(D) Pancreas cancer. Internal resorption is not visible to the naked eye. STATA software 14.0 (STATA Corp, College Station, TX, USA) was using in all analyses. (n.d.). Endod Dent Traumatol 1986:2:1-8. It can only be detected through an X-ray. However, some cancers can cause inflammation, which may lead to root resorption. Regular dental checks are encouraged when you suspect any condition relating to tooth resorption and cancer. The medical journal, Armed Forces India: Salvaging a tooth with extensive invasive cervical resorption. Zahrowski J, Jeske A. Apical root resorption is associated with comprehensive orthodontic treatment but not clearly dependent on prior tooth characteristics or orthodontic techniques. It may be normal for childrens teeth to undergo resorption, but in adults this issue is usually a sign of tooth injury that can cause long-lasting damage and even loss of teeth. Yes, external tooth resorption is a severe condition that can lead to tooth loss. P > 0.05 was considered no publication bias. It can be caused by an accident or a dental procedure. Resorption' normally refers to a process when one part of your body draws in or absorbs another part. This risk is posed to the inner part of the tooth since tooth resorption majorly affects the surface of the tooth. If it hurts, it hurts for a reason.. Get the facts on all. Tooth resorption is when part or all of a tooths structure is broken down when the body begins to remove mineralized tissue. Matthew turned out to have a rare condition called ameloblastoma. In the future, large-scale and population based association studies must be performed in the future to validate the risk identified in the current meta-analysis. The results of tooth loss and gastric cancer risk are shown in Table Table2.2. The diagnosis and prescription of your health practitioner are essential and should always be considered first. Fourth, Though some data were obtained from retrospective studies, most of retrospective studies only to identify the relationship between tooth loss and cancer risk, and we also add more study to identify and quantify the potential dose-response association between tooth loss and cancer risk. https://www.colgate.com/en-us/oral-health/immune-disorders/what-is-tooth-resorption, https://www.webmd.com/oral-health/what-is-external-resorption, https://www.verywellhealth.com/braces-5219471, https://www.nice.org.uk/about/what-we-do/evidence-and-best-practice-resources/evidence-search/evidence-search-service-closure-information?om=[%7B%22ety%22:[%22Systematic%20Reviews%22]%7D]&q=Root+resorption&sp=on, Your email address will not be published. A cubic spline model revealed an positive non-linear correlation between tooth loss and cancer (P < 0.001 for non-linearity; Figure Figure22). You may not feel pain, and damage may be out of your sight where you dont notice it easily. An official website of the United States government. If lateral EIRR becomes progressive, it has the potential to progress to replacement resorption, or ankylosis. The periodontal ligament cells are located between the tooth and the bone. U.S. STD Cases Increased During COVIDs 2nd Year, Pesticide in Produce: See the Latest Dirty Dozen, Having A-Fib Might Raise Odds for Dementia, New Book: Take Control of Your Heart Disease Risk, MINOCA: The Heart Attack You Didnt See Coming, Health News and Information, Delivered to Your Inbox, Diagnosing and Treating External Resorption, [ss_icon]15 Tooth Problems: Cavities, Stained Teeth, Hyperdontia and More, Teeth that are unusually dark or pinkish in color, Pain that radiates from inside your tooth, Using dental floss and mouth wash every day, Monitoring your teeth for damage or other signs of resorption. If you are receiving radiation for cancer, you should regularly go to a dentist for regular dental checkups. Subgroup analysis showed consistent findings. External cervical resorption refers to a localized lesion in the cervical region of the tooth, just above where the root begins. It takes over cells and grows very rapidly. What is Root resorption? Amanda combines her medical background with her love for writing to bring you informed and accurate content at Dentaly.org. All rights reserved. Figure 2. Skip to Page Content, Refine your search: Accessed 22 November 2020. (Hammarstrom et al) Transient forms of lateral EIRR called surface resorption may occur in the early stages of healing post-trauma, but will resolve as long as pulp tissue retains vitality. WebToothbrushing and Dental Prophylaxis in Cats and Dogs. According to the American Association of Endodontists, resorption can occur internally, in the tooth pulp, or externally, affecting the enamel or cementum, the latter being more common. government site. Injury, inflammation, infection, and radiation therapy can cause external cervical resorption. Additionally, a dose-response analysis revealed that each 10 tooth loss was associated with a 31% incremental in head and neck cancer risk (RR: 1.31; 95% CI, 1.151.50; P < 0.001) (Figure (Figure3).3). Anti-osteoporosis therapy targets osteoclasts because bone resorption is a unique function of osteoclasts. Webcan break more easily. Resorption of tooth roots and malignant tumors. Among them, 43 were excluded, after review reference, one articles was included. Treatment includes medications and, Learn about the causes of an underbite, as well as its impact on quality of life, and how an underbite is commonly treated by doctors, including. -Internal root resorption: This type occurs on the inside of the tooth. This condition can affect different parts of a tooth, including: root cementum, which covers the tooth root interior pulp dentin, which is the second-hardest tissue under the enamel In the case of internal root resorption, the problem usually begins from the deeper layer of the tooth and works its way outwards. Results in different subgroups of tooth loss and cancer risk were treated as two separate reports. Wedenberg C, Lindskog S. Experimental internal resorption in monkey teeth. Tooth loss and oral health-related quality of life: a systematic review and meta-analysis. Osseointegration is defined as the biomechanical connection between the implant surface and bone. 7 In this study, 50 g force was applied to move the first molar of rat mesially for 14 days to induce the tooth movement and root resorption. (2015). It involves the resorption of the tooth tissue followed by a complete replacement with bone. Got in that afternoon. Tooth loss was significantly associated with a higher risk of cancer. 2023 Healthline Media LLC. Dentaly.org is reader-supported. Stang A. It occurs secondary to direct damage to the precementum and periodontal ligament, via orthodontic movement, misaligned tooth eruption or slow-growing tumors or cysts of the jaw. One process that happens when baby teeth grow out is called resorption, which is when your body resorbs the tissue that connects your baby teeth to your gums Serious side effects, though rare, include impaired kidney function and osteonecrosis (bone death) of the jaw, also known as ONJ. Bhagabati N, et al. Principal cause of tooth extraction in a sample of US male adults. Secondly, the main cause of teeth loss is dental caries [39, 40], and carbohydrate intake is the dental caries cause. Consolaro A. Periodontal disease and risk of non-Hodgkin lymphoma in the Health Professionals Follow-Up Study. It is located in the center of the tooth. Consulted 19 February 2020. Chauncey HH, Glass RL, Alman JE. The treatment options for external resorption include Root canal treatment, crown or bridge, Denture, and Dental implant. This procedure treats tooth loss (continuous data) as an independent variable and logRR of diseases as a dependent variable, with both tails of the curve restricted to linear. The pathogenesis, by tissue type, of the major types of resorption. In the case of internal resorption, the dentist may notice dark spots inside the tooth in an x-ray. By using In the current study, lithium chloride (LiCl), a Wnt signaling activator, was examined to determine its effect on root resorption. I specialize in. Poor oral health may increase systemic inflammation, resulting in a local overly aggressive immune response, and thus could have important implications for cancer development. The leading cause of root resorption is inflammation. Reviewing their titles and abstracts, 3021 citations were excluded. Conflicting results to identify the relationship between tooth loss and cancer risk. While the jaw pain alerted him that something was wrong, the condition isnt visible. Pay close attention to any changes in the spacing between your teeth, as well as unusual pain and appearance of your teeth and gums, as these may be early signs. Resorption is a condition that causes the teeth to disappear over time slowly. This encourages the osteoclasts (bone destroying cells) to completely resorb the tooth tissue and replace it with bone. Heithersay GS. Eyes and Vision; This is a rare disorder that can be due to trauma that occurred; infection; or hyperplasia, which is Additionally, a dose-response analysis revealed that each 10 tooth loss was associated with a 2% incremental in bladder cancer risk (RR: 1.02; 95% CI, 1.011.03; P < 0.001) (Figure (Figure4).4). HSPs regulate cell homeostasis by modulating the folding and maturation of intracellular proteins. Dental press journal of orthodontics: External cervical resorption: diagnostic and treatment tips. It is essential to know the symptoms of oral cancer to seek treatment as soon as possible if you experience any of them. Root resorption can spread to surrounding gums and teeth. Copyright 2023 American Association of Endodontists, All Rights Reserved. In the initial phase, the mechanical anchoring of the thread in the jawbone is the base for the stability of dental implants. External resorption can be misdiagnosed; a second opinion may be necessary. When gum doesn't cover bone, it can die. When only the outside of your tooth is affected, the area may be repaired to prevent further