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FACT SHEET: Schizophrenia1

Date of Publication: June 20, 2019

Is the initiation of non-invasive dental hygiene procedures* contra-indicated?

  • Yes, unless the patient/client is under medical management.
  • Yes, if the patient/client displays psychotic signs/symptoms that pose a risk to himself/herself or the dental hygienist during procedures (e.g., disorganized behaviour).

Is medical consult advised?

  • Yes, before dental/dental hygiene treatment is started to establish the patient/client’s current status, medications the patient/client is taking, and the ability of the patient/client to give informed consent for treatment. (This may involve consultation with either the patient/client’s psychiatrist or primary care physician.)
  • Yes, if previously undiagnosed schizophrenia is suspected.
  • Yes, if previously diagnosed schizophrenia is suspected to be suboptimally managed, including relapse and antipsychotic medication side effects. Immediate referral is indicated if suicidality or homicidality is suspected.
  • Yes, if akathisia2 or tardive dyskinesia is newly suspected.
  • Yes, if severe xerostomia is suspected to be related to antipsychotic use (which may improve if an alternative antipsychotic is a consideration).

Is the initiation of invasive dental hygiene procedures contra-indicated?**

  • See above under “initiation of non-invasive dental hygiene procedures”.
  • Yes, if the patient/client is taking the antipsychotic drug clozapine, which may cause bone marrow suppression3; the procedures should not begin until the dental hygienist confirms with the patient/client’s physician that the white blood cell count is within normal limits.

Is medical consult advised?

  • See above.

Is medical clearance required?

  • Yes, if severe leukopenia (i.e., reduced white blood cell count, and hence immunosuppression), agranulocytosis, or thrombocytopenia is suspected with antipsychotic medication use (e.g., clozapine).

Is antibiotic prophylaxis required?

  • No (in absence of immunosuppression).

Is postponing treatment advised?

  • Yes, if medical clearance is pending regarding possible immunosuppression associated with use of antipsychotic medication.
  • Yes, if patient/client has previously undiagnosed schizophrenia.
  • Yes, if suboptimally treated schizophrenia exists (which can adversely affect informed consent, decision-making, and behaviour). Attainment of better control of signs/symptoms may be indicated before attempting elective dental/dental hygiene treatment.
  • Yes, if patient exhibits psychotic signs/symptoms that may pose risk during, or cause inability to perform, procedures, in which case medical treatment is first needed.4
  • Yes, if patient/client is medically unstable. Malignant neuroleptic syndrome in the operatory is a medical emergency, which necessitates cessation of dental/dental hygiene treatment, immediate contact with emergency medical services, and supportive management pending hospital transfer.5
  • Yes, if patient/client has not complied with pre-medication (e.g., sedative), when indicated and as directed by the prescribing physician.

Oral management implications

  • Management implications are dependent on the type of schizophrenia exhibited by the patient/client (e.g., catatonic versus paranoid), the level of its control, and the side effects of drug treatment.6
  • Non-compliance in taking prescribed antipsychotic medication occurs in over 50% of patients/clients.
  • Morning appointments are generally preferred, with the patient/client being accompanied by a family member/attendant when possible to maximize comfort and familiarity.
  • Confrontation on the part of the oral healthcare professional should be avoided. If the standard approach does not allow for proper dental/dental hygiene management, sedation may have to be considered in consultation with the patient/client’s physician.
  • Paranoid patients/clients may feel frightened or enraged due to a delusion of persecution or a perceived threat. A perceived slight may prompt hostility or guarding.
  • Postural hypotension can result from use of antipsychotic medications, and thus the dental hygienist should take this into account during position changes of the patient/client.
  • Epinephrine should be used with caution in patients/clients taking antipsychotic drugs, because severe hypotension may result.
  • The dental hygienist should be alert for signs of tardive dyskinesia, particularly in patients/clients who have been taking antipsychotics for many years.
  • The dental hygienist should be alert for oral lesions resulting from antipsychotic-induced agranulocytosis, leukopenia, or thrombocytopenia. If the dental hygienist notes oral lesions, fever, or sore throat in a patient/client taking an antipsychotic drug, the patient/client should be referred for medical evaluation.
  • Because most persons with schizophrenia smoke, the dental hygienist should be vigilant for signs of oral cancer.
  • The dental hygienist should assess the ability and willingness of the patient/client to perform preventive hygiene procedures. For patients/clients unable to perform oral hygiene procedures, or lacking motivation, a family member or attendant should be instructed on the procedures.
  • Management of iatrogenic xerostomia is important. Patients/clients should be asked whether their saliva seems reduced and if they have trouble swallowing, speaking, or eating dry foods. Other appropriate queries relate to lip dryness and cracking, halitosis, and mouth sores. If severe antipsychotic-related xerostomia is found, the patient/client’s physician may be able to prescribe an antipsychotic with less anticholinergic activity.

