Citation Nr: 20072828 Decision Date: 11/12/20 Archive Date: 11/12/20 DOCKET NO. 14-12 534 DATE: November 12, 2020 ORDER Service connection for a low back disability is denied. Service connection for a right knee disability is denied. Service connection for sleep apnea is denied. Service connection for a cardiovascular disability is denied. Service connection for a gastrointestinal disability, claimed as irritable bowel disease and Crohn's disease, is denied. Service connection for diabetes mellitus, type II, is denied. Service connection for narcolepsy is denied. Service connection for a dental disability, claimed as bone loss, is denied. REMANDED Service connection for a respiratory disability, claimed as asbestosis is remanded. Service connection for varicose veins is remanded. REFERRED The issue of entitlement to a total disability rating based on individual unemployability due to service-connected disabilities (TDIU) has been raised repeatedly during the course of this appeal and is referred to the Agency of Original Jurisdiction (AOJ) for adjudication. FINDINGS OF FACT 1. Symptoms of low back and right knee disabilities were not continuous or recurrent in service or since service separation; arthritis did not manifest to a compensable degree during or within one year of active service; and there is no medical nexus between the claimed back and right knee disabilities and active service, including as due to exposure to asbestos, dioxins, radiation, chemicals, or other contaminants. 2. Symptoms of sleep apnea, a cardiovascular disability, a gastrointestinal disability, diabetes, and narcolepsy were not continuous or recurrent in service or since service separation; and there is no medical nexus between the current disabilities and active service, including as due to exposure to asbestos, dioxins, radiation, chemicals, or other contaminants. 3. A current dental disability, to include bone loss, is not demonstrated by the evidence of record. CONCLUSIONS OF LAW 1. The criteria for service connection for a low back disability have not been met. 38 U.S.C. §§ 101, 1101, 1110, 1112, 1113, 1131, 5103(a), 5103A, 5107; 38 C.F.R. §§ 3.102, 3.159, 3.303, 3.304, 3.307, 3.309, 3.311. 2. The criteria for service connection for a right knee disability have not been met. 38 U.S.C. §§ 101, 1101, 1110, 1112, 1113, 1131, 5103(a), 5103A, 5107; 38 C.F.R. §§ 3.102, 3.159, 3.303, 3.304, 3.307, 3.309, 3.311. 3. The criteria for service connection for sleep apnea have not been met. 38 U.S.C. §§ 101, 1101, 1110, 1112, 1113, 1131, 5103(a), 5103A, 5107; 38 C.F.R. §§ 3.102, 3.159, 3.303, 3.304, 3.307, 3.309, 3.311. 4. The criteria for service connection for a cardiovascular disability have not been met. 38 U.S.C. §§ 101, 1101, 1110, 1112, 1113, 1131, 5103(a), 5103A, 5107; 38 C.F.R. §§ 3.102, 3.159, 3.303, 3.304, 3.307, 3.309, 3.311. 5. The criteria for service connection for a gastrointestinal disability have not been met. 38 U.S.C. §§ 101, 1101, 1110, 1112, 1113, 1131, 5103(a), 5103A, 5107; 38 C.F.R. §§ 3.102, 3.159, 3.303, 3.304, 3.307, 3.309, 3.311. 6. The criteria for service connection for diabetes mellitus type II have not been met. 38 U.S.C. §§ 101, 1101, 1110, 1112, 1113, 1131, 5103(a), 5103A, 5107; 38 C.F.R. §§ 3.102, 3.159, 3.303, 3.304, 3.307, 3.309, 3.311. 7. The criteria for service connection for narcolepsy have not been met. 38 U.S.C. §§ 101, 1101, 1110, 1112, 1113, 1131, 5103(a), 5103A, 5107; 38 C.F.R. §§ 3.102, 3.159, 3.303, 3.304, 3.307, 3.309, 3.311. 8. The criteria for service connection for a dental disability for both compensation and treatment purposes have not been met. 38 U.S.C. § 1712; 38 C.F.R. §§ 3.381, 4.150, 17.161. REASONS AND BASES FOR FINDINGS AND CONCLUSIONS The Veteran, who is the Appellant in this case, had active service from September 1969 to July 1976. This matter comes before the Board of Veterans’ Appeals (BVA or Board) from a May 2010 rating decision by the Department of Veterans Affairs (VA) Regional Office (RO) in St. Petersburg, Florida. The Veteran provided testimony at a September 2017 videoconference hearing before the undersigned Veterans Law Judge at the RO. A transcript of the hearing is associated with the claims folder. In March 2018 and May 2019, the Board remanded the case for further development. While the Board regrets the delay, additional development is required prior to appellate review with regard to the claimed respiratory disability and varicose veins. The development requested with regard to the remaining issues has been completed, and those claims are appropriate for appellate review. Service Connection Service connection may be granted for a disability resulting from disease or injury incurred in or aggravated by active military, naval, or air service. 38 U.S.C. §§ 1110, 1131; 38 C.F.R. § 3.303(a). Establishing service connection generally requires (1) competent evidence of a current disability; (2) medical or, in certain circumstances, lay evidence of in-service incurrence or aggravation of a disease or injury; and (3) competent evidence of a nexus between the claimed in-service disease or injury and the present disability. Shedden v. Principi, 381 F.3d 1163, 1167 (Fed. Cir. 2004). The United States Court of Appeals for Veterans Claims (Court) has held that “Congress specifically limits entitlement for service-connected disease or injury to cases where such incidents have resulted in a disability. In the absence of proof of a present disability there can be no valid claim.” Brammer v. Derwinski, 3 Vet. App. 223, 225 (1992); see also Rabideau v. Derwinski, 2 Vet. App. 141, 143-44 (1992). Where a veteran who served for ninety days or more during a period of war (or during peacetime service after December 31, 1946) develops certain chronic diseases, such as arthritis, to a degree of 10 percent or more within one year from separation from service, such diseases may be presumed to have been incurred in service even though there is no evidence of such disease during the period of service. This presumption is rebuttable by affirmative evidence to the contrary. See 38 U.S.C. §§ 1101, 1112, 1113, 1137; 38 C.F.R. §§ 3.307, 3.309(a). In this case, as discussed below, the medical evidence of record demonstrates current arthritis of the back and right knee. Where the veteran asserts entitlement to service connection for a chronic disease but there is insufficient evidence of a diagnosis in service, service connection may be established under 38 C.F.R. § 3.303(b) by demonstrating a continuity of symptomatology since service or diagnosis within the presumptive period after service, but only if the chronic disease is listed under 38 C.F.R. § 3.309(a). Walker v. Shinseki, 708 F.3d 1331, 1338-39 (Fed. Cir. 2013); 38 C.F.R. § 3.307 (service connection authorized for chronic diseases diagnosed within the presumptive period). However, for the reasons set forth below, the Veteran was not diagnosed with arthritis within one year of separation from service, nor has there been continuity of symptomatology. With specific regard to continuity of symptomatology, for the showing of chronic disease in service, there is required a combination of manifestations sufficient to identify the disease entity, and sufficient observation to establish chronicity at the time. With chronic disease as such in service, subsequent manifestations of the same chronic disease at any later date, however remote, are service connected, unless clearly attributable to intercurrent causes. If a condition, such as arthritis, noted during service is not shown to be chronic, then generally, a showing of continuity of symptoms after service is required for service connection. 38 C.F.R. § 3.303(b). The remaining conditions at issue are not among the “chronic diseases” listed under 38 C.F.R. § 3.309(a); therefore, 38 C.F.R. § 3.309(b) (requiring continuity of a condition after service if chronicity is not found in service) does not apply to those disorders. See Walker, 708 F.3d 1331. Service connection may also be granted for any disease diagnosed after discharge, when all the evidence, including that pertinent to service, establishes that the disease was incurred in service. 