Although the dental health of patients with autism has been examined in a number of studies,^10,12–18 many of these studies had small sample sizes, and almost all were limited to autism only. We conducted a study to evaluate the demographics, caries experience and behavior of patients with ASD and compare these characteristics with those in a group of unaffected patients by means of a cross-sectional analysis.

	SUBJECTS AND METHODS

TOP ABSTRACT SUBJECTS AND METHODS RESULTS DISCUSSION CONCLUSIONS REFERENCES

 
We searched the nonarchived records at the dental department of Franciscan Hospital for Children (FHFC) (Boston) and identified 395 patients with a primary diagnosis of ASD who were active dental patients. We randomly selected a group of 386 unaffected patients from the same population of active dental patients at FHFC. The unaffected patients were those who required dental treatment at the dental department of the FHFC but were otherwise healthy, did not have any medical conditions and were not receiving any medication. Supervised pediatric dentistry residents or attending faculty at FHFC treated the patients. We determined that patients had ASD by reviewing their medical histories, which were completed and updated by their parents or legal guardians during routine dental visits. The Boston University Institutional Review Board approved this study.

Two calibrated researchers (C.Y.L. and R.M.G.) obtained data from the most recent dental visits of patients in both the unaffected and ASD groups. They collected data from the patients’ charts regarding age, sex, caries prevalence and severity, type of dental treatment provided (preventive only versus restorative or surgical) and whether treatment was performed while the patient was under general anesthesia. They defined caries prevalence as the proportion of patients with a positive dental caries history: sum of decayed and filled teeth (dft) greater than 0 for the primary dentition, and sum of DMFT greater than 0 for the permanent dentition. They used dft and DMFT scores, which are referred to as DMFT in this article, to determined caries severity. The behavior of each patient as assessed by means of the Frankl scale¹⁹ (definitively negative [––], negative [–], positive [+] and definitively positive [++]) also was recorded. The researchers also obtained data regarding residence (home versus institution or group home), primary diagnosis (ASD category), presence of seizure disorder, additional diagnosis (mental retardation, cerebral palsy, self-injurious behavior or pica) and current medication for patients in the ASD group from the patients’ charts. They categorized patients with ASD who were receiving antipsychotic agents, antidepressant agents, anxiolytic medications, mood-stabilizing agents or stimulant agents as using psychotropic medications.

We used the Wilcoxon rank sum test, Kruskal-Wallis nonparametric test, ² test, Fisher exact test and multiple logistic regression analyses for statistical comparison at the P < .05 level of significance. We performed all analyses using statistical analysis software (SAS, Version 9.1, SAS Institute, Cary, N.C.).

	RESULTS

TOP ABSTRACT SUBJECTS AND METHODS RESULTS DISCUSSION CONCLUSIONS REFERENCES

 
Within the ASD group, there were significantly more males (317) than females (78) (P < .0001), with a male:female ratio of 4:1. Within the unaffected group, sex distribution (193 male, 193 female) was equal. Within the ASD group, 28 patients (7.1 percent) were from the same family.

Patients in the ASD group were significantly older (median age, 12 years; interquartile range, 7 years; age range, 3–28 years) than patients in the unaffected group (median age, 8 years; interquartile range, 7 years; age range 3–20 years) (P < .0001). Fourteen patients (3.5 percent) in the ASD group were older than 21 years. We noted no significant difference in age between males and females in the ASD group or the unaffected group (P = .2 and .4, respectively).

Caries prevalence was lower in the ASD group than in the unaffected group (P < .0001). A total of 269 (68.1 percent) patients in the ASD group had a positive dental caries history (DMFT > 0) compared with 332 patients (86.0 percent) in the unaffected group. The caries severity of patients in the ASD group was significantly lower (median DMFT, 3; interquartile range, 7; range, 0–30) than that in the unaffected group (median DMFT, 5; interquartile range, 7; range, 0–21) (P < .0001). We noted no significant difference in the DMFT scores of males and females in the ASD or the unaffected groups (P = .3 and .4, respectively).

When we conducted a multiple logistic regression analysis controlling for age and sex, we noted a significant association between ASD and caries prevalence. Patients with ASD were 70.5 percent less likely to have a positive caries history than were unaffected patients (adjusted odds ratio [OR], 0.30; 95 percent confidence interval [CI], 0.20–0.44; P < .0001).

