File Name: development of mandible and maxilla .zip
- Age Changes of Jaws and Soft Tissue Profile
- Facial and Palatal Growth
- Mandible and Tongue Development
Age Changes of Jaws and Soft Tissue Profile
Transverse maxillary and mandibular growth during and after Bionator therapy: study with metallic implants. METHODS: Measurement of transverse dimensions between posterior maxillary and mandibular implants, as well as the distances between the buccal, gonial and antegonial points were recorded. Keywords: Keywords: Activator appliances.
Angle Class II malocclusion. Maxillofacial development. Palavras-chave: Aparelhos ativadores. Desenvolvimento maxilofacial. Few studies evaluating the transverse growth of the face were carried out so far, especially regarding sagittal growth. This is due to problems such as difficulty on identification and consequent reproducibility of cephalometric points, 18,21 standardization of the head positioning, 20,11 radiographic magnification 9,11,15,27 and standardization of the sample.
The longitudinal examination using metallic implants carried out so far refers to Class I patients with or without treatment 4,5,10,17 or to mixed samples.
The cephalometric studies in teleradiographs with metallic implants proved to be the most efficient method to longitudinally assess the craniofacial growth 3,5 due to the difficulty of identification of cephalometric points and remodeling that occurs on the surface of the jaws.
The objective of the present study is to evaluate the maxillary transverse growth and its relation to the treatment, through posteroanterior radiographs, during 6 years after the use of Balters' bionator in patients with metallic implants.
The sample consisted of 25 patients that used bionator 15 boys and 10 girls , participants on a prior study 1 and treated in the Department of Orthodontics at the School of Dentistry of Araraquara - Unesp.
The other patients could not be contacted. On the final sample, one patient did not present the posterior implants on the maxilla in T 3 and on the mandible in T 1 , other patient did not present one anterior implant in T 3 and another patient did not present one of the posterior implants on the mandible.
Table 1 shows age and gender of the sample and Table 2 characterizes the sample. Lateral and posteroanterior teleradiographs were obtained in three time periods: T 1 at the beginning of treatment with bionator, T 2 at the end of the bionator therapy and T 3 5.
The teleradiographs were manually traced and the cephalometric points were digitized twice on Dentofacial Planner Plus DFP Plus, version 2. The cephalometric points used on the posteroanterior teleradiographs are described on Table 3 and Figure 1. The transverse growth was calculated by the transverse linear distance between the cephalometric points on the right and on the left. Corrections for magnification on transverse linear measurements were necessary before classifying the growth data, because although the posteroanterior teleradiographs had been taken with cephalostat, the radiographic magnification of the region of the metallic implants is different from the region of the acoustic meatus center plane because it is closer to the radiographic film, especially compared to the anterior implants on the maxilla.
Another reason for correction is that, with the facial growth, maxilla move forward carrying together the metallic implants making them closer to the radiographic film. These variations on radiographic magnification were mathematically corrected by a combination of information of lateral and posteroanterior teleradiograph using correction method recommended by Hsiao et al.
The following transverse measurements were performed:. Statistical analysis. The mean and standard deviation were calculated for each variable. The different variables presented normal distribution and the Student's t test was used to evaluate the significance of the changes during evaluation periods T 2 - T 1 , T 3 - T 2 , and T 3 - T 1.
To evaluate the error on the localization of cephalometric points and digitalization procedures all tracings were digitalized again after two weeks by the same examiner. The random error was evaluated using Dahlberg's formula and the systematic errors were evaluated using paired t test.
The method random error Dahlberg's formula did not exceed 0,33 mm. The paired t test did not show statistically significant systematic error. Table 4 shows the transverse dimension of the maxilla and mandible on the three periods of evaluation. Table 5 shows that there was statistically significant increase of the maxillary transverse distances on the region of anatomic cephalometric points Go, Ag and J and of implants in all evaluated periods, except for the region of anterior implants of the maxilla that did not show statistically significant growth at no time.
