This study was conducted to assess the positional changes of hyoid bone following the use of activator in Angles class III malocclusion patients with functional factors. For this study, 40 Angle's class I patients and 40 Angle's class III patients, totally 80 subjects were used. They are all in Hellman's dental age IIIB-IIIC ranges. In lateral cephalogram to compare Angle's class I group and Angle's class III group, and the positional changes of the hyoid bone before and after the use of activator in Angle's class III malocclusion group. The results were obtained as follows; 1. Comparison of Angle's class I group and Angle's class III group. In comparison to Angle's class I group, hyoid bone is more anteriorly and superiorly positioned in Angle's class III group. The hyoid bone showed reverse inclination to the mandibular plane in Angle's class III malocclusion group. 2. Comparison of the hyoid positional change before and after use of Activator in Angle's class III malocclusion group. The hyoid bone is displaced posteriorly and inferiorly in vertical relationship. The hyoid bone also showed counter-clockwise rotation. 3. No statistical difference was found between after Activator use data of Angle's class III malocclusion group and Angle's class I group. It is concluded that the hyoid bone in Angle's class III malocclusion group changed its position, similar to Angle's class I malocclusion group.
Humans ; Hyoid Bone* ; Malocclusion*

The configuration of mandibular symphysis is likely to be dependent upon the genetic predeterminants and/or compensatory adjustments onto functional demands. The interrelation of morphological distinctives of symphysis in conjunction to the craniofacial skeleton had been scarcely anecdotal, therefore, the objective was to determine the correlation of morphological modifications between the mandibular symphysis and craniofacial complex. Lateral cephalometric headfilms of 212 subjects were employed for the conventional measurements. The proportion of chin height against chin depth length was referred as chin ratio, then, Low Symphysis (IS) and High Symphysis (HS) groups were turned out by means of the chin ratio. These samples yielded 35 in LS and 35 in HS groups. The data per capita were statistically analyzed and the following results were drawn ; 1. Overall characteristics of the craniofacial skeleton in HS group manifested hyperdivergence and LS group showed hypodivergence. 2. Gonial angle increased as chin ratio increased and was highly correlated to the chin ratio. 3. The chin ratio presented high correlation to the vertical face height, especially in terms of the chin height to anterior face height and the chin depth to posterior face height. 4. The morphological configuration of chin was hardly correlated with hyoid bone position.
Chin ; Hyoid Bone ; Skeleton*

No abstract available.
Hyoid Bone* ; Mandibular Fractures* ; Masks*

The positional changes of the hyoid bone over entire growth period were studied by cephalometric method in order to determine the average position and average growth changes of the hyoid bone in koreans with normal occlusion. The materials included cephalometric radiographs obtained on twenty six males and twenty two females over the period from 8.7 years to 16.7 years of age in average. The results of this study might be summarized as follows: . The mean value and standard deviation of each measurement were obtained in each age and gender. . The hyoid bone tended to positioned forwardly in female at the age of 12.7, 14.7, and 16.7 years of age as compared with male. . The hyoid bone positioned more downwardly in male than in female.
Female ; Humans ; Hyoid Bone* ; Male

No abstract available.
Humans ; Hyoid Bone ; Orthognathic Surgery

No abstract available.
Hyoid Bone ; Orthognathic Surgery ; Recurrence

Various studies have documented a variability of hyoid bone position in relation to changed mandibular position or head position. The aim of this study was to evaluate the hyoid bone position and inclination on the lateral cephalometric radoigraphs of two group of patients exhibiting Class I normal occlusion and Class III maloccluslon, so to verify the relatlonships between hyoid bone position, pharyngeal airway and relative mandibular position In the class I group, there were 16 femailes, while the Class III group consisted of males and females. The results were as follows 1. By the length of A-Aph, N-APH, and GoP-PPH, the hyoid of Class IIIgroup was more anteriorly and inferiorly positioned than Class I group 2. On the analysis of soft tissue airway, the measurement(PNS-ad) of Class III group were smaller than Class I group 3. In the comparison of the variances betwwen male and female, hyoid bone was inferiority positioned and showed sinificantly more lager pharyngetal with of haled tissue in the Class I male and In the Class III male, same tendancy about hyoid position and pharyngeal wldth was seen and more anteriorly positioned 4. There was no statiscally significances between pharyngeal airway measurements and relative mandidular position, but statistical significance between wits appraisal and hyold bone position was seen. 5. The S-N-Pog which shows relative mandibular protrusion inverse ratio in the in the analysis with A-APH , N-APH and Facial ratio with LAH-Mp also showed Inverse ratio.
Female ; Head ; Humans ; Hyoid Bone* ; Male

Clear cell chondrosarcoma, first described by Unni in 1976, is distinguished from classical chondrosarcoma by a typical histological picture, mostly an epiphyseal site of origin, and relatively a benign clinical course. We present a case of clear cell chondrosarcoma arising from hyoid bone in a 70-year-old male. Histologically, large areas of closely packed cells with characteristic clear cytoplasm were seen in addition to the usual elements of a conventional chondrosarcoma. Our search and review of the literature did not reveal any reported case of clear cell chondrosarcoma arising from hyoid bone.
Aged ; Chondrosarcoma* ; Cytoplasm ; Humans ; Hyoid Bone* ; Male

This study was performed to evaluate the hyoid bone position and airway in skeletal class III malocclusion and to prove the correlation between airway, hyoid bone position and mandibular position. The sample, considered of 47 class III malocclusion patients for experimental group and 52 class I malocclusion students for control group. Twenty three linear and angular measurements about hyoid bone position, airway size, mandibular position were taken from the lateral cephalograms. The differences between skeletal class III malocclusion group and normal occlusion group were compared and the correlation were evaluated statistically. The results obtained were as follows, 1. There were significant difference in S-APH, A-APH, N-APH, LAH-PBR, AA-PNS, PNS-ad between class I and class III malocclusion groups. 2. The hyoid bone was more anteriorly positioned in class III malocclusion group than class I malocclusion group and skeletal airway size in class III malocclusion group was smaller than class I malocclusion group. 3. There were significant difference in several measurements especially vertical and angular measurements of hyoid bone position and airway size between male and female. Usually the measurements in male were larger than female. 4. There were no significant correlation between hyoid bone position and airway size also airway size, and didn't showed significant correlation with mandibular position. 5. S-APH showed negative correlation with Wits appraisal and A-APH, N-APH showed positive correlation with Wits appraisal. On the contrary vertical measurements of hyoid bone position showed positive correlation with lower facial height.
Female ; Humans ; Hyoid Bone* ; Male ; Malocclusion*

Chondrosarcoma is a rare malignant tumor arising in bony or cartilagenous system. Chondrosarcoma of the hyoid bone is extremely rare, with approximately 10 cases having been reported in the english literature. Chondrosarcoma is a slow-growing, locally aggressive tumor which frequently recurs. Wide surgical excision is generally regarded as the treatment of choice for chondrosarcoma. The prognosis is best judged by three factors:tumor site, tumor grade and tumor resectability. Authors experienced a case of chondrosarcoma that originated from the greater cornu of the hyoid bone. The patient underwent wide excision of the tumor with total hyoidectomy and postoperative radiotherapy was performed.
Chondrosarcoma* ; Humans ; Hyoid Bone* ; Prognosis ; Radiotherapy