Previous studies focused on description of DED in CD. In fact, this will not reflect how much common is CD among patients presenting with DEDs. In the current study, CD was the underlying cause of DEDs in 17.86% of the studied patients compared to 0.97% of normal children without DEDs. This high frequency justifies consideration of DED patients as candidates for screening for CD. The North American Society for Pediatric Gastroenterology, Hepatology, and Nutrition (NASPGHAN) included the presence of specific dental enamel defects as a risk factor for CD [17
]. The same was recommended by Aine et al. and Petrecca et al. [5
Avşar and Kalayci [18
] reported that the prevalence of DED in CD subjects was significantly higher (42.2%) than in healthy subjects (9.4%) (P
< 0.001). Grade 1 type enamel defects were most commonly diagnosed in both groups (20.3% and 6.3%, resp.).
Wiernik et al. [19
] found that 55% celiac patients had DED against 18% control subjects. Similarly, Páez et al. [20
] detected DED in 83.3% of the celiac children versus 53.3% of the controls. On the other hand, Procaccini et al. [21
] found that the prevalence of enamel hypoplasia was not higher in the study population than in the control group.
The prevalence of CD in normal children in this cohort was 0.97%, which was a little bit higher than Abu-Zekry et al. [22
], who reported a frequency of 0.53 in Egyptian children. The frequency is near to most of western reports (around 1%) [23
] and lower than an African report (around 5%) [25
In our study, grades 1, 2, and 3 of DED are more common than grade 4 pathology. Grades 2 and 3 are more common in CD than nonceliac. Improvement of grades, up to normalization of some cases, was significantly more achieved in CD than nonceliac patients who were maintained on routine dental care. The better improvement can be either attributed to direct effect of GFD on enamel or to improved nutritional status after such a regimen.
Ciacci et al. [26
], reported that DEDs were found in 15 patients of transient GFD, 43 of never on GFD and zero of the GFD group.
The high mean age of CD patients was in agreement of Kuloğlu et al. [27
] who reported that the age of children with classical type (7.5 ± 4.3 years) was significantly lower than the age of children with atypical form (10.8 ± 4.3 years). Other studies [28
] reported a changing pattern in the presentation of pediatric CD towards more predominance of atypical presentations of CD and older age at diagnosis.
The Celiac Disease Guideline Committee of the NASPGHAN recommended that children and adolescents with symptoms of celiac disease or an increased risk for celiac disease should have a blood test for antibody to tissue transglutaminase, then those with an elevated TTG be referred for an intestinal biopsy to confirm the diagnosis [23
Serum IgA is routinely measured to avoid bias of false-negative tTG IgA type. In our study, there was no difference between children with and without CD as regards serum total IgA level. According to many studies [32
], selective IgA deficiency should be considered during screening for CD especially with TTG IgA. TTG antibody is recommended as a screening test for CD by many authors [24
In our study, consanguinity is evident in 60 children among cases with dental enamel defects (42.86%), while in controls it was 169 (23.47%) with a P < 0.0001. Moreover, consanguinity was significantly more encountered in patients with CD (64%) compared to those without celiac pathology (38.26%). It is noticeable that patients with DED without CD still shows significant higher frequency of consanguinity compared to those without DED (X2 = 9.35 and P = 0.0022). This reflects already high consanguinity rates among normal Egyptian population. It also reflects that a genetic factor may be working in patients with DED with or without CD.
In patients with CD, serum calcium was significantly lower and serum alkaline phosphatase was significantly higher compared to those without CD. Moreover, serum calcium was the most important predictor of celiac pathology in patients with DED as shown by regression analysis.
Compared with controls, Praticò et al. [39
] stated that celiac patients show at diagnosis a significant increase of serum phosphate and a decrease of calcium level. The authors concluded that CD affects clearly mineral metabolism. Actually, the tendency to hypocalcemia may be attributed to abnormalities of the intestinal mucosa. Similarly, Zanchi et al. [40
] reported that calcium and the 25(OH) vitamin D3 levels were lower in children with CD than in control subjects, and the parathyroid hormone level was higher in children with CD than in control subjects.
In the current study, weight and height were significantly lower in CD patients compared to nonceliac ones. Many studies [27
] found that weight and height were below the 3rd percentile in studied CD children.
In the present study, celiac patients with DEDs had high rates of vomiting, diarrhea, constipation, abdominal pain, and flatulence but difference from nonceliac patients was not significant. Similar to our results, Rashid et al. [38
] found that the most frequent symptom was abdominal pain (90.0%) followed by diarrhea (65.0%), vomiting (53.0%), and constipation (30.0%). In contrast to the above-mentioned results, Kuloğlu et al. [27
] reported that the most frequent symptom was diarrhea (53.2%) followed by failure to thrive (45.9%), short stature (42.2%), abdominal pain (40.4%), abdominal distention (26.6%), fatigue (27.5%), pallor (23.9%), and vomiting (12.8%).
The variable results reported concerning the frequency of symptoms of CD can be explained by the wide spectrum of classical and nonclassical presentations of CD. Also, the difference in population homogeneity, environmental, dietary, and genetic factors may explain the variable results in each study. However, many studies reported that abdominal pain and diarrhea are the most frequent symptoms in classical CD.
The lack of predictive value of the gastrointestinal manifestations to pick up CD among DED patients is of utmost importance. It is, with the high frequency of CD in this context, a good evidence for a true need for celiac screening among DED patients.
We can conclude that the prevalence of CD, among children with dental enamel defects, is much higher than in the general population. These enamel problems might be the only manifestation of celiac disease. So, screening for CD is highly recommended among those patients especially in presence of underweight and hypocalcemia.
What is known?
Dental enamel defects are common among celiac compared to nonceliac children.
What is not known?
To take a look at the other face of the coin, what is the magnitude of CD among patients with dental enamel defects? In other words, is CD common enough in this sector of patients to deserve routine screening?