38 C.F.R. § 3.303(d). The Veteran contends that he was exposed to asbestos, dioxins (including Agent Orange), radiation, PCBs, and multiple other chemicals that have been classified as carcinogens during active service while stationed at Treasure Island, and aboard the USS Wilson and Biddle, and that such exposure led to the development of his claimed disabilities. In support of this contention, he has submitted a number of articles and documents demonstrating that Treasure Island was found to have a number of contaminants, including low-level radioactive waste, polychlorinated biphenyls (PCBs), dioxins, pesticides, waste oil and fuel, solvents, asbestos, acids, and heavy metals. He has also stated that he was exposed to asbestos in the engine and boiler rooms of the USS Wilson and Biddle, and that he slept inches from asbestos-wrapped pipes on those ships. Further, he states that, while stationed at Treasure Island, he was trained around military equipment that contained “radium and other ionized radiation.” See, e.g., articles and correspondence received on September 8, 2010, May 18, 2011, August 30, 2013, and December 20, 2018. A January 2013 DPRIS response indicated that there was no DD Form 1141 or other record of exposure to radiation in the Veteran’s service records, nor was there any record of exposure to herbicides. A March 2014 DPRIS response indicated that the 1970 command history submitted by the Naval Schools Command (NSC) and Naval Station (NS), Treasure Island, San Francisco, CA was reviewed, and that the history does not document Agent Orange/tactical herbicides/plutonium/radium/radiation exposure as described by the Veteran. In addition, the Department of Defense (DOD) listing of herbicide spray areas and test sites outside of Vietnam was reviewed, and, according to that document, Agent Orange and other tactical herbicides were not used, tested, disposed of, or stored at Treasure Island during the period January 1 through December 31, 1970. Further, the Superfund Redevelopment Program submitted by the EPA was reviewed; the Treasure Island Naval Station (NS) is listed under the non-National Priority List sites. The EPA has identified the Hunters Point Naval Shipyard as a Superfund site for contamination of the site’s surface and ground water. However, DPRIS stated that it could not document or verify that the Veteran was exposed to Agent Orange/tactical herbicides/plutonium/radium/radiation or that he was in the specific vicinity of the program. Available unit histories do not document or mention that unit members performed duties in the program site areas. The RO was instructed to contact the Navy and Marine Corps Public Health Center for information regarding inquiring concerning non-AO herbicide issues such as chemicals, asbestos, pesticides, and radiation. In May 2020, the Navy and Marine Corps Public Health Center responded that the center does not retain medical records, nor does it retain records regarding the use of chemicals, pesticides, or insecticides at Naval Station Treasure Island in 1970. However, a search of the Navy’s Asbestos Medical Surveillance Program registry for information regarding the Veteran produced no records. This is most likely due to the fact the during the time the Veteran served (1970), there were no requirements to monitor exposure. Additionally, the Naval Dosimetry Center conducted a review of their exposure registry by name and command, which also revealed no reports of occupational exposure to ionizing radiation pertaining to the Veteran. There is no specific statutory guidance with regard to asbestos-related claims, nor has VA promulgated any regulations in regard to such claims. However, VA has issued a circular on asbestos-related diseases (DVB Circular 21-88-8, Asbestos-Related Diseases (May 11, 1988) (DVB Circular)) that provides guidelines for considering compensation claims based on exposure to asbestos. The DVB Circular was subsumed verbatim as § 7.21 of Adjudication Procedure Manual, M21-1, Part VI. See also VAOPGCPREC 4-00. The guidelines provide that the latency period for asbestos- related diseases varies from 10 to 45 years or more between first exposure and development of disease. It is noted that an asbestos- related disease can develop from brief exposure to asbestos or as a bystander. The Court has held that VA must analyze an appellant’s claim to entitlement to service connection for asbestosis or asbestos-related disabilities under the administrative protocols under these guidelines. Ennis v. Brown, 4 Vet. App, 523, 527 (1993); McGinty v. Brown, 4 Vet. App. 428, 432 (1993). Inhalation of asbestos fibers can produce fibrosis (the most commonly occurring of which is interstitial fibrosis, or asbestosis); tumors; pleural effusions and fibrosis; pleural plaques; and, cancers of the lung, bronchus, larynx, pharynx and urogenital system (except the prostate). M21-1, IV.ii.2.C.2.b. Specific effects of exposure to asbestos include lung cancer, gastrointestinal cancer, urogenital cancer, and mesothelioma. Disease-causing exposure to asbestos may be brief and/or indirect. Current smokers who have been exposed to asbestos face greater risk of developing bronchial cancer, but mesotheliomas are not associated with cigarette smoking. M21-1, IV.ii.2.C.2.c. In Dyment v. West, 13 Vet. App. 141, 145 (1999), the Court found that provisions in former paragraph 7.68 (predecessor to paragraph 7.21) of VBA Manual M21-1, Part VI, did not create a presumption of exposure to asbestos. Medical nexus evidence is required in claims for asbestos related disease related to alleged asbestos exposure in service. VAOPGCPREC 4-00. Notably, the Veteran in this case has not been diagnosed with any of the conditions associated with asbestos exposure as listed in the VBA Manual M21-1, and, for the reasons discussed below, the weight of the evidence is against a finding of a medical nexus between any of the claimed conditions and asbestos exposure. Service connection can also be presumed if a veteran was exposed to an herbicide agent during active service. 38 C.F.R. § 3.309(e). In this case, based on the Veteran’s service record, there is no presumed exposure to herbicides during active service and no other evidence in his service record of herbicide exposure, and he has not been diagnosed with any of the conditions subject to presumptive service connection due to herbicide exposure under 38 C.F.R. § 3.309(e). However, if there is no presumptive service connection available, as in this case, direct service connection can be established if the record contains competent medical evidence of a current disease process with a relationship to exposure to an herbicide agent while in military service. See 38 U.S.C. §§ 1110, 1131; 38 C.F.R. § 3.303; Combee v. Brown, 34 F.3d 1039, 1043-44 (Fed. Cir. 1994). For the reasons discussed below, the weight of the evidence is against a medical nexus between any of the claimed disabilities and herbicide or other dioxin exposure in service. Finally, the Veteran has also claimed that he was exposed to ionizing radiation during active service, and that this led to several of his claimed disabilities, including the claimed cardiovascular and gastrointestinal disabilities. Service connection for a disorder which is claimed to be attributable to ionizing radiation exposure during service can be accomplished in three different ways. See Ramey v. Brown, 9 Vet. App. 40, 44 (1996), affirmed at 120 F.3d. 1239 (Fed. Cir. 1997). First, there are certain types of cancer which will be presumptively service connected for radiation-exposed veterans. The Veteran in this case has not been diagnosed with any of the diseases presumptively related to radiation exposure. See 38 U.S.C. § 1112(c); 38 C.F.R. § 3.309(d). Second, 38 C.F.R. § 3.311(b) includes a list of “radiogenic diseases” which will be service connected provided that certain conditions specified in that regulation are met. For purposes of this section the term “radiogenic disease” means a disease that may be induced by ionizing radiation and includes a number of cancers. The regulation states that, if the veteran has one of the radiogenic diseases, a radiation dose assessment will be obtained and the case will be referred to the Under Secretary for Benefits for review as to whether sound scientific medical evidence supports the conclusion that it is at least as likely as not that the veteran’s disease resulted from radiation exposure during service. In this case, the Veteran has not been diagnosed with any of the radiogenic diseases listed in 38 C.F.R. § 3.311(b). Third, direct service connection can be established by “show[ing] that the disease or malady was incurred during or aggravated by service, a task which includes the difficult burden of tracing causation to a condition or event during service.” See Combee, 34 F.3d at 1043. The Court has taken judicial notice that naval radar equipment emits microwave-type non-ionizing radiation, which is not subject to review under the ionizing radiation statute and regulations. Rucker v. Brown, 10 Vet. App. 67 (1997), citing The Microwave Problem, Scientific American, September 1986; Effects upon Health of Occupational Exposure to Microwave Radiation (RADAR), American Journal of Epidemiology, Vol. 112, 1980; and Biological Effects of Radiofrequency Radiation, United States Environmental Protection Agency, September 1984. Thus, the Veteran’s contentions that he was exposed to radiation from military equipment, which are accepted as accurate, do not place his claim under the scope of the cited provisions addressing diseases associated with ionizing radiation and radiogenic diseases, and development under these provisions is not necessary. See 38 C.F.R. § 3.311(b). As above, the Board also notes none of the claimed disabilities are listed among the radiogenic diseases under 38 C.F.R. § 3.311(b), and a search of department records by the Naval Dosimetry Center has not indicated that the Veteran had in-service exposure to ionizing radiation. Accordingly, as there is no evidence from official sources of actual exposure to ionizing radiation in this case, the Board finds that the provisions pertaining to claims based on radiation exposure are not for application in this case, and that further development pursuant to 38 C.F.R. § 3.311 is not necessary in this case. Moreover, for the reasons discussed below, the weight of the evidence is against a finding of a medical nexus between any of the claimed disabilities and exposure to non-ionizing radiation in active service. 