Pica: a Direct Link to Oral Health

Hannah Daniel, RDH; Mikayla Feemster, RDH; Sara Bryant, RDH; and Rockeisha Bonds, RDH

May 2019 Course - Expires May 31st, 2022

American Dental Hygienists' Association


Pica is an eating disorder in which a person craves nonnutritive substances, such as bricks, clay, hair, soil, laundry starch, fingernails, and ice. Over time, consumption of these items will affect the oral cavity and periodontium. This article will describe the clinical manifestations of pica. It will also explain that the condition is prevalent among children with special needs. The link between pica and nutritional deficiencies will be discussed. The article will conclude by emphasizing the importance of screening patients for pica and why dental professionals should be educated about the condition.

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Craving ice, biting your fingernails, and chewing pencil erasers are behaviors associated with pica, which almost every individual will experience in their lifetime. Often referred to as a type of eating disorder, pica is a condition in which a person craves nonnutritive substances such as bricks, clay, hair, soil, laundry starch, fingernails, ice, and many other items.1,2 Over an extended period of time, consumption of these items will alter the health of the oral cavity and periodontium.

Pica occurs worldwide in all cultures, ethnic groups, sexes, and age groups.1 People with special needs, especially children, are more susceptible to pica than the general public, and so are pregnant women and people with nutritional deficiencies. No matter the demographic group, there is a correlation between these dietary habits and a decline in their overall oral health.There are 11 main types of pica disorder (Table 1).3 Each one comes with its own health implications. Several of these types of pica have been recognized as being detrimental to the health of the oral cavity.

Clinical Manifestations of Pica

A 30-year-old woman went to an oral surgeon with the chief complaint of "wearing away of teeth and sensitivity." Upon initial investigation, the patient presented with pale-colored mucosa, absence of papillae on the tongue, chronic attrition, severe caries on tooth No. 14, and history of extraction of Nos. 18, 30, and 31 as a result of decay. She had no signs of bone loss or deep pocketing representing periodontal disease. A blood count indicated that the patient had iron deficiency anemia. After detailed questioning, the patient hesitantly revealed that, since age 13, she had picked up small pieces of bricks and gravel from the ground, held them between her teeth for varying amounts of time, chewed, and swallowed them. She attributed the initiation of this habit to a significant amount of stress in her life at a young age.1

Another woman ingested dirt (geophagia) for up to 20 years. A venous blood test showed low levels of serum ferritin. She was diagnosed with iron deficiency anemia as well as aggressive periodontitis. Clinical and radiological examination found tooth loss, recession and "pathologic migration." She had poor oral hygiene and was not a smoker. The gingiva around her teeth and the edentulous mucosa were swollen, but the patient stated there was no pain even with the mobility. She had severe pocketing extending beyond the apices and extreme alveolar bone loss radiographically. Only 11 teeth were present, with no or minimal bone support.4

A 7-year-old girl reported to her physician for chronic pain in the upper right posterior for the previous 3 years. Medical personnel learned that the child had practiced the parafunctional habit of eating and ingesting brick for 2 years despite her parents taking multiple approaches to stop the behavior. Clinical oral investigation found severe attrition and caries in several of her teeth. Stool and urine tests showed that the child was deficient in her serum ferritin, calcium, and zinc. She received restorative dental care and deworming and was instructed to take iron, calcium, and zinc supplements. After 6 months, the patient had successfully stopped her habit.5

Pica and Special Needs

Pica is extremely prevalent in children with special needs.6 Pica occurs across all different cultures, genders, ages, locations, and ethnicities, with most patients having developmental disabilities such as intellectual disabilities and autism spectrum disorder.6,7 As much as 26% of people with any form of cognitive impairment present signs of pica, and 60% to 66% of people with autism exhibit signs of pica.3,6

For children with special needs, the consumption of nonnutritive items is considered normal behavior unless that consumption is severe enough to demand clinical attention.6 In pica associated with a mental disorder, psychological and dental clinical treatment are both important.3 The reason for eating inedible material, specifically in cases with a mental condition, tends to relate to psychological and sensory factors. Many simply enjoy the taste, texture, and/or smell of the object, whereas others use the behavior to compensate for low self-esteem or sense of control.3

There are many severe, life-threatening consequences of pica, but the ones relating to dentistry and dental hygiene are tooth erosion, dental injury such as chipping teeth (possibly from consuming hard objects), abfraction, abrasion, etc.3,8 The most severe complications found in pica patients with a mental disorder include caries, gingival disease, and periodontal disease.9 Dental treatment for individuals with pica and some form of intellectual disability can require accommodation. Typically, these patients do not cooperate with treatment; therefore, as a clinician, one must be informed and aware of appropriate techniques for proper dental care.3

