Comparative evaluation of cephalometric and occlusal characteristics between the Long Face pattern and Pattern I

Methods: Through evaluation of frontal and right side extraoral photographs, three previously calibrated and experienced examiners selected 30 Long Face patients (Group 1) and 30 Pattern I patients (Group 2), aged between 9 and 19 years, of both genders. The cephalometric characteristics were assessed by the following variables: SN.GoGn, NS.Gn, AIFH, SNA, SNB, ANB, 1.1, 1.NA,1-NA, 1.NB, 1-NB, NA.Po, nasolabial angle and H-Nose. Clinical evaluations were also performed to determine the presence of posterior crossbite, anterior open bite and type of Angle’s malocclusion. The cephalometric data were compared by independent t test. The chi-square test was used to evaluate the association between qualitative variables.


INTRODuCTION
The long face is a deformity with skeletal implication and with unfavorable esthetics, 8,10 that can be observed in the three sagittal dental relations, being however, more associated to Class II sagittal discrepancies. 7,10[9][10][11] The diagnosis of Long Face pattern is based in evaluations of the face morphology and cephalometry.The facial analysis allows to verify several characteristics common to these individuals such as: Absence of passive lip seal and contraction of mentalis muscles during labial closure, 1 besides a great exposure of upper incisors when lips are resting and great gingival exposure during smile, 1,4,30 the nose is generally long, with narrowing of the alar bases and the lower third of the face is increased, resulting in retrognathia appearance of the mandible. 1,26,30he cephalometry constitutes a necessary instrument to define, locate and quantify the skeletal disharmony present in patients with Long Face pattern, which can be associated to a horizontal growth of the condyle 6,26 and/or to an excessive posterior growth of the maxilla. 15,30egarding the cephalometric characteristics, it is observed an increase on the total anterior height of the face and on the anterior and inferior facial height. 15,17he anterior and superior facial height is generally normal, 1,4,30 but the proportion between medium and lower third is reduced. 3The angle of the mandibular plane is increased, 4,8,11,15,28,29 as well as the gonial angle. 8,11It is observed a mandibular retropositioning in relation to the skull base. 1,11The maxilla, however, is well positioned in relation to the skull base. 1,15ately, it is observed in literature 13,21 that the cephalometric means, used in several cephalometric tracings, cannot be generically applied for diagnosis and treatment.Several researchers 5,20,23 concluded that most cephalometric standards varies significantly, when compared to several facial patterns.Before this, a more individualized interpretation of the cephalometry must become a rule, or rather, an association between the cephalometric analysis and the facial analysis must be standard for diagnosis, plan-ning of treatment and orthodontic treatment.Therefore, the final decision of a planning must be taken based in cephalometric and facial findings.This way, this work had as objective to perform a comparative study of cephalometric and intraoral characteristics between Long Face patients and Pattern I, diagnosed by the subjective facial analysis, besides evaluating the associations between subjective facial patterns and cephalometric facial patterns.

Material
The sample was selected according to the following criteria of inclusion: » Caucasians; » Long Face pattern or Pattern I; » Full orthodontic records; » Ages between 9 and 19 years; » No previous orthodontic treatment.

