This study analyzed 1,100 patients with primary cleft lip, cleft palate, or both who visited our specialized outpatient department during the 30-year period between 1981 and 2011.

The results were as follows:

1 . This study identified 1,100 primary cases of cleft lip, cleft palate, or both among patients attending the outpatient department.

2 . Of the 1,100 patients, 368 had cleft lip (33.5%), 408 had cleft lip and cleft palate (37.0%), and 324 had cleft palate (29.5%).

3 . There were 564 male patients and 536 female patients, corresponding to a male-to-female ratio of 1.05:1.

4 . The age of patients at the first visit was recorded, and we found that 684 patients (62.2%) presented to the department within 1 month of birth.

5 . The average birth weight of the patients was 2,934.4 g. The birth weight of 400 patients, representing the largest proportion (36.4%), ranged from 2,500 g to 2,999 g.

6 . A total of 870 patients (79.0%) were living in Kagoshima Prefecture. The proportion of remote island residents in Kagoshima Prefecture was 5.0%.

7 . The largest proportion of patients was introduced to our department by obstetricians. The second largest proportion of patients was introduced to us by dentists or oral surgeons.

8 . A total of 122 patients (11.1%) had a congenital anomaly.

9 . The number of visits, which started in 2006, has increased since 2011. The number of prenatal consultations ranged from 1 to 6 per year. The proportion of patients who sought prenatal consultations was low.

10. A comparison of the study variables according to the survey period showed that the total number of patients had increased slightly in the intermediate and late periods. The most common abnormality throughout the study was cleft lip and cleft palate. In the early and late periods, there were higher proportions of men than women. In the intermediate period, there was a higher proportion of women. During the early period, less than 50% of patients presenting at the clinic were younger than 1 month. During the intermediate and late periods, 70% of the patients were younger than 1 month at their first outpatient visit. The proportion of low-birth-weight infants (birth weight less than 2,500 g) has gradually increased. High proportions of patients had cleft palate as a congenital malformation in all periods.