In addition to clinical expertise, one must display extreme patience, responsibility, care, and other emotional skills when dealing with these special cases. It may take multiple appointments to get to know the unique details of each patient to develop an effective treatment plan. The most important aspect of the initial appointment is to establish trust with the patient and patient's family.3 A guardian should provide a comprehensive review of the patient's situation, including daily autistic activities, eating and dietary habits, past dental visits and expectations, routine oral hygiene, likes and dislikes, sensitivities, etc. However, even after this detailed interview, the best way to obtain information is through observation during one-on-one time with the patient. After the provider has an understanding of the patient's situation, dental intervention may begin. Depending on the case, this could include, but not be limited to, scaling, restorations, maxillofacial surgery, orthodontic devices, bone fixation screws, root canal or oral prophylaxis.3

Pica and Nutritional Deficiencies

Along with various psychosocial and cultural hypotheses over the cause of pica, there have been numerous links to nutritional deficiencies. This suggests that appetite-regulating brain enzymes, altered by an iron or zinc deficiency, trigger specific cravings, although the nonnutritive items do not supply the nutrients needed.5

While a majority of patients initially practice pica for sensation satisfaction, the continuation of the disorder can be related to other factors. A research study from the University of Pennsylvania suggests that the craving to eat freezer frost or ice, known as pagophagia, is due to stimulation of neurophysiological processing speed in people who are deficient in iron. The study performed tested the ability of healthy persons and iron-deficient persons as they ingested ice and water using the TOVA test, a test designed to assess cognitive function of ADHD patients. The results of the study suggested two options as to why eating ice stimulates neurophysiological processing speed. The first idea is "the dive reflex." Due to the lack of oxygen-rich blood supplied to the brain in iron-deficient patients, the application of cold water to the face stimulates vasoconstriction, supplying more oxygen-rich blood to the brain and heart. The alternative explanation is that eating ice stimulates the sympathetic nervous system. This stimulates the blood flow by increasing blood pressure and heart rate. This is significant because, in contrast, "individuals with normal iron levels have sufficient oxygen available for normal attention, and therefore would not be expected to benefit from the effects of chewing ice because they would already be at ceiling on the relevant measures."10

Although pica has been most commonly linked to iron deficiency, it is sometimes adopted by those who have normal hemoglobin levels.11 Despite that there is no conclusive correlation between iron-deficiency anemia and periodontitis in humans, evidence shows that human periodontal tissue may have end-organ deficiencies of nutritional factors such as iron, ascorbate, and folic acid.4 In some studies, ice has been shown to serve as an analgesic for glossitis, xerostomia, or other oral insults. In fact, ice may be more effective than drinking water for xerostomia relief.12 Pagophagia can also be detrimental in cases where a patient ingests freezer frost contaminated by freezer contents.13 Pagophagia can lead to issues involving dental health and overall health. The mastication of ice or freezer frost can lead to abrasion, abfraction, attrition, fractures, wear facets, and other occlusal anomalies. Ingesting freezer frost or ice from a freezer can also be detrimental to overall health due to the potential contamination of the ice by products found in freezers, such as meat or poultry, and the number of bacteria present in freezers. There are several dental risks of pagophagia: tooth sensitivity, enamel loss, and cracked teeth.13

Highlighting the role of nutritional deficiency, a study involving a 56-year-old woman who reportedly held small pieces of grit and stone between her teeth for different amounts of time throughout her lifespan showed signs of resulting oral trauma.2 The patient was diagnosed with iron deficiency anemia as well as significant stress in her personal life. A dentist found increased widespread loss of tooth surface resulting from the abrasiveness, fractures, and roughening of porcelain crowns, and wear and tear on the lower anterior teeth from the previous dental visits.2

Iron deficiency has been linked to symptoms involving gastrointestinal distress, gastrointestinal bleeding, aspirin ingestion, increased bleeding during menstruation, and increased demand for nutrients during pregnancy and childhood.4 Due to the increased demand for specific nutrients during pregnancy, many women experience abnormal cravings. Theories explaining pica show that eating clay or dirt helps relieve nausea, control diarrhea, increase salivation, remove toxins, and alter odor or taste perception during pregnancy.5 Abnormal cravings for ice, clay or soil, and starch are common in pregnant women. A total of 70 studies condensed into one analysis found that almost one-third of pregnant and postpartum women admitted to experiencing pica.14


Pica associated with cognitive conditions, nutritional deficiencies, and pregnancy contributes to an increase in dental complications. Currently, pica is not routinely discussed during oral health care or medical visits. Pica could be added to the list of topics addressed when discussing medical history with a patient and when performing an initial examination. Dietary habits, both nutritive and nonnutritive, have a direct effect on the quality of oral health. While tooth wear patterns may suggest an obvious etiology, making assumptions could lead to serious physical and physiologic consequences for patients. Clinicians must be comprehensively educated and aware of the full spectrum of eating disorders present today. The only way pica will become something that is commonly mentioned to patients during their time in the office is for professionals to be educated on this condition and the effects it could ultimately have on dental and overall health.