1. Service connection for a low back disability is denied. The Veteran contends that his current back disability is related to active service. Specifically, he avers that his back condition is the result of one leg being shorter than the other, which altered his gait, and that this condition was aggravated by active service, including exposure to contaminants. For the reasons discussed below, the Board finds that the weight of the evidence is against a finding of a medical nexus between the current back disability and active service, including exposure to asbestos, dioxins, radiation, or other chemicals and contaminants during active service. Reviewing the most relevant evidence of record, service treatment records are entirely negative for any signs, reports, findings, treatment, or diagnoses of a back problem, including the May 1976 Resignation of Commission examination report which demonstrates normal clinical evaluation of the spine. Following separation from service, in May 2009, the Veteran sought treatment for back pain, which he had chronically since a car accident in 1988. He stated that that that time, it was found that he had a leg-length discrepancy, with the right leg being a few centimeters shorter than the left, and for which he currently wore a lift. The clinician diagnosed lumbago and chronic low back pain, exam suspicious for L5 or S1 radiculopathy. An MRI was ordered, and he was referred to PT. The May 2009 of lumbar spine revealed degenerative disc disease at L5-S1 with grade 1 retrolisthesis and facet hypertrophy, mild foraminal stenosis slightly worse on the right, L4-L5 bulging disc and facet hypertrophy, mid disc bulges at L2-3 and L3-4 without significant herniation, and mild facet hypertrophy. In July 2009, the Veteran reported lower back problems for “many years,” and the clinician noted that he was diagnosed with degenerative disc disease, nonsurgical. The Veteran was told to follow up as needed. In 2009, the Veteran filed for Social Security Disability benefits, and on his application for benefits, he indicated that he began to have problems with his back in 1997. The Veteran’s Social Security Administration records have been associated with the claims file, and an October 2009 SSA Disability Determination and Transmittal indicates that the Veteran was found not to be disabled. A January 2011 x-ray of the lumbosacral spine revealed disc disease at L5-S1, with no other abnormalities except for minimal degenerative changes with small osteophytes. At a March 2011 VA spine examination, the Veteran reported that he injured his neck in a whiplash injury in 1970 and specifically denied any other injuries in the military. He reported that he eventually developed pain in his lower back, which radiated down from his neck to his lower back. Imaging from January 2011 showed lumbar degenerative disc disease at L5-S1 with osteophytes. Diagnoses were cervical strain and lumbar spine degenerative disc disease. The VA examiner did not provide any opinion regarding the lumbar spine condition, as the purpose of the examination was for the neck disability. At the September 2017 Board hearing, the Veteran testified that he injured his low back during active service when he was lifted from a ship with a collar and transported to a carrier. He stated that he sought treatment in the infirmary for this injury on one occasion and did not receive any medication or physical therapy. An October 2019 VA treatment note indicates that the Veteran reported a chronic history of low back pain with a gradual non-specific onset of symptoms. After a review of all the evidence of record, lay and medical, the Board finds that the weight of the competent evidence demonstrates there is no relationship between the Veteran’s current back disability and his military service, including no credible evidence of continuous or recurrent symptoms of the claimed disability during active service, continuous or recurrent symptomatology of the claimed disability following service separation, or competent medical evidence establishing a link between the current disability and active service, including as due to asbestos, dioxin, radiation, or other chemical exposures. Therefore, the Board finds that a preponderance of the evidence that is of record weighs against the claim for service connection for the back disability and outweighs the Veteran’s more recent contentions regarding in-service continuous or recurrent symptoms and continuous or recurrent post-service symptoms. First, as discussed above, service treatment records are entirely negative for any signs, symptoms, reports, treatment, or diagnoses of a back disability, including the negative May 1976 examination. Thus, the evidence weighs against a finding of chronic symptoms of the claimed disability during active service. Next, the preponderance of the evidence demonstrates that arthritis did not manifest to a compensable degree within one year of service separation. The preponderance of the evidence demonstrates no arthritis symptoms during the one-year period after service, and no diagnosis or findings of arthritis of any severity during the one-year post-service presumptive period. Indeed, the evidence does not demonstrate a diagnosis of back arthritis until 2009. For these reasons, the Board finds that arthritis did not manifest to a compensable degree within one year of service separation; therefore, the presumptive provisions for arthritis are not applicable in this case. 38 C.F.R. §§ 3.307, 3.309. The Board next finds that the preponderance of the evidence demonstrates that symptoms of a back disability were not continuous or recurrent since separation from active service in July 1976. The first post-service documentation of a back problem was in 2009, when the Veteran reported back pain since a post-service 1988 car accident, as outlined above. The absence of post-service complaints, findings, diagnosis, or treatment for back problems for 33 years after service separation is one factor that tends to weigh against a finding of continuous or recurrent symptoms of the claimed disability after service separation. See Buchanan v. Nicholson, 451 F.3d 1331, 1336 (Fed. Cir. 2006) (the lack of contemporaneous medical records is one fact the Board can consider and weigh against the other evidence, although the lack of such medical records does not, in and of itself, render the lay evidence not credible). Additional evidence demonstrating that symptoms of the claimed disability were not continuous or recurrent since service separation includes the Veteran’s own statements made in the course of seeking treatment, such as in May 2009, when he reported back pain since the 1988 car accident, and in his 2009 application for SSD benefits, when he stated his back problems began in 1997. These statements provide highly probative evidence against the current claim of continuous back symptoms since active service and place inception of back symptoms many years after service separation. With regard to the Veteran’s more recent assertions made in the context of the current disability claim of continuous or recurrent back disability symptoms since service, the Board finds that, while the Veteran is competent to report the onset of symptoms of the claimed disability, these more recent assertions are outweighed by the other, more contemporaneous, lay and medical evidence of record, both in service and after service, and are not reliable. See Charles v. Principi, 16 Vet. App. 370 (2002). The Board finds that the Veteran’s assertions of continuous or recurrent symptoms of the claimed disability after service are not accurate because they are outweighed by other evidence of record that includes the more contemporaneous service treatment records, which are entirely negative for any signs, symptoms, reports, findings, treatment, or diagnoses of a back disability; the Veteran’s statements in 2009 that his back pain began after a post-service 1988 car accident, and that he first experienced back problems in 1997, placing inception of back problems many years after