DISCUSSION
Although palatal fistula is one of the most common complications of cleft palate surgery, its presentation in patients who have not undergone surgery is rare, and the cases that have been reported involved submucous cleft palate [
1234567]. In 1931, Veau and Borel [
8] first reported the phenomenon of congenital palatal fistula. Since then, approximately 30 cases have been reported in the literature worldwide. The majority of the reported cases presented with palatal fistula at birth or it was not stated whether the fistulae were acquired after birth or otherwise. Fara [
2] reported that congenital defects of the hard palate were involved in 0.17% of cleft palates, 0.32% of isolated medial palate clefts, and 6.02% of submucous cleft palates. Mehendale and Sommerlad [
5] reported that 2.17% of submucous cleft palate patients presented with perforation.
However, in the present case, the palatal fistulae were acquired after birth, indicating that they were not congenital. Very few reports of acquired palatal fistulae have been published. Similar to this case, Karabulut et al. [
9] reported hard palate perforation due to invasive aspergillosis in patients with acute lymphoblastic leukemia. However, those patients suffered from an immunosuppressive disease and thus were vulnerable to fungal infections. Two reports similar to the present case have been published, describing cases of acquired palatal fistula with an isolated cleft palate. Weijerman and Heybroek [
10] reported perforation in a case of submucous cleft palate due to an aphthous ulcer. Guzel et al. [
11] reported a case of palatal fistula that developed after primary tuberculous dacryoadenitis. However, in these cases, the perforation occurred when the patients were adults, at the ages of 20 and 40 years, respectively.
The mechanism of palatal fistula in patients who have not undergone surgery is debatable. The controversy lies in whether the prenatal or postnatal palatal fistula is acquired secondary to destruction of the thin mucosa in a submucous cleft palate or is an isolated condition regardless of cleft palate. Fara [
2] proposed that it is due to the intrauterine rupture of a wide submucous cleft in the area of the greatest tension, which is the posterior part of the hard palate. Furthermore, in other studies, the mucosa in the submucous cleft palate was intact at birth but subsequently presented with a hole, suggesting spontaneous rupture or a traumatic etiology [
5610]. In several reports, submucous cleft palate was not accompanied by palatal perforation, suggesting that it occurred due to an embryological malformation [
13]. The present case strongly supports the former etiology; that is, oral candidiasis was the cause of palatal fenestration, which is supported by the photograph taken before the perforation (
Fig. 1).
In the present case report, case 1 is notable in that it is the first case of acquired palatal fistula to have occurred in a patient with suspected submucous cleft palate in early infancy due to oral candidiasis. Although oral candidiasis is prevalent in patients with acquired immune deficiency syndrome, in immunocompromised patients, or in patients taking glucocorticosteroids, superficial infections are not uncommon in infants and the elderly [
12]. Furthermore, the photograph taken before the perforation demonstrates the patient's clinical history, whereas previous reports only contain narrations of patients' histories. Case 2 is remarkable in that the palatal mucosa was perforated spontaneously in an area that was discontinuous with the existing incomplete cleft.
Unlike the other forms of cleft palate, submucous cleft palate may not result in speech disorders [
13]. Submucous cleft palate is associated with poorer speech outcomes after surgery than incomplete cleft palate [
14]. Therefore, it is widely accepted that surgical correction should be delayed until the age of 3 or 4 years, when velopharyngeal incompetence becomes apparent. Here, we that recommend surgeons observe submucous and incomplete cleft patients regularly before surgery, as palatal perforation may occur spontaneously.