Depth and area of dental erosions, and dental caries, in bulimic women

Oro-dental manifestations of eating disorders: a systematic review

BACKGROUND

Eating disorders (EDs) pose a significant risk to health, especially when not diagnosed early. For several years EDs and oral health has been extensively studied, and now it is quite clear the existence of a correlation between specific oral manifestations and these disorders. While these oral signs could potentially aid early diagnosis of EDs, their identification and the eventual establishment of a correlation is currently heavily limited to the clinician's experience. The present systematic review critically examines existing literature, offering an updated overview of oro-dental manifestations associated with EDs.

METHOD

MEDLINE (via PubMed), Web of Science, Scopus, and grey literature were searched, and relevant epidemiological comparative studies were screened using the Rayyan software. No limitations have been imposed on the research regarding oro-dental outcomes, encompassing all medically diagnosed EDs. The quality of the studies was valuated using AXIS appraisal tool for cross-sectional studies.

RESULT

Out of 3990 studies, 32 fulfilled the eligibility criteria and were included in the synthesis. The identified eating disorders include Anorexia Nervosa, Bulimia Nervosa and/or Eating Disorders Not Otherwise Specified, predominantly among female subjects, primarily originating from Europe. The evaluated oro-dental outcomes include dental erosion, caries, saliva assessment, hygiene-periodontal parameters, and mucosal tissue appearance. The association with erosion is confirmed while gingival recession, dentinal hypersensitivity, salivary flow thresholds and aspects relating to oral pathology are receiving increasing support from emerging evidence.

DISCUSSION

This trend emphasizes the critical role of the complete intraoral examination to detect significant oro-dental signs that may indicate the onset of an ED.

Eating Disorders and Dental Erosion: A Systematic Review

Both eating disorders and dental erosion are increasingly affecting adolescents and young adults. Thus, our systematic review was designed to answer the question: "Is there a relationship between dental erosion and eating disorders?" Following the inclusion and exclusion criteria, 31 studies were included in this systematic review (according to the PRISMA statement guidelines). Based on the meta-analysis, 54.4% of patients with bulimia nervosa and 26.7% with anorexia nervosa experienced tooth erosion. For the whole group of 1699 patients with eating disorders, erosive lesions were observed in 42.1% of patients. Bulimics were more than 10 times more likely to experience dental erosion compared to healthy individuals (OR = 10.383 [95%CI: 4.882-22.086]). Similarly, more than 16 times increased odds of tooth erosion were found in patients with self-induced vomiting (OR = 16.176 [95%CI: 1.438-181.918]). In conclusion, eating disorders are associated with an increased risk of developing erosive lesions, especially in patients with bulimia nervosa.

Effect of Mouthrinses containing Olive Oil, Fluoride, and Their Combination on Enamel Erosion: An in vitro Study

AIM

The aim of the study was to evaluate the effect of mouth-rinses containing olive oil, fluoride, and their combination on enamel erosion.

MATERIALS AND METHODS

An in vitro study of 45 enamel specimens, which were prepared from 45 extracted teeth, was employed. Each specimen was subjected to 10 alternative demineralization and remineralization cycles. Remineralizing cycle includes 5 minutes exposure with one of the mouthrinse, and demineralizing cycle includes 3 minute exposure to 1% citric acid. Mean surface roughness (Ra) was measured from surfometry before and after cycles. Statistical tests used were Student's unpaired t-test and one-way analysis of variance (ANOVA), followed by Tukey's post hoc test.

RESULTS

Among the three mouthrinses, Listerine and Xerostom showed maximum protection against erosion on enamel. The 2% olive oil mouthrinse showed the least protection against erosion on enamel.

CONCLUSION

The study indicated that the Listerine and Xerostom mouthrinses are valuable preventive measures.

CLINICAL SIGNIFICANCE

Mouthrinses are effective for lessening erosive demineralization and in aggregating remineralization of tooth surfaces which are the important factors to prevent enamel erosion.

Tooth erosion and eating disorders: a systematic review and meta-analysis

Background

Eating disorders are associated with the highest rates of morbidity and mortality of any mental disorders among adolescents. The failure to recognize their early signs can compromise a patient's recovery and long-term prognosis. Tooth erosion has been reported as an oral manifestation that might help in the early detection of eating disorders.