Oral manifestations

  • Periodontal disease, dental caries, and loss of teeth occur at elevated rates in persons with schizophrenia, related to decreased self-care.
  • Orofacial self-mutilation can occur during an acute psychotic episode, and may take the form of autoextractions7, glossectomy, and excoriation of gingival tissues with fingernails.
  • Xerostomia is commonly seen in patients/clients using antipsychotic (neuroleptic) medications, many of which have anticholinergic side effects. In contrast, hypersalivation is seen in more than 1/3 of patients/clients taking the antipsychotic clozapine.
  • Akathisia can develop during the early stages of treatment with antipsychotic medications. This can manifest as lip smacking and tongue thrusting.
  • Tardive dyskinesia, the most common late extrapyramidal adverse effect associated with antipsychotics, can affect the lingual, buccal, and masticatory muscles, resulting in “flycatcher’s tongue” (i.e., tongue darting in and out between the lips), “bonbon sign” (i.e., tongue pushing into cheek), chewing movements, and/or grimaces. Dysphagia and impaired gag reflex may also occur. An early sign of tardive dyskinesia is wormlike movement of the tongue within the mouth.
  • Premature tooth wear, speech impairment, and impaired retention of removable prostheses are consequences of oral dyskinesia.
  • Bruxism and temporomandibular joint (TMJ) disorders occur at elevated rates. Tardive dyskinesia can result in TMJ dislocation.
  • Oral lesions (e.g., mucosal ulcerations) may result from agranulocytosis, leukopenia, or thrombocytopenia associated with use of antipsychotic medications (particularly clozapine). Candidiasis may be seen in immunocompromised patients/clients.
  • In an acute psychotic state, the patient/client may hallucinate that worms are crawling in the mouth.

Related signs and symptoms

  • Schizophrenia is the most common and serious form of psychosis8 affecting mood, thought, and behaviour. This severe, chronic, and disabling mental illness affects about 1% of the Canadian population9, with men tending to develop the illness earlier than women. The specific cause is unknown but is generally believed to involve interaction between genetic and environmental factors10, with schizophrenia being more common if there is a family history of the disease. Onset usually occurs in adolescence or early adulthood heralded by a prodromal phase, with social or occupational functioning having deteriorated. There is currently no cure, but it can be controlled by the use of antipsychotic (also known as neuroleptic) medications, brain stimulation therapies, and psychosocial treatments.11
  • Characteristics of schizophrenia include disordered thinking, inappropriate emotional responses, and grossly disorganized or catatonic behaviour. The 5 subtypes12 of schizophrenia are paranoid, catatonic, disorganized, undifferentiated, and residual. Paranoid schizophrenia is characterized by hallucinations with or without delusions, which usually are of persecution or perceived threat. Catatonic schizophrenia is characterized by effects on mobility, which may be excessive, reduced, or include unusual postures. Disorganized (also known as hebephrenic) schizophrenia is characterized by confusion, strange ideas, poor concentration, muted emotion, and disorganized and inappropriate behaviour and speech.
  • “Positive” symptoms include hallucinations (auditory, visual, tactile, olfactory, and/or gustatory), delusions (i.e., firm convictions perceived by the patient/client that have no basis in reality, such as thought broadcasting or being controlled by another person), and agitation. The most common auditory hallucination is hearing non-existent voices.
  • “Negative” symptoms include flat affect, alogia (poverty of speech), avolition (lack of drive, motivation, or desire), and anhedonia (inability to experience pleasure).
  • “Disorganized” symptoms include rapid shift of ideas, poor thought relation, inability to concentrate on one subject for any length of time, and bizarre stereotypical behaviours (e.g., facial grimacing, repetitive awkward movements, pacing, and mutism).
  • Dystonias and extrapyramidal adverse effects (i.e., motor or movement disorders) can result from use of antipsychotic medications. These side effects may either be acute during the first few days of antipsychotic treatment (e.g., akathisia) or result from longer-term antipsychotic use (e.g., tardive dyskinesia, which involves involuntary movements including the upper and lower extremities and trunk as well as the head).
  • Lethargy and drowsiness are commonly seen when a patient/client initially takes an antipsychotic medication. However, tolerance usually develops after several days.
  • Urinary retention, constipation, obstructive jaundice, skin pigmentation, and cataracts are adverse effects of antipsychotic drugs.
  • Malignant neuroleptic syndrome is a rare but potentially life-threatening complication of antipsychotic drugs. It combines hyperthermia, autonomic dysfunction, and extrapyramidal dysfunction. Signs/symptoms include tachycardia, dyspnea, labile blood pressure, tremors, muscle rigidity, catatonic behaviour, dystonia, and marked elevation of temperature (up to 41º C).
  • Substance abuse (most commonly alcohol and cannabis13) involves up to 80% of patients/clients affected with schizophrenia, and nicotine addiction approaches 90%.
  • Readmission to hospital for stabilization is common as a result of non-compliance with medication.
  • The long-term course of schizophrenia is variable, with about 25% of patients/clients experiencing significant remission of symptoms (with ongoing medication and psychotherapy) and another 25% having ongoing mild yet persistent symptoms. The remaining 50% continue to have chronic to moderate to severe symptoms throughout their lifetime. About half of patients/clients with schizophrenia will attempt suicide, with 10% to 15% ultimately accomplishing this end.
  • Compared with the general population, persons with schizophrenia have higher risk of developing significant health problems such as obesity (sometimes related to use of some of the second-generation antipsychotic medications), diabetes, coronary artery disease, chronic obstructive pulmonary disease, etc.

