanical benefits of the splinting concept were confirmed: the peri-implant overloaded volume around NDIs splinted by means of the three-unit bridge was significantly reduced in comparison with the nonsplinted condition and, most importantly, proved even smaller than that around nonsplinted implants with a larger diameter (RDIs). However, splinted NDIs supporting the all-on-four prosthesis led to the highest risk of overloading found in the study, due to the increase in compressive stress generated around the tilted implant when loading the cantilevered molar.
Collapse
|
9
|
Mouthwash With Alcohol and Oral Carcinogenesis: Systematic Review and Meta-analysis. J Evid Based Dent Pract 2020; 20:101407. [PMID: 32473798 DOI: 10.1016/j.jebdp.2020.101407] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2019] [Revised: 07/25/2019] [Accepted: 07/30/2019] [Indexed: 10/25/2022]
Abstract
BACKGROUND It has been shown that the risk of developing oral cancer is closely related to the intensity and duration of exposure to alcohol and tobacco. Even so, the use of mouthwashes with alcohol in their compositions and the increased risk of oral cancer has been a source of controversy for decades. OBJECTIVE This study proposes a systematic review and a meta-analysis of the literature, to assess the possible relationship between the use of mouthwashes with alcohol and the development of oral and pharyngeal cancers. MATERIALS AND METHODS A systematic search was done using the Medline and PubMed databases. Exclusion criteria were as follows: articles published in languages other than English or Spanish, systematic reviews, and expert opinions. No limitations were used for publication date. RESULTS A total of 14 articles were obtained, 11 case-control studies and 3 clinical trials. Three case-control studies found no statistically significant evidence between the relationship of mouthwash use and oral cancer and the remaining 8 case-control studies found statistically significant evidence. The 3 clinical trials observed a relationship between the use of mouthwashes with alcohol and the possibility of developing cancer due to the genotoxicity and mutagenic capacity of alcohol in chronic contact with oral tissues and mucous membranes. The meta-analysis resulted in an OR = 1.480 and a P-value = .161 (95% CI: 0.855; P-value = 2.561) for the analysis of studies of cancer risk and consumption of mouthwashes with alcohol and OR = 1.057 0.364 (95% CI: 0.951; P-value = 1.174) for studies that related the risk of cancer and mouthwash use without taking into account the presence of alcohol. CONCLUSIONS There is no sufficient evidence to accept the proposition that the use of mouthwashes containing alcohol can influence the development of oral cancer.
Collapse
|
10
|
Horizontal augmentation of the maxillary alveolar ridge to change the prosthetic profile: Clinical and radiological results of a retrospective study. JOURNAL OF STOMATOLOGY, ORAL AND MAXILLOFACIAL SURGERY 2019; 121:25-29. [PMID: 31408677 DOI: 10.1016/j.jormas.2019.08.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Revised: 08/01/2019] [Accepted: 08/05/2019] [Indexed: 01/01/2023]
Abstract
BACKGROUND In this retrospective study, we aimed to analyze the clinical and radiological results of compensating the long-term deficiencies in hard and soft tissues of edentulous patients by placing dental implants and performing a horizontal ridge augmentation. MATERIAL AND METHODS We treated patients with edentulous maxillaries (Cawood-Howell type III or IV) by combining 4 implants, or 6 implants, or using zygomatic and conventional anterior implants as appropriate. Simultaneously, horizontal ridge augmentation was performed by combining autologous bone with Bio-Oss and membranes. RESULTS A total of 14 zygomatic and 80 standard implants were used for the rehabilitations in 16 edentulous patients. The success rates were 93.75% and 85.71% for the standard and zygomatic implants, respectively. Also, respective gains of 5.79mm and 3.25mm were obtained at the levels of the midsagittal line and canines, with respective resorption rates of 10% and 8.6% after 20months. CONCLUSION The millimeters gained by performing a horizontal augmentation optimizes the relation between the implant position and the prosthetic profile. This allows the different prostheses to be selected and for rehabilitation to be optimized. In this way, mucosal coverage can be avoided and fixed prosthetic design can be enhanced.