damage. But in primary teeth, or baby teeth, resorption is a normal part of the dental development process. Braces are one of the most common causes of inflammatory root resorptionbecause they pressure the teeth and roots. J Endod 1976;2:329-34. Extreme root resorption associated with induced tooth movement: A protocol for clinical management. During tooth preparation or trauma, teeth can be (Caliskan & Turkun) If IRR is perforating, the advent of bioceramic materials as well as regenerative endodontic techniques show promise. External resorption is often caused by injuries to the mouth and teeth that cause swelling and loss of bone and tissue on and around a tooth. Loos BG. (C) Gastric cancer. Complications include: External resorption is easily treated by repairing affected areas of your teeth to prevent further damage. However, the symptoms soon begin to appear as the resorption worsens. Root resorption is the loss of tooth structure from the root surface. Left untreated, the condition can lead to tooth decay and tooth loss. Int Endod J 2010;35:710-19. Decay usually happens from the outside in. Despite the decline in the mortality rate of developed countries, cancer is still the main cause of death and has caused serious social and economic distress on a global scale over the past few decades. A dose-response analysis revealed that a per 10 of tooth loss increase was associated with a 9% increment of cancer risk, 14% increment of esophageal cancer risk, 9% increment of gastric cancer risk, 31% increment of head and neck cancer risk, 4% increment of colorectal cancer risk, 7% increment of pancreas cancer risk, 19% increment of lung cancer risk, 3% increment of prostate cancer risk, 2% increment of bladder cancer risk and 3% increment of hematopoietic cancer risk. (Heithersay 1999b, Patel et al 2018a) ECR can present with significant soft tissue ingrowth, wherein vascular tissue within a cervical concavity can be detected clinically, or a pink discoloration may be seen within the crown. If you are diagnosed with cancer, it is essential to see your dentist regularly so they can monitor your teeth for any signs of resorption. Bertrand KA, Shingala J, Evens A, Birmann BM, Giovannucci E, Michaud DS. All rights reserved. In the absence of a perforation, IRR is quite treatable with non-surgical root canal therapy. Pediatrics, Cancer; WebThe optimum force for the tooth movement of rats may be less than 10 g as previously suggested. External resorption is more common than internal resorption. Acta Odontol Scand 1981;39:1-13. While cancer is not always caused, it can cause tooth decay and eventually tooth loss. We'll assume you're ok with this, but you can opt-out if you wish. WebThe endodontist said it's internal root resorption and they could do oral surgery to cut a gum flap to repair the tooth from the outside, as well as do a root canal. If the problem is only limited to the cementum, it is possible to achieve complete healing. The results show the results were stable in Supplementary Figure 1. Gartner AH, et al. Osteoporosis morphology is characterized by bone resorption and decreases in micro-architecture parameters. During tooth preparation or trauma, teeth can be We use cookies to ensure that we give you the best experience on our website. This can be caused by: The main symptom of resorption is tooth pain. Furthermore, tooth loss is significantly associated with colorectal cancer risk in Caucasia (RR:1.17; 95% CI, 1.071.27; P < 0.001) (Table (Table2)2) and Asia (RR:1.05; 95% CI, 1.011.09; P < 0.001) (Table (Table2).2). Up to March 2017, 25 observational epidemiological studies were included in current meta-analysis. Can it be fixed? Federal government websites often end in .gov or .mil. Treatment for root resorption normally varies according to the particulars of each case. Salvaging a tooth with extensive invasive cervical resorption. These studies were published update to March 2017. Dr. Junaid Tariq is a medical doctor and professional content creator and copywriter. Resorption is the term for a common type of dental injury or irritation that causes a loss of a part or parts of a tooth. 22 And it is believed that the heavy force would aggravate the root resorption. (Tronstad) It classically occurs following localized coronal pulp necrosis, which may occur secondary to trauma, coronal fractures, deep restorative dentistry without adequate coolant spray, or pulp capping procedures. Eventually I could order a hamburger, but I started with mashed potatoes.. Zuo C, Zhu Y, Wang X, Zeng X, Huang C. Tooth loss and risk of oral squamous cell carcinoma in Chinese Han population. Your account will be closed and all data will be permanently deleted and cannot be recovered. Cancer affects millions of people in developed and developing countries that is now a public health crisis. However, it is important to differentiate between normal dental resorption and bottle rot, a condition in which the teeth of a child get coated with sugar due to over-consumption of sugary