Condylar Positional Changes in Skeletal Class II and Class III Malocclusions after Bimaxillary Orthognathic Surgery.

Orthognathic surgery is indicated to modify the position of the maxillomandibular structure; changes in the mandibular position after osteotomy can be related to changes in the position of the mandibular condyle in the articular fossa. The aim of this study was to determine changes produced in the mandibular condyle 6 months after orthognathic surgery. A cross-sectional study was conducted that included subjects who had undergone bimaxillary orthognathic surgery to treat dentofacial deformity of Angle class II (group CII) or Angle class III (group CIII). Standardized images were taken using cone-beam computed tomography 21 days before surgery and 6 months after surgery; measurement scales were used to identify the condylar position and its relations with the anterior, superior, and posterior joint spaces. The results were analyzed using the Shapiro-Wilk and Student's t-tests, while considering a value of p < 0.05 as indicating a significant difference. Fifty-two joints from 26 patients, with an average age of 27.9 years (±10.81), were analyzed. All subjects in both group CII and group CIII showed a significant change in the anterior, superior, and posterior joint spaces. However, postoperative changes in the position of the condyle in the articular fossa were not significant in the anteroposterior analysis. We conclude that orthognathic surgery causes changes in the sagittal position of the mandibular condyle in subjects with mandibular retrognathism and prognathism.

Retrospective Analysis of the Airway Space Changes in Dentofacial Deformity after Two-Jaw Orthognathic Surgery Using Cone Beam Computed Tomography.

Orthognathic surgery is used to modify anomalies in maxillomandibular position; this process can significantly affect the anatomy of the airway and cause functional changes. This study aims to define the impact of mandibular maxillary movement on the airway of subjects with dentofacial deformity. A retrospective study was conducted on subjects with Angle class II (CII group) and Angle class III (CIII group) dentofacial deformities. The subjects were treated via bimaxillary surgery; for all of them, planning was performed with software and 3D printing. Cone beam computed tomography (CBCT) was obtained 21 days before surgery and 6 months after surgery and was used for planning and follow-up with the same conditions and equipment. Was used the superimposition technique to obtain the maximum and minimum airway areas and total airway volume. The data were analyzed with the Shapiro-Wilk test and Student's t-test, while Spearman's test was used to correlate the variables, considering a value of p < 0.05. Thus, 76 subjects aged 18 to 55 years (32.38 ± 10.91) were included: 46 subjects were in CII group, treated with a maxillo-mandibular advancement, and 30 subjects were in the CIII group, treated with a maxillary advancement and a mandibular setback. In the CII group, a maxillary advancement of +2.45 mm (±0.88) and a mandibular advancement of +4.25 mm (±1.25) were observed, with a significant increase in all the airway records. In the CIII group, a maxillary advancement of +3.42 mm (±1.25) and a mandibular setback of -3.62 mm (±1.18) were noted, with no significant changes in the variables measured for the airway (p > 0.05). It may be concluded that maxillo-mandibular advancement is an effective procedure to augment the airway area and volume in the CII group. On the other hand, in subjects with mandibular prognathism and Angle class III operated with the maxillary advancement and mandibular setback lower than 4 mm, it is possible to not reduce the areas and volume in the airway.

TMJ Position in Symmetric Dentofacial Deformity.

