The changes of soft tissue profile in skeletal class II patients with mandibular retrognathy treated by the extraction of maxillary first premolars

The purpose of this research is to measure the change of soft tissue profile, both antero-posteriorly as well as vertically in s�eletal class �� patients with man�ibular retrognathy cases, treate� with e�traction of the ma�illary first premolars. Pre an� post treatment result of 16 patient treate� with the �tan�ar� E�gewise fi�e� appliance were compare� using a �anon �6�6u series scanner an� �orel �raw 1�� computer programme, utilizing the TVL line as plane of orientation. The result was analyze� with paire� t-test. �tatistical analysis show significant anteroposterior an� vertical soft tissue changes in facial profile in s�eletal class �� patients with man�ibular retrognathy treate� with e�traction of ma�illary first premolars using the �tan�ar� E�gewise fi�e� appliance, measure� with �T�A-VTL metho�.


INTRODUCTION
The main objective of ortho�ontic treatment is to achieve balance functional occlusion an� a harmonious facial esthetics. 1Generally, the patients motivation to get ortho�ontic treatment is because they have a �entition �isarrangement an� facial esthetic problems.The treatment performe� is aime�, both �irectly an� in�irectly, at improving the patient's facial appearance or profile.�� The relationship between the soft tissue profile with the facial esthetic an� �ental occlusion is still �ebatable.�ome e�perts suggeste� that there is a relationship between �ental occlusion an� facial esthetics while the others refuse� this assumption. 3The results from a stu�y on a group of beauty pageant queens in U� shows that some of them have class �� �ivision � malocclusion. 3n s�eletal class �� malocclusion, there is a gap in the relationship of the jaws in the anteroposterior perspective.A s�eletal class �� malocclusion may happen �ue to lower jaw retrognathy with a normal upper jaw, upper jaw prognathy an� normal lower jaw, or combination of the two where there is an upper jaw prognathy an� lower jaw retrognathy.� Proffitt 5 sai� that class �� malocclusion might be cause� by �entoalveolar, s�eletal or neuro-muscular abnormalities with the s�eletal factor as the most common factor.A research in the Unite� �tates prove� that almost all class �� malocclusion cases are cause� by abnormal lower jaw growth.Moyers 6 state� that the s�eletal class �� malocclusion may happen horizontally, vertically an� transversally.The horizontal abnormality is cause� by the relationship of ma�illa towar�s a normal cranium with retrognathic man�ible that creates big overjet.�t may happen that there is a prognathic ma�illa an� normal man�ible with large or normal overjet.A more severe con�ition is foun� when there is a prognathic ma�illa an� a retrognathic man�ible.Bishara 7 state� that the vertical abnormality in s�eletal class �� malocclusion is �ue to an abnormal vertical growth of the ma�illa an� man�ible so that the lower facial height is shorter than the upper facial height.The transversal abnormality may be cause� by a ma�illary palatal arch that is narrower than the man�ible arch. 7lass �� �ivision 1 malocclusion has a main signs that inclu�e large overjet, �eepbite an� hyperactive mentalis muscle. 6The overjet will become more severe when there is a large anteroposterior �iscrepancy between the ma�illary �entition an� the man�ibular �entition.�eepbite is foun� �ue to a man�ibular rotation upwar� an� forwar�, e�cessive lower incisive eruption or insufficient posterior teeth eruption. 5Accor�ing to Karlsen 8 , in patients with class �� �ivision 1 malocclusion that is accompanie� by �eepbite, the lower anterior facial height is smaller than those without �eepbite.The �eepbite in patients is mar�e� by increase� upper anterior facial height.However, in patients with open bite, an increase� lower anterior facial height is foun�. 9 There are three types of treatment that can be use� to treat class �� malocclusion, i.e. growth mo�ification, compromise� treatment an� orthognathic surgery.A s�eletal growth mo�ification treatment an� orofacial functional treatment can be performe� to patients who are still growing.The compromise� treatment is aime� more on fi�ing �ental �isarrangement an� interjaw �ental relationship without correcting the s�eletal part while the surgery treatment is aime� at fi�ing jaw relationship through orthognathic surgery approach. 10he compromise� treatment for s�eletal class �� �ivision � malocclusion is generally con�ucte� through e�tracting two upper premolars to retract si� anterior teeth.This action is performe� to re�uce large overjet an� to improve patient's facial esthetic profile. 5The changes in the facial vertical height after ortho�ontic treatment with premolar e�traction often trigger controversy among researchers.�ome researchers state� that e�tracting premolar to retract anterior teeth may lea� to �ecrease� facial vertical height while others believe that there is no change. 11here are various ways to ju�ge facial esthetics, inclu�ing using ra�iograph by assessing soft tissue relate� to facial profile using lateral cephalogram.�� To fin� out if there is a change in soft tissues in terms of ortho�ontic treatment, some analyses of profile, lips an� tongue can be performe�.A lot of e�perts suggest to use soft tissue analysis as a truste� gui�eline to assess ortho�ontic treatment results. 1 There are several analysis that can be use� to evaluate lips posture an� soft tissue profile esthetics.Each analysis has a�vantages an� �isa�vantages.Ric�ett's "E" line is very much affecte� by nasal soft tissue growth.�teiner's "�" line ignores integumental profile changes �ue to nasal growth.Hol�away's "H" line ignores the effects of nasal growth in evaluating lips posture.Merrifiel� "Z" angle shows lip protrusion in malocclusion cases.1�� Viaziz "V" angle can show profile conve�ity because it is concentrate� in facial lower half part. 13This measurement can be �one manually or by using computer programs.
Recently, the use of computer programs in ortho�ontic analysis has grown rapi�ly.One of the programs is �T�A (�oft Tissue �ephalometric Analysis).�T�A is an analysis for facial soft tissue cephalometry that can be use� to �iagnose five �ifferent facial areas that are interconnecte�.The areas inclu�e �entos�eletal, soft tissue component, facial height, TVL projection an� facial harmony parts.The �T�A is ma�e in a position where the hea� is in line with the floor an� the lips are passive.1� One of the �T�A measurement is the TVL from Arnett et al. 1� TVL (true vertical line) is use� to measure soft tissue anteroposterior an� the �istance of the �entos�eletal position combine� with the thic�ness of soft tissue that lines the har� tissue lan�mar�.The horizontal �istance of the facial soft tissue profile for each in�ivi�ual that is measure� towar�s TVL is calle� the absolute lan�mar� value.The a�vantage of using this TVL is that this line is not affecte� by soft tissue growth because this line is ma�e perpen�icular towar�s Fran�fort Horizontal Plane.1�,15