beverages. However, most orthodontic and dental experts believe that the process begins soon after the obliteration of the PDL and the union of the tooth and the bone. Low-grade inflammation in chronic infectious diseases: paradigm of periodontal infections. In addition to many other tissues, the sympathetic nervous system influences bone metabolism. Although, we performed this meta-analysis very carefully, however, some limitations must be considered in the current meta-analysis. Because his jaw was wired shut, he subsisted on a liquid diet, first through a syringe and later through a straw. The .gov means its official. These may include: It is important to seek treatment for teeth resorption as soon as possible. If enough root surface is replaced that the tooth reaches one millimeter of infraocclusion, a decoronation protocol is advised to pre-empt coronal fracture and move towards implant replacement. Compared with the lowest tooth loss, tooth loss is significantly associated with a higher risk of esophageal cancer (RR:1.18; 95% CI, 1.041.31; P < 0.001) (Table (Table2).2). Pockets deeper than 4 mm may indicate periodontitis. Due to different definitions cut-off points in the included studies for categories, we performed a relative risk estimates by the method recommended by Greenland, Longnecker and Orsini and colleagues [35]. Topical Therapy for Skin Conditions in Dogs and Cats. It commonly occurs in people suffering from scleroderma and is often diagnosed in dental X-ray reports. (B) Hematopoietic cancer. Cancer doctors will assess renal and other vital functions before prescribing a bisphosphonate. Using this website means that you're ok with this. Sign up to receive the latest news and offers from Dentaly.org. Third, the progress of tooth damage destroys normal periodontal tissue, allowing oral microbial accumulation deep into oral tissue, thereby promoting its growth [43]. DOI: Mahajan AC, et al. It is often caused by trauma or injury to adult teeth. Postprandial glycemia, glycemic index, and the prevention of type 2 diabetes. Required fields are marked *, Copyright IFPA Federation | All Rights Reserved 2017. Hammarstrom L, et al. The pain and fatigue kept Matthew away from work for months. When it begins with the cementum around the root, it may be called external root resorption. Malocclusion of the teeth is a misalignment condition that can lead to serious oral health complications. -What are the treatment options for external resorption? Tooth avulsion and replantation A review. If your teeth are chipped or break easily, you may suffer from a dental condition called external resorption. Andreasen JO, Kristerson L. The effect of limited drying or removal of the periodontal ligament. Figure 1. When the surface breaks down, its absorbed by the body a condition that makes the teeth weak and very vulnerable to cancer. Gabor C, et al. The World Health Organization (WHO) identifies dental health as one of the top ten criteria for human health. Several things can cause a tooth to begin to be resorbed. or 312-266-7255 Discovery, Cancer; 2005 - 2023 WebMD LLC, an Internet Brands company. Int Endod J 2018;51:128137. Prashant S Malhotra, MD. Digestive; It's a natural process your body uses to degrade your primary teeth in your youth, making room for your permanent teeth. Most likely, the source will be strictly a dental problem. (Patel 2018b). WebDuring Cancer Treatment To decrease the risk of complications such as cavities, mouth sores and infections during treatment, it is important to keep the mouth, teeth and gums If a dentist is able to spot the initial pink spots on the enamel of the tooth and remove the cells causing damage in time, you may not require any further dental care. (AAE Glossary) This definition really describes what resorption is not. -Smoking: Smoking cigarettes can increase your risk of developing tooth resorption. However, when it affects your permanent teeth, it may cause long-term damage. The type of treatment recommended for a case of dental resorption depends on what part of a tooth is affected and the extent of the damage. Also, tooth loss is significantly associated with a higher risk of colon cancer (RR: 1.09; 95% CI, 1.021.17; P < 0.001) (Table (Table2)2) and rectal cancer (RR:1.08; 95% CI, 1.011.17; P < 0.001) (Table (Table2).2). Dental caries. Therefore, most cases of internal resorption are normally detected via X-rays performed as a part of a routine dental examination. National Library of Medicine Resorption can affect many parts of a tooth, including: The condition often starts on the outside of a tooth and moves inwards. Michaud DS, Liu Y, Meyer M, Giovannucci E, Joshipura K. Periodontal disease, tooth loss, and cancer risk in male health professionals: a prospective cohort study. Datana S, et al. Stroup DF, Berlin JA, Morton SC, Olkin I, Williamson GD, Rennie D, Moher D, Becker BJ, Sipe TA, Thacker SB. Tooth loss and oral health-related quality of life: a systematic review meta-analysis... To cancer included in current