The aim of this research was to analyze the facial class, presence of malocclusion, and the mandibular plane and to relate this to the mandibular condyle position. A cross-sectional study in subjects under analysis for orthognathic surgery was done. The mandibular plane, the gonial angle, and the molar class were included to compare the coronal and sagittal position of the condyle and the joint space observed in the CBCT. The measurements were obtained by the same observer at an interval of two weeks. In addition, the Spearman test was performed to determine the correlation using a p value < 0.05 to observe any significant differences. Eighty-nine male and female subjects (18 to 58 years old, 24.6 ± 10.5) were included. In the coronal section, subjects with CIII had a greater mediolateral distance (MLD, p = 0.0001) and greater vertical distance (SID, p = 0.0001) than subjects with CII. In terms of the skeletal class and the mandibular plane, it was observed that subjects in the CII group had a greater mandibular angle (open angle) (p = 0.04) than the CII group and was related to the anterior position of the condyle. The most anterior condylar position was observed in the CII group (p = 0.03), whereas a posterior condylar position was significant in CIII subjects (p = 0.03). We can conclude that the sagittal position of the TMJ was related to the mandibular plane and the skeletal class showing a higher mandibular angle and most anterior position of the condyle in CII subjects and a lower mandibular angle and most posterior position of the condyle in CIII subjects. The implications for surgical treatment have to be considered.

Morfología ósea facial en cirugía ortognática. ¿existe tendencia hacia el avance facial? / Facial morphology in orthognathic surgery: is there a facial advance trend?

RESUMEN: El objetivo de esta investigación fue determinar los movimientos preferidos en maxila y mandíbula para obtener normalidad en morfología facial utilizando técnicas de superimposición en análisis 3D. Se realizó un estudio descriptivo para evaluar el desplazamiento óseo bimaxilar y del hueso hioides en sujetos clase facial tipo II y clase facial tipo III sometidos a cirugía ortognática. Para la superimposición se utilizó como puntos fijos Nasion - Silla - Porion y la sutura cigomática-maxilar. Estos puntos se superpusieron en CBCT pre quirúrgico y postquirúrgico y se evaluó el desplazamiento de la espina nasal anterior, Punto A, Punto B, mentón y del hueso hioides. Para la evaluación y comparación de las variables continuas antes y después de la cirugía ortognática se utilizó la prueba T de Student. Para la correlación entre las variables, se utilizó el Test de Spearman considerando un valor p<0,05 como diferencia significativa. 44 sujetos de entre 18 y 40 años de ambos sexos, fueron incluidos en esta investigación. En el 90 % de los sujetos se realizó un movimiento sagital de avance de la maxila. El movimiento sagital de avance mandibular se realizó en el 100 % de los sujetos con clase facial tipo II, mientras que el 100 % de los sujetos con clase facial tipo III se realizó se le retroceso mandibular. El hueso hioides presentó un avance en 26 de los 27 sujetos con clase facial tipo III. Es posible concluir que existe una tendencia al avance maxilar independiente de la deformidad facial.

ABSTRACT: The objective of this research was to determine the preferred movements in the maxilla and mandible to obtain normality in facial morphology using superimposition techniques in 3D analysis. A descriptive study was carried out to evaluate bimaxillary bone displacement and hyoid bone in subjects facial class II and facial class III undergoing orthognathic surgery. were used as fixed points for superimposition: Nasion (N) - Silla (S) - Porion (Po) and the zygomatic-maxillary suture (Z). These points were superimposed in pre-surgical and post- surgical CBCT and was evaluated to displacement of the anterior nasal spine, Point A, Point B, Chin and the hyoid bone. For the evaluation and comparison of continuous variables before and after orthognathic surgery, was used the Student's t test. For the correlation between the variables, the Spearman test is used, considering a p value <0.05 as a significant difference. 44 subjects between 18 and 40 years old of both sexes were included in this research. A 90% of subjects a was performed a maxillay sagittal movement. The sagittal movement of mandibular advancement was performed in 100% with facial class type II, while 100 % of the subjects with with facial class type III had a mandibular recession. The hyoid bone advanced in 26 of the 27 subjects with facial class type II. It is possible to conclude that there is a tendency for maxillary advancement, independent of facial deformity.

The Airway Volume Related to the Maxillo-Mandibular Position Using 3D Analysis.