Orthodontic records
Extraoral, frontal and right side photographs from the orthodontic records belonging to patients registered for orthodontic treatment on the Specialization Course in Orthodontics, of the Odontology Academy of Ceará were used.The sample was selected by three experienced and previously calibrated examinators, in distinct moments and each one individually, to avoid that the evaluation of one examinator interfered on the others.Only the patients who had diagnostic concordance were selected.
All photographs were performed by the same radiology center (Prof.Perboyre Castelo), presenting a pattern.The patients during the photographs were in natural position of the head (NPH): 22 standing,with the feet 10 cm apart from each other, lips at rest, looking to an oval mirror located 1 meter before the patient and instructed to observe their own eyes reflection, keeping the pupils on the eye center.
The patients classiied with Long Face pattern, [7][8][9][10][11] were on the frontal and right side photograph with excessive exposure of the resting teeth and gingiva when smiling, lower third of the face increased in relation to the medium third, diiculty of lip seal, resting upper lip with short appearance, everted lower lip, retruded mandible and short chin-neck line (Figs 1 and 2).
The Pattern I patients [7][8][9][10][11]13 were identiied by the facial normality and characterized by balanced vertical and skeletal sagittal relations on the front and proile evaluations. In rontal photograph they had apparent symmetry, proportion between the facial thirds, proportional volume of the lips vermilion and passive lip seal (Fig 3).On the evaluation of the right side photograph, Pattern I patients had mild facial convexity, expressive chin-neck line and parallel to Camper plane, and esthetically pleasant mentolabial sulcus, built with equal participation of the mentum and lower lip (Fig 4).
The patient's full name, gender and date of birth were obtained also from the orthodontic records.The date of birth allowed the accurate calculus of initial ages of the patients.
All patients that agreed to participate in the research filled out a form with their data, as well as signed a free informed term of consent (FITC), approved by the ethics committee in research (CER) of the University Center of Maranhão (UNICEUMA), protocol number 00469/08, according to standards of the resolution CNS 196/96.

Cephalometry
Ater evaluation of the photographs from orthodontic records for selection of the sample, the facial pattern was evaluated through cephalometry with variables that determined the facial growth pattern: SN.GoGn, NS.Gn (Axis Y) and AIFH (anterior inferior facial height).
The radiographs were performed by the digital panoramic x-ray device (Orthopantomograph OP100-D, Instrumentarium, Palodex group, Tuusula, Finland,  2006).This digital device used a sensor that sent the images captured in the radiographic take to the computer screen.These images were saved in CD and printed in ilms by laser printer model Dryview 8150.The digital radiographic images were inserted on the program Cef X (CDT Sotware, Dourados, Mato Grosso, Brazil, version 2.1.24,1995) and the reference points, lines and planes were demarcated.
The cephalometric facial pattern was determined when the patient showed at least two measures alterated.It was considered: Dolichofacial the patient that showed SN.GoGn with values higher than 34 degrees, 19 NS.Gn (Axis Y) with values higher than 69.9 degrees 19 and AIFH with values higher than 71 mm; 27 mesofacial the patient that showed SN.GoGn with values within 30 and 34 degrees, 19 NS.Gn with values within 63.5 and 69.5 degrees 19 and AIFH with values within 63 and 71 mm 27 and brachyfacial the patient that showed SN.GoGn with values lower than 30 degrees, 19 NS.Gn with values lower than 63.5 degrees, 19 and AIFH with values lower than 63 mm. 27riginal article Oliveira EGS, Pinzan-Vercelino CRM a group of 20% of the radiographs, that were digitalized again and had their points demarcated by the same researcher.It was applied the dependent Student's t test in order to assess the systematic error. 18For evaluation of the random error it was used the Dahlberg's formula. 12

Statistical test
It was used the descriptive statistics (mean and standard deviation) for initial age and all cephalometric measures used.
The independent t test was applied to verify the compatibility between the initial ages of studied groups and to compare the cephalometric variables between groups.
It was applied the Chi-square test to evaluate the compatibility of groups regarding the proportion between genders, to verify the association between subjective facial pattern and cephalometric facial pattern and to evaluate the association of Long Face pattern and intraoral characteristics (posterior crossbite, anterior open bite and Angle's malocclusion).
Besides these tests, it was determined the prevalences of cephalometric facial patterns, posterior crossbite, anterior open bite and the type of Angle's malocclusion in relation to subjective facial pattern.Results with p < 0,05 were considered statistically significant.Tests were applied through BioEstat 5.0 (AYRES, Sociedade Civil Mamirauá, MCT-CNPq, Belém, PA, Brazil, 2005).