Collapse
|
11
|
Medication-related osteonecrosis of the jaw associated with implant and regenerative treatments: Systematic review. Med Oral Patol Oral Cir Bucal 2019; 24:e195-e203. [PMID: 30818312 PMCID: PMC6441601 DOI: 10.4317/medoral.22691] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2018] [Accepted: 01/03/2019] [Indexed: 11/05/2022] Open
Abstract
BACKGROUND The aim of this study was to determine if the treatment with bisphosphonates other anti-resorptive and antiangiogenic agents influences the success of regenerative and / or implant treatments. MATERIAL AND METHODS We reviewed the literature from the last 5 years in the PubMed database, using the following words: "Sinus Floor Augmentation"[Mesh] OR "Dental Implants"[Mesh]) OR "Guided Tissue Regeneration"[Mesh]) AND "Osteonecrosis"[Mesh]. The articles were selected following the inclusion and exclusion criteria and were evaluated using the 22 items of the STROBE declaration. The following PICO clinical question was applied: Does the treatment with agents associated with drug osteonecrosis influence the success of regenerative and implant treatments? RESULTS The initial search resulted in a total of 27 articles. After eliminating those that did not refer to the topic, were duplicated or did not meet the inclusion / exclusion criteria, a full reading of the articles was made evaluating their methodological quality, obtaining six studies with high methodological quality and two with moderate. CONCLUSIONS The literature regarding this topic is scarce, randomized clinical trials would be necessary to establish protocols relative to implant treatment in patients on antiresorptive treatments. The risk of developing an osteonecrosis associated with the regeneration / implant placement in patients with benign bone diseases is scarce, but it exists and it should not be underestimated. Especially, in the posterior areas of the jaw, if the duration of treatment with BP is greater than 3 years, and if the patient is under therapy with systemic corticosteroids.
Collapse
|
12
|
Quality of life related to oral health and its impact in adults. JOURNAL OF STOMATOLOGY, ORAL AND MAXILLOFACIAL SURGERY 2019; 120:234-239. [PMID: 30763780 DOI: 10.1016/j.jormas.2019.02.004] [Citation(s) in RCA: 61] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Accepted: 02/04/2019] [Indexed: 10/27/2022]
Abstract
Oral health is part of general health, and is recognized as an essential component of quality of life (QoL). For years, oral health was determined solely by the clinic, which did not allow an evaluation of the true impact of oral diseases on the patients' daily lives. The development of instruments for assessing QoL related to oral health has occurred due to the urgency of determining the effects of changes in the oral cavity of individuals. This study aims, through a bibliographical survey, to describe issues involving the relationship between QoL and oral health focusing on methodological and conceptual aspects as well as considering how oral health of adult individuals affects their QoL in a general way. Research in this area has developed the concept of "quality of life related to oral health", which comprises four categories: functional factors, psychological factors, social factors and existence of discomfort or pain. The negative impacts that poor oral health of the population have on their QoL makes this issue a relevant problem for public health. Although most oral problems do not represent an immediate risk of death, they are responsible for decreasing the QoL of individuals as they prolong states of pain and suffering, and cause functional, aesthetic, nutritional and psychological problems. Actions focused on health education with emphasis on self-perception, self-protection and self-care should be explored. Programs based on equity seeking to reduce inequalities and their negative effects on people's QoL should also be explored.
