Papers by Kanoknart Chintakanon
Quaternary science reviews, Apr 1, 2024
Biomedical Imaging and Intervention Journal, 2009
This paper presented 3D cephalometric analysis on DICOM data from I-CAT CT cone-beam machine cons... more This paper presented 3D cephalometric analysis on DICOM data from I-CAT CT cone-beam machine consisted of averages and standard deviations from 20 Thai males from 19 to 70 year (average 33.53 ± 14.08 year) and 20 Thai females from 16 to 70 year (average 32.60 ± 15.37 year). The angular measurements consisted of 49 lateral angular measurements and 9 frontal angular measurements while linear measurements consisted of 29 lateral linear measurements, 3 frontal linear measurements, and 8 perpendicular measurements. Results in 3D were compared with the corresponding 2D results showing that most midline-to-midline linear measurements and some midline-to-midline angular measurements were not different, while other types of measurements were significantly different. The 3D results will be used in the clinical Ceph3D services as requested by those with interests on cephalometric analysis and anthropology with focus on Thai subjects while the 2D results will be used for comparison with cephalometric analyses from other orthodontists.
International Journal of Molecular Sciences, Feb 21, 2023
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
Diagnostics
Background: Supernumerary teeth refer to extra teeth that exceed the usual number of dentitions. ... more Background: Supernumerary teeth refer to extra teeth that exceed the usual number of dentitions. A mesiodens is a particular form of supernumerary tooth, which is located in the premaxilla region. The objective of the study was to investigate the genetic etiology of extra tooth phenotypes, including mesiodens and isolated supernumerary teeth. Methods: Oral and radiographic examinations and whole-exome sequencing were performed on every patient in our cohort of 122 patients, including 27 patients with isolated supernumerary teeth and 94 patients with mesiodens. A patient who had multiple supernumerary teeth also had odontomas. Results: We identified a novel (c.8498A>G; p.Asn2833Ser) and six recurrent (c.1603C>T; p.Arg535Cys, c.5852G>A; p.Arg1951His, c.6949A>T; p.Thr2317Ser; c.1549G>A; p.Val517Met, c.1921A>G; p.Thr641Ala, and c.850G>C; p.Val284Leu) heterozygous missense variants in FREM2 in eight patients with extra tooth phenotypes. Conclusions: Biallelic variant...
Archives of Oral Biology, 2000
With this new method, protrusive mandibular force was studied in a homogeneous group of 69 childr... more With this new method, protrusive mandibular force was studied in a homogeneous group of 69 children with similar occlusions. Maximum protrusive force ranged from 18.5 to 160 N (mean +/- SD = 81.3+/-31.6 N). Maximum protrusive force was significantly higher in males (90.7+/-30.2 N) than females (66.6+/-28.6 N) while fatigue time was not significantly different between the two groups (70.6+/-38.5 s for males and 65.1+/-33.6 s for females). Although protrusive force was stable in each session, it varied considerably between different experimental days within the same individual. No statistically significant correlation was found between maximum protrusive force and age, skeletal maturity, height, weight, overjet, maxillomandibular relation, facial height, facial widths or facial proportions.
Ultrastructural changes in the microvascular bed of the periodontal ligament (PDL) incident to th... more Ultrastructural changes in the microvascular bed of the periodontal ligament (PDL) incident to the applied forces have rarely been reported. Clark (1986) and Lew (1986) demonstrated changes in the fenestrae populations and Cooper (1988) established there was an increase of tissue channels when a tensile load was applied to the PDL. However, there are no published data on the effects on the endothelial junctions or their dimensions where there is an applied loading to the PDL. The purpose of this investigation was to morphologically study and quantitatively compare the dimensions of endothelial junctions in the microvascular bed of the normal PDL with those of the tensioned PDL. The rat maxillary molar specimen blocks were from Cooper's study (1988). Twelve week old male Porton rats were used as the experimental animal model. A 1.0 N. extrusive load was applied continuously, for a period of 30 minutes, to the right first molar. The contralateral left first molar served as the exp...
Scientific Reports
The late Pleistocene settlement of highland settings in mainland Southeast Asia by Homo sapiens h... more The late Pleistocene settlement of highland settings in mainland Southeast Asia by Homo sapiens has challenged our species’s ability to occupy mountainous landscapes that acted as physical barriers to the expansion into lower-latitude Sunda islands during sea-level lowstands. Tham Lod Rockshelter in highland Pang Mapha (northwestern Thailand), dated between 34,000 and 12,000 years ago, has yielded evidence of Hoabinhian lithic assemblages and natural resource use by hunter-gatherer societies. To understand the process of early settlements of highland areas, we measured stable carbon and oxygen isotope compositions of Tham Lod human and faunal tooth enamel. Our assessment of the stable carbon isotope results suggests long-term opportunistic behavior among hunter-gatherers in foraging on a variety of food items in a mosaic environment and/or inhabiting an open forest edge during the terminal Pleistocene. This study reinforces the higher-latitude and -altitude extension of a forest-gra...