MATERIALS AND METHODS
The instruments use� in this stu�y inclu�e: illuminator lamp, acetate paper, �H pencil, eraser, computer an� �orel �raw software, an� scanner.
The 3�� cephalograms were �ivi�e� into 16 pre-treatment cephalograms an� 16 posttreatment cephalograms.The cephalograms were then co�e�.The ne�t step was facial soft tissue tracing for each cephalogram.Each tracing result was then scanne� using �anon �6�6u scanner.Orientation lines an� points were then �etermine�, FHP line was ma�e an� then TVL line that is perpen�icular to FHP was �etermine�.The TVL was place� through N point.The facial balance (profile) measurement using TVL metho� (Arnett) was performe� by measuring the �istance between the upper lips an� lower lips to TVL line using �orel �raw 1�� software.The tracing an� measurement for each cephalogram was �one twice with 1 wee� interval for �ata calibration.All �ata was note� an� analyze�.
The anatomical points use� in this stu�y are TVL (True Vertical Line) which is a line through subnasal an� perpen�icular to FHP (7° from �N line).�n this stu�y, the TVL line is place� through N point.NT (Nose tip) is the tip of the nose in the mi�line area.�n (�ubnasale) is a point in nasal septum that connect nostril an� upper lips to mi�line.A' point is the �eepest point of upper lip mi�line between the subnasal an� labiale superius.ULA (upper lip anterior) is an upper

Average changes in anteroposterior soft tissue profile
The results of the stu�y �ata analysis on the changes in anteroposterior profile change in 16 patients before an� after treatment are liste� in Table 1.�t is apparent that the nose tip (NT), upper lip anterior (ULA) an� lower lip anterior (LLA) points as well as the �eepest point in the upper lip mi�line between subnasal an� labiale superius (A'), the �eepest point of the lower lip mi�line between labiale inferius an� pogonion of the soft tissue (B') an� the most prominent anterior point in chin soft tissue in the mi�sagittal (Pog'),  e�perience changes before an� after fi�e� ortho�ontic treatment �n Table �� there are A, B, � RA, � RB an� Pog points that e�perience changes before an� after a fi�e� ortho�ontic treatment.
�n Table 3 it is apparent that the facial vertical height in patients with s�eletal class �� malocclusion an� man�ibular retrognathy an� normal ma�illa with upper premolar e�traction treate� using E�gewise �tan�ar� technique e�periences changes after treatment.