Collapse
|
13
|
Cutaneous, genital and oral lichen planus: A descriptive study of 274 patients. Med Oral Patol Oral Cir Bucal 2019; 24:e1-e7. [PMID: 30573709 PMCID: PMC6344000 DOI: 10.4317/medoral.22656] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Accepted: 11/13/2018] [Indexed: 12/20/2022] Open
Abstract
Background Lichen planus (LP) is a chronic autoimmune disease that affects the oral mucosa as well as the skin, genital mucosa and other sites. Objective: to evaluate the correlation between oral, genital and cutaneous lichen planus, in a sample of LP patients. Material and Methods This descriptive study reviewed 274 clinical histories of patients, who all presented histological confirmation of lichen planus verified by a pathologist, attending research centers in Barcelona. Results A total of 40 LP patients (14.59%) presented genital lesions. Of 131 patients with cutaneous LP (47.8%), the most commonly affected zones were the body’s flexor surfaces, representing 60.1% of cases. 24% of patients (n=55) related the start of the lesions with previous stress events. Of the 131 subjects with cutaneous lesions, 19% (n=25) also presented oral lichen planus (OLP). Of the total sample, 53.6% (n=147) of patients presented oral lesions. The systemic diseases most commonly associated with this patient sample were psychological problems such as stress, anxiety and depression (48%), hypertension (27%), gastric problems (12%), and diabetes (9.7%). A family history of lichen planus was found in only 2 cases (0,72%) out of the total of 274. Conclusions Any patient with OLP should undergo a thorough history and examination to investigate potential extraoral manifestations. The fact that 37 patients with OLP in this patient series were identified with simultaneous involvement at more than one site highlights the need for thorough evaluation and multidisciplinary approaches to this disease. Key words:Oral lichen planus, extra-oral manifestations, cutaneous lichen planus, genital lichen planus.
Collapse
|
14
|
Periodontal treatment on patients with cardiovascular disease: Systematic review and meta-analysis. Med Oral Patol Oral Cir Bucal 2018; 23:e681-e690. [PMID: 30341272 PMCID: PMC6261003 DOI: 10.4317/medoral.22725] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2016] [Accepted: 01/21/2018] [Indexed: 12/12/2022] Open
Abstract
Background Atherosclerotic cardiovascular disease is the main cause of mortality in developed countries. It is a chronic and systemic inflammatory disease with a multifactorial etiology. Periodontal disease is one of the many factors that contribute to its development. Objective To analyze the effects of periodontal treatment on cardiovascular risk parameters in patients with atherosclerotic cardiovascular disease. Material and Methods A systematic research was conducted in the Pubmed/Medline databases for clinical trials published up to and including the year 2017. Results Ten articles were included for analysis. Periodontal treatment reduced C-reactive protein levels (77.8% of clinical trials), tumor necrosis factor-alpha (66.7%), interleukin-6 (100%) and leukocytes (50%). Fibrinogen levels also improved considerably (66.7%). Effects on lipid parameters were more limited, whereby only oxidized low density lipoprotein and very low density lipoprotein cholesterol decreased significantly. Meta-analysis showed a statistically significant decreased in C-reactive protein and leukocytes values when patients were submitted to non-surgical periodontal treatment in contrast to receiving no treatment at all (mean difference 1.199 mg/L, 95% confidence interval: 1.100-1.299, p<0.001; and mean difference 0,79 g/L, 95% confidence interval: 0.717-0.879, p<0.001, respectively). Conclusions Periodontal treatment has a beneficial effect on some of the biochemical parameters considered to represent cardiovascular risk. Further randomized clinical trials are necessary, with longer follow-up periods including regular periodic monitoring, in order to determine the extent of the impact of periodontal treatment. Key words:Periodontal disease, cardiovascular disease, atherosclerosis, periodontal therapy, periodontal treatment.
Collapse
|
15
|
Autogenous teeth used for bone grafting: A systematic review. Med Oral Patol Oral Cir Bucal 2018; 23:e112-e119. [PMID: 29274156 PMCID: PMC5822533 DOI: 10.4317/medoral.22197] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Accepted: 11/03/2017] [Indexed: 01/10/2023] Open
Abstract
BACKGROUND Recently, bone graft materials using permanent teeth have come to light, and clinical and histological outcomes of this material have been confirmed by some studies. The aim of this systematic review was to evaluate the reliability of the autogenous tooth bone graft material applied to alveolar ridge augmentation procedures. MATERIAL AND METHODS A systematic review of literature was conducted analyzing articles published between 2007 and 2017. The following four outcome variables were defined: a) implant stability b) post-operative complication c) evaluation of implant survival and failure rates, and d) histological analysis. A total of 108 articles were identified; 6 were selected for review. Based on the PICO (problem, intervention, comparison, outcome) model, the chief question of this study was: Can patients with alveolar ridge deficiency be successfully treated with the autogenous teeth used as bone graft? RESULTS The mean primary stability of the placed implants was 67.3 ISQ and the mean secondary stability was 75.5 ISQ. The dehiscence of the wound was the most frequent complication with a rate of 29.1%. Of the 182 analyzed implants, the survival rate was 97.7% and the failure rate was 2.3%. In the histological analysis, most of studies reported bone formation. CONCLUSIONS There is insufficient evidence regarding the effects of autogenous teeth used for bone grafting to support any definitive conclusions, although it has been shown clinically safe and good bone forming capacity, and good results are shown about implant stability.
