Morphological variations of median maxillary labial frenum: A clinical study

Median maxillary labial frenum (MMLF) appears as a fold of mucous membrane extending from the lining of the mucous membrane of the lips towards the crest of the alveolar ridge on the labial surface. MMLF can demonstrate certain variations in their shape, size and position, both among individuals and within the same individual at different ages. Many clinicians, not being aware of the normal variations of median maxillary labial frenum misinterpret them as pathological entities.

The objectives of the study were to determine the prevalence of morphologic variations of MMLF, to classify the morphological variations of MMLF on the basis of their location on the frenum and to compare the morphological variations of MMLF among different age groups and genders.

The study was conducted on 700 males and 700 females of age 5 to 74 yrs, chosen randomly. They were equally divided on the basis of age into 7 groups, each group having equal gender distribution. The morphological variations of MMLF were classified according to Sewerin's classification and the attachments on the freni were further sub-classified.

The commonest type of frenum was found to be the simple type, whereas bifid frenum was not found at all. Statistically significant difference was found in proportion of types of frenum among the different age groups and also in proportion of types of frenum among the different sites of presence of frenal attachments. No statistically significant difference was found in proportion of types of frenum in male and female subjects.

This study shows that MMLF presents with an array of morphological variations. These morphological variations may sometimes pose a complicating factor in maintaining oral hygiene, speech, mastication, esthetics, denture construction, etc. Hence, appropriate recognition of frenal variations and subsequent modification of treatment procedures are essential for a successful outcome of therapy.