Objectives

The aim of this systematic review and meta-analysis was to search for scientific evidence regarding the following clinical question: Do eating disorders increase the risk of tooth erosion?

Methods

An electronic search addressing eating disorders and tooth erosion was conducted in eight databases. Two independent reviewers selected studies, abstracted information and assessed its quality. Data were abstracted for meta-analysis comparing tooth erosion in control patients (without eating disorders) vs. patients with eating disorders; and patients with eating disorder risk behavior vs. patients without such risk behavior. Combined odds ratios (ORs) and a 95% confidence interval (CI) were obtained.

Results

Twenty-three papers were included in the qualitative synthesis and assessed by a modified version of the Newcastle-Ottawa Scale. Fourteen papers were included in the meta-analysis. Patients with eating disorders had more risk of tooth erosion (OR = 12.4, 95%CI = 4.1–37.5). Patients with eating disorders who self-induced vomiting had more risk of tooth erosion than those patients who did not self-induce vomiting (OR = 19.6, 95%CI = 5.6–68.8). Patients with risk behavior of eating disorder had more risk of tooth erosion than patients without such risk behavior (Summary OR = 11.6, 95%CI = 3.2–41.7).

Conclusion

The scientific evidence suggests a causal relationship between tooth erosion and eating disorders and purging practices. Nevertheless, there is a lack of scientific evidence to fulfill the basic criteria of causation between the risk behavior for eating disorders and tooth erosion.

Dental approach to erosive tooth wear in gastroesophageal reflux disease

BACKGROUND

The duration of gastro-esophageal reflux disease (GERD), the frequency of reflux, the pH and type of acid, and the quality and quantity of saliva affect the severity of dental erosion due to GERD.

OBJECTIVE

To summarize the diagnostic protocol and treatment of dental erosion due to GERD.

METHODS

A Medline literature search was performed to identify articles associated with a dental approach to GERD.

RESULTS

The dental professional must carry out a diagnostic protocol, which includes collecting data on the patient's medical and dietary history, occupational/recreational history, dental history, and oral hygiene methods. Intraoral, head and neck, and salivary function examinations should be performed to expose the dental implications of GERD symptoms.

CONCLUSION

Diagnosing the cause of erosive tooth wear can help prevent further damage. Patients must be informed about how to prevent GERD.

Oral health status, salivary factors and microbial analysis in patients with active gastro-oesophageal reflux disease

AIM

To present a complex oral health status including salivary factors, microbial analysis and periodontal and hygiene indices in patients with active gastro-oesophageal reflux disease (GORD). Return of stomach contents is quite common in cases of gastro-oesophageal reflux. Pathological acid movement from the stomach into the oesophagus and oral cavity may lead to a development of dental erosion. Long-lasting untreated GORD may damage hard dental and periodontal tissues and alter the oral microbial environment. The quality and amount of the saliva play an important role in hard and soft oral tissues changes.

METHOD

Fifty patients with diagnosed GORD using 24-hour pH manometry underwent dental examination; 24 patients had active GORD and had been waiting for surgical therapy. In this patient group oral health status and salivary analysis were evaluated.

RESULTS

Indicated low salivary flow rates and buffering capacity with a low caries risk but a high risk for dental erosion progression.

Erosive lesions in patients with alcoholism

BACKGROUND

The authors conducted a study to determine the occurrence of erosive tooth lesions in patients with alcoholism and to establish the influence of salivary flow rates and pH levels on their appearance.

METHODS

The authors conducted a cross-sectional study in 140 participants (70 with clinically diagnosed alcoholism who were undergoing therapy for their addiction were in the test group and 70 who did not consume alcohol were in the control group). The authors determined the participants' salivary statuses by measuring the flow rates and pH levels of both unstimulated and stimulated saliva.

RESULTS

The authors found more erosive lesions in the test group (P < .01). They detected a higher number of erosive lesions in participants in the test group who had a pH range of 5 to 6 compared with a pH range of 6 to 7 (P = .01). They found a significant correlation between alcoholism and unstimulated salivary flow rate (P < .05).

CONCLUSIONS

The salivary flow rate was similar in control and test groups. The prevalence of erosion in the test group was higher than that in the control group, which may be related to the decrease in salivary pH of both stimulated and unstimulated saliva in this group. The results of the study showed no connection between erosion prevalence and pH levels and stimulated salivary flow rates.

