Palatal rugae morphology in an adult mediterranean population.

BACKGROUND

The use of the palatal rugae in forensic odontology is based on their unique and individual characteristics. Few studies have assessed the palatal rugae in Mediterranean populations and none in the Lebanese population.

OBJECTIVE

Assess the shape and other morphological features of the palatal rugae in a Lebanese adult population, and compare them with reported similar features in other populations.

MATERIALS AND METHODS

Rugae characteristics were assessed on the maxillary dental casts of 217 non-growing subjects (95 males, 122 females, age 25.5 ± 7.6 years) according to guidelines established by Thomas and Kotze (1983) and Lysell (1955). The overall number of rugae and numbers of primary rugae (> 5mm in length), secondary rugae (3-5mm) and fragmentary rugae (2-3mm) on either side were recorded. Rugae were classified according to shape, direction and presence of unification. Z-tests were used to compare the proportions between right and left sides and between genders. The mean numbers of rugae in each category were compared with independent samples t-tests between males and females; paired samples t-tests were employed to compare mean numbers of rugae in each category between right and left sides. The data were compared with published reports on other Mediterranean cohorts.

RESULTS

The average number of rugae was 7.7 per individual, 3.81 on the right and 3.89 on the left. Curved, wavy and straight rugae patterns were equally common (one third each). The spatial direction of most rugae (49.3%) was backward. Circular, non-specific and convergent rugae were rare (< 2% each). Rugae numbers (total, primary, secondary, fragmentary) were symmetrical but shape, direction and the occurrence of convergence were asymmetrical (p < 0.05). None of the examined characteristics showed gender dimorphism. Tabulated comparisons disclosed the equality of rugae patterns as major differences with findings from other Mediterranean studies.

CONCLUSIONS

The palatal rugae in the Lebanese population display shape distinct from other reported Mediterranean and non-Caucasian populations. Studies in large samples and primary comparisons with other Mediterranean populations are warranted.