Biomedical subjects

Hung-Huey Tsai

Publications and source records attributed to Hung-Huey Tsai.

13 recordsLinked to original sources

PubMed2005

Factors associated with mandibular third molar eruption and impaction.

A retrospective study, using panoramic radiographs, was conducted on 152 Taiwanese (72 males and 80 females) to investigate mandibular third molar eruption and impaction. The following measurements were made: inclinations and mesiodistal crown widths of the mandibular molars, vertical and horizontal spaces between the distal surface of the second molar and the anterior surface of the ramus, lengths and widths of the mandibular ramus and body, the ramus inclination, the mandibular plane angle, and the mandibular gonial angle. Differences between non-impaction and impaction groups were studied, and the variables were analyzed with multivariate discriminatory analysis. Significant differences between the two groups were found; variables describing spaces between the anterior of the ramus and the distal of the mandibular second molar and tooth size appeared to be the primary contributors to the differences observed.

Adult↗

PubMed2004

Morphology of the palatal vault of primary dentition in transverse view.

The purpose of this study was to investigate the transverse view of the morphology of the palatal vault in the primary dentition at the primary second molar level. Observations were obtained from 150 dental stone casts of normal children (78 boys and 72 girls; aged four to five years). Palatal width, palatal depth, arch width, and primary second molar angulation were measured. There were no significant differences in palatal depth and primary second molar angulation between boys and girls or between the right and left sides. However, girls had a statistically significantly narrower upper dental arch width and palatal width than did boys. Palatal widths on the left side were statistically significantly larger than those on the right side for both sexes. Asymmetry in the palatal width greater than two mm was present in 21.8% of boys and 16.7% of girls. There was a correlation between buccal tipping in the upper primary second molar and greater palatal width.

Cephalometry↗

PubMed2004

Maximum bite force and related dental status in children with deciduous dentition.

Six hundred seventy-six Taiwanese children with deciduous dentition were sampled for maximum bite force and related dental status. Sixty-seven percent of children had at least one decayed tooth. The mean number of decayed teeth of all children was 2.97+/-3.58, and the mean plaque index of the right maxillary central incisor was 2.00+/-0.75. Twenty-seven percent of children had occlusal anomalies. Boys had a statistically significantly larger maximum bite force than did girls. Children with normal occlusion had statistically significantly larger maximum bite forces than did children with malocclusion. A statistically positive correlation was found between the number of decayed teeth and the plaque index. However, a statistically negative correlation was found between the number of decayed teeth and the maximum bite force and between the plaque index and the maximum bite force.

Bite Force↗

PubMed2004

Panoramic radiographic findings of the mandibular foramen from deciduous to early permanent dentition.

The purpose of this study was to investigate the position of the mandibular foramen from deciduous (Hellman's stage IIA) to early permanent dentition (Hellman's stage IVA). Panoramic radiographs of 311 Taiwanese children were used. The results revealed that the distances between the mandibular foramen and ramus anterior plane were greater than those between the mandibular foramen and ramus posterior plane through all stages. The mean difference between them was the smallest (0.25 mm) in stage IIA and the greatest (1.18 mm) in stage IIIC. The distance from the mandibular foramen to the alveolar crest plane showed a little change from stage IIA (3.99 mm) to IVA (5.26 mm). The gonial angle had a negative correlation with the distances between the mandibular foramen and each mandibular border. Evaluation of the mandibular foramen from the oral aspect can be influenced by the degree of mouth opening.

Adolescent↗

PubMed2004

Growth changes of general and dental health status in Taiwanese children from mixed to early permanent dentition.

For this study, the general and dental health status of 463 Taiwanese children aged 9 to 12 years was evaluated. There were statistically significant increases in all measurements from Hellman's dental developmental stages IIIA to IVA except for the maximum mandibular protrusive, right lateral, and left lateral movements. Maximum bite forces had diminished in stage IIIB. Boys had larger maximum bite forces and hand-grip forces than did girls after stage IIIC. The proportion of subjects with TMD signs or symptoms increased to 60% by stage IVA.

Age Determination by Teeth↗

PubMed2003

A study of growth changes in the mandible from deciduous to permanent dentition.

This cross-sectional study investigated mandibular developmental changes in untreated normal Taiwanese from the deciduous to permanent dentition. Differences in the mean values for ramus height and body length between males and females were statistically significant after eruption of the permanent second molars. SNB angles significantly increased and gonial and L1-MP angles significantly decreased from deciduous to permanent dentition in both sexes. The SN-MP angle in females significantly decreased and ramus inclination in males significantly increased from the early mixed to permanent dentition.