CLINICAL IMPLICATIONS

Patients with alcoholism may be at risk of developing erosive lesions on their teeth owing to the low pH level of their oral environment and decreased saliva levels.

Extra-esophageal manifestations of gastroesophageal reflux

Gastroesophageal reflux disease (GERD) is a common medical condition affecting approximately 35-40% of the adult population in the western world. The role of GERD in causing extra-esophageal symptoms including laryngitis, asthma, cough, chest pain, and dental erosions is increasingly recognized with renewed interest among gastroenterologists and other specialists. Direct injury by mucosal contact, and vagally mediated reflex from distal esophageal acid exposure are the two possible mechanisms by which reflux-related extra-esophageal tissue injuries may occur. Several investigational techniques may be used to diagnose gastroesophageal reflux; however, because of the poor sensitivity of endoscopy and pH monitoring, and the poor specificity of laryngoscopy, empiric therapy with proton-pump inhibitors (PPI) is now considered the initial diagnostic step in patients suspected of having GERD-related symptoms. In those who improve with such therapy, it is likely that GERD may be the cause of the extra-esophageal presentation. In those who are unresponsive to such therapy, other diagnostic testing such as impedance/pH monitoring may be reasonable in order to exclude continued acid or weakly acid reflux. However, PPI-unresponsive patients usually have causes other than GERD for the extra-esophageal symptoms and signs.

Dental fear, regularity of dental attendance and subjective evaluation of dental erosion in women with eating disorders

This questionnaire study, with a response rate of 53%, examined self-induced vomiting, erosions and dental attendance in women with eating disorders (EDs) as well as dental fear and its effect on attendance and communication with the dentist. A survey of 371 responding women with EDs, who were recruited from a self-help organization, revealed that dental fear was higher in women with EDs compared to the general population. Dental fear was present in 32.1% of women with EDs, and very high dental fear was present in 16.5% of women with EDs. Of those with very high dental fear, 32.3% had not visited a dental clinic at all in the preceding 2 yr, and 43.5% only initiated contact when they had symptoms. Self-induced vomiting was especially frequent in women with bulimia nervosa (87.9%) and in those with more than one ED (the 'mixed group') (80.6%). Among those with self-induced vomiting, 45.3% thought that they had erosions, although only 28.4% had erosions diagnosed by a dentist. Of women with EDs, 61.4% failed to disclose their condition. High dental fear did not affect willingness to disclose the ED. We conclude that dentists should examine ED patients carefully for dental erosions. Moreover, they should realize that most ED patients avoid disclosing their disorder and that dental fear further complicates dental treatment in these patients.

Endodontic sequelae of dental erosion

BACKGROUND

The incidence of pulp involvement in patients with excessive wear has not been extensively documented.

METHODS

Clinical records of 448 patients with excessive tooth wear were reviewed and 52 cases (11.6 per cent) with near or frank pulp exposures or root canal treatments were found and their numbers and sites were tabulated. Light microscopy of study models was used to determine aetiology at each site of exposure as attrition, erosion or abrasion, scanning electron microscopy (SEM) was performed on some individual teeth.

RESULTS

Forty sites of near exposure and 57 sites of frank exposures or root canal treatments were found, some cases had both types of exposure. The commonest sites exposed by erosion were the palatal surfaces of maxillary, and the incisal surfaces of mandibular anterior teeth. Posterior teeth were not commonly affected. Toothbrush abrasion had exacerbated some lesions as shown by SEM.

CONCLUSIONS

Endodontic sequelae were found in 11 per cent of tooth wear patients as late stages of dental erosion. Near and frank exposures of the pulp thus constitute a small but significant, problem for the Australian dental profession's concern in the management of the tooth wear cases.

Oral profiles of bulimic women: Diagnosis and management. What is the evidence?