service separation and following a post-service accident; and the lack of any medical documentation of reports or treatment for back pain until 2009, more than several decades after service separation. As such, the Board does not find that the evidence sufficiently supports continuous or recurrent symptomatology of the claimed disability since service so as to warrant a grant of service connection. Finally, the Board finds that the weight of the competent medical evidence weighs against a finding of a medical nexus between the current back disability and active service. The Board notes that no competent medical opinions have been received relating the claimed back disability to active service to include exposure to asbestos, dioxins, radiation, or other chemicals and contaminants, nor does the medical evidence of record otherwise suggest such an etiological relationship. The Board also notes that the Veteran denied any injury to his back at the March 2011 VA examination. The Board acknowledges the Veteran’s belief that his back disability is related to his active service. However, his statements alone do not establish a medical nexus. Indeed, while the Veteran is competent to provide evidence regarding matters that can be perceived by the senses, he is not shown to be competent to render medical opinions on questions of etiology. See Jandreau v. Nicholson, 492 F.3d 1372 (Fed. Cir. 2007); see also Barr v. Nicholson, 21 Vet. App. 303 (2007) (lay testimony is competent to establish the presence of observable symptomatology). As such, as a layperson, he is without the appropriate medical training and expertise to offer an opinion on a medical matter, including the diagnosis, etiology, or causation of a specific disability. The question of diagnosis and causation, in this case, involves complex medical issues that the Veteran is not competent to address. Jandreau. For these reasons, the claim must be denied. Because the preponderance of the evidence is against the claim, the benefit of the doubt doctrine is not for application. See 38 U.S.C. § 5107; 38 C.F.R. § 3.102. 2. Service connection for a right knee disability is denied. The Veteran contends that his current right knee disability is related to active service. Specifically, he avers that his right knee condition was caused by asbestos exposure in active service. For the reasons discussed below, the Board finds that the weight of the evidence is against a finding of a medical nexus between the current right knee disability and active service, including exposure to asbestos, dioxins, radiation, or other chemicals and contaminants during active service. Reviewing the most relevant evidence of record, service treatment records are entirely negative for any signs, reports, findings, treatment, or diagnoses of a right knee problem, including the May 1976 Resignation of Commission examination report which demonstrates normal clinical evaluation of the lower extremities. Following separation from service, in August 2006, the Veteran reported 6 to 7 months of right knee pain with no specific injury. X-ray revealed moderate medial joint line narrowing consistent with arthritis, very mild in nature. MRI revealed degenerative changes within the medial meniscus without any evidence of a distinct tear. He also had a Baker’s cyst. The diagnosis was osteoarthritis of the right knee with degenerative meniscal changes consistent with the arthritis. At the September 2017 Board hearing, when asked what happened in service to cause his current right knee disability, the Veteran replied that he did not know, but that after he separated from active service, a Baker’s cyst was discovered in his right knee. After a review of all the evidence of record, lay and medical, the Board finds that the weight of the competent evidence demonstrates there is no relationship between the Veteran’s current right knee disability and his military service, including no credible evidence of continuous or recurrent symptoms of the claimed disability during active service, continuous or recurrent symptomatology of the claimed disability following service separation, or competent medical evidence establishing a link between the current disability and active service, including as due to asbestos, dioxin, radiation, or other chemical exposures. Therefore, the Board finds that a preponderance of the evidence that is of record weighs against the claim for service connection for the right knee disability and outweighs the Veteran’s more recent contentions regarding in-service continuous or recurrent symptoms and continuous or recurrent post-service symptoms. First, as discussed above, service treatment records are entirely negative for any signs, symptoms, reports, treatment, or diagnoses of a right knee disability, including the negative May 1976 examination. Thus, the evidence weighs against a finding of chronic symptoms of the claimed disability during active service. Next, the preponderance of the evidence demonstrates that arthritis did not manifest to a compensable degree within one year of service separation. The preponderance of the evidence demonstrates no arthritis symptoms during the one-year period after service, and no diagnosis or findings of arthritis of any severity during the one-year post-service presumptive period. Indeed, the evidence does not demonstrate a diagnosis of right knee arthritis until 2006. For these reasons, the Board finds that arthritis did not manifest to a compensable degree within one year of service separation; therefore, the presumptive provisions for arthritis are not applicable in this case. 38 C.F.R. §§ 3.307, 3.309. The Board next finds that the preponderance of the evidence demonstrates that symptoms of a right knee disability were not continuous or recurrent since separation from active service in July 1976. The first post-service documentation of a right knee problem was in 2006, when the Veteran reported right knee pain for the previous 6 or 7 months, as outlined above. The absence of post-service complaints, findings, diagnosis, or treatment for right knee problems for 30 years after service separation is one factor that tends to weigh against a finding of continuous or recurrent symptoms of the claimed disability after service separation. See Buchanan v. Nicholson, 451 F.3d 1331, 1336 (Fed. Cir. 2006) (the lack of contemporaneous medical records is one fact the Board can consider and weigh against the other evidence, although the lack of such medical records does not, in and of itself, render the lay evidence not credible). Additional evidence demonstrating that symptoms of the claimed disability were not continuous or recurrent since service separation includes the Veteran’s own statements made in the course of seeking treatment; namely, in 2006, he reported right knee pain of 6 or 7 months’ duration, placing inception of the right knee symptoms many years after service separation. In addition, at an October 2010 Agent Orange Protocol Examination, the Veteran reported that he had experienced right knee discomfort since the 1980s, which he attributed to a discrepancy in leg length. These statements provide highly probative evidence against the current claim of continuous right symptoms since active service. With regard to the Veteran’s more recent assertions made in the context of the current disability claim of continuous or recurrent right knee disability symptoms since service, the Board finds that, while the Veteran is competent to report the onset of symptoms of the claimed disability, these more recent assertions are outweighed by the other, more contemporaneous, lay and medical evidence of record, both in service and after service, and are not reliable. See Charles, 16 Vet. App. 370. The Board finds that the Veteran’s assertions of continuous or recurrent symptoms of the claimed disability after service are not accurate because they are outweighed by other evidence of record that includes the more contemporaneous service treatment records, which are entirely negative for any signs, symptoms, reports, findings, treatment, or diagnoses of a right knee disability; the Veteran’s statements in 2006 that his right knee pain began 6 or 7 months prior, placing inception of right knee problems many years after service separation; and the lack of any medical documentation of reports or treatment for right knee pain until 2006, more than several decades after service separation. As such, the Board does not find that the evidence sufficiently supports continuous or recurrent symptomatology of the claimed disability since service so as to warrant a grant of service connection. Finally, the Board finds that the weight of the competent medical evidence weighs against a finding of a medical nexus between the current right knee disability and active service. The Board notes that no competent medical opinions have been received relating the claimed right knee disability