Comparison of the changes in facial profile after orthodontic treatment, with and without extractions.

Abstract

A study was made of 31 patients with Angle Class II malocclusion. Fifteen patients did not undergo extraction of teeth (Group A), while 16 underwent extractions of four premolars (Group B). Data was obtained from the corresponding lateral radiographs of the head taken both before and after orthodontic treatment. The main aim of the study was to compare the response of the soft and hard tissues of the facial profile in Class II malocclusion treated with the extraction of four premolars and the response of borderline cases presenting with similar malocclusions, but not subjected to extraction. In this latter group reasonable doubt existed as to whether or not to remove teeth in order to solve the occlusal and aesthetic problems. It is concluded that significant hard tissue differences between the groups at the end of treatment were limited to a more retruded position of the incisors and a reduced overbite amongst those patients subjected to extraction. The main soft tissue differences between the groups at the end of treatment were a more retruded lower lip and a more pronounced lower labial sulcus in those patients subjected to extraction.

Cephalometric changes in Class II division 1 patients treated with two maxillary premolars extraction

“…In this study, this increase was greater than the expected being corroborated by some authors that reported similar results in literature. 4,7,23 On the maxillomandibular relation, there was a significant alteration of the anteroposterior skeletal discrepancy, shown by the reduction of angle ANB (Table 1). This alteration was expected because the orthodontic treatment aimed the correction of Class II malocclusion and of the overjet initially increased by upper incisors retraction.…”

“…26,27 Several authors did not find significant differences on the alterations of soft tissue between groups treated with extraction of four premolars and without extractions 7,30 while other authors observed a tissue profile retrusion. 1, 3,4 Considering that a retraction of upper incisors necessarily imply in a retrusion of the upper lip, 30 it is known that the muscle-skeletal-functional complex of the upper lip contributes for the variability observed on alterations of upper lip with the treatment protocol with premolars extractions. 29 In this work the nasolabial angle did not present statistically significant alteration (Table 1).…”

“…The criteria for inclusion of patients in the selected sample was based on presence of the following characteristics: Angle Class II malocclusion division 1 with molar relation of at least ½ Class II (cuspto-cusp relation), absence of crowding or with mild crowding, presence of all permanent teeth erupted until the first premolars, overjet of at least 5 mm 4,25 and orthodontically treated with extractions of upper first premolars. Patients with Class II malocclusion subdivision were excluded from the sample.…”

Can commonly used profile planes be used to evaluate changes in lower lip position?

“…Although not statistically significant, greater changes in the position of the labrale inferiorus were observed in extraction cases than in nonextraction cases. It has been previously shown 9,10,21 that the extraction cases become significantly more retrusive than nonextraction cases based on measurements determined by the E-line and B-Line. In contrast, Janson et al 22 showed no significant differences between nonextraction and maxillary first premolar extraction cases using the Steiner's S1-line and the Rickett's E-line; they did find significant differences based on the Burstone's B-line.…”

“…The Hline and B-line have been used to determine the amount of protrusion or retrusion of the lips that occurs during treatment. 10 More recently Stalpers et al 11 used the E-line to measure the changes that occur in lower lip position with the extraction of maxillary first permanent molars in Class II division I patients, and Zablocki et al 12 relied upon the E-line to evaluate lower lip changes produced with a transpalatal ach during the treatment of extraction cases. Pecora et al 13 used the E-line to measure the changes in the lip position that occur between late adolescence, mid-adulthood, and late adulthood.…”