Clinical assessment
It was illed out a clinical form for each patient containing data obtained from orthodontic records and observations such as: Initial age, presence of open bite and/ or crossbite and classiication of Angle's malocclusion.
The patients classiied with presence of posterior crossbite, were those with abnormal buccolingual relation between superior and inferior teeth, of at least three teeth, when the dental arches were in centric relation, being uni or bilateral 25 and with presence of anterior open bite when showed a negative overbite between the edges of anterior, superior and inferior teeth, with measurement larger than 1 mm, obtained in millimetric ruler. 25n the investigation of the dental relation, it was observed a sagittal relation between the upper and lower permanent irst molars. 2 The patients were classiied as Class I, when presented a molar relation with the upper permanent irst molar's mesiobuccal cusp occluding the lower permanent irst molar's mesiobuccal sulcus, 2 as Class II when presented the lower permanent irst molar positioned distally in relation to the upper permanent irst molar and as Class III when presented the lower permanent irst molars situated mesially to the upper permanent irst molars. 2

Method error
To determine the reliability of the obtained cephalometric results, ater 15 days, it was randomly selected

RESuLTS
The sample consisted of photographs and teleradiographs of 60 patients, divided in two groups according to facial pattern (Table 1).
Regarding the method error, for the cephalometric variables it was not detected any random error and only one systematic error.For the variable NS.Gn, it was found, on the irst measurement, a mean value of 72.62 degrees, and for the second measurement a mean value of 73.97 degrees.Considering that it occurred only one systematic error (7.15%) with variation of 1.35 degrees between the measurements, and none random error, the obtained results can be considered reliable.
The groups were compatible in relation to age and distribution of genders (Tables 2 and 3).
The Long Face pattern was associated to dolichofacial cephalometric facial pattern, and the Pattern I was associated to mesofacial cephalometric facial pattern (Table 3).
The Long Face pattern patients were associated to posterior crossbite, anterior open bite and Angle Class II malocclusion (Table 3).
Among the Long Face pattern patients 93.3% were dolichofacial patients, 43.3% with presence of posterior crossbite, 16.6% with presence of anterior open bite and 60% with Angle Class II malocclusion (Table 4 4).