Average changes in antero-posterior facial soft tissue profile
The results of this stu�y on the anteroposterior facial soft tissue profile measurement show that there are significant changes after fi�e� ortho�ontic treatment with upper premolar e�traction.The average changes in nose tip (NT) is 0.8� mm, upper lip anterior (ULA) is 3.88 mm, lower lip anterior (LLA) is 5.��7 mm, the �eepest upper lip mi�line point (A') is 3.36 mm, the �eepest lower mi�line point (B') is �.�� mm, the most anterior point of the chin (Pog') is �.�0.
Koca�ereli 18 state� that the premolar e�traction followe� by canine �istalization an� incisive retraction will cause changes in lip tissue position an� will re�uce lip conve�ity.The incisive movement towar�s sagittal �irection creates changes in soft tissue of 60-70% from the incisive total movement 5 , showing that each anterior �ental retraction will cause changes in soft tissue.Nan�a 9 stu�y shows that upper incisive retraction of 3.1 mm causes the upper lips to move bac�war� 1.9 mm.The result of this stu�y shows that the upper incisive point (U�P) changes in average of 5.97 mm, �ubspinal point (A) of 1.56 mm, �upramental point (B) of �.39 mm, lower incisive (L�) of �.60 mm, Pogonion (Pog) of �.�8 mm.�n this stu�y, the upper incisive point change ratio an� upper lip anterior point is 5.97:3.88mm (�RA:ULA = 1:0.65).The comparison of upper incisive average changes with �ubspinal A point that e�perience changes of 1.56 mm is �RA:A=1:0.��6.The comparison of upper incisive average changes with point A' that e�periences an average change of 3.36 mm is �RA:A'=1:0.56.The changes in the location of upper lip anterior (ULA) an� lower lip anterior (LLA) points are big enough approaching TVL line showing that there is a change in facial anteroposterior profile conve�ity.
Talass 16 research on the correlation of the incisive position changes an� lip position changes in 133 white women with s�eletal class �� �ivision 1 malocclusion shows that upper incisive retraction average of 6.7 mm will cause the upper lip to move bac�war� for an average of �.3 mm.�n this stu�y, there are changes in upper incisive point of 5.97 mm, causing changes in upper lip anterior point of 3.88 mm.

Average changes in facial vertical height after a fixed orthodontic treatment
The results of the stu�y show that there is some vertical �imension changes.The average of facial height change is �.91 mm, upper facial height (ULL) is 1.37 mm, lower facial height (LLL) is ��.79This is in line with Nan�a 9 stu�y that showe� for treatment of �eepbite patients with short lower anterior facial height, a vertical �imension a��ition can be attaine� by e�tracting posterior teeth.�n this research, a facial vertical height increase is foun�.The facial vertical height changes after the ortho�ontic treatment with premolar e�traction is still a controversy among researchers. 11The stu�y performe� by �hua et al. 17 shows that lower anterior facial height changes may happen without premolar e�traction while treatment with premolar e�traction �oes not cause lower anterior facial height change.
The results of Kim 11 stu�y in fi�e� ortho�ontic treatment case with two first premolar e�tractions show changes in facial soft tissue vertical profile, total facial height (N'-Me') that, in average, increases 3.�� mm, lower anterior facial height (AN�'-Me') increases ��.06 mm, upper anterior facial height increases (N'-AN�') 1.39 mm.Ko�aracelli 18 state� that first premolar e�traction in ortho�ontic treatment will cause anterior facial height changes.The anterior facial height becomes higher �.67 mm while lower anterior facial height (AN�-Menton) e�periences a change of ��.93 mm higher after treatment with first premolar e�traction is performe�.The ortho�ontic treatment with first premolar �ental e�traction lea�s to increase� lower facial anterior height that will affect the total facial height. 19CONCLUSION There were alterations of soft tissue an� anteroposterior facial profile in s�eletal class �� malocclusions in patients with man�ibular retrognathy an� normal ma�illa before an� after e�traction of two upper premolar treate� using E�gewise �tan�ar� fi�e� ortho�onthics.The alteration of facial anterior-posterior before an� after treatment has a rather high value.Therefore, it is better that before the treatment the operator e�plains the possible changes in patient's anterior-posterior soft-tissue an� facial vertical profile through cephalometer soft an� har� tissue analysis using the TVL metho�s, to prevent complaints at the en� of treatment from the patient.Further research more samples is nee�e� in or�er to be use� as a stan�ar� for �n�onesian people.
margin central point in upper lip membrane.LLA (lower lip anterior) is the mi�point in lower lip membrane margin.Point B' is the �eepest point in the lower lip mi�line between labiale inferius an� soft tissue pogonion.Pog' is the most prominent anterior point in chin soft tissue in the mi�sagittal area.Point Na' is the Na (Nasion) point projection in the facial soft tissue.Point Me' is a projection of Me (Menton) point of the facial soft tissue.ULL is the upper lip length.LLL is the lower lip length.Facial height is the height of the face measure� from point Na' (Nasion point projection in soft tissue) to Me' (Menton point projection in soft tissue).

Figure 1 .
Figure 1.Line and orientation points of anteroposterior profile and vertical point of the facial soft tissue measurement towards the TVL line used in the study.