This article is a critical appraisal of the literature on the oral complications of bulimia. The MEDLINE database yielded a total of 82 English-language reports published between 1966 and 2002 that were pertinent to the topic of oral manifestations and treatment of bulimia. The literature is composed primarily of reviews, letters, case reports with or without restorative management, and descriptive studies of small sample sizes. At present, retrospective case-control studies are the only studies available with levels of evidence in the vicinity of 3 to 4. From these studies it is apparent that bulimic women present with a variety of oral and pharyngeal signs and symptoms, including dental caries and tooth erosion, dental pain, increased levels of cariogenic bacteria, orthodontic abnormalities, xerostomia (the subjective complaint of a dry-mouth) and decreased saliva secretion (the objective measure), decreased salivary pH, decreased periodontal disease, parotid enlargement, and swallowing impairments. Dental erosion is the major finding associated with bulimia. Case reports describe restoration of damaged surfaces with porcelain-laminated veneers, dentin-bonded crowns with minimal tooth preparation, composites, and complete-coverage restorations. However, what is really needed is identification of oral markers of bulimic behavior for early detection of bulimic patients by dentists and by physicians that can prevent the deleterious effects of frequent vomiting on the oral/dental tissues.

Studies on dental erosion: An in vivo-in vitro model of endogenous dental erosion--its application to testing protection by fluoride gel application

BACKGROUND

The objective in this study was to develop an in vivo-in vitro model of endogenous erosion, with a view to exploring the potential for some degree of its control by the use of topical fluoride gel application to teeth.

METHODS

Six volunteers each wore a small clasp retained palatal acrylic appliance to which six sterilized enamel tiles were bonded. Three tiles on each appliance were coated extra-orally with either 1.23 per cent acidulated phosphate fluoride (APF) or 2.2 per cent sodium fluoride (NaF) neutral gel for four minutes prior to multiple periods of exposure to the simulated gastric acid, cumulating in 16, 36, 80 and 150 minutes of exposure. Impressions of the enamel tiles prior to and following acid exposure permitted dies to be prepared. These were sectioned through the exposed areas and examined under a stereomicroscope to assess maximum depths of erosion.

RESULTS

The depth of erosive demineralization of enamel was found to be greatly reduced with increased frequency of APF gel application. The reduction in enamel loss was less following topical application of NaF gel.

CONCLUSIONS

It was concluded that fluoride gels significantly reduced enamel erosion using this in vivo-in vitro model and therefore, if prescribed appropriately, should help reduce tooth tissue loss from endogenous erosion.

Is there a relationship between asthma and dental erosion? A case control study

OBJECTIVES

The aims of this study were firstly to assess and compare the prevalence of dental erosion and dietary intake between three groups of children; children with asthma, those with significant tooth erosion but with no history of asthma, and children with no history of asthma or other medical problems. Secondly, to discover whether there was a relationship between medical history and dietary practises of these children and the levels of dental erosion. Thirdly, to measure and compare their salivary flow rates, pH and buffering capacity.

METHODS

The study consisted of 3 groups of children aged 11-18 years attending Birmingham Dental Hospital: 20 children with asthma requiring long-term medication, 20 children referred with dental erosion, and 20 children in the age and sex matched control group. Tooth wear was recorded using a modification of the tooth wear index (TWI) of Smith and Knight. Data on the medical and dietary history were obtained from a self-reported questionnaire supplemented by a structured interview. The salivary samples were collected under standard methods for measurements.

RESULTS

Fifty percent of the children in the control group had low erosion and 50% moderate erosion. However, high levels were recorded in 35% of children in the asthma group and 65% in the erosion group. There appeared to be no overall differences in diet between the groups. There was an association between dental erosion and the consumption of soft drinks, carbonated beverages and fresh fruits in all the three groups. More variables related to erosion were found in the erosion and asthma groups. A comparison between the three groups showed no significant differences in unstimulated and stimulated salivary flow rates, or pH and buffering capacity.

CONCLUSION

There were significant differences in the prevalence of erosion between the three groups, children with asthma having a higher prevalence than the control group. Although there was a relationship between the levels of erosion and some medical history and acidic dietary components, these did not explain the higher levels in asthmatic children. Further investigation is required into the factors affecting the increased prevalence of erosion in children with asthma.

Gastroesophageal reflux disease: New oral findings

OBJECTIVE

The objective of this study was to investigate the effects of gastroesophageal reflux disease (GERD) on dentition, salivary function, and oral mucosa.

STUDY DESIGN

Thirty-one patients with esophagitis underwent medical evaluation, which included taking their medical history, performing both an esophagogastroduodenoscopy and esophagus biopsy, and conducting a stomatologic examination. The latter consisted of an extraoral and intraoral physical examination, saliva tests (flow, buffer capacity, and pH), and biopsy and morphometry of the palatal mucosa, as well as taking a history of the patients' habits. Fourteen healthy volunteers from the same population were used as a control group.