DISCuSSION
The subjective facial analysis represents an important tool of orthodontic diagnosis, 13 that can be easily used for identification of Long Face pattern patients.These patients generally present several occlusal problems that may be associated to this facial growth pattern as: posterior crossbite, anterior open bite and Class II malocclusion.Many times, when the problem of vertical growth is identified through the face, the problem is also cephalometrically confirmed, however, when the problem is diagnosed cephalometrically first, it is not necessarily confirmed on the face, ie, the facial analysis allows a more accurate diagnosis of the Long Face pattern.
On the cephalometric assessment, the groups presented significative differences in relation to the following variables: SN.GoGn, NS.Gn, AIFH, ANB, 1.1, 1-NA, 1.NB, 1-NB and NA.Pog.The Long Face pattern patients presented increase on the angles: SN.GoGn (41.80±6.78),NS.Gn (70.90±4.64),indicating vertical growth pattern;  11 They observed that Long Face pattern individuals presented increase of the cephalometric measures located below the palatal plane. 11apelozza Filho et al 8 evaluating the cephalometric characteristics of Long Face pattern, did not observe signiicative diferences in relation to sexual dimorphism and showed that male Long Face pattern patients, when compared to Pattern I patients, presented disparities in relation to magnitudes related to facial height, to growth pattern and to sagittal relation.
The assessment of maxillomandibular relation, based on value of angle ANB, was greater also in Long Face pattern individuals evaluated by Cardoso et al 9 and Capelozza Filho et al, 8 showing the tendency to Class II malocclusion that the carriers of this deformity present.The values for anterior and inferior facial height were higher for the Long Face pattern group with statistical significance, also observed in studies performed by Cardoso et al 9 and Capelozza Filho et al. 8 This result was also expected, since the increase on anterior inferior facial height constitutes the essence of the studied disease, being frequently found in literature.
Regarding the mandibular plane (SNGoGn), the mean values of this angle for Long Face pattern individuals were close to the maximum values of Pattern I individuals.This implies on the necessity of association of several cephalometric characteristics for deinition of the Long Face pattern.Values above 37 degrees for the angle of the mandibular plane were reported in litera-Comparative evaluation of cephalometric and occlusal characteristics between the Long Face Pattern and Pattern I original article ture 4,14,15,16,20,28,29 as parameter to deine Long Face pattern individuals.Although the values found in the studies performed by Capelozza Filho et al 8 and Cardoso et al 9 overcome this value, they cannot be used separately.In fact, the disease consists in an imbalance between the vertical components, and, therefore, a single parameter must not be used; therefore in this study it was associated to the mandibular plane (SN.GoGn), the measurement of the Y axis of growth (Ns.Gn) and the measurement of the anterior and inferior facial height for determination of cephalometric facial pattern.
The mandibular retrusion was emphasized with the assessment of NAP angle which was significantly different between Long Face pattern and Pattern I groups also in the study by Cardoso et al, 10 showing greater mandibular retrognathia and convexity of bone profile in Long Face pattern patients.
As for the cephalometric growth pattern, it was obtained 93,3% of dolichofacial patients on Group 1 (Long Face pattern) and 83.3% of mesofacial patients on Group 2 (Pattern I).The Chi-square test showed presence of association between the subjective facial pattern and the cephalometric facial pattern, which allows to conclude that the studied facial patterns, classiied by the subjective analysis, are associated to cephalometric classiication of the facial pattern, enabling the methodology used for identiication of patients by subjective facial analysis, besides allowing the comparison between results from this study and other results from works in literature.
The patients on Group 1 presented a prevalence of 43.3% of posterior crossbite and the patients on Group 2 presented 13.3% of posterior crossbite.In relation to the Chi-square test it was observed an association between facial pattern and posterior crossbite.The prevalence of posterior crossbite in Long Face pattern patients is according to the observed in a study by Cardoso et al 10 in which the authors showed a prevalence of 34.2% of this malocclusion.
Regarding the presence of anterior open bite, the patients on Group 1 presented a prevalence of 16.6%, while on Group 2, no patients showed anterior open bite.In relation to the Chi-square test, it was observed an association between the Long Face pattern and the presence of anterior open bite.About Angle's classiication, the patients on Group 1 presented: 36.6%Class I, 60% Class II and 3.33% Class III; now the patients on Group 2 presented: 70% Class I and 30% Class II.As result of the Chi-square test, it was found an association between the facial pattern and Angle's classiication.Patients on Group 1 were associated to Class II malocclusion and patients on Group 2 were associated to Class I malocclusion.This result agrees with the study performed by Cardoso et al 10 who found in Long Face pattern patients the following prevalences in relation to Angle malocclusions: 13.2% Class I, 71% Class II and 15.8% Class III.Probably, the Long Face pattern is associated to Class II malocclusion for these patients present a clockwise mandibular rotation, which facilitate a Class II sagittal relation.

CONCLuSIONS
The Long Face pattern was associated to Angle Class II malocclusion, to presence of posterior crossbite and to anterior open bite.The subjective Long Face pattern was associated to dolichofacial cephalometric facial pattern.

Figure 1 and 2 -
Figure 1 and 2 -Frontal and right side photograph of long face pattern patient.

Figure 3 and 4 -
Figure 3 and 4 -Right side and frontal photograph of Pattern I patient.

Table 3 -
Analysis of the compatibility of genders, facial pattern, cephalometric facial pattern, posterior crossbite, anterior open bite and classiication of the Angle's malocclusions between the groups, according to Chi-square test.

Table 1 -
Classiication of the sample according to age and gender.

Table 2 -
Comparative analysis of cephalometric variables and age between groups, according to independent t test.

Table 4 -
Prevalence of cephalometric facial patterns, posterior crossbite, anterior open bite and type of Angle's malocclusion on the diferent groups.Cardoso et al 11 also found significative differences in relation to the variables ANB, AIFH, SN.GoGn and NA.Pog when compared the cephalometric characteristics of Long Face pattern and of Pattern I.