Collapse
|
16
|
Histological differences in the adherence of connective tissue to laser-treated abutments and standard abutments for dental implants. An experimental pilot study in humans. Med Oral Patol Oral Cir Bucal 2017; 22:e774-e779. [PMID: 29053657 PMCID: PMC5813997 DOI: 10.4317/medoral.21949] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2017] [Accepted: 05/11/2017] [Indexed: 11/26/2022] Open
Abstract
Background The goal of the current study is to assess the difference in connective tissue adherence to laser microtextured versus machined titanium abutments. Material and Methods Six patients were selected and each of them received 2 implants, one combined with a laser treated abutment and one with a machined abutment. After three months, the abutments were retrieved together with their surrounding gingival tissue for histological analysis. Qualitative and quantitative evaluation of microscopical images was performed to assess the presence or absence of adherence between the soft tissues and the abutment, and the percentage of soft tissue adhered to the two different surfaces. Results Intimate adherence between connective tissue and the laser treated abutments, while on machined abutments no adherence was detected. A significant difference was found in the percentage of surface in contact with soft tissue between both implant abutments p=0.03. Conclusions Within the limitation of the current study, it can be concluded that connective tissues show enhanced adherence to microtextured abutments compared to machined abutments. Key words:Abutment, connective tissue, dental implant, gingiva, human, laser.
Collapse
|
17
|
Oral manifestations of Diabetes Mellitus. A systematic review. Med Oral Patol Oral Cir Bucal 2017; 22:e586-e594. [PMID: 28809366 PMCID: PMC5694181 DOI: 10.4317/medoral.21655] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2016] [Accepted: 01/24/2017] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND Diabetes Mellitus has become a global epidemic and presents many complications, usually proportional to the degree and duration of hyperglycemia. The aim of this systematic review was to investigate the different oral manifestations associated with Diabetes Mellitus. MATERIAL AND METHODS A MEDLINE search for "Diabetes Mellitus and oral manifestations" was performed. A further search was conducted for "diabetes" and its individual oral manifestation. Inclusion criteria were as follows: human clinical studies with a minimum of 30 patients; studies published in relevant scientific journals between January 1998 and January 2016. Nineteen studies fulfilled the inclusion criteria and were analyzed, assessing the strength of scientific evidence according to recommendations made by the Centre for Evidence-Based Medicine, Oxford (OCEBM), which permits adequate assessment of prevalence studies. RESULTS A total 3,712 patients (2,084 diabetics) were included in the studies reviewed. Of the 19 studies analyzed, 4 were longitudinal studies and 15 cross-sectional studies. Periodontal disease, periapical lesions, xerostomia and taste disturbance were more prevalent among diabetic patients. An association between diabetes and caries and mucosal lesions proved positive in 5 out of 10 studies. CONCLUSIONS Despite multiple oral manifestations associated with DM, awareness of the associations between diabetes, oral health, and general health is inadequate. It is necessary for doctors and dentists to be aware of the various oral manifestations of diabetes in order to make an early diagnosis.