OBJECTIVE: The aim of this research was to compare three cephalometric analyses and their correlation with the airway volume in subjects with different skeletal classes using 2D and 3D images. Study Design. Cross-sectional descriptive study. Material and Method. Steiner, McNamara, and Ricketts analyses and the airway volume were compared in 115 subjects who were candidates for orthognathic surgery under diagnosis using cone beam computed tomography (CBCT); 46 males (40%) and 69 females (60%) were included. The sagittal positions of the maxilla and mandible, the angulation of the mandibular plane, the sagittal positions of the upper and lower incisors, measurements of the largest or shortest airway area, and the volume were compared using Spearman's test considering a p value < 0.05. RESULTS: Differences were observed between the Steiner and McNamara techniques for the sagittal position of the maxilla (p = 0.01). For mandibular angulation, there was a greater difference between values for Steiner and Ricketts techniques (p = 0.001). In the upper incisor, the results for McNamara and Ricketts techniques were significantly different (p = 0.004). Analysing the airway, subjects with a class II skeletal pattern had a smaller volume than those with a class III pattern (p = 0.034). CONCLUSION: It may be concluded that skeletal class II patients have a significantly smaller airway volume than class III patients. The skeletal parameter does not always relate to the airway volume; however, the high mandibular angle could be related to the airway conditions.

3-D airway analysis related to facial morphology / Análisis 3-D de la vía aerea relacionado con la morfología facial

The aim of this investigation was to define the volume and area of the airway in subjects with Class II and Class III skeletal deformity. A cross-sectional study was designed including subjects with facial deformity defined by Steiner's analysis in subjects with indication of orthognathic surgery who presented diagnosis by cone beam computerised tomography. We determined the measurements of maximum area, minimum area and volume of the airway. The data were compared using Spearman's test, with statistical significance defined as p<0.05. 115 subjects were included: 61.7 % Class II and 38.3 % Class III, mean age 27.8 years (± 11.6). A significant difference was observed in the area and volume measurements in the groups studied, with significantly smaller measurements found in Class II (p=0.034). The minimum area was 10.4 mm2 smaller in Class II patients than in Class III, while the general volume of the airway was 4.1 mm3 smaller in Class II than in Class III. We may conclude that Class II subjects present a smaller airway volume than Class III subjects.

El objetivo de esta investigación de definir el volumen y área de vía aérea en sujetos con deformidad esqueletal clase II y III. Se diseñó un estudio de corte transversal incluyendo sujetos con deformidad facial definida según análisis de Stainer en sujetos con indicación de cirugía ortognática que presentaran una tomografía computadorizada de haz cónico como elemento diagnóstico; en este examen se determinaron medidas de área mayor, menor de vía aérea y volumen presente; los datos fueron comparados utilizando pruebas estadísticas con el test de spearman considerando el valor de p<0,05 para definir significancia estadística. 115 sujetos fueron incluidos, siendo 61,7 % de tipo clase II y 38,3 % de sujetos clase III, con una edad promedio de 27,8 años (± 11,6). Se observó una diferencia significativa en mediciones de area y volumen en los grupos estudiados, siendo el grupo de clase II significativamente menor (p=0,034). El área de menor tamaño fue 10,4 mm2 en pacientes clase II que en pacientes clase III, mientras que el volumen general de la vía área fue 4,1 menor en los clase II que en los clase III. Es posible concluir que los sujetos de clase II presentan menor volumen de vía área que los sujetos clase III.

Urgencias Odontológicas en la Provincia de Cautín - Chile, entre los Años 2009 a 2013 / Dental Emergencies in the Cautín - Chile Province between 2009 to 2013

