Related Experiment Video
Updated: Jul 19, 2026

Method of Studying Palatal Fusion using Static Organ Culture
Published on: September 19, 2015
Epidemiological studies on the frequency of clefts in Europe and world-wide
Karsten K H Gundlach1, Christina Maus
1Rostock Interdisciplinary Center for Clefts of Lip, Alveolus and Palate and Craniofacial Anomalies, Rostock, University, Germany. karsten.gundlach@med.uni-rostock.de
Background:
Most textbooks present data on the various frequencies of clefts in different human "races". This was studied in more detail.
Material And Methods:
In a major literature study the frequencies of clefting reported in more than 100 publications were studied and the following data was collected: Incidences of clefts in Mongolians, Caucasians and Negroids; relative frequencies of clefts of the primary (and secondary) palate versus that of clefts of the secondary palate (only); data on cleft location (right, left, bilateral) and on genders affected.
Results:
There was most confusing data on incidences in the different "races" whilst all other data was rather consistent: complete clefts (i.e. primary plus secondary palate affected) were most common with left sided ones being reported most often; males were more prone to have a cleft of the primary palate than females and females were more often affected by clefts of the secondary palate than males.
Discussion:
The types of data bases having been evaluated varied from report to report indicating that today's data pools are of different qualities. Regional or national registries are necessary to collect reliable data with strict definitions applied in all countries.
Related Concept Videos
Introduction to Epidemiology
Prevalence and Incidence
Prevalence indicates the proportion of individuals in a population who have a specific disease or health condition at a...
Bias in Epidemiological Studies
Sutures of the Skull
Sutures are immobile joints between adjacent bones of the skull. The narrow gap between the bones is filled with dense, fibrous connective tissue that unites the bones. The long sutures located between the skull bones are not straight but instead follow irregular, tightly twisting paths. These twisting lines tightly...
Development of the Oral Microbiota
Study Designs in Epidemiology
Observational studies are those where the researcher does not intervene but rather observes natural variations. They include cross-sectional, cohort, and case-control studies.