Collapse
|
18
|
Probiotics and oral health: A systematic review. Med Oral Patol Oral Cir Bucal 2017; 22:e282-e288. [PMID: 28390121 PMCID: PMC5432076 DOI: 10.4317/medoral.21494] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2016] [Accepted: 01/17/2017] [Indexed: 12/14/2022] Open
Abstract
Background Probiotics are microorganisms, mainly bacteria, which benefit the host’s health. Many studies support the role of probiotics as a contributor to gastrointestinal health, and nowadays many authors are trying to prove its influence in oral health maintenance. Objectives To review the published literature with the purpose of knowing the importance of using probiotics as a preventive and therapeutic method for oral infectious diseases management. Material and Methods An electronic search in PubMed database with the keywords “oral health AND probiotics AND dentistry” was conducted. The inclusion criteria were: randomized clinical trials (RCTs) that assess the action of any probiotic strain in the treatment and / or prevention of an infectious oral disease, RCTs that assess the action of any probiotic strain on counting colony forming units (CFU) of oral pathogens, systematic reviews and meta-analysis. The Jadad scale was used to assess the high quality of RCTs. Results Fifteen articles were considered for this review. Of which, 12 were RCTs of good / high quality (Jadad scale), two meta-analysis and one systematic review. Conclusions The literature reviewed suggests probiotics usage could be beneficial for the maintenance of oral health, due to its ability to decrease the colony forming units (CFU) counts of the oral pathogens. However, randomized clinical trials with long-term follow-up periods are needed to confirm their efficacy in reducing the prevalence/incidence of oral infectious diseases. Furthermore, the recognition of specific strains with probiotic activity for each infectious oral disease is required, in order to determine exact dose, treatment time and ideal vehicles. Key words:Probiotics, periodontal diseases, dental caries, oral health.
Collapse
|
19
|
Inflammatory papillary hyperplasia: A systematic review. Med Oral Patol Oral Cir Bucal 2017; 22:e36-e42. [PMID: 27918740 PMCID: PMC5217495 DOI: 10.4317/medoral.21405] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2016] [Accepted: 11/03/2016] [Indexed: 12/14/2022] Open
Abstract
INTRODUCTION Inflammatory papillary hyperplasia (IPH) is a benign lesion of the palatal mucosa. It is usually found in denture-wearers but also has been reported in patients without a history of use of a maxillary prosthesis use. OBJECTIVES The aim of this study is to review the literature to assess the prevalence of denture stomatitis and inflammatory papillary hyperplasia and the etiological factors associated. MATERIAL AND METHODS A search was carried out in PubMed (January 2005 to October 2015) with the key words "inflammatory papillary hyperplasia", "denture stomatitis", "granular stomatitis" and "Newton's type III" The inclusion criteria were studies including at least a sample of 50 apparently healthy patients, articles published from 2005 to 2015 written in English. The exclusion criteria were reviews and non-human studies. RESULTS Out of the 190 studies obtained initially from the search 16 articles were selected to be included in our systematic review. The prevalence of denture stomatitis was 29.56% and 4.44% for IPH. We found 5 cases of denture stomatitis among non-denture-wearer individuals. All IPH cases were associated with the use of prosthesis. Smoking and continued use of ill-fitting dentures turned out to be the most frequent risk factors for developing IPH. CONCLUSIONS IPH is a rare oral lesion and its pathogenesis still remains unclear. Its presentation among non-denture-wearers is extremely unusual.
Collapse
|
20
|
Glycemic control and maternal and fetal outcomes in pregnant women with type 1 diabetes according to the type of basal insulin. Eur J Obstet Gynecol Reprod Biol 2016; 206:84-91. [DOI: 10.1016/j.ejogrb.2016.07.490] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2015] [Revised: 07/08/2016] [Accepted: 07/26/2016] [Indexed: 10/21/2022]
|
21
|
Correlation between periodontal disease management and metabolic control of type 2 diabetes mellitus. A systematic literature review. Med Oral Patol Oral Cir Bucal 2016; 21:e440-6. [PMID: 26827070 PMCID: PMC4920457 DOI: 10.4317/medoral.21048] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2015] [Accepted: 11/11/2015] [Indexed: 12/23/2022] Open
Abstract
Background Diabetes and periodontal disease share common features in terms of inflammatory responses. Current scientific evidence suggests that treatment of periodontal disease might contribute to glycemic control. The objective of the study is a review of the last three years. Material and Methods A literature search was performed in the MEDLINE (PubMed), Cochrane, and Scopus databases, for articles published between 01-01-2013 and 30-06-2015, applying the key terms “periodontal disease” AND “diabetes mellitus”. The review analyzed clinical trials of humans published in English and Spanish. Results Thirteen clinical trials were reviewed, representing a total of 1,912 patients. Three of them had samples of <40 patients, making a total of 108 patients and the remaining ten samples had >40 patients, representing a total of 1,804. Only one article achieved a Jadad score of five. Seven articles (998 patients, 52.3% total), presented a statistically significant decrease in HbA1c (p<
0.05) as a result of periodontal treatment. In the six remaining articles (representing 914 patients, 47.8% of the total), the decrease in HbA1c was not significant. Patient follow-up varied between 3 to 12 months. In three articles, the follow-up was of 3, 4, and 9 months, in two 6 and 12 months. Conclusions The majority of clinical trials showed that radicular curettage and smoothing, whether associated with antibiotics or not, can improve periodontal conditions in patients with diabetes mellitus. However, few studies suggest that this periodontal treatment improves metabolic control. However, there is no clear evidence of a relation between periodontal treatment and improved glycemic control in patients with type 2 diabetes mellitus. Key words:Diabetes, periodontal disease, HbA1c, metabolic control.