RESULTS

No relationship between GERD and changes in the oral cavity was shown by saliva tests, oral clinical examination, or histopathologic examination of the palatal mucosa. However, morphometric analysis of the palatal epithelium showed a statistically significant difference between the patients with GERD and the control group.

CONCLUSIONS

GERD is associated with microscopic alterations in the palatal mucosa (epithelial atrophy and increased fibroblast number), which are only detected by morphometry.

Structured review of enamel erosion literature (1980-1998): a critical appraisal of experimental, clinical and review publications

OBJECTIVE

To attain an objective account of the methods to measure enamel erosion used in 1980-1998 publications, a structured review of the literature was undertaken.

METHODS

Inclusion and exclusion criteria were applied to 731 clinical/experimental research and review reports. Eighty-five included papers were subsequently rated according to 'hierarchy of evidence' guidelines to assess the strength of the report's design and the relevance of the evidence to replicating enamel erosion in vivo in humans. Scores were assigned to rate each aspect in the guidelines.

RESULTS

A total of 16 clinical, 13 review and 56 experimental papers were assessed; 36.4% were published during 1996-1998. Excluding reviews, 16 papers were qualitative and 56 quantitative; 51 used human enamel. Our classification yielded nine groups of methods (five scoring systems and 26 measurement techniques). CTFPHE (Can Med Assoc J 1992; 147: 443) grading of research reports indicated that 2.8% provided evidence grade I; 20.8%, grade IIa; 63.9%, grade III; and 12.5%, grade IV.

CONCLUSIONS

There has been a consistent increase in the body of knowledge. The overall quality of publications has not substantially changed over time. Experimental studies were more often quantitative, and quantitative studies had better research designs. No single group of research methods had obviously superior research designs.

Eating disorders and the dentist

Dentists are likely to encounter patients who have eating disorders. The paper explains the various types and considers both the risk factors, and the psychological and medical complications. The effect on oral health and the principles of dental management are outlined. Dentists have an important part to play in the overall care of these patients.

Bulimia and tooth erosion

Eating disorders are often associated with regurgitation of gastric contents into the mouth and dental erosion. In this study the dental status was evaluated in bulimic patients. Thirty-five bulimics, diagnosed in the Outpatient Departments of Psychiatry and Adolescent Psychiatry of the University Central Hospital in Helsinki, and 105 controls matched for age, sex, and educational level were examined clinically, and the factors associated with dental erosion and caries were evaluated in an interview. Severe dental erosion and dental caries were significantly commoner among bulimics than controls. Bulimics commonly had a low salivary flow rate, but other apparent risk factors of dental erosion did not differ from those of controls. A feeling of dry mouth was commoner among bulimics than controls, and bulimics had an increased tooth sensitivity to cold and touch. More should be done to protect teeth from dental erosion among bulimics, because loss of tooth tissue remains even if the eating disorder disappears.

The relationship between gastro-oesophageal reflux disease and dental erosion

It is well known that acid regurgitated from the stomach into the mouth will erode teeth. Conditions such as anorexia and bulimia nervosa, chronic alcoholism and gastric disturbances cause palatal dental erosion. The common factor in these conditions is the role played by the stomach and oesophagus in the acid movement. Acid moving through the lower oesophageal sphincter into the oesophagus is described as gastro-oesophageal reflux (GOR). In some patients the acid movement becomes chronic, painful and requires treatment and is termed gastro-oesophageal reflux disease (GORD). It is felt by many gastroenterologists that GORD is a failure of the anti-reflux mechanism, which is predominantly controlled by the lower oesophageal sphincter (LOS). Regurgitation is the reflux of gastric juice through the upper oesophageal sphincter and into the oral cavity. Once the acid has reached the mouth the potential exists for damage to the teeth. This paper reviews the role of GOR, GORD and regurgitation in the aetiology of dental erosion.

