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Biomedical subjects

J Chaiwat

Publications and source records attributed to J Chaiwat.

4 recordsLinked to original sources
PubMedDate not supplied

[Bite jumping appliance with lower lip bumper].

The removable bite jumping appliance with lower lip bumper is a new orthodontic appliance designed to correct the abnormal habit of lower lip biting children with mentalis muscle hyperactivity. Upper anterior teeth protrusion, mandible retrusion, lower anterior teeth lingual collapse and anterior deep bite usually are found in association with this lower lip biting habit, especially in the mixed dentition period (7-12 yrs). The function of this appliance is similar to the partial functional appliance. It is made into two parts: upper removable plate with anterior inclined bite plane and lower lip bumper attached to the upper plate. Three cases are discussed and compared before and after treatment. Changes in both skeletal and dental pattern were recorded in the following aspects: increase in the posterior rotation of mandible (increased SN-MP), stimulation of forward growth of the mandible (the increase is SNB value overcomes the increase in SNA, through reduction ANB), retroclination of upper maxillary teeth (reduced 1-NA), proclination of lower anterior teeth (increased 1-NB), the reduction of overjet. Additionally, the normal position of the lower lip provided by this appliance effectively corrects the lip biting with mentalis muscle hyperactivity.

Activator Appliances↗
PubMedDate not supplied

Accuracy of Moyers' probability chart in a group of Thai subjects.

The objective of this study is to investigate the accuracy of Moyers' probability chart in predicting canine and premolar sizes from the sum of lower incisors in a group of Thai subjects. The fifty models of orthodontic patient, Faculty of dentistry, Mahidol University with no loss of tooth material mesio-distally, fully erupted permanent teeth, no mesial or distal restoration and normal tooth morphology were selected. The results of this study show that the under-estimation less than or equal to 2 mm. is 32 casts on upper (64%) and 28 casts on lower (56%) and the over estimation greater than 2 mm. is 16 casts on upper (32%) and 18 casts on lower (36%). In comparison of 14 models which have the same value of sum of lower incisors, there is a significant (alpha = 0.05) difference between the combined canine and premolar size of this study and Moyers' probability chart.

Humans↗
PubMedDate not supplied

[Congenital absence and loss of teeth in an orthodontic patient group].

Panoramic radiographs of 1,160 orthodontic patients, 655 females and 505 males, 6-15 years of age were selected for study in congenital absence, loss of permanent teeth and premature loss of deciduous teeth. The result from this investigation showed congenital absence for 100 subjects (8.6%, not including third molars) and 185 subjects (16%, third molars included). The permanent upper lateral incisors are most frequently missing (22.4%, third molars excluded), followed by upper second premolar, 17.8%, lower second premolar, 15.1%, and then lower lateral incisor, 12.5%. The study also showed loss of permanent teeth of 105 subjects (9.1%). The lower first molars are most frequently lost (52.8%), followed by the upper first molar (18.2%). There is no statistical significance (alpha = 0.01) between females and males in both congenital absence and loss of permanent teeth. The premature loss of deciduous teeth was found in 467 subjects (40.3%). The most frequently loss happened to second deciduous molars, followed by first deciduous molars and then deciduous canines. There is more statistical significance (alpha = 0.01) in females than in males.

Adolescent↗