Methods: Retrospective analysis of 100 CBCT scans (n = 200) was performed on both sides of the mandible. Cross-sectional and panoramic images were reconstructed. The length of the MIC and the horizontal distances between the MIC and the buccal and the lingual cortical plates were measured at the three different points (starting, mid-, end points). Independent samples t-test and one-way ANOVA test were used to analyse the variation in the length and course of the MIC in gender, age, dental status and Malaysian races.
Results: The mean length of the MIC was 11.31 ± 2.65 mm, with the Malays having the longest MIC, followed by the Chinese and the Indians (p
OBJECTIVE: To evaluate and compare the treatment effect of Reverse Twin-Block (RTB) and Reverse Pull Face Mask (RPFM) on Pharyngeal Airway Space (PAS) in early and late mixed dentition Class III samples.
METHODS: Ninety-five mixed dentition Malay children with Class III malocclusion were included in this study. Data consists of 190 pre- and post-treatment lateral cephalograms of early (8-9 years) and late (10-11 years) mixed dentition Class III samples. forty-nine samples were under RTB and forty-six samples were under RPFM. Treatment changes were evaluated by McNamara airway analysis and changes in tongue and hyoid bone position.
RESULTS: Both upper and lower pharyngeal airway width were increased after treatment with RTB and RPFM ruling out the chance of airway constriction. There was also posterior positioning of the tongue and hyoid bone indicating mandibular retrusion. No significant treatment changes were found on the Pharyngeal Airway Space by the factor age, gender or type of appliance.
CONCLUSIONS: Both RTB and RPFM increased the Pharyngeal Airway Space and produced similar treatment effect. As age does not affect the treatment outcome significantly, treatment can be delayed until late mixed dentition stage.
METHODS: This is a retrospective non-randomized study of outcomes and tumor recurrence of all patients diagnosed with mandibular ameloblastoma from August 1997 until August 2017 (20 years) requiring free fibula osteocutaneous flap reconstruction at a single institution. The patients were identified through an electronic operative database; subsequently, their medical records and photo documentation were retrieved.
RESULTS: Twenty-seven patients were included in this study. Eighteen patients were male, while nine were female. The majority of the patients (48.1%) were in their third decade of life when they were diagnosed with ameloblastoma. All of them underwent radical resection of the tumor with a surgical margin of 2 cm (hemimandibulectomy in cases with a large tumor) and immediate mandibular reconstruction with a free fibula osteocutaneous flap. Two patients required revision of a vascular anastomosis due to venous thrombosis postoperatively, while one patient developed a flap recipient site infection. The flap success rate was 100%. There was no tumor recurrence during a mean follow-up period of 5.6 years.
CONCLUSIONS: Mandibular ameloblastoma should be treated with segmental mandibulectomy (with a surgical margin of 2 cm) to reduce the risk of recurrence. Subsequent mandibular and adjacent soft tissue defects should be reconstructed immediately with a free fibula osteocutaneous flap.
MATERIALS AND METHODS: The test group included 9 participants rehabilitated by maxillary CD opposing mandibular IRO, while the control group consisted of 4 participants with CDs. Blood flow was measured by laser Doppler flowmetry (LDF) after denture removal for 0, 30, 60, and 90 minutes. RRR was quantified as reduction in bone volume a year post-treatment. The measurement of blood flow was then compared to the quantification of RRR.
RESULTS: The mean blood flow measure for the IRO group was significantly lower than CD after immediate denture removal and 30 minutes later. After 60 minutes, the mean difference was not significant between groups, and at 90 minutes, the mean blood flow of both groups equalized to reach a steady state of 377 BPU. The mandibular IRO had reduced the initial blood flow measure in the opposing anterior maxilla mucosa to almost a quarter (103 BPU) of the steady state value (377 BPU) compared to the CD, which reduced it to only about one half (183 BPU), suggesting greater blood flow disturbance in the IRO group. This result is in tandem with the greater reduction of bone volume observed in the IRO group, which was 7.3 ± 1.3% after a year, almost three times higher than CD group at 2.6 ± 1.7%.
CONCLUSION: IRO may cause significantly higher blood flow disturbance than CD and may have contributed to greater RRR in the anterior maxilla.
METHODS: A retrospective analysis has been performed on patients with dento-skeletal class III deformity who had undergone orthognathic 2-jaw surgery with segmentations, presenting both pre- and post-surgical cone-beam computed tomographys. Three-dimensional skeletal movements, pharyngeal airway changes and hyoid bone position were measured and correlated.