to active service to include exposure to asbestos, dioxins, radiation, or other chemicals and contaminants, nor does the medical evidence of record otherwise suggest such an etiological relationship. The Board also notes that the Veteran was unable to identify any injury or incident in service which led to right knee symptoms in active service at the 2017 Board hearing. The Board acknowledges the Veteran’s belief that his right knee disability is related to his active service. However, as above, his statements alone do not establish a medical nexus. Indeed, while the Veteran is competent to provide evidence regarding matters that can be perceived by the senses, he is not shown to be competent to render medical opinions on questions of etiology. See Jandreau, 492 F.3d 1372; see also Barr, 21 Vet. App. 303 (lay testimony is competent to establish the presence of observable symptomatology). As such, as a layperson, he is without the appropriate medical training and expertise to offer an opinion on a medical matter, including the diagnosis, etiology, or causation of a specific disability. The question of diagnosis and causation, in this case, involves complex medical issues that the Veteran is not competent to address. Jandreau. For these reasons, the claim must be denied. Because the preponderance of the evidence is against the claim, the benefit of the doubt doctrine is not for application. See 38 U.S.C. § 5107; 38 C.F.R. § 3.102. 3. Service connection for sleep apnea is denied. 4. Service connection for a cardiovascular disability is denied. 5. Service connection for a gastrointestinal disability, claimed as irritable bowel disease and Crohn’s disease, is denied. 6. Service connection for diabetes mellitus, type II, is denied. 7. Service connection for narcolepsy is denied. The Veteran contends that his current sleep apnea, cardiovascular disability, gastrointestinal disability, diabetes, and narcolepsy are related to asbestos, herbicide, and/or ionized radiation exposure in active service. For the reasons discussed below, the Board finds that the weight of the evidence is against a finding of a medical nexus between the claimed disabilities and active service, to include exposure to asbestos, dioxins, radiation, or other chemicals and contaminants during active service. Reviewing the most relevant evidence of record, service treatment records are silent as to any reports, findings, treatment, or diagnoses of the claimed disabilities. Following separation from active service, in May 2000, the Veteran reported rectal bleeding and a colonoscopy and biopsy confirmed a diagnosis of chronic active colitis. Private treatment records from May 2003 show a diagnosis of diabetes mellitus. In May 2004, the Veteran was diagnosed with Crohn’s disease, confirmed again by colonoscopy in June 2006. In April 2005, a polysomnography demonstrated obstructive sleep apnea. In May 2007, on a medical history report, the Veteran denied a history of coronary artery disease. In June 2008, a rectum biopsy showed moderate acute and chronic inflammation with granulation tissue consistent with Crohn’s disease. There was no evidence of dysplasia or malignancy. There was a benign hyperplastic polyp of the rectum. A September 2008 private treatment record indicates that the Veteran reported fatigue and stated that he frequently fell asleep during the day. An Epworth Sleepiness Scale was a 12 (abnormal). He stated he was scheduled to have a sleep study done 3 to 4 years ago but did not follow through with that, even though the evidence of record includes the 2005 polysomnography report above. The diagnosis was obstructive sleep apnea and fatigue, and another sleep study was ordered, which was conducted in November 2008 and again demonstrated obstructive sleep apnea. In November 2008, the Veteran reported a diagnosis of Crohn’s for the last 6 to 7 years. In December 2008, the Veteran presented with sleeping problems. It was noted that he had mild sleep apnea and excessive daytime sleepiness. He had been diagnosed with sleep apnea in 2005 and was prescribed positional therapy. He did not have any improvement in daytime fatigue and got a CPAP, which helped. He had a narcolepsy panel draw which was positive for 2 markers. Currently his fatigue was mild and much improved. The diagnosis was sleep apnea. The doctor discussed his narcolepsy panel results with him, noting that he was doing well on CPAP and would continue this for 3 months; if he had any persistent daytime sleepiness, he would need an MSLT to further evaluate for narcolepsy. In an April 2009 private treatment record, the Veteran stated he began having blood in his stool in 2000, which led to diagnosis of his gastrointestinal problems. A November 2009 VA treatment record indicates that the Veteran was switched to Humira secondary to a November 2008 E. Coli infection, and that his last dose of prednisone was in July 2009. The diagnosis was Crohn’s disease in remission. The Veteran was afforded a VA gastrointestinal examination in December 2009. The Veteran was reportedly diagnosed with Crohn’s disease in 2000 and has had intermittent recurrent episodes of diarrhea and colitis since then per record review. No mention of a relationship between colitis and asbestos was found in the records. The Veteran reported that he began having bleeding with stools in 2000, and that he believes that this was caused by asbestos exposure in service. The VA examiner opined that it is less likely as not that the current Crohn’s disease was caused by or related to asbestos exposure in service. She based this opinion on medical literature review, medial record review, and clinical experience. She reasoned that medical literature review did not support a relationship between Crohn’s disease and asbestos exposure. The Veteran was afforded a VA respiratory examination in December 2009. He reported that he served aboard the USS Milwaukee and served as a division weapons officer and missile test engineer. Therefore, the RO, in its examination request, stated that asbestos exposure was conceded. The Veteran reported that he was diagnosed with sleep apnea in 2009 and had not been diagnosed with asbestosis so far. PFT was normal, as was pulmonary examination. The VA examiner stated that sleep apnea was not due to or caused by asbestos exposure, basing the opinion on medical literature, which stated there was no basis for such an association. An April 2010 colonoscopy revealed normal digital-rectal examination, extensive diverticulitis, and redundant colon. There was one 12 mm polyp in the rectum (benign appearing), which was not removed due to location and proximity to dentate margin. There was erythematous (hyperemic) ileal mucosa which was biopsied and mild proctitis was noted on retroflexion as well. An April 2010 private treatment record indicated that the Veteran had a routine EKG performed at VA in March 2010 and was told that it was abnormal, showing sinus bradycardia, right bundle branch block, and left anterior hemiblock. He denied any cardiac symptoms. He was physically active and had no chest discomfort, shortness of breath, or easy fatigue. He denied palpitations, dizziness, or syncope. EKG done today revealed sinus rhythm with left anterior hemiblock and right bundle branch block. Impression was that Veteran had a bifascicular block on EKG but had no symptoms of any cardiovascular problems at this time. Though he is not an elderly individual, the doctor suspected that the bifascicular blocks were probably nothing more than a manifestation of senile degeneration in the cardiac conduction system. Other than the EKG abnormality, there was no clinical sign of any significant cardiac issue. To rule out any cardiac issues, he was to undergo an echocardiogram and nuclear stress test. A myocardial perfusion study performed later that month was normal, with normal wall motion and LV ejection fraction of 67 percent. An echocardiogram revealed mild to moderate biatrial enlargement, interatrial septal aneurysm, trivial aortic regurgitation, mild mitral regurgitation, mild to moderate tricuspid regurgitation with normal RV systolic pressure, pulmonic regurgitation. At the September 2017 Board hearing, the Veteran testified that he believed his sleep apnea, cardiovascular disability, gastrointestinal disability, diabetes, and narcolepsy were all related to asbestos, herbicide, radiation, or other chemical/contaminant exposure during active service, and stated that he had not undergone the MSLT testing for narcolepsy recommended by his doctor in 2008. In a December 2018 letter, a private physician, Dr. P., stated that he reviewed the Veteran’s VA treatment records, service treatment records, and his own treatment records, and opined that the Veteran’s obstructive sleep apnea, irritable colon syndrome (IBD, colitis, Crohn’s disease, GI disorders), diabetes, cardiovascular disability (coronary artery disease), and narcolepsy