Adolescent↗

PubMed2003

Variations among the primary maxillary dental arch forms using a polynominal equation model.

This study identifies arch symmetry and describes arch form variations in normal primary maxillary dental casts. Sixty-two percent of casts had asymmetrical arches, and 38% had symmetrical arches. Six types of arch form were identified according to the ratio of arch width to length. There were more long types than short types. The rounded and short types tended to have a more-symmetrical arch than did the long type.

Cephalometry↗

PubMed2002

Panoramic radiographic findings of the mandibular growth from deciduous dentition to early permanent dentition.

The outlines of mandibular rami, condyles, coronoid process, and corpus in panoramic radiographs of normal children from deciduous to early permanent dentition were traced and digitized. Nine linear and four angular measurements were measured. During the observation period, the lengths for all the linear measurements increased, however, the angles for all the angular measurements decreased. The shape of condyle and gonion significantly correlated with the growth of ramus and corpus.

Analysis of Variance↗

PubMed2002

Cephalometric characteristics of bimaxillary dentoalveolar protrusion in early mixed dentition.

The children with bimaxillary dentoalveolar protrusion in early mixed dentition were compared with the normal occlusion children. The bimaxillary dentoalveolar protrusion children had significant smaller inter-incisal angle and greater convexity, A-B plane, and ANB angles than the normal children. Maxillary and mandibular growths of the bimaxillary dentoalveolar protrusion girls were greater than those of normal girls. The direction of the mandibular growth of the bimaxillary dentoalveolar protrusion boys showed a tendency of downward and backward.

Cephalometry↗

PubMed2002

The positional changes of hyoid bone in children.

The purpose of this study was to investigate the developmental changes of the hyoid bone position in children from deciduous dentition to early permanent dentition. There was no sexual dimorphism in hyoid bone positions. The growth of the structures around the hyoid bone began to decline from late mixed dentition stage. During growth, Go-H was almost equal to C3-H and the hyoid bone was located near and above the line that connected C3 and Me.

Cephalometry↗

PubMedDate not supplied

A computerized analysis of dental arch morphology in early permanent dentition.

To determine the positions of teeth and the size and shape of the dental arches, 53 dental casts of children (29 boys and 24 girls) with their early permanent dentition and normal occlusions were examined. The coordinates of cusp tips and line angles of anterior teeth and cusp tips, contact points, and fossa of posterior teeth were digitized. Computer-generated curves were created for both arches using a polynomial model. There were 2 cusp-to-fossa relations and 4 cusp-to-marginal ridge relations for posterior segment intercuspation. Mean values of posterior arch lengths were statistically larger in boys than in girls. Mean curves of boys' dental arch forms were larger than those of girls and the ranges between the largest and smallest curves for both arches in boys were larger than those in girls. The boys' and girls' smallest curves for both arches were almost the same size.

Bicuspid↗

PubMedDate not supplied

Dental crowding in primary dentition and its relationship to arch and crown dimensions.

PURPOSE: The purpose of this study was to compare dental arch size, mesiodistal and buccolingual crown widths, and crown shapes between 2 groups of children, 1 with anterior crowding in both dental arches and another with anterior spacing in both dental arches. METHODS: Sixty-one sets (27 crowded and 34 spaced arches) of dental casts of normal occlusions were examined. RESULTS: For both lower and upper arches, crowded arches had statistically significantly smaller arch widths than did the spaced arches. The buccolingual width of the upper second primary molar of the crowded arches was statistically significantly larger than that of the spaced arches. However, there were little significant differences between crowded and spaced arches in arch length, mesiodistal crown width, and crown shape. CONCLUSIONS: It can be concluded that the factor that determines whether a primary dental arch is crowded is the absolute width of the arch.

Cephalometry↗

PubMedDate not supplied

Positional changes of the upper canine and posterior teeth, hard palate, and sinus floor from primary to permanent dentition.

This cross-sectional study investigated normal positional changes of the upper permanent canine and posterior teeth, hard palate, and sinus floor in normal Taiwanese children from the deciduous to early permanent dentition. In total, 261 panoramic radiographs were used. During the observation period, almost all structures changed their positions toward the distal and occlusal direction. The vertical positional changes of crowns of all teeth were greater than those of the root apices through all developmental stages. There were small positional changes in the mesial surfaces of the crowns of the upper buccal teeth until their roots had formed. There were continuous positional changes in the crowns and root apices of the permanent molars during tooth development and eruption. There were no significant changes in tooth inclination for any of the buccal teeth, whereas there were conspicuous changes in tooth inclination for the permanent molars. The floor of the maxillary sinus remarkably changed its position in an occlusal direction during the active eruption period of the first molar and buccal teeth.

Adolescent↗