Etiology of dental erosion--intrinsic factors

Dental erosion due to intrinsic factors is caused by gastric acid reaching the oral cavity and the teeth as a result of vomiting or gastroesophageal reflux. Since clinical manifestation of dental erosion does not occur until gastric acid has acted on the dental hard tissues regularly over a period of several years, dental erosion caused by intrinsic factors has been observed only in those diseases which are associated with chronic vomiting or persistent gastroesophageal reflux over a long period. Examples of such conditions include disorders of the upper alimentary tract, specific metabolic and endocrine disorders, cases of medication side-effects and drug abuse, and certain psychosomatic disorders, e.g. stress-induced psychosomatic vomiting, anorexia and bulimia nervosa or rumination. Based on a review of the medical and dental literature, the main symptoms of all disorders which must be taken into account as possible intrinsic etiological factors of dental erosion are thoroughly discussed with respect to the clinical picture, prevalence and risk of erosion.

Tooth erosion, gastroesophageal reflux, and salivary buffer capacity

To obtain information on the connection between tooth erosion and acid gastroesophageal reflux, 14 patients (mean age, 15.7 years) with tooth erosion were investigated with simultaneous 24-hour pH monitoring in the esophagus and the oral cavity. Salivary parameters were also investigated in a larger group of 62 erosion patients (mean age, 21 years) and compared with a group of 50 controls (mean age, 28 years). No changes in oral pH were observed in a total of 339 acid reflux episodes, not even in long supine reflux episodes. Extended periods of lowered intra-oral pH to the level of 4 to 5 were observed but not connected with gastroesophageal reflux episodes. Significantly more (p < 0.001) erosion patients (34 of 62) had low salivary buffer capacity compared with controls (10 of 50).

Gingivitis/stomatitis in cats

Any alteration in the balance of bacterial challenge versus the host's ability to resist and repair will result in oral lesions that are similar in appearance. The bacterial cause of gingivitis and periodontitis in humans and in all other animals in which it has been studied is firmly established, and specific species of predominantly gram-negative anaerobes have been implicated. Naturally occurring or acquired immunopathologies are likely to result in premature dental disease. When oral disease is associated with the accumulation of plaque, a positive response can be achieved by reducing the bacterial challenge to the host through the maintenance of oral hygiene by timely professional dental prophylaxis and home care. Disease that is the result of atypical immune responses, however, can be much more difficult to manage. Such oral disease can occur with either immune deficiencies or exaggerated immune responses, and it is likely that multiple mechanisms are active concurrently. In any case, gram-negative anaerobes present in plaque are likely to be a major contributing factor. Therefore patients with chronic refractory gingivitis-stomatitis must be considered to be plaque intolerant. Only with a frequent regimen of aggressive and thorough professional dental treatment plus meticulous oral home care on a daily basis can one expect to keep these cases in remission. Because this is often unrealistic, the only other way to keep these patients free of disease is by total dental extraction. The tissues that are colonized by the causative organisms must be eliminated. All root tips and bony sequestra must be removed and healing with intact epithelium accomplished before these cases will go into remission. Edentulous feline patients that continue to have signs of gingivostomatitis have been found to have an area of nonhealed bony sequestrum and chronic osteomyelitis. Once effective debridement has been accomplished and epithelial healing completed, nonresponsive cases can be expected to go into remission (Color Plate 2, Figure 7). It is hoped that as more is learned about this frustrating problem, the many factors influencing feline oral disease will be scientifically documented. In the future, actual diagnoses can be systematically made early on in disease, and treatment will be more than just symptomatic.

Dental ceramics: the state of the science

This review covers the properties of dental ceramics. Castable systems, bioactive glass, PMF systems, CAD/CAM, and ceramic brackets in orthodontics are briefly discussed. Many of the advances made between 1960 and 1975 were directed toward the understanding, controlling, and developing of new ceramic processes. New and deeper understanding of the structure of non-crystalline solids, structural imperfections, sintering physics, and other physical phenomena related to the melting and solidification processes has brought ceramics from the near-total art form process of the mid-century to the status of a highly sophisticated science it enjoyed in the 1980's.

Stress-induced cervical lesions

The increasing occurrence of dental lesions at the cervical surfaces requires more knowledge of the causes of the process. Acidic and abrasive mechanisms have clearly been documented as causes but the stress theory by Lee and Eakle is still controversial. This report describes several incidences of possible stress-induced lesions according to the characteristics described by Lee and Eakle. The occurrences of subgingival lesions lend credence to the stress-induction theory by exclusion of other superimposing etiologic factors. With the current concepts, a perceptive approach to the treatment of cervical lesions can be executed.