The lowest gains obtained were on the distance between mandibular implants and the highest were found on the inter-gonial distance. The size of the sample cannot be considered representative of the population in a statistical sense, on the other side, due to the use of metallic implants, a detailed analysis can provide information on the facial growth.
The study confirmed the increase of bone bases and evidenced that the maxillary growth was greater than the mandibular. The mean increase of the distance between posterior implants of the maxilla during all evaluated period, T 1 -T 3 , was of 3. The result in this work was a little higher, but considering the standard deviation the values are similar because they also observed great variability. The differential maxillary transverse increase regarding the anterior and posterior region implies in a transverse rotation between the sides.
Table 6 shows that the annual growth of the posterior region of the maxilla was the greatest among the studies that used metallic implants. A previous study 19 showed 1. This difference may be related to the therapy used because when comparing Class II our results were higher and when compared Class I they were lower, but it must be emphasized that Class II patients present the maxillary transverse dimension smaller than Class I patients. In one year of treatment with Frankel's appliance, a study 8 showed 0.
It was concluded that the treatment was capable to increase the basal transverse distances of the maxilla.
As the values of annual growth in the present study, were higher it is believed that the bionator also has the capacity to increase the maxillary bone base, 1 although it is not clinically significant. During the bionator therapy, the presented mandibular basal transverse growth was 0. Another study, 16 on the same period of evaluation, found 0,46 mm and despite not presenting similar sample to the present study, it could be assumed that the bionator has the ability of increasing the mandibular bone base, when used appropriately.
This information was already reported by another study 1 that did not find statistically significant mandibular transverse increase during one year of treatment with bionator, but observed higher value on the treated group. Evaluating the annual changes of growth on the two periods it is observed that on the stage of treatment with bionator the maxillary and mandibular basal transverse growth was 0. After therapy, the normal growth showed 0.
The mandibular basal transverse increase is a supposition, but at a dental and dentoalveolar matter it was already identified in studies with functional appliances.
This result may represent that Class II patients have lower potential of mandibular basal transverse growth even if treated at a young age, however some authors 19 did not identify difference on the mandible between Class I and II patients. After therapy with bionator, the remodeling on the Jugal point found by the present study was greater than the ones shown by several articles with similar period of observation.
The mandibular transverse distance, both on the region of Gonion and Antegonion, evaluated in T 3 , is lower than the presented by Lux et al 19 evaluating 15 years old Class I or II patients. It was also lower than presented in other studies. Besides, the gonial region showed wide remodeling during growth and it is the transverse dimension of the lower third of the face that presents greater growth and possibility of morphological variation.
Another aspect is that the comparison of normative values between the studies is not appropriated due to radiographic magnification. Some articles do not mention the correction and other do not describe appropriately the used methodology.
The findings in this study are limited by the size of the sample, bias of the treatment potential and lack of control group. Besides, additional studies with larger samples are necessary to provide better estimates of variation on transverse increase by growth.
There is also the possibility of influence of the treatment subsequent to the bionator on the transverse increase although it is hardly likely that conventional fixed appliances have some potential of orthopedic effect. Transverse skeletal base adaptations with Bionator therapy: a pilot implant study. Am J Orthod Dentofacial Orthop. Data and patterns of transverse dentofacial structure of 6- to year-old children: a posteroanterior cephalometric study.
Mandibular remodeling measured on cephalograms: 2. A comparison of information from implant and anatomic best-fit superimpositions. Growth in width of the maxilla studied by the implant method. Scand J Plast Reconstr Surg. Growth of the maxilla in three dimensions as revealed radiographically by the implant method. Br J Orthod. Facial growth in man, studied with the aid of metallic implants.
Acta Odontol Scand. Variations in growth pattern of the human mandible: Longitudinal radiographic study by the implant method. J Dent Res. Maxillary skeletal and dental change with Frankel appliances: an implant study. Angle Orthod. Transverse development of the jaws: Norms for the posteroanterior cephalometric analysis.