Although it is crucial for dental professionals to screen for pica, it is also essential for all other providers to be educated on its signs and symptoms to properly diagnose and enhance patient outcomes. In regard to interprofessional collaboration, it is important to gain knowledge from other care providers concerning pica patients to provide appropriate care as well as oral health instructions specific to this population.

Addressing the topic of any form of self-injury with patients can be difficult to handle in an appropriate manner. Therefore, the authors wanted to provide practitioners with some resources that will make the transition less uncomfortable for everyone involved. Chris Fox, PhD, did extensive research on pica and provided the authors with an online webinar and an assessment that clinicians could perform on the patient in the dental chair. (This information is available at https://shriver.umassmed.edu/programs/cdder/webinars/pica).15 Another option is to use the Questions About Behavioral Function (QABF) questionnaire. The QABF is successful in predicting pica in 75% of all cases. Results showed that 67% of patients presenting with pica had non-social functions as calculated by the QABF. It may not be necessary to perform a written assessment in every situation, but by using expertise and background knowledge, clinicians can make the decision to further investigate if suspicions arise.16 The QABF can be found at https://www.liberty.k12.ga.us/ourpages/auto/2016/2/1/43422828/Doc_%205%20QABF%20Questions%20About%20Behavioral%20Functions.pdf.17

About the Authors

Hannah Daniel, RDH; Mikayla Feemster, RDH; Sara Bryant, RDH; and Rockeisha Bonds, RDH, recently graduated from the College of Health Professions at the University of Arkansas for Medical Sciences. The faculty mentor for this edition of Student Focus is Assistant Professor Claire Tucker, RDH.


1. Aparna PV, Austin RD, Mathew P. PICA. Indian J Dent Res. 2012;23(3):426-427.

2. Barker D. Tooth wear as a result of pica. Br Dent J. 2005;199(5):271-273.

3. Singh H, Agarwal S, Singh V, et al. PICA disorder with autism: intervention in dental settings. J Res Advancement Dent. 2015;4(3):281-291.

4. Toker H, Ozdemir H, Ozan F, et al. Dramatic oral findings belonging to a pica patient: a case report. Int Dent J. 2009;59(1):26-30.

5. Advani S, Kochhar G, Chachra S, Dhawan P. Eating everything except food (PICA): a rare case report and review. J Int Soc Prev Community Dent. 2014;4(1):1-4.

6. Hui Lui Y, Pesch MH, Lumeng JC, Stein MT. Pica in a four-year-old girl with global developmental delay. J Dev Behav Pediatr. 2015;36(9):758-760.

7. Call N, Simmons C, Mevers J, Alvarez J. Clinical outcomes of behavioral treatments for pica in children with developmental disabilities. J Autism Dev Disord. 2015;45(7):2105-2114.

8. Sewell J. The world of autism. RDH. 2015;35(8):44-47.

9. Khatib A, Tekeya M, Tantawi M, Omar T. Oral health status and behaviors of children with Autism Spectrum Disorder: a case-control study. Int J Paediatr Dent. 2014;24:314-323.

10. Atuahene B, Belfer S, Hunt M. Pagophagia improves neuropsychological processing speed in iron-deficiency anemia. Medical Hypotheses. 2014;83(4):473-476.

11. Rose EA, Procerelli JH, Neele AV. Pica: common but commonly missed. J Am Board Fam Med. 2000;13(5):353-358.

12. Rabel A, Leitman SF, Miller JL. Ask about ice, then consider iron. J Am Assoc Nurs Pract. 2016; 28(2):116-120.

13. Mills ME. Craving more than food: the implications of pica in pregnancy. Nurs Womens Health. 2007;11(3):266-273.

14. Fawcett EJ, Fawcett JM, Mazmanian D. A meta-analysis of the worldwide prevalence of pica during pregnancy and the postpartum period. Int J Gynecol Obstetrics. 2016;133(3):277-283.

15. Fox, C., PhD. Pica. University of Massachusetts Medical School. 2013, Retrieved from https://shriver.umassmed.edu/programs/cdder/webinars/pica.

16. Williams, D., & McAdam, D. (2012). Assessment, behavioral treatment, and prevention of pica: Clinical guidelines and recommendations for practitioners. Research in Developmental Disabilities, 33(6), 2050-2057.

17. Questions about behavioral function [PDF File]. 2019, Retrieved from https://www.liberty.k12.ga.us/ourpages/auto/2016/2/1/43422828/Doc_%205%20QABF%20Questions%20About%20Behavioral%20Functions.pdf.

Table 1

Table 1

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PROVIDER: American Dental Hygienists' Association
SOURCE: American Dental Hygienists' Association | May 1, 2019

Learning Objectives:

  • Describe the clinical manifestations of pica.
  • Explain why it is important for dental professionals to screen patients for pica.
  • Discuss how to have a conversation about pica with patients and their families.


The author reports no conflicts of interest associated with this work.