Collapse
|
22
|
High prevalence of radiolucent periapical lesions amongst patients with inherited coagulation disorders. Haemophilia 2013; 19:e110-5. [DOI: 10.1111/hae.12089] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/12/2012] [Indexed: 02/07/2023]
|
23
|
Gait parameters in a reference sample of healthy Spanish schoolchildren: multivariate descriptive statistics and asymmetries observed in left and right cycles. Neurologia 2012; 28:145-52. [PMID: 22703633 DOI: 10.1016/j.nrl.2012.04.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2011] [Revised: 03/17/2012] [Accepted: 04/01/2012] [Indexed: 11/16/2022] Open
Abstract
INTRODUCTION Instrumental gait analysis is an emerging technology used increasingly to evaluate motor disorders in children. Normal reference data is necessary in order to evaluate patients, but there are few reference resources for the Spanish paediatric population. OBJECTIVE We aim to describe the values of 16 clinically relevant gait variables in healthy Spanish schoolchildren, and identify any linear associations or left-right asymmetries. SUBJECTS AND METHODS The values of 16 gait variables were determined in schoolchildren (n=27, aged 5-13 years) using instrumental gait analysis. We analysed asymmetries for each variable (Student's t-test for dependent samples) and calculated their confidence intervals (95% of the standardised difference in right and left means [SMD]). Values and associations between variables were represented using a heat map. RESULTS Our project presents normal values tables for 16 variables in the gait cycle. Significant asymmetries were detected in the mean values for minimum hip flexion (SMD: 0.25 95% CI, 0.11-0.39) and peak hip abduction in swing (SMD: -1.05 95% CI: -1.71--0.27). Functional associations among gait variables are present. CONCLUSIONS We present a reference dataset for Spanish school-aged children in which left-right asymmetries and functional associations may be observed for different variables.
Collapse
|
24
|
Diabetes mellitus, periapical inflammation and endodontic treatment outcome. Med Oral Patol Oral Cir Bucal 2012; 17:e356-61. [PMID: 22143698 PMCID: PMC3448330 DOI: 10.4317/medoral.17452] [Citation(s) in RCA: 80] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2010] [Accepted: 02/26/2011] [Indexed: 12/25/2022] Open
Abstract
The possible connection between chronic oral inflammatory processes, such as apical periodontitis and periodontal disease (PD), and systemic health is one of the most interesting aspects faced by the medical and dental scientific community. Chronic apical periodontitis shares important characteristics with PD: 1) both are chronic infections of the oral cavity, 2) the Gram-negative anaerobic microbiota found in both diseases is comparable, and 3) in both infectious processes increased local levels of inflammatory mediators may have an impact on systemic levels. One of the systemic disorders linked to PD is diabetes mellitus (DM); is therefore plausible to assume that chronic apical periodontitis and endodontic treatment are also associated with DM. The status of knowledge regarding the relationship between DM and endodontics is reviewed. Upon review, we conclude that there are data in the literature that associate DM with a higher prevalence of periapical lesions, greater size of the osteolityc lesions, greater likelihood of asymptomatic infections and worse prognosis for root filled teeth. The results of some studies suggest that periapical disease may contribute to diabetic metabolic dyscontrol. Key words: Apical periodontitis, diabetes mellitus, endodontics, root canal treatment.