Maxillary and mandibular width changes studied using metallic implants. Effect of film-object distance on posteroanterior cephalometric measurements: suggestions for standardized cephalometric methods. Functional appliances and arch width. Transverse skeletal and dentoalveolar changes during growth. A method of magnification correction for posteroanterior radiographic cephalometry. Change in the width of the mandibular body from 6 to 23 years of age: an implant study.
Eur J Orthod. Korn EL, Baumrind S. Transverse development of the human jaws between the ages of 8. Landmark identification error in posteroanterior cephalometric radiography. A systematic review. Dental arch widths and mandibular-maxillary base widths in Class II malocclusions between early mixed and permanent dentitions. Effect of head orientation on posterior anterior cephalometric landmark identification. Landmark identification error in posterior anterior cephalometrics. The effect of head rotation on cephalometric radiographs.
Owen AH. Am J Orthod. Norms of size and annual increments of seven anatomical measures of maxillae in boys from three to sixteen years of age. A longitudinal cephalometric study of transverse and vertical craniofacial growth. Vargevik K. Morphologic evidence of muscle influence on dental arch width.
Transverse growth of the maxilla and mandible in untreated girls with low, average, and high MP-SN angles: a longitudinal study.
Facial and Palatal Growth
Transverse maxillary and mandibular growth during and after Bionator therapy: study with metallic implants. METHODS: Measurement of transverse dimensions between posterior maxillary and mandibular implants, as well as the distances between the buccal, gonial and antegonial points were recorded. Keywords: Keywords: Activator appliances. Angle Class II malocclusion. Maxillofacial development. Palavras-chave: Aparelhos ativadores.
Accessory cartilages. MAXILLA PROPER. It develops in the mesenchyme of the maxillary process of the mandibular arch as intramembranous ossification. It.
Mandible and Tongue Development
Age-related changes of jaws and soft tissue profile are important both for orthodontists and general dentists. Mouth profile is the area which is manipulated during dental treatment. These changes should be planned in accordance with other components of facial profile to achieve ultimate aim of structural balance, functional efficacy, and esthetic harmony. Through this paper, the authors wish to discuss age changes of the hard and soft tissues of human face which would help not only the orthodontists but also oral surgeons, prosthodontists, pedodontists, and general dentists.
The tongue and mandible have common origins. They arise simultaneously from the mandibular arch and are coordinated in their development and growth, which is evident from several clinical conditions such as Pierre Robin sequence. Here, we review in detail the molecular networks controlling both mandible and tongue development.
The purpose of this investigation was to study the interrelations between maxillary and mandibular growth by restricting the growth of the maxilla. The control group, also 78 rats, did not undergo this operation. In order to evaluate the role of the occlusion in the regulation of the jaw interrelation the incisors were cut and the occlusal surfaces ground in 10 experimental and 10 control rats. Dry mandibular halves and sagittal sections from the temporomandibular joints were examined. The length of the mandible, as measured from the condyle to the incisor, first molar or mental foramen was diminished after 50 days, but its height was increased and the condylar process seemed more vertically oriented. The histological sections showed the condylar cartilage to be thinner in the experimental rats from 22 to 50 days.
Определенно. - Так вы успели его рассмотреть. - Господи. Когда я опустился на колени, чтобы помочь ему, этот человек стал совать мне пальцы прямо в лицо. Он хотел отдать кольцо.
The Scientific World Journal
Но всякий раз, когда я перехватывал очередное сообщение, Танкадо был все более и более убедительным. Когда я прочитал, что он использовал линейную мутацию для создания переломного ключа, я понял, что он далеко ушел от нас. Он использовал подход, который никому из нас не приходил в голову. - А зачем это нам? - спросила Сьюзан. - В этом нет никакого смысла.
В голосе ее прозвучала удивительная решимость: - Мы должны установить с ним контакт.