were caused by exposure to asbestos, ionized radiation, dioxin, PCBs, and various other toxic contaminant during active service. The doctor explained that it has been well-documented by competent researchers and accepted by VA that the latency period from exposure to development can be as long as 50 plus years. Further, Dr. P. stated that, with regard to the diabetes and cardiovascular disability, according to the literature, diagnosis, and treatment, it is evident that the condition is related to the Veteran’s various exposures. Dr. P. stated that autoimmune disease secondary to hazardous exposure was the cause of the narcolepsy, and that hazardous exposures also caused cardiorespiratory compromise which led to ischemic heart disease. An article submitted along with Dr. P.’s letter stated that scientists have found a significant association between polychlorinated biphenyl (PCB) exposure and risk of diabetes in a highly exposed community in the United States. Another article stated that dioxins can cause damage to the immune system, interfere with hormones, and cause cancer, and that once dioxins enter the body, they last a long time. Although Dr. P. stated that he reviewed his own treatment records in reaching these conclusions, the Veteran, during a November 2019 telephone conversation with a VA representative, stated that he did not have any additional private medical records to submit as evidence, nor did he provide a VA Form 21-4142 to allow VA to obtain Dr. P.’s records in response to VA’s request that he do so following the Board’s 2019 remand. A February 2020 VA treatment note indicates that the Veteran’s history of asbestos exposure was causing his Crohn’s disease. No rationale was provided for this statement. In July 2020, VA obtained an opinion as to the etiology of the Veteran’s sleep apnea. The examiner reviewed the Veteran’s claims file and medical literature, and opined that the Veteran’s sleep apnea is less likely as not (less than 50/50 probability) caused by active service, to include as a result of exposure to asbestos, dioxins, radiation, PCBs, and multiple other chemicals. The examiner cited to medical literature which described the physiology of sleep apnea and identified factors which increased the risk of developing sleep apnea, including excess weight, fat deposits around the upper airway, neck circumference, a narrowed airway, tonsils or adenoids, being male, being older, family history, use of alcohol, sedatives or tranquilizers, smoking, nasal congestion, congestive heart failure, high blood pressure, type 2 diabetes, and Parkinson’s disease, hormonal disorders, prior stroke and chronic lung diseases such as asthma. Medical literature review reveals Obstructive Sleep Apnea is a prevalent medical condition in the general population. Based on available population-based studies, the prevalence of obstructive sleep apnea associated with accompanying daytime sleepiness is approximately 3 to 7 percent for adult men. In addition, the examiner stated that the Veteran had many of the increased risk factors for the development of sleep apnea listed above. In a VA opinion regarding the claimed cardiovascular disability, the examiner stated that the Veteran’s coronary artery disease is less likely as not (less than 50/50 probability) caused by active service, to include as a result of exposure to asbestos, dioxins, radiation, PCBs, and multiple other chemicals. The examiner cited to medical literature which stated that risk factors of developing coronary artery disease included smoking, high blood pressure, high cholesterol, diabetes or insulin resistance, and sedentary lifestyle, age, being male, family history, being overweight, high stress, and autoimmune diseases. The examiner noted that when grouped together, certain risk factors make a person even more likely to develop coronary artery disease. Sometimes coronary artery disease develops without any classic risk factors. Researchers were studying other possible risk factors, including sleep apnea. The examiner stated that coronary heart disease is the most common type of heart disease, killing 365,914 people in 2017. About 18.2 million adults age 20 and older have CAD (about 6.7%). Medical literature review reveals CAD is a prevalent medical condition in the general population. The examiner stated that the Veteran met many of the risk factors for the development of CAD listed above. An opinion was obtained regarding the etiology of the Veteran’s diabetes in July 2020 as well. The examiner opined that the diabetes is less likely as not (less than 50/50 probability) caused by active service, to include as a result of exposure to asbestos, dioxins, radiation, PCBs, and multiple other chemicals. The examiner explained the physiology of diabetes and stated that risk factors for diabetes included being overweight, fat distribution, inactivity, family history, race, and age. More than 34 million Americans have diabetes (about 1 in 10), and approximately 90-95% of them have type 2 diabetes. Type 2 diabetes most often develops in people over age 45, but more and more children, teens, and young adults are also developing it. Medical literature review reveals DM Type II is a prevalent medical condition in the general population. The Veteran met many of the risk factors for the development of DM Type II listed above. With regard to the gastrointestinal condition, the July 2020 VA examiner opined that it is less likely as not (less than 50/50 probability) caused by active service, to include as a result of exposure to asbestos, dioxins, radiation, PCBs, and multiple other chemicals. The examiner noted that according to medical literature, the exact cause of Crohn’s disease remains unknown. Previously, diet and stress were suspected, but now doctors know that these factors may aggravate but don’t cause Crohn’s disease. A number of factors, such as heredity and a malfunctioning immune system, likely play a role in its development. Risk factors for Crohn’s disease may also include age, ethnicity, family history, cigarette smoking, nonsteroidal anti-inflammatory medications, and where you live. In 2015, an estimated 1.3% of US adults (3 million) reported being diagnosed with IBD (either Crohn’s disease or ulcerative colitis). This was a large increase from 1999 (0.9% or 2 million adults). Medical literature review revealed that inflammatory bowel disease/Crohn’s disease is a prevalent medical condition in the general population. In a July 2020 report addressing the etiology of narcolepsy, the VA examiner opined that it is less likely as not (less than 50/50 probability) caused by active service, to include as a result of exposure to asbestos, dioxins, radiation, PCBs, and multiple other chemicals. The examiner noted that according to medical literature, the exact cause of narcolepsy is unknown. People with type 1 narcolepsy have low levels of the chemical hypocretin (hi-poe-KREE-tin). Hypocretin is an important neurochemical in your brain that helps regulate wakefulness and REM sleep. Hypocretin levels are particularly low in those who experience cataplexy. Exactly what causes the loss of hypocretin-producing cells in the brain isn’t known, but experts suspect it’s due to an autoimmune reaction. It’s also likely that genetics play a role in the development of narcolepsy. Research also indicates a possible association with exposure to the swine flu (H1N1 flu) virus and a certain form of H1N1 vaccine that’s currently administered in Europe, though it’s not yet clear why. There are only a few known risk factors for narcolepsy, including age and family history. Medical literature review reveals Narcolepsy is a prevalent medical condition in the general population. Based on the evidence of record, lay and medical, the Board finds that there is no medical nexus between the current sleep apnea, cardiovascular disability, gastrointestinal disability, diabetes, or narcolepsy and active service. First, the weight of the evidence demonstrates that the Veteran’s sleep apnea, cardiovascular disability, gastrointestinal disability, diabetes, and narcolepsy were not continuous or recurrent in service. As noted above, service treatment records are negative for any report, findings, treatment, or diagnosis of the claimed disabilities in active service. The Board next finds that the weight of the evidence demonstrates that symptoms of the claimed disabilities were not continuous or recurrent since separation from active service in July 1976. Following separation from service in July 1976, the evidence of record does not show any complaints, diagnosis, or treatment for a gastrointestinal condition until 2000, diabetes until 2003, sleep apnea until 2005, possible narcolepsy until 2008, and a cardiovascular problem until 2010. The absence of post-service complaints, findings, diagnosis, or treatment for the claimed disability for more than 2 decades after service separation