Collapse
|
25
|
Inferior alveolar nerve injury resulting from overextension of an endodontic sealer: non-surgical management using the GABA analogue pregabalin. Int Endod J 2011; 45:98-104. [PMID: 21883296 DOI: 10.1111/j.1365-2591.2011.01939.x] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
AIM To describe a case of endodontic sealer (AH Plus) penetration within the mandibular canal after root canal treatment with resolution of pain and paraesthesia after a non-surgical approach, including treatment with prednisone and pregabalin. SUMMARY A 37-year-old woman underwent root canal treatment of the left mandibular second molar tooth. Postoperative periapical radiographs revealed the presence of radiopaque canal sealer in the mandibular canal. The day after, the patient reported severe pain in the tooth and paraesthesia/anaesthesia in the region innervated by the left inferior alveolar and mental nerve. Diagnosis of injury to the inferior alveolar nerve because of extrusion of AH Plus was established. The non-surgical management included 1 mg kg(-1) per day prednisone, two times per day, in a regimen on a daily basis, and 150 mg per day pregabalin, two doses per day, monitoring the progress with periodic follow-up visits. One month after the incident, the signs and symptoms were gone. KEY LEARNING POINTS This case illustrates the care required when performing root canal treatment, especially when the root apices are in close proximity to the inferior alveolar nerve canal. The complete resolution of paraesthesia and the control of pain achieved in the present case suggests that a non-surgical approach combining prednisone and pregabalin is a good option in the management of the inferior alveolar when it is contacted by extruded root filling material.
Collapse
|
26
|
Response to topical clonazepam in patients with burning mouth syndrome: a clinical study. BULLETIN DU GROUPEMENT INTERNATIONAL POUR LA RECHERCHE SCIENTIFIQUE EN STOMATOLOGIE & ODONTOLOGIE 2010; 49:19-29. [PMID: 22750263] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Received: 05/21/2010] [Indexed: 06/01/2023]
Abstract
Burning Mouth Syndrome (BMS) is a difficult disease for patients and clinicians. Moreover, there is not a general consensus on how to treat the disease. The main objective of this paper is to evaluate BMS patients' response to topical clonazepam treatment. A double blind study was performed. Among a total of 66 patients, 33 were treated with tablets of clonazepam and another 33 were treated with a placebo. Symptoms were evaluated after 1 month and 6 months of treatment and scored on an analogical scale from 0 to 10. Among the 33 patients treated with clonazepam, 23 showed at least a 50% reduction in symptoms after 1 month of treatment. On the contrary, only 4 in the placebo group exhibited significant improvement. After 6 months, significant differences were observed again, as 23 of the 33 patients treated with the drug reported at least a 50% reduction in symptoms, whereas only 2 among those treated with the placebo significantly improved. However, when measured in terms of a complete cure (lack of symptoms), the differences were not significant: 5 drug-treated patients and one belonging to the placebo group were asymptomatic after one month of treatment. In summary, it seems that clonazepam applied topically was effective in treating BMS in a large proportion of patients.
Collapse
|
27
|
[Calcification of the thoracic yellow ligament as a cause of myelopathy]. Rev Neurol 2002; 34:750-3. [PMID: 12080496] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/25/2023]
Abstract
INTRODUCTION Ossified yellow ligaments are a rare cause of thoracic myelopathy, which has been reported mainly in Japanese patients. The lower thoracic spine is the most common site affected and symptomatic patients usually begin to develop spactic paraparesis in combination with reduced depth sensation. CLINICAL CASE A 45 year old female that since 8 months presented progressive gait disturbance with paresthesias to both lower extremities. Neurologic examination revealed a spactic gait with exaggeration of lower extremities reflexes, positive bilateral Babinski sign and reduced depth sensation. The MRI revealed concentric narrowing of the spinal canal between D(8) to D(11) with spinal cord compression due to enlarged calcified yellow ligaments and hypertrophy of articular processes. A D(9)-D(10) laminectomy was performed, with removed of calcified yellow ligaments, and foraminotomy in affected levels. The postoperative follow up during 30 months has been uneventful. CONCLUSION Calcified yellow ligaments are a poorly understood cause of thoracic myelopathy which should be treated as early as possible in symptomatic patients.