References and sources of more detailed information

Date: November 5, 2018
Revised: June 5, 2023


1 Three other mental illnesses, while belonging to the schizophrenia spectrum disorders, are distinct clinical entities. These are schizoaffective disorder (which shows features of both schizophrenia and a mood disorder ― such as depression ― simultaneously), schizophreniform disorder (which includes 2 or more major symptoms of schizophrenia, but which lasts less than 6 months), and schizotypal personality disorder.
2 akathisia = extreme motor restlessness
3 Clozapine is associated with a 1% to 2% incidence of agranulocytosis, and patients/clients treated with this medication should be monitored weekly with complete blood cell counts. The most recent white blood cell count should be reviewed before dental/dental hygiene treatment is started.
4 Only 5% or less of patients/clients with schizophrenia are considered dangerous, and this includes persons who exhibit primarily acute psychotic symptoms (e.g., from non-compliance with prescribed antipsychotic medications), often exacerbated by the use of alcohol and/or street drugs.
5 Treatment involves stopping all neuroleptic medications, body cooling, rehydration, and treatment with bromocriptine.
6 First generation drug treatment involves “typical” antipsychotic medications (e.g., chlorpromazine, fluphenazine, haloperidol, loxapine, and thioridazine) that are effective for “positive” symptoms but less effective or non-effective for “negative” and “disorganized” symptoms. Second generation (“atypical”) antipsychotic medications (such as aripiprazole, asenapine, brexpiprazole, cariprazine, clozapine, iloperdone, lurasidone, olanzapine, paliperdone, quetiapine, risperidone, and ziprasidone) are effective, to varying degrees, for “positive”, “negative”, and “disorganized” symptoms; these second-generation drugs have supplanted the older medications for many indications, and they have decreased the occurrence of movement disorders.
7 An individual with schizophrenia may believe, for instance, that a tooth or filling contains a transmitter device.
8 Psychosis involves distortion of, or loss of contact with, reality due to impaired thought and emotions. While schizophrenia is a common type of psychotic illness, psychosis can also occur in other conditions, including severe depression, bipolar illness, substance use disorder, and biochemical or brain abnormalities.
9 This equates to about 380,000 affected persons in Canada and 145,000 in Ontario.
10 The predominant biologic hypothesis is the dopamine hypothesis, which attributes the symptoms of schizophrenia, in part, to disturbance in the dopamine-mediated neuronal pathways of the brain. Schizophrenia appears to be triggered by certain environmental events in a genetically predisposed individual; these triggers may include stressful psychosocial events and family dynamics, illness, drugs, and viral infection.
11 Psychosocial treatments include psychotherapy, drug and alcohol treatment, family education, and rehabilitation for living skills and employment. Brain stimulation therapies include electroconvulsive therapy and transcranial magnetic stimulation. In addition to antipsychotic medications, mood stabilizers (e.g., lithium), sedatives, and antidepressants may also be employed.
12 These 5 subtypes are not included in the fifth edition of Diagnostic and Statistical Manual of Mental Disorders of the American Psychiatric Association, because the APA found that they were “not helpful to clinicians because patients’ symptoms often changed from one subtype to another and presented overlapping subtype symptoms….”
13 Cannabis use is also a risk factor for the manifestation of schizophrenia in genetically prone adolescents.

* Includes oral hygiene instruction, fitting a mouth guard, taking an impression, etc.
** Ontario Regulation 501/07 made under the Dental Hygiene Act, 1991. Invasive dental hygiene procedures are scaling teeth and root planing, including curetting surrounding tissue.