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*

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*

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.
Hyoid Bone ; Orthognathic Surgery ; Recurrence

No abstract available.
Humans ; Hyoid Bone ; Orthognathic Surgery

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

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

OBJECTIVE: To examine the differences in lateral cephalometric characteristics between patients with dental protrusion and crowding in order to determine what factors affect dental protrusion or crowding while both malocclusion types are caused by large tooth size. METHODS: Twenty nine individuals with dental protrusion and 22 individuals with dental crowding were enrolled in this study. All subjects had larger teeth than average and Class I molar relationships. Craniofacial characteristics and hyoid bone positions were determined from lateral cephalograms and compared between the two groups. RESULTS: In the comparisons of craniofacial characteristics, the measurements indicating maxillary length and facial convexity showed greater values in the protrusion group than in the crowding group. Comparisons of hyoid bone positions showed that the hyoid bone was positioned more anteriorly and superiorly in the protrusion group than in the crowding group. CONCLUSIONS: The results of the present study indicate that some craniofacial characteristics and tongue position may affect the development of dental protrusion or crowding; when an individual has large teeth, dental protrusion or crowding might be determined according to maxillary growth and tongue position.
Humans ; Hyoid Bone ; Malocclusion ; Molar ; Tongue ; Tooth