is one factor that tends to weigh against a finding of continuous or recurrent symptoms of the claimed disabilities after service separation. See Buchanan, 451 F.3d at 1336 (the lack of contemporaneous medical records is one fact the Board can consider and weigh against the other evidence, although the lack of such medical records does not, in and of itself, render the lay evidence not credible). Additional evidence demonstrating that the claimed disabilities have not been continuous or recurrent since service separation includes the history provided by the Veteran in multiple treatment records that he was first diagnosed with or began experiencing symptoms of the claimed disabilities many years after service separation. For instance, in May 2007, he denied a history of coronary artery disease. In November 2008, he reported having Crohn’s disease for the last 6 to 7 years, and that he was diagnosed with sleep apnea in 2005. In April 2009, he reported that he began experiencing blood in his stool in 2000, which led to his diagnosis of gastrointestinal problems. At the December 2009 VA gastrointestinal examination, he again reported that he began experiencing gastrointestinal bleeding in 2000. In April 2010, when the Veteran’s EKG was abnormal, he denied any cardiovascular symptoms. His statements provide highly probative evidence that he did not experience symptoms of the claimed disabilities continuously since active service, as it is expected that he would provide an accurate history of his symptoms in order to receive the best treatment. With regard to the Veteran’s more recent assertions made in the context of the current disability claim of continuous or recurrent symptoms of the claimed disabilities since service, the Board finds that these more recent assertions are outweighed by the other, more contemporaneous, lay and medical evidence of record, both in service and after service, and are not reliable. See Charles. The Board finds that the Veteran’s assertions of continuous or recurrent symptoms of the claimed disabilities after service are not accurate because they are outweighed by other evidence of record that includes the more contemporaneous service treatment records, which are negative for signs or symptoms of the claimed disabilities; the history of symptoms and diagnoses provided by the Veteran when seeking treatment for the claimed disabilities, as described above; and the lack of any documentation of reports or treatment for symptoms of the claimed disabilities for nearly more than 2 decades after service separation, also outlined above. As such, the Board does not find that the evidence sufficiently supports continuous or recurrent symptoms of the claimed disabilities since service so as to warrant a grant of service connection. Finally, the Board finds that the weight of the competent medical evidence weighs against a finding of a medical nexus between the current disabilities and active service. In this regard, the Board finds that the 2009 and 2020 VA nexus opinions, discussed above, are the most probative evidence of record. The VA opinions are competent and probative medical evidence because they are factually accurate and are supported by adequate rationale. The 2009 VA examiner interviewed and examined the Veteran, both examiners were informed of the pertinent evidence, reviewed the Veteran’s claims file, and fully articulated the opinions in the examination reports, citing to specific medical evidence. The VA opinions are more probative than the favorable opinion of Dr. P., whose rationale consisted of the statement that medical literature showed that the latency period from exposure to asbestos and other contaminants to development (of presumably any condition resulting from such exposure) can be as long as 50 plus years, but did not cite to any medical literature showing an etiological relationship between exposure to asbestos, ionized radiation, dioxin, PCBs, and various other toxic contaminants and any of the claimed disabilities (other than diabetes), nor did he provide any other rationale for his opinion. With regard to the article that stated that scientists had found significant association between PCB exposure and risk of diabetes in a highly exposed community in the United States, the Board finds it to be of little probative value in that it shows correlation, not causation, and, in relying upon this article to support his opinion, Dr. P. assumed that the Veteran had high exposure to PCBs in active service, which is not demonstrated by his service records, as discussed above. The Board acknowledges the belief of the Veteran that his sleep apnea, cardiovascular disability, gastrointestinal disability, diabetes, and narcolepsy are related to his active service. However, as above, his statements alone do not establish a medical nexus. Indeed, while the Veteran is competent to provide evidence regarding matters that can be perceived by the senses, he has not been shown to be competent to render medical opinions on questions of etiology. See Jandreau; see also Barr. As such, as a layperson, he is without the appropriate medical training and expertise to offer an opinion on a medical matter, including the diagnosis, etiology, or causation of a specific disability. The question of diagnosis and causation, in this case, involves complex medical issues that the Veteran is not competent to address. Jandreau. Based on the evidence of record, the weight of the competent evidence demonstrates no relationship between the Veteran’s claimed sleep apnea, cardiovascular disability, gastrointestinal disability, diabetes, or narcolepsy and his military service, including no credible evidence of continuous or recurrent symptoms of the claimed disabilities during active service, continuous or recurrent symptoms following service separation, or competent medical evidence establishing a link between the claimed disabilities and active service, including as due to exposure to asbestos, dioxins, radiation, or other chemicals and contaminants during active service. Therefore, the Board finds that a weight of the lay and medical evidence that is of record is against the claim for service connection for sleep apnea, cardiovascular disability, gastrointestinal disability, diabetes, and narcolepsy, and outweighs the Veteran’s more recent contentions regarding in-service continuous or recurrent symptoms and continuous or recurrent post-service symptoms of the claimed disabilities. For these reasons, the claim must be denied. Because the preponderance of the evidence is against the claim, the benefit of the doubt doctrine is not for application. See 38 U.S.C. § 5107; 38 C.F.R. § 3.102. 8. Service connection for a dental disability, claimed as bone loss, is denied. The Veteran contends that he has a dental disability consisting of bone loss that is related to active service. The Board finds that the weight of the evidence is against a finding of a current dental disability, and that, as such, service connection is denied for both compensation and treatment purposes. Dental disorders which may be compensable include irreplaceable missing teeth, and disease and damage to the jaw. 38 C.F.R. § 4.150, DCs 9900-9916. Tooth loss is only compensable where it is due to loss of substance of the body of the maxilla or mandible without loss of continuity. Id., DC 9913. Treatable carious teeth, replaceable missing teeth, dental or alveolar abscesses, and periodontal disease will be considered service-connected solely for the purpose of establishing eligibility for outpatient dental treatment. In determining service connection, the condition of teeth and periodontal tissues at the time of entry into active duty will be considered. Treatment during service, including filling or extraction of a tooth, or placement of a prosthesis, will not be considered evidence of aggravation of a condition that was noted at entry, unless additional pathology developed after 180 days or more of active service. See 38 C.F.R. § 3.381; see also 38 C.F.R. § 17.161. Reviewing the most relevant evidence of record, a September 1969 initial dental exam indicates tooth number 3 was missing. A February 1970 Officer Candidate School examination report indicates that he had missing teeth numbered 1 and 3 on the right and 17 on the left; and restorable teeth 31 and 32 on the right and 10 on the left. For dental defects and diseases, he was assessed as Class 2 (a patient with an oral condition that has the potential bus is not expected to result in dental emergencies within a 12-month period). An August 1973 augmentation examination report indicates missing tooth 3 on the right; restorable teeth 6 through 8 and 30 and 31 on the right, and 14 and 15 on the left. Assessment was class 2, qualified. The May 1976 Resignation of Commission examination report indicates that the Veteran was dentally qualified following examination performed by a medical officer. In