No abstract available.
Arthritis* ; Open Bite*

This study was undertaken to find out the factor highly correlated to the depth of overbite among the skeletal factors of the franiofacial complex using lateral roentgenocephalograms. The subjects cconsited of fifty normal occlusions, sixty Class I malocclusions, sixty Class II division 1 malocclustions and sixty Class III malocclusion. The results were as follows, 1. Ans-Go-Me angle and lower gonial angle showed high correlation to the depth of overbite in the total malocclusion sample. 2. The mean values of Ans-Go-Me angle and lower goinal angle for the normal sample were 49.8degrees and 75.6degrees , respectively. 3. Ans-G0-Me angle above 56degrees or lower gonial angle above 84degrees indicated a tendency toward an openbite Conversely, Ans-Go-Me angle below 48degrees or lower goinal angle below 73degrees indicated a tendency toward a deepbite.
Malocclusion ; Open Bite ; Overbite*

To analyze the skeletal characteristics of the open bite, the faces of normal occlusion and open bite were measured using a cephalogram. The factors which were greatly different form normal occlusion were selected. The effects of these factors on the incisal overbite and correlation on these factors were studied. The following results were obtained. 1. The 13 factors which comprised the characteristics of the open bite were obtained. (Table 5) 2. The cause and amount of the open bite were dependent on the skeletal angulation than skeletal length. 3. For determining the incisal overbite, most highly correlated sigle factor was the interincisal angle. 4. The correlation on the selected 13 factors which comprised the characteristics of the open bite was obtained. (Table 6) 5. The open bite was due to combination of various factors than due to single factor. (Table 3,4)
Open Bite* ; Overbite

The purpose of this study was to evaluate the postoperative stability of the severe open bite or mandibular prognathic patients after mandibular set back surgery by Obwegeser II method. There were 19 patients who had been undergone Obwegeser II method. The horizontal and vertical position of the cephalometric points were measured preoperation and immediate postoperation, postoperative 1 month, postoperative 6 months ; were analyzed by linear measurement to evaluate changes in skeletal landmark and the relapse was compared between open bite group and prognathism group. By the operation, horizontal change of B was 6.84+/-4.35mm and vertical change of B was 6.28+/-3.25mm in open bite group and horizontal change of B was 14.20+/-4.81mm and vertical change of B was 1.99+/-2.66mm in prognathism group, horizontal change of Pog was 3.82+/-5.71mm and vertical change of Pog was 5.38+/-2.11mm in open bite group and horizontal change of Pog was 13.24+/- 5.99mm and vertical change of Pog was 1.91+/-0.94mm in prognathism group. Between immediate postoperation and postoperative 1 month, all skeletal landmarks change was no statistical difference (p>0.05) and there were no statistical difference between open bite group and prognathism group except x-Me landmark (p>0.05). Between postoperative 1 month and 6 months, horizontal change of B was 0.12+/-1.35mm and vertical change of B was 1.47+/-1.48mm in open bite group and horizontal change of B was 1.43+/-1.35mm and vertical change of B was 0.82+/-1.99mm in prognathism group, horizontal change of Pog was 0.13+/-1.40mm and vertical change of Pog was 0.88+/-1.71mm in open bite group and horizontal change of Pog was 1.08+/-1.74mm and vertical change of Pog was 0.47+/-1.57mm in prognathism group (p>0.05) and there were no statistical difference between open bite group and prognathism group (p>0.05). Between immediate postoperation and postoperative 6months, horizontal change of B was 0.24+/-1.17mm and vertical change of B was 1.87+/-1.63mm in open bite group and horizontal change of B was 1.54+/-1.55mm and vertical change of B was 1.04+/-1.96mm in prognathism group, horizontal change of Pog was 0.91+/-1.46mm and vertical change of Pog was 1.18+/-2.05mm in open bite group and horizontal change of Pog was 0.96+/-1.62mm and vertical change of Pog was 1.23+/-2.35mm in prognathism group (p>0.05) and there were statistical difference between open bite group and prognathism group in x-B, x-Pog, x-Gn, x-Me (p<0.05). Obwegeser II method is considered as one of the best operation when surgical correction of severe open bite or severe mandibular prognathism is needed.
Humans ; Open Bite* ; Prognathism ; Recurrence

The study was undertaken to ascertain the speech defect of patients with malocclusion, especrally of poenbite patients, by means of the spectral analysis method. The expermental group was composed of ten female openbite patients and their mean age was 13.8 yrs. The control group was also composed of ten female girls ans then mean was 13.7 yrs. As for the speech materisl, eight Korean monphthrongs ans two Korean fricatives and two affricatives were used Speeches were recorded and then analyzed by a Kay 7800 drgital sonagraph. Formant frequency level or range was used as a phonemic parameter. The results were as follows. 1. Among Vowels /a/ F1,F3, and F1/F2 showed abnormahty /o/and/omega/F2,F2-F1 and F1/F2 showed abonrmahty. 2. Among Consonants /s/and/h/ The upper and lower borders of the frequency range showed abnormahty. /f/ The lower border of the ferquency range showed abonormahty. /C(h)/ The upper and lower borders of the frequency range and concentration point showed abonormahty.
Female ; Humans ; Malocclusion ; Open Bite*