We subsequently performed regression analysis controlling for age and sex to compare the caries prevalence of the ASD and unaffected groups in the primary and permanent dentitions. Regarding patients with primary dentition (younger than 6 years), patients with ASD were 83.4 percent less likely to have a positive caries history than were unaffected patients (adjusted OR, 0.17; 95 percent CI, 0.06–0.44; P = .0003). Regarding patients with mixed or permanent dentition (age 6–17 years), patients with ASD were 65.9 percent less likely to have a positive caries history than were unaffected patients (adjusted OR, 0.34; 95 percent CI, 0.22–0.54; P < .0001).

Patients in both the ASD and unaffected groups exhibited a full range of behavior on the Frankl scale (Figure). We noted a significant difference in the distribution of behavior in the unaffected and ASD groups (P < .0001). In the ASD group, 55.2 percent of patients were uncooperative (that is, exhibited either negative or definitely negative behavior), and 9.2 percent of patients exhibited definitely positive behavior. In the unaffected group, 25.4 percent of the patients were uncooperative, and 46.6 percent exhibited definitely positive behavior (Figure).

View larger version (66K): [in this window] [in a new window]   Figure. Distribution of behavior in the unaffected and autism spectrum disorder (ASD) groups (P < .0001). Behavior was assessed by means of the Frankl scale: definitely positive (++), positive (+), negative [–] and definitely negative (––).19

Within the ASD group, 78.8 percent of patients had a diagnosis of autism, 19.5 percent of patients had a diagnosis of PDD-NOS, and 1.8 percent of patients had a diagnosis of Asperger syndrome. We noted no significant difference in age (P = .29), sex distribution (P = .9) or caries severity (P = .57) among the three ASD diagnosis groups. We also noted no significant difference in the percentage of patients with an additional diagnosis (P = .45), with a seizure disorder (P = .9), receiving psychotropic medication (P = .43) or requiring treatment to take place under general anesthesia (P = .4) among the three ASD diagnosis groups.

A total of 187 patients in the ASD group (47.3 percent) were receiving medication to treat associated features of autism; 85 of these patients (45.5 percent) were taking two or more medications. Seventy-seven patients (41.2 percent) were receiving antipsychotic agents, the most commonly prescribed class of medication; seven (3.7 percent) of these patients were receiving two antipsychotic medications. Risperidone was the most commonly prescribed antipsychotic medication (61.6 percent).

A total of 31.4 percent of patients with autism spectrum disorder resided in an institution or group home, and 68.6 percent resided at home.

A total of 16.2 percent of patients with ASD were receiving anticonvulsant agents to manage seizures. The most common anticonvulsant agents—valproate (54.7 percent), lamotrigine (10.9 percent) and carbamazapine (9.4 percent)—also have mood-stabilizing properties. Seventy-nine patients (20.0 percent) with ASD received central nervous system stimulants, antihypertensive agents, a selective norepinephrine reuptake inhibitor and an anticholinergic drug to manage hyperactivity and improve attention span; the most commonly used was clonidine, an antihypertensive agent (50.6 percent). Antidepressant agents that are used to manage fear, anxiety, depression and repetitive thoughts and behaviors, were prescribed to 11.6 percent of patients. The most commonly used antidepressant agents were selective serotonin reuptake inhibitors (63.0 percent), followed by a tetracyclic antidepressant agent (trazodone) (21.7 percent), lithium (10.9 percent), a tricyclic antidepressant agent (doxepin) (2.2 percent) and a serotonin-norepinephrine reuptake inhibitor (venlafaxine) (2.2 percent).

Antipsychotic agents, antidepressant agents, anxiolytic medications, mood stabilizers and stimulants used to manage hyperactivity are categorized as psychotropic medications. Patients with ASD who received psychotropic medication were significantly older (median age, 14 years; interquartile range, 6 years) than patients who did not receive psychotropic medication (median age, 10 years; interquartile range, 7 years) (P = .0002). We noted no significant difference in DMFT scores between these two groups (P = .20).

Within the ASD group, the 17.2 percent of patients who had a seizure disorder were significantly older (median age, 14 years; interquartile range, 6 years) than those who did not have a seizure disorder (median age, 11 years; interquartile range, 7 years) (P < .0001). We noted no significant difference in DMFT scores between these two groups (P = .3).

Within the ASD group, 64 patients (16.2 percent) had an additional diagnosis of at least one condition associated with ASD. These were mental retardation (49 patients), cerebral palsy (eight patients), self-injurious behavior (seven patients) and pica (eight patients). Patients with ASD who had an additional diagnosis (median age, 14 years; interquartile range, 7 years) were significantly older than patients with ASD who did not have an additional diagnosis (median age, 12 years; interquartile range, 7 years) (P < .0001), but we noted no significant difference in DMFT scores between these two groups (P = .075). Patients with a seizure disorder (30.9 percent) were more likely to have an additional diagnosis than were patients without a seizure disorder (13.1 percent) (P = .0003).