May 2009, the Veteran had bone scan because he had back pain and was taking medication which put him at risk for osteoporosis. The bone scan was normal and bone density study was also normal. There was also no mention of dental bone loss. A January 2011 bone densitometry indicated osteopenia, but again there was no mention of a dental or oral bone loss. At the September 2017 Board hearing, the Veteran testified that her recently had a periodontal examination and that he had to have artificial bone inserted into his gums due to bone loss. Subsequent to the Board’s remand, VA asked the Veteran to complete a VA Form 21-4142 for any treatment providers for his claimed disabilities, including the claimed dental disability, but the Veteran declined to do so and informed a VA representative during a November 2019 telephone conversation that he did not have any outstanding private medical records to submit. Post-service VA treatment records are silent as to any dental condition. The Board acknowledges the Veteran’s testimony at the Board hearing that he has bone loss which requires dental treatment. However, the medical evidence of record does not show a current disability, and the Veteran has not provided VA with the information necessary to obtain evidence which may assist him in substantiating his claim. The duty to assist a veteran in developing evidence is not always a “one-way street.” Wamhoff v. Brown, 8 Vet. App. 517, 522 (1996). A veteran must cooperate when he is asked for information that is essential in obtaining the putative evidence. Wood v. Derwinski, 1 Vet. App. 190, 193 (1991). Otherwise, he denies VA evidence which might have helped establish his claim. In this case, the Veteran was provided with the opportunity to identify his dental treatment providers and provide VA with the necessary release forms to obtain those records but did not do so. Without a showing of a current disability, the claim for service connection for residuals of a head injury must be denied. “Congress specifically limits entitlement to service-connected disease or injury where such cases have resulted in a disability... in the absence of a proof of present disability there can be no claim.” Brammer, 3 Vet. App. at 225. The Board recognizes that the Court has held that the presence of a chronic disability at any time during the claim process can justify a grant of service connection, even where the most recent diagnosis is negative. McClain v. Nicholson, 21 Vet. App. 319 (2007). However, where the overall record fails to support a current disability, as is the case here, that holding would not apply. Service connection for a dental disability, to include bone loss, is denied for both compensation and treatment purposes. REASONS FOR REMAND 1. Service connection for a respiratory disability, claimed as asbestosis is remanded. In February 2015, the Veteran denied chest pain but reported dyspnea on exertion and stated that his breathing was heavy at times at rest. The clinician noted that a CT of the chest from December 2014 revealed multiple bilateral pulmonary nodules measuring up to 6 mm. The clinician stated that the nodules were of unclear etiology but most likely benign process. The diagnosis was restrictive lung disease, intrinsic, and the clinician stated that there is a probability that the intrinsic restrictive ventilatory dysfunction (RVD) is due to prior asbestos exposure. An August 2019 pulmonary function test revealed mild restrictive ventilatory dysfunction (RVD) and normal diffusion capacity. A February 2020 VA treatment note lists a history of lung nodules due to asbestos exposure. The 2009 and 2020 VA examination and opinion only addressed the presence (or lack thereof) of asbestosis. Therefore, the Board finds that a remand is necessary to obtain a VA examination to address the etiology of the Veteran’s RVD and pulmonary nodules, to include an opinion as to whether they are due to asbestos exposure. 2. Service connection for varicose veins is remanded. In October 2017, Dr. P., a private physician, indicated that he reviewed the Veteran’s service and post-service treatment records, and opined that the Veteran’s varicose veins were at least as likely as not caused by or a result of asbestos and dioxin exposure, noting that varicose veins are caused by circulatory compromise. Dr. P. did not provide any further rationale for his opinion. The Board therefore finds that a VA examination or opinion is necessary to address the etiology of the Veteran’s varicose veins, to include an opinion as to whether they are caused by in-service exposure to asbestos, dioxins, radiation, or other chemicals and contaminants. The matters are REMANDED for the following action: 1. Afford the Veteran the opportunity to attend a VA examination with an appropriate specialist to address the nature and etiology of the Veteran’s claimed respiratory condition, to include pulmonary nodules and restrictive ventilatory dysfunction (RVD). Any and all indicated evaluations, studies, and tests deemed necessary by the examiner should be accomplished, and a rationale for any opinion expressed should be provided. The claims file must be made available to the examiner for review of the history in conjunction with the examination, and the examination report should reflect that such review was accomplished. (a.) The examiner should first identify any and all respiratory conditions. (b.) The examiner should offer the following opinion: Is it at least as likely as not (i.e., to at least a 50/50 degree of probability) that the Veteran’s respiratory condition, to include pulmonary nodules and RVD, was incurred during or caused by active service, to include as due to asbestos exposure? The examiner should cite specifically to any medical literature used in support of his/her opinion. Note: The term “at least as likely as not” does not mean merely within the realm of medical possibility, but rather that the weight of medical evidence both for and against a conclusion is so evenly divided that it is as medically sound to find in favor of causation as it is to find against it. All opinions are to be accompanied by a rationale consistent with the evidence of record. A discussion of the pertinent evidence, relevant medical treatises, and generally accepted medical principles is requested. If the examiner cannot provide an opinion without resorting to speculation, he or she shall provide complete explanations stating why this is so. In so doing, the examiner shall explain whether any inability to provide a more definitive opinion is the result of a need for additional information, or that he or she has exhausted the limits of current medical knowledge in providing an answer to that particular question. 2. Obtain a VA opinion, or examination if deemed necessary, from an appropriate specialist to address the nature and etiology of his varicose veins. Any and all indicated evaluations, studies, and tests deemed necessary by the examiner should be accomplished, and a rationale for any opinion expressed should be provided. The claims file must be made available to the examiner for review of the history in conjunction with the examination, and the examination report should reflect that such review was accomplished. (a.) The examiner should offer the following opinion: Is it at least as likely as not (i.e., to at least a 50/50 degree of probability) that the Veteran’s varicose veins were incurred during or caused by active service, to include as a result of exposure to asbestos, dioxins, radiation, or other chemicals and contaminants? The examiner should cite specifically to any medical literature used in support of his/her opinion. Note: The term “at least as likely as not” does not mean merely within the realm of medical possibility, but rather that the weight of medical evidence both for and against a conclusion is so evenly divided that it is as medically sound to find in favor of causation as it is to find against it. All opinions are to be accompanied by a rationale consistent with the evidence of record. A discussion of the pertinent evidence, relevant medical treatises, and generally accepted medical principles is requested. If the examiner cannot provide an opinion without resorting to speculation, he or she shall provide complete explanations stating why this is so. In so doing, the examiner shall explain whether any inability to provide a more definitive opinion is the result of a need for additional information, or that he or she has exhausted the limits of current medical knowledge in providing an answer to that particular question. Cynthia M. Bruce Veterans Law Judge Board of Veterans’ Appeals Attorney for the Board T. Sherrard, Counsel The Board’s decision in this case is binding only with respect to the instant matter decided. This decision is not precedential and does not establish VA policies or interpretations of general applicability. 38 C.F.R. § 20.1303.