Las urgencias odontológicas ambulatorias comprenden un conjunto de patologías bucomaxilofaciales, de aparición súbita, de etiología múltiple, que se manifiestan principalmente por dolor agudo y que provocan una demanda espontánea de atención. El objetivo de esta investigación fue reconocer la evolución de la urgencia odontológica en los sistemas de Atención Primaria de Salud (APS) entre los años 2009 y 2013. Se realizó un estudio retrospectivo para analizar la demanda entre los años mencionados; la información se obtuvo desde los registros estadísticos mensuales de las comunas pertenecientes al Servicio de Salud Araucanía Sur (SSAS) y fueron analizados con estadística descriptiva en el programa computacional Microsoft Excel. Los resultados mostraron una tendencia a la disminución de las consultas por urgencia tanto en las garantías explicitas en salud (GES) como en las no incluidas (No GES) en los últimos años; grupos prioritarios aun son consultantes en la urgencia donde el grupo de embarazadas sufrió un aumento en las atenciones de urgencia odontológica durante los años analizados; del total de urgencias se observó una disminución de 25.000 consultas aproximadamente desde el año 2009 hasta el año 2013 con variaciones menores entre los años 2010 y 2011. Se concluye que existe una tendencia a disminuir las consultas por urgencia GES y No GES en la población analizada aunque se deben analizar las condicionantes de grupos prioritarios en la urgencia odontológica.

Dental emergencies in ambulatory system included multiple oral and maxillofacial diseases with sudden onset and different etiologies; acute pain and related conditions are associated to spontaneous admission. The aim of this research was to know the evolution of the dental emergency in the public health system related to "Primary Health Attention" (HPA) between 2009 to 2013. A retrospective research was carried out on admissions between 2009 and 2013; the information was obtained from the statistical register of "Servicio de Salud Araucanía Sur"; the data was studied by descriptive statistic with Microsoft Excel software. The results showed a tendency to decrease the consultation by dental emergency in the GES group and the No-GES group; priority groups continue to use dental emergency services and the pregnant group showed an increase in dental emergency consult during the last few years; from the total amount of consults a reduction of approximately 25,000 was observed from 2009 to 2013 with lesser variations in the 2010 and 2011 period. It is concluded that there is a tendency of fewer GES and No-GES consultations in the analyzed population and it is necessary to understand the condition of priority groups in the dental emergency.

Estructura nasal en pacientes con deformidad facial clase III / Structure of the nose in patients with class III facial deformities

El objetivo de esta investigación fue conocer aspectos morfológicos de la estructura nasal en sujetos con diagnóstico de deformidad facial clase III. Se realizó un estudio con tomografía computadorizada Cone Beam sobre 20 pacientes entre 18 y 35 años para identificar mediciones a nivel de la apertura piriforme, huesos propios de la nariz y ángulos de dorso nasal y labio superior. El estudio se realizó en el software del sistema realizando las mediciones de acuerdo a condicione estándar; el análisis de datos fue de forma descriptiva y mediante la prueba t de student considerando el valor de p<0,05 para obtener significancia estadística. Los resultados demostraron importantes variaciones en la altura de los huesos nasales y la forma de la apertura piriforme; las mediciones mostraron algunas variaciones donde el ángulo nasolabial fue el que presentó valores bajo los 104, considerados fuera de la normalidad; no se presentaron relaciones significativa en ninguna de las evaluaciones realizadas en esta muestra. Se puede concluir que existen importantes variaciones anatómicas y que nuevas mediciones deben ser evaluadas para utilizarlas en métodos de diagnóstico y tratamiento.

The aim of this study was to obtain information on some morphological aspects of the nose structure in subjects with class III facial deformities. A study was carried out by computed cone beam tomography in 20 patients between 18 and 35 years of age to measure pyriform aperture, nasal bones, dorsal nasal angle and superior lip angle; the study was realized on system software, measurement was realized in standardized conditions and the data analyzed was descriptive and with student ´t´ test considering p<0.05 for statistical significance. The results showed high variations in nasal bones height and pyriform aperture shape; measurement showed some variations with nasal-lip angle with values less than 104o, considered outside of the normality. In some of the measurements, anatomical variations of the nose in these subjects was clear; there were no significant statistical differences in any of the measurements in this sample. It was concluded that there are important variations in the anatomical form and new measurements should be evaluated for their use in diagnosis and treatment.