The present study was carried out to investigate the relationships between the depth of overbite and the masseteric silent period Normal subjects of 44 were selected, which consisted of 9 open bites, 24 normal overbites and 11 deep bites, all were 19-29 years of age EMG activity was recorded on the bilateral masseteric muscles and craniofacial radiography was done. The following results were obtained 1. The mean duration of masseteric silent period was 18.58+/-4.50 msec in open bite, 17.37+/-7.05 msec in normal overbite and 19.30+/-7.62 msec in deep bite groups. 2. There were no significant differences on masseteric silent period among open bite, normal overbite and deep bite groups. 3. There were no significant correlations between masseteric silent period and craniofacial variables.
Muscles ; Open Bite* ; Overbite* ; Radiography

OBJECTIVETo investigate the effect of occlusal force on the etiology of open bite patients who suffer from temporomandibular disorders (TMD).

METHODSOne hundred and two women patients with open bite were divided into TMD (+) group and TMD (-) group according to patients with or without TMD. Occlusal force, occlusal contact areas, occlusal average pressure and occlusal center were evaluated with pressure sensitive sheets. The results were analyzed by SPSS 11.0 statistic software.

RESULTSOcclusal force and occlusal contact areas in TMD (+) group were significantly lower than that in TMD (-) group. Occlusal average pressure and occlusal center had no significance between two groups.

CONCLUSIONThe results indicate that the decrease of occlusal force and occlusal contact areas may have some relationships with TMD in open bite patients.

In case of class II malocclusion, mandible has morphological characteristics such as size and position. To investigate morphological characteristics of mandible, most study has been done in indirect measurement using cephalogram. Recently, it is possible to measure directly Three dimensional skeletal model reconstructed from computed tomography images. This study aimed to know characteristics of mandible in class II malocclusion, analyzing Three dimensional mandible models of class I and II malocclusion which are acquired from computed tomography images of 80 cadavers. In open bite type of class II malocclusion, the size of mandible had no difference from class I malocclusion but the sagittal ramus angle and condylar angle were smaller 3 degree than class I. These findings inform that the ramus and condylar process of open bite type of class II malocclusion stand more erectly than class I and then the mandible is placed posteriorly. In deep bite type of class II malocclusion, the length of mandible was shorter 4 mm and, the sagittal ramus angle and condylar angle were larger 5 degree than class I. These findings, short length of mandible and more lying ramus and condylar process, make the mandible in the feature of deep bite of class II malocclusion. In comparison of past issued articles which used cehpalometry mainly, the values of measurements agree partially. It is the differences of measuring points and methods to make inconsistency between indirect measurement like cephalometric study and 3 dimensionally direct measurement like this study. To increase accuracy of Three dimensionally direct measurement, standardization of measuring points and method for the measurement is required.
Cadaver ; Deception ; Malocclusion* ; Mandible* ; Open Bite ; Overbite

Spinal muscular atrophy is one rare type of autosomal recessive disorder. The disease is characterized by the progressive degeneration of spinal cord anterior horn motor neurons and brainstem motor nuclei, which leads to muscle atrophy and paralysis. One case of spinal muscular atrophy with open bite was reported here.
Humans ; Muscular Atrophy, Spinal ; Open Bite

This study was intended to investigate the effect of mesiodistal crown widths of the anterior teeth on the incisor relationship and to determine whether mcisor width ratio and anterior width tatio could be used to assess interarch tooth width harmony. From thr casts taken from 63 subjects, 26 of open bite, 18 of deep bite and 19 of normal over bite sith age of 17-20, mesiodistal crown widths of maxillary and mandibular 6 anterior teeth were measured with Boley gauge. On the basis of tooth measurements, anterior and incisor width ratio were calculated. The cephalograms were taken from same subjects to measure the degree of over bite and over jet and to compare the craniofacial bony structures between open bite, deep bite and normal over bite. Correlations among the anterior width ratio, incisor width ratio, over bite and over jet were calculated. The results were as follows. 1. There were no differences in mesiodistal widths of anterior teeht, incisor width ratio and anterior width ratio between open bite, deep bite and normal over bite. 2. The mcisor width ratio and anterior width ratio can bw useful in the assessment of tooth width harmony because the incisor width ratio and anterior width ratio were stable statistically and significantly correlated with each other. 3. Over bith and over jet were not correlated with incisor width ratio and anterior width ratio.
Crowns* ; Incisor* ; Open Bite ; Overbite ; Tooth*