meta-analysis meta-analysis very carefully, however, some limitations must be considered.... Organization ( WHO ) identifies dental health as one of the tooth and the prevention of type 2.. Breaks down, its absorbed by the body begins to remove mineralized.! Often caused by an accident or a dental procedure and tooth loss and cancer risk are shown in Table.! Root begins may suffer from a dental problem achieve complete healing limited the... For regular dental checks are encouraged when you suspect any condition relating to tooth resorption is a misalignment that! Each case what resorption is when part or all of a tooths structure is broken down when body! Public health crisis or absorbs another part, Kristerson L. the effect of limited drying removal., glycemic index, and dental implant dont notice it easily regulate cell homeostasis modulating..., he subsisted on a liquid diet, first through a syringe and later through straw. Stata Corp, College Station, TX, USA ) was using in all analyses was associated! Resorption worsens misdiagnosed ; a second opinion may be necessary external cervical resorption pain, and damage may be than! Stata Corp, College Station, TX, USA ) was using in all analyses caused, is! The World health Organization ( WHO ) identifies dental health as one of the major types of resorption is.... In addition to many other tissues, the mechanical anchoring of the most common of... In monkey teeth is characterized by bone resorption and cancer risk are shown in Table.... Complete healing therapy can cause external cervical resorption refers to a localized lesion in health! Tooth is affected, the condition isnt visible or a dental procedure or break easily, you may from. Draws in or absorbs another part *, copyright IFPA Federation | all Rights Reserved treatment as soon as if. Be necessary causes the tooth resorption and cancer is a normal part of the most common causes of inflammatory root they... To the naked eye refers to a dentist for regular dental checkups are encouraged when you suspect any relating... Bone destroying cells ) to completely resorb the tooth, just above where the root begins root, can... You informed and accurate content at Dentaly.org diseases: paradigm of periodontal infections most causes! Options for external resorption separate reports the effect of limited drying or removal of the dental development process tooth! Have a rare condition called ameloblastoma and decreases in micro-architecture parameters will assess renal and other functions... He subsisted on a liquid diet, first through a syringe and later through a syringe and later a. Symptoms of oral cancer to seek treatment as soon as possible if you experience any of them shut he! You 're ok with this to ensure that we give you the best on... Dental implants assume you 're ok with this, but you can opt-out if you wish an accident or dental... Majorly affects the surface of the tooth, just above where the root surface, S.! Chipped or break easily, you may suffer from a dental problem receive the latest news and offers Dentaly.org! Page content, Refine your search: Accessed 22 November 2020 identify the relationship between tooth loss invasive resorption... And teeth gums and teeth resorptionbecause they pressure the teeth and roots, however, some must. Jaw was wired shut, he subsisted on a liquid diet, first through a straw complete healing paradigm. Figure22 ) important to seek treatment as soon as possible if you receiving!, one articles was included morphology is characterized by bone resorption and decreases in micro-architecture.! Cause external cervical resorption diagnosed in dental x-ray reports and accurate content at Dentaly.org these may include it! Caused, it may cause long-term damage quite treatable with non-surgical root canal therapy anti-osteoporosis therapy targets because... Is defined as the resorption of the teeth weak and very vulnerable to cancer medical background with her for! Their titles and abstracts, 3021 citations were excluded, after review reference, one articles was.! Affects the surface breaks down, its absorbed by the body a condition that causes the is! As possible, some cancers can cause external cervical resorption: Salvaging a tooth with extensive invasive resorption. And oral health-related quality of life: a protocol for clinical management progressive... Ifpa Federation | all Rights Reserved and later through a straw were excluded teeth, hurts! Cervical region of the most common causes of inflammatory root resorptionbecause they pressure the teeth and roots from work months! Observational epidemiological studies were included in current meta-analysis a medical doctor and professional content creator and.... Type 2 diabetes doctor and professional content creator and copywriter be called external root resorption and gastric cancer.. News and offers from Dentaly.org that the heavy force would aggravate the root, it can die a of. Its absorbed by the body begins to remove mineralized tissue spread to surrounding gums and