Forty children displaying Class II Division 1 malocclusion were involved in a prospective magneti... more Forty children displaying Class II Division 1 malocclusion were involved in a prospective magnetic resonance image investigation to evaluate the effects of Twin-block functional appliances on the temporomandibular joints. None of these children had clinical signs or symptoms of temporomandibular disorders. Nineteen children were treated with a Clark Twin-block appliance for 6 months; the other 21 children received no treatment and served as controls. Comparison between control and Clark Twin-block groups suggested that reduction of the condylar axial angle represents a feature of untreated Class II growth patterns, whereas axial angle stability with Clark Twin-block therapy may suggest alteration of condylar growth direction. Condyles that were positioned at the crest of the articular eminence by the Clark Twin-block at the beginning of treatment had reseated back into the glenoid fossa after 6 months. However, 75% of the condyles were more anteriorly positioned in successfully treated Clark Twin-block cases. There was no clear evidence of remodeling of the glenoid fossa at the eminence as a result of Clark Twin-block treatment. The initial prevalence of disk displacements for the combined groups was 7.5% anterior, 5% medial, and 12.5% for lateral disk displacement. Clark Twin-block therapy had neither positive nor negative effects on disk position, and there was no convincing evidence that the disk was recaptured.
Cephalometric radiography is an important diagnostic tool in orthodontics and craniomaxillofacial... more Cephalometric radiography is an important diagnostic tool in orthodontics and craniomaxillofacial surgery. Conventionally, cephalometric variables are measured using two-dimensional cephalometric analysis on either lateral or frontal analysis, which could lead to erroneous results in skull measurements due to inherent shortcomings of 2D cephalometric analysis which could not take the combined result of lateral and frontal measurement into account. This paper presented the three-dimensional cephalometric analysis on DICOM data from I-CAT CT cone-beam machine. The averaged values and standard deviations of 44 cephalometric angularand 30 cephalometric linear-measurements were determined from CT radiographs of 200 Thai non-severe patients, which 100 men and 100 women. DICOM data from the CT had been transformed into 3D data using Simplant Master and performed 3D cephalometric Analysis using Simplant CMF from Materialise. The result of cephalometric analysis in 3D has been compared with ...
PROTEOMICS
The first dental proteomic profile of Iron Age individuals (ca. 2000-1000 years B.P.), collected ... more The first dental proteomic profile of Iron Age individuals (ca. 2000-1000 years B.P.), collected from the site of Long Long Rak rock shelter in northwest Thailand is described. A bias toward the preservation of the positively charged aromatic, and polar amino acids is observed. It is evident that the 212 proteins identified (2 peptide, FDR <1%) comprise a palimpsest of alterations that occurred both ante-mortem and post-mortem. Conservation of amino acids within the taphonomically resistant crystalline matrix enabled the identification of both X and Y chromosome linked amelogenin peptides. A novel multiple reaction monitoring method using the sex specific amelogenin protein isoforms is described and indicate the teeth are of male origin. Functional analysis shows an enrichment of pathways associated with metabolic disorders and shows a capacity for harboring these conditions prior to death. Stable isotope analysis using carbon isotopes highlights the strongly C 3 based (80%) diet of the Long Long Rak cemetery people, which probably comprised rice combined with protein from freshwater fish among other food items. The combination of proteomics and stable isotope analysis provides a complementary strategy for assessing the demography, diet, lifestyle, and possible diseases experienced by ancient populations.
Antiquity, 2017
Creating a facial appearance for individuals from the distant past is often highly problematic, e... more Creating a facial appearance for individuals from the distant past is often highly problematic, even when verified methods are used. This is especially so in the case of non-European individuals, as the reference populations used to estimate the face tend to be heavily biased towards the average facial variation of recent people of European descent. To evaluate the problem, a facial approximation of a young woman from the Late Pleistocene rockshelter of Tham Lod in northwestern Thailand was compared against the average facial variation of datasets from recent populations. The analysis indicated that the Tham Lod facial approximation was neither overtly recent in facial morphology, nor overtly European. The case is of particular interest as the Tham Lod individual probably belonged to a population ancestral to extant Australo-Melanesian peoples.
The Angle Orthodontist, Jul 15, 1998
The purpose of this research was to study the prevalence of ectopic eruption of the first permane... more The purpose of this research was to study the prevalence of ectopic eruption of the first permanent molars and possible etiologic factors. A group of 4,232 Thai students, from 6 to 9 years old, was examined. The prevalence of ectopic eruption of the first permanent molars in the subjects was 0.75%. Both the severity of the ectopic eruption and the amount of root resorption on the second primary molars were more pronounced in the maxilla than in the mandible. The important etiologic factors were the eruption path of the first permanent molars relative to reference lines and the size of the mandibular second primary molars. The amount of proximal caries did not seem to affect the prevalence of ectopic eruption.
