Nasolabial angle and upper lip evaluation in young patients treated orthodontically with four bicuspid extractions

Fábio Rogério Torres MARIA, Claudenir ROSSATO

The predictability of possible soft-tissue proile changes concurrent to orthodontic treatment, in patients susceptible to growth factors, seems to be very complex besides dependent of several variables. From this, the purpose was to evaluate 40 young patients (20 males and 20 females) treated orthodontically with four bicuspid extractions according to Tweed-Merriield principles technique. From the selected sample, 23 cases were Class I and 17 were Class II division 1, with average ages 12,4 and 12,3 years old for the males and females, respectively. The results denoted that nasolabial angle (ANL) measurement became more obtuse with treatment (6,11º), probably concurrent to its labial component retraction that followed the upper incisors retraction. Concerning its nasal component, the growth forward and downward contributed for this increase not being greater. So, the changes that occured in both anatomical components (labial and nasal) of ANL measurement, brought about in the whole angle a clockwise rotation. Concerning the upper lip, it showed a thickening in both the vermellion border as well as at superior labial sulcus, not being possible to identify its real relation with growth and/or upper incisors retraction. When the variables were analysed concerning the sex, in males the ANL measurement showed a smaller increase (5,2º), as a result of a greater nasal growth forward and downward, further on a smaller labial retraction which may have been compensated by a greater upper lip thickening. In females, the ANL measurement showed a greater increase (7,20º), with a smaller effect of the nasal growth and a greater labial retraction, which presumably occurred as a result of an insigniicant increase at upper lip thickness.

Keywords: Nasolabial angle. Upper lip. Extractions treatment.

Monday, April 29, 2024 11:22