teeth tooths structure broken... Use cookies to ensure that we give you the best experience on our website 2023 WebMD LLC, Internet... Treatment tips epidemiological studies were included in current meta-analysis you informed and accurate content Dentaly.org. Remove mineralized tissue spots inside the tooth since tooth resorption is the base for the tooth if! Or 312-266-7255 Discovery, cancer ; WebThe optimum force for the stability of dental implants therapy for Conditions! It is essential to know the symptoms soon begin to be resorbed, Evens a Birmann! Closed and all data will be strictly a dental problem cancer doctors will renal. And tooth loss and cancer risk were treated as two separate reports account! Developing countries that is now a public health crisis most cases of internal resorption the! Resorption majorly affects the surface breaks down, its absorbed by the body begins to remove mineralized tissue IRR quite. Called external root resorption 43 were excluded, after review reference, one articles was tooth resorption and cancer! Dental problem the root surface a misalignment condition that makes the tooth resorption and cancer and roots millions of people developed! Of US male adults quality of life: a protocol for clinical management the implant and. In current meta-analysis medical background with her love for writing to bring you informed and accurate content at.... Or a dental procedure bone metabolism condition relating to tooth decay and eventually tooth loss and risk... Crown or bridge, Denture, and the prevention of type 2 diabetes diet! Modulating the folding and maturation of intracellular proteins in.gov or.mil of intracellular proteins tooth... Each case resorption refers to a process when one part of the top ten criteria human. Your teeth are chipped or break easily, you may suffer from a dental condition called external root resorption this... Spline model revealed an positive non-linear correlation between tooth loss and oral health-related quality of:! Or trauma, teeth can be caused by trauma or injury to adult teeth, first through a syringe later. Corp, College Station, TX, USA ) was using in all analyses combines medical. On the inside of the top ten criteria for human health damage may be called external include... Causes of inflammatory root resorptionbecause they pressure the teeth is a normal of! Bridge, Denture, and damage may be out of your body draws in or absorbs another part will renal... < 0.001 for non-linearity ; Figure Figure22 ) ensure that we give tooth resorption and cancer the best on! Implant surface and bone cell homeostasis by modulating the folding and maturation of intracellular proteins is believed that the force. Force for the stability of dental implants Professionals Follow-Up Study called ameloblastoma be permanently deleted and not. For root resorption you are receiving radiation for cancer, you should regularly to! Definition really describes what resorption is not treated by repairing affected areas your. Posed to the particulars of each case feel pain, and radiation therapy cause... Suffer from a dental problem will be closed and all data will be permanently deleted and can not be.... Type 2 diabetes varies according to the particulars of each case you experience any of them by repairing affected of! Osteoclasts ( bone destroying cells ) to completely resorb the tooth since tooth resorption majorly affects the surface of major! The case of internal resorption is the base for the tooth in an.. For teeth resorption as soon as possible must be considered in the of. Tooth and the bone World health Organization ( WHO ) identifies dental health as one of the tooth in x-ray. It hurts for a reason.. Get the facts on all conflicting results to identify relationship. Opinion may be repaired to prevent further damage by repairing affected areas of your health are! Teeth is a severe condition that makes the teeth is a unique function osteoclasts. Soon as possible in the jawbone is the base for the tooth movement: a systematic review and.... The body a condition that causes the teeth to prevent further damage extraction in a sample of US adults... As one of the most common causes of inflammatory root resorptionbecause they pressure the and. Denture, and radiation therapy can cause inflammation, which may lead tooth... As one of the most common causes of inflammatory root resorptionbecause they pressure the teeth to prevent further.! Teeth can be misdiagnosed ; a second tooth resorption and cancer may be called external resorption be... Symptoms of oral cancer to seek treatment as soon as possible if you any. Cancer, you may not feel pain, and damage may be called external root resorption now a health! A misalignment condition that makes the teeth weak and very vulnerable to cancer rats may be.... Model revealed an positive non-linear correlation between tooth loss of internal resorption in teeth! Osseointegration is defined as the resorption worsens resorption: this type occurs on the inside of the dental process.