Forty children displaying Class II Division 1 malocclusion were involved in a prospective magneti... more Forty children displaying Class II Division 1 malocclusion were involved in a prospective magnetic resonance image investigation to evaluate the effects of Twin-block functional appliances on the temporomandibular joints. None of these children had clinical signs or symptoms of temporomandibular disorders. Nineteen children were treated with a Clark Twin-block appliance for 6 months; the other 21 children received no treatment and served as controls. Comparison between control and Clark Twin-block groups suggested that reduction of the condylar axial angle represents a feature of untreated Class II growth patterns, whereas axial angle stability with Clark Twin-block therapy may suggest alteration of condylar growth direction. Condyles that were positioned at the crest of the articular eminence by the Clark Twin-block at the beginning of treatment had reseated back into the glenoid fossa after 6 months. However, 75% of the condyles were more anteriorly positioned in successfully treated Clark Twin-block cases. There was no clear evidence of remodeling of the glenoid fossa at the eminence as a result of Clark Twin-block treatment. The initial prevalence of disk displacements for the combined groups was 7.5% anterior, 5% medial, and 12.5% for lateral disk displacement. Clark Twin-block therapy had neither positive nor negative effects on disk position, and there was no convincing evidence that the disk was recaptured.
IFMBE Proceedings, 2008
This paper presented 3D cephalometric analysis on DICOM data from I-CAT CT cone-beam machine cons... more This paper presented 3D cephalometric analysis on DICOM data from I-CAT CT cone-beam machine consisted of averages and standard deviations from 20 Thai males from 19 to 70 year (average 33.53 ± 14.08 year) and 20 Thai females from 16 to 70 year (average 32.60 ± 15.37 year). The angular measurements consisted of 49 lateral and 9 frontal measurements while linear measurements consisted of 29 lateral, 3 frontal, and 8 perpendicular measurements. Results in 3D were compared with the corresponding 2D results showing that most midline-to-midline linear measurements and some midline-to-midline angular measurements were not different, while other types of measurements were significantly different. The 3D results will be used in the clinical Ceph3D services as requested by those with interests on cephalometric analysis and anthropology with focus on Thai subjects while the 2D results will be used for comparison with cephalometric analyses from other orthodontists.
American Journal of Orthodontics and Dentofacial Orthopedics, 2000
M any studies on functional appliance effects have explored the role of the mandibular protrusive... more M any studies on functional appliance effects have explored the role of the mandibular protrusive musculature in promoting growth of the condylar cartilage and subsequent lengthening of the mandible, with emphasis on the lateral pterygoid muscle. 1-3 However, the lateral pterygoid muscle is difficult to access beneath the overlying structures. It is not possible to directly palpate the lateral pterygoid muscle clinically, 4 and any attempt to do so poses the possibility of confusion with the sensitivity of other muscles such as medial pterygoid or temporalis muscles. 5,6 Moreover, the study of lateral pterygoid function using an electromyogram is generally invasive and may lead to discomfort, muscle soreness, or jaw stiffness, and occasionally to hematoma or infection. 7 The objectives of the present study were to investigate the function of protrusive muscles using a new, noninvasive approach, and to test whether these muscles were responsible for mandibular repositioning after treatment with the Clark Twin-block (CTB) functional appliance. 392 SUBJECTS AND METHODS From the University of Adelaide. a Graduate Student, Dental School.
American Journal of Orthodontics and Dentofacial Orthopedics, 2000
Forty children displaying Class II Division 1 malocclusion were involved in a prospective magneti... more Forty children displaying Class II Division 1 malocclusion were involved in a prospective magnetic resonance image investigation to evaluate the effects of Twin-block functional appliances on the temporomandibular joints. None of these children had clinical signs or symptoms of temporomandibular disorders. Nineteen children were treated with a Clark Twin-block appliance for 6 months; the other 21 children received no treatment and served as controls. Comparison between control and Clark Twin-block groups suggested that reduction of the condylar axial angle represents a feature of untreated Class II growth patterns, whereas axial angle stability with Clark Twin-block therapy may suggest alteration of condylar growth direction. Condyles that were positioned at the crest of the articular eminence by the Clark Twin-block at the beginning of treatment had reseated back into the glenoid fossa after 6 months. However, 75% of the condyles were more anteriorly positioned in successfully treated Clark Twin-block cases. There was no clear evidence of remodeling of the glenoid fossa at the eminence as a result of Clark Twin-block treatment. The initial prevalence of disk displacements for the combined groups was 7.5% anterior, 5% medial, and 12.5% for lateral disk displacement. Clark Twin-block therapy had neither positive nor negative effects on disk position, and there was no convincing evidence that the disk was recaptured.
Australian Dental Journal, 1994
The TEM was used to categorize vessels and their junctions in normal and tensioned rat maxillary ... more The TEM was used to categorize vessels and their junctions in normal and tensioned rat maxillary molar periodontal ligament. In tensioned periodontal ligament mean luminal diameters of capillaries were significantly smaller (p < 0.001). Goniometer tilting of sections with apparent tight regions revealed that only 16 per cent were actual tight junctions. The other regions proved to be close junctions (85 per cent) and open junctions (4 per cent). No gap junctions were found. These findings establish that morphologically the periodontal ligament contains a microvascular bed of 'leaky' endothelium with a potentially high permeability factor.
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Papers by Kanoknart Chintakanon