A total of 31.4 percent of patients with ASD resided in an institution or group home, and 68.6 percent resided at home. Patients who lived in an institution (median age, 14 years; interquartile range, 5 years) were significantly older than those who lived at home (median age, 10 years; interquartile range, 7 years) (P < .0001). Patients with Asperger syndrome were the least likely to live in an institution (14.3 percent), followed by those with autism (28.9 percent) and PDD-NOS (42.9 percent) (P = .04). Patients who received an additional diagnosis (46.9 percent) were more likely to reside in an institution than were those who did not receive an additional diagnosis (28.4 percent) (P = .004). Patients who had a seizure disorder (47.1 percent) were more likely to reside in an institution than were patients without a seizure disorder (28.1 percent) (P = .002). Patients receiving psychotropic medication (42.9 percent) were more likely to reside in an institution than were those not receiving psychotropic medication (28.6 percent) (P = .0002). When we compared patients who lived in an institution with those who lived at home, we noted no significant difference in DMFT scores (P = .6), treatment requiring general anesthesia (P = .7), treatment type needed (P = .08), sex distribution (P = .5) or behavior (P = .2).

The results of our multiple logistic regression analysis of the ASD group showed that after adjustments for age and sex, there was no association between caries prevalence and ASD diagnosis group (P = .9), behavior (P = .9), use of psychotropic medication (P = .9), presence of seizure disorder (P = .2), additional diagnosis (P = .5) or institutionalization (P = .1).

Caries prevalence and severity in patients with autism spectrum disorder were lower than those in unaffected patients.

	DISCUSSION

TOP ABSTRACT SUBJECTS AND METHODS RESULTS DISCUSSION CONCLUSIONS REFERENCES

 
FHFC’s dental department serves a large number of people with a variety of special needs, including ASD. We conducted our cross-sectional study to generate a profile of current patients with ASD who receive dental care at FHFC and to compare this profile with that of a group of unaffected patients. To our knowledge, this is one of only two studies on the dental status of patients with autism to include people with Asperger syndrome and PDD-NOS; the other study compared the oral health status of 39 children with ASD with that of 16 children with other developmental disabilities.¹⁷

The male:female ratio of 4:1 that we observed in the ASD group in our study was consistent with previously reported sex ratios of 3.7:1.0⁵ and 4.3:1.0.²⁰ In our study, 7.1 percent of patients within the ASD group were from the same family, which concurs with the previously reported recurrence rate of 2 to 8 percent in siblings.¹

In our study, patients in the ASD group were significantly older than those in the unaffected group because FHFC’s dental department retained some patients with ASD after they were 21 years of age. Continued care with an established dental environment has been recommended because patients with ASD need continuity, familiarity and routine.⁸

Results from our study showed that the caries prevalence and severity in patients with ASD were lower than those in unaffected patients. Kamen and Skier¹³ also found that caries susceptibility was lower in people with autism than in unaffected people, while others^10,14,16,17 found that the caries prevalence was similar in both groups. Lowe and Lindemann¹⁰ reported that at an initial examination, patients with ASD had a higher caries index in the primary dentition than did unaffected patients but that rates were similar at recall examination.¹⁰ They also reported that the caries index in the permanent dentition were similar in the two groups at both initial and recall examinations. Shapira and colleagues¹⁶ found that noninstitutionalized children with autism had caries rates similar to those of unaffected children, whereas adults with autism who were institutionalized had a lower caries rate than did functionally independent adults. Morinushi and colleagues¹⁵ found that the caries experience of a group of Japanese children with autism in 1980 was similar to that of unaffected children in 1981. They also observed lower caries prevalence and severity in children with autism in 1995 compared with those of unaffected children in 1993. This may have been due to good home care by the patients’ parents or caregivers and a less cariogenic diet. They suggested that children with autism are less partial to sweets and are more regular in their behavior at meals than are unaffected children. Therefore, a lower frequency of snacking between meals and lower intake of carbohydrates could have contributed to the lower caries rate observed. Although ASD is not associated with increased dental caries prevalence or severity, dental professionals need to emphasize the importance of regular preventive measures and good dietary habits, because sweet foods may be used in behavior modification techniques.¹⁴

Results from our study showed that caries prevalence and severity did not differ between patients who were institutionalized and not institutionalized or among the three ASD diagnosis groups. Caries prevalence and severity were not associated with use of psychotropic medication, presence of seizure disorder or additional diagnosis. On the other hand, more patients in the ASD group required restorative or surgical dental treatment than did patients in the unaffected group. The larger proportion of patients with ASD who required treatment to take place under general anesthesia may have contributed to this observation because a less conservative approach is used when treatment is performed with general anesthesia.