Collapse
|
28
|
Abstract
Ionic currents of enzymatically dispersed type I and type II cells of the carotid body have been studied using the whole cell variant of the patch-clamp technique. Type II cells only have a tiny, slowly activating outward potassium current. By contrast, in every type I chemoreceptor cell studied we found (a) sodium, (b) calcium, and (c) potassium currents. (a) The sodium current has a fast activation time course and an activation threshold at approximately -40 mV. At all voltages inactivation follows a single exponential time course. The time constant of inactivation is 0.67 ms at 0 mV. Half steady state inactivation occurs at a membrane potential of approximately -50 mV. (b) The calcium current is almost totally abolished when most of the external calcium is replaced by magnesium. The activation threshold of this current is at approximately -40 mV and at 0 mV it reaches a peak amplitude in 6-8 ms. The calcium current inactivates very slowly and only decreases to 27% of the maximal value at the end of 300-ms pulses to 40 mV. The calcium current was about two times larger when barium ions were used as charge carriers instead of calcium ions. Barium ions also shifted 15-20 mV toward negative voltages the conductance vs. voltage curve. Deactivation kinetics of the calcium current follows a biphasic time course well fitted by the sum of two exponentials. At -80 mV the slow component has a time constant of 1.3 +/- 0.4 ms whereas the fast component, with an amplitude about 20 times larger than the slow component, has a time constant of 0.16 +/- 0.03 ms. These results suggest that type I cells have predominantly fast deactivating calcium channels. The slow component of the tails may represent the activity of a small population of slowly deactivating calcium channels, although other possibilities are considered. (c) Potassium current seems to be mainly due to the activity of voltage-dependent potassium channels, but a small percentage of calcium-activated channels may also exist. This current activates slowly, reaches a peak amplitude in 5-10 ms, and thereafter slowly inactivates. Inactivation is almost complete in 250-300 ms. The potassium current is reversibly blocked by tetraethylammonium. Under current-clamp conditions type I cells can spontaneously fire large action potentials. These results indicate that type I cells are excitable and have a variety of ionic conductances. We suggest a possible participation of these conductances in chemoreception.
Collapse
|
29
|
Low pO2 selectively inhibits K channel activity in chemoreceptor cells of the mammalian carotid body. J Gen Physiol 1989; 93:1001-15. [PMID: 2738574 PMCID: PMC2216240 DOI: 10.1085/jgp.93.5.1001] [Citation(s) in RCA: 168] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
The hypothesis that changes in environmental O2 tension (pO2) could affect the ionic conductances of dissociated type I cells of the carotid body was tested. Cells were subjected to whole-cell patch clamp and ionic currents were recorded in a control solution with normal pO2 (pO2 = 150 mmHg) and 3-5 min after exposure to the same solution with a lower pO2. Na and Ca currents were unaffected by lowering pO2 to 10 mmHg, however, in all cells studied (n = 42) exposure to hypoxia produced a reversible reduction of the K current. In 14 cells exposed to a pO2 of 10 mmHg peak K current amplitude decreased to 35 +/- 8% of the control value. The effect of low pO2 was independent of the internal Ca2+ concentration and was observed in the absence of internal exogenous nucleotides. Inhibition of K channel activity by hypoxia is a graded phenomenon and in the range between 70 and 120 mmHg, which includes normal pO2 values in arterial blood, it is directly correlated with pO2 levels. Low pO2 appeared to slow down the activation time course of the K current but deactivation kinetics seemed to be unaltered. Type I cells subjected to current clamp generate large Na- and Ca-dependent action potentials repetitively. Exposure to low pO2 produces a 4-10 mV increase in the action potential amplitude and a faster depolarization rate of pacemaker potentials, which leads to an increase in the firing frequency. Repolarization rate of individual action potentials is, however, unaffected, or slightly increased. The selective inhibition of K channel activity by low pO2 is a phenomenon without precedents in the literature that explains the chemoreceptive properties of type I cells. The nature of the interaction of molecular O2 with the K channel protein is unknown, however, it is argued that a hemoglobin-like O2 sensor, perhaps coupled to a G protein, could be involved.
Collapse
|