Relación entre el tamaño condilar y la asimetría facial transversal en individuos con hiperplasia condilar / Relationship between condylar size and transverse facial asymmetry in subject with condylar hyperplasia

La asimetría facial es una patología de compromiso funcional y estético que puede estar generado por hiperplasia condilar; el objetivo de esta investigación es determinar la influencia del tamaño condilar en la asimetría facial. Doce sujetos fueron estudiados mediante el análisis de tomografía computadorizada cone beam; todos los pacientes presentaron cintigrama óseo que determino la presencia de hiperplasia condilar activa; el análisis se realizo en un software del sistema de captura modelo Pax Zenith, marca Vatech (Korea 2011), utilizando 90 kV y 120 mA; se obtuvo mediciones de la distancia antero-posterior, superior-inferior y medio-lateral de la cabeza del cóndilo, relacionándose con la posición del cóndilo con la línea mediana facial y la posición de puntos faciales entre incisivos centrales superior e inferior así como con el mentón. Los resultados mostraron un promedio de desvío de mentón de 6,5 mm considerando un cóndilo hiperplásico con un tamaño de 2,7 mm mas que los cóndilos normales. El desvío de incisivo central inferior determinó que por cada 1 mm de desvío dentario existe 2,2 mm de desvío de mentón. El cóndilo hiperplásico fue de mayor tamaño y se posiciono casi 2 mm mas hacia lateral que los cóndilos no hiperplásicos. Es posible concluir que el cóndilo hiperplásico presenta clara influencia en la asimetría facial transversa y es posible estimar una relación de tamaño condilar con grado de asimetría facial.

Facial asymmetry is a functional and esthetic pathology that can be related to condylar hyperplasia; the aim of this research was to asses the condylar size in the facial asymmetry. Twelve subjects was studies with cone beam computed tomography; the analysis was realized in the software Pax Zenith, Vatech (Korea 2011), using 90 kV and 120 mA and was realized anterior-posterior measurement, superior and inferior measurement and medial-lateral measurement of condylar head and was realized the relations with condylar position with the medial facial line and the position of facial point between superior central incisior, inferior central incisior and chin. The results show that the chin was displaced 6.5 mm from middle line being a hyperplasic condyle with a 2.7 mm more than no hyperplasic condyle. 1 mm of displacement of low central incisor was associated to 2.2 mm of chin displacement. The hyperplasic condyle presented more size and was posicionated 2 mm more lateral than non-hyperplasic condyle. Is conclude that the hyperplasic condyle present a clear influence in the facial transversal asymmetry and in possible to establish a relation between the size of hyperplasic condyle and the facial asymmetry.

[Relationship Between Condylar Size and Transverse Facial Asymmetry in Subject with Condylar Hyperplasia]. / Relación Entre el Tamaño Condilar y la Asimetría Facial Transversal en Individuos con Hiperplasia Condilar.

Facial asymmetry is a functional and esthetic pathology that can be related to condylar hyperplasia; the aim of this research was to asses the condylar size in the facial asymmetry. Twelve subjects was studies with cone beam computed tomography; the analysis was realized in the software Pax Zenith, Vatech (Korea 2011), using 90 kV and 120 mA and was realized anterior-posterior measurement, superior and inferior measurement and medial-lateral measurement of condylar head and was realized the relations with condylar position with the medial facial line and the position of facial point between superior central incisior, inferior central incisior and chin. The results show that the chin was displaced 6.5 mm from middle line being a hyperplasic condyle with a 2.7 mm more than no hyperplasic condyle. 1 mm of displacement of low central incisor was associated to 2.2 mm of chin displacement. The hyperplasic condyle presented more size and was posicionated 2 mm more lateral than non-hyperplasic condyle. Is conclude that the hyperplasic condyle present a clear influence in the facial transversal asymmetry and in possible to establish a relation between the size of hyperplasic condyle and the facial asymmetry.