Medication often is used to manage some of the symptoms associated with ASD. We found that 47.3 percent of patients with ASD were receiving prescription medication, and 45.5 percent of these patients were taking two or more medications. This finding is comparable with that of a recent study that reported 53 percent of children with autism required prescription medication.⁵ The most commonly prescribed class of medication was antipsychotic drugs that are used to manage symptoms of irritability, agitation, self-injurious behavior, aggression, repetitive behaviors, delusions and hallucinations.⁷ As many of these drugs have adverse effects and adverse interactions with drugs used in dentistry, dentists must be familiar with the properties of these medications. A comprehensive review of the medications used to treat autism, their orofacial and systemic reactions, and the adverse interactions of these drugs with dental therapeutic agents was published recently.⁷ For example, the orofacial adverse effects of these medications include xerostomia, sialorrhea, dysphagia, sialadenitis, dysgeusia, stomatitis, gingivitis, gingival enlargement, glossitis, bruxism, edema and discoloration of the tongue. We found that 17.2 percent of patients with ASD had seizure disorders, which concurs with the previously reported median rate of 16.8 percent,²⁰ although a rate of 28 percent has been reported,¹² and it has been estimated that approximately one-third of people with autism have experienced at least two unprovoked epileptic seizures before reaching adulthood.¹

More patients in the autism spectrum disorder group required restorative or surgical dental treatment than did patients in the unaffected group.

In the ASD group, 55.2 percent of patients were uncooperative, compared with only 25.4 percent of the unaffected group. Therefore, 44.8 percent of patients with ASD exhibited cooperative behavior during dental treatment, which is similar to the results of a recent study that showed that 35 percent of subjects with autism were cooperative during dental appointments¹¹ and another study that reported a 50 percent success rate for obtaining bitewing radiographs at the first attempt in patients with autism.¹⁰ On the other hand, the results of a survey of parents of children with autism showed that 77 percent of children with autism were frightened and uncooperative at their initial visit to the dentist.⁹ Owing to the behavioral problems in patients with autism, it has been recommended that long and involved treatment procedures be performed under general anesthesia.⁷ The 37.2 percent of patients with ASD who required dental treatment to take place under general anesthesia in our study is almost the same as the 37 percent reported previously.¹²

Patients who were institutionalized represented 31.4 percent of those with ASD, and they were significantly older than noninstitutionalized patients. This finding is in agreement with that of a previous study that reported that patients living in a group home represented 30 percent of those with autism and were significantly older than patients not living in a group home.¹² As there is an increase in aggressivity, self-injury and psychiatric illnesses (for example, anxiety disorder, mood disorders, attention-deficit/hyperactivity disorder, obsessive-compulsive disorder and schizophrenia during adolescence),⁷ a higher proportion of older patients will have these associated conditions and may require institutionalization. We also found that patients with ASD who had an additional diagnosis, had seizure disorders and were receiving psychotropic medication were more likely to reside in an institution or group home.

The limitations of our study include its cross-sectional character, the possible inaccuracy of a parental report of ASD diagnosis and dental care being provided by multiple clinicians. Also, in our study, we did not control for socioeconomic status, which may be a determinant of caries prevalence and severity.²¹ Despite these limitations, our study is one of nine studies of the dental status of patients with autism and is one of only two studies to include patients with Asperger syndrome and PDD-NOS. The results we obtained in this study were based on a large sample, although the number of patients with Asperger syndrome was insufficient for us to conduct a conclusive comparative analysis.

Oral health is integral to general health and quality of life, and basic oral health services are an essential component of primary health care. Considering the high prevalence of patients with ASD, dentists must be familiar with the manifestations of ASD and associated features to optimize patient cooperation and the delivery of dental treatment.

	CONCLUSIONS

TOP ABSTRACT SUBJECTS AND METHODS RESULTS DISCUSSION CONCLUSIONS REFERENCES

 
The results of our study show that when we controlled for age and sex, there was a statistically significant association between ASD and caries prevalence. There also was a significant association between ASD and caries severity; patients with ASD were more likely to be caries-free and have lower DMFT scores than were unaffected patients. There was no significant difference in the caries prevalence or caries severity between patients with ASD who were institutionalized and those who were not institutionalized. When compared with unaffected patients, significantly more patients with ASD were uncooperative and required dental treatment to take place under general anesthesia.