RESULTS: The mean short term postsurgical review period for all included 47 patients was 5.8 ± 2.2 months. Thirteen patients among them provided a mean long term period of 26.4 ± 3.4 months. The mean postsurgical maxillary movement was 2.29 ± 2.49 mm in vertical, 2.02 ± 3.45 mm in horizontal direction, respectively, while the mandibular movement was 6.49 ± 4.58 mm in vertical, and -5.85 ± 6.13 mm in horizontal direction. In short-term, the vertical length of nasopharynx was found to be reduced (P = 0.005) but increased for the oropharynx (P 0.05) detected between patients with and without genioplasty advancement.
CONCLUSION: Two-jaw orthognathic surgery in dento-skeletal class III patients led to a statistically non-significant reduction of the post-surgical airway volume in both short- and long-term. Although the post-surgical oropharyneal minimum cross-sectional area was decreased significantly in the short term, this finding did not persist in the long term.
Material and Methods: A total of 5 ml of unstimulated saliva was collected from each subject (10 non-orthodontic patients and 15 post-orthodontic patients with 6-months retention phase). Samples were then subjected to LC-MS analysis. The expressed proteins were identified and compared between groups. Incisor irregularity for both maxilla and mandible were determined with Little's Irregularity Index at 6-months retention phase.
Results: 146 proteins and 135 proteins were expressed in control and 6-months retention phase group respectively. 15 proteins were identified to be co-expressed between groups. Immune system process was only detected in 6-months retention phase group. Detected protein in immune system process was identified as Tyrosine-protein kinase Tec. Statistical significant of incisor irregularity was only found in mandible at 6-months retention phase.
Conclusions: Our study suggests that immune system process protein which is Tyrosine-protein kinase Tec could be used as biomarker for prediction of stability during retention phase of post-orthodontic treatment. Key words:Orthodontics, proteomics, retention, LC-MS, saliva.
MATERIALS AND METHODS: 18 patients were rehabilitated with maxillary CD opposing mandibular IRO, and 4 patients were prescribed with conventional CD. Cone beam computed tomography (CBCT) scans of the maxilla were acquired before and 1 year post-treatment and converted into 3D models using Mimics research software. RRR was quantified by measuring the changes in bone volume following superimpositioning and sectioning of these models at the anterior maxillary region. Subsequently, the sectioned 3D models of the anterior maxilla were exported to 3-Matic software to reveal the predominant region and depth of RRR.
RESULTS: The mean reduction in bone volume of the anterior maxilla in the CD group was 2.60% (SD = 1.71%, range = -4.89 % to -0.92%, median = -2.30%), while the mean reduction in the IRO group was almost three times higher at 7.25% (SD = 3.16%, range = -13.25 to -1.50, median = -7.15%). The predominant areas of RRR were on the buccal and occlusal ridge of the anterior maxilla.
CONCLUSION: Within the limits of this study, it may be concluded that an IRO caused significantly higher RRR of the anterior maxilla than a CD.
METHODS: Relations between skeletal movement, hyoid bone position and three-dimensional pharyngeal airway changes were retrospectively analyzed on pre- and post-surgical CBCTs in dento-skeletal class II patients who underwent orthognathic two-jaw surgery with segmentation.
RESULTS: While long-term significant reductions in length (P= 0.003), surface area (P= 0.042) and volume (P= 0.004) were found in the nasopharynx, the highly significant increases in oropharyngeal airway length, surface area, volume and the minimal cross-sectional area (P
AIM: The aim of the present study was to determine sex of human mandible from morphology, morphometric measurements as well as discriminant function analysis from the CT scan.
MATERIALS AND METHODS: The present retrospective study comprised 79 subjects (48 males, 31 females), with age group between 18 and 74 years, and were obtained from the post mortem computed tomography data in the Hospital Kuala Lumpur. The parameters were divided into three morphologic and nine morphometric parameters, which were measured by using Osirix MD Software 3D Volume Rendering.
RESULTS: The Chi-square test showed that men were significantly association with square-shaped chin (92%), prominent muscle marking (85%) and everted gonial glare, whereas women had pointed chin (84%), less prominent muscle marking (90%) and inverted gonial glare (80%). All parameter measurements showed significantly greater values in males than in females by independent t-test (p< 0.01). By discriminant analysis, the classification accuracy was 78.5%, the sensitivity was 79.2% and the specificity was 77.4%. The discriminant function equation was formulated based on bigonial breath and condylar height, which were the best predictors.
CONCLUSION: In conclusion, the mandible could be distinguished according to the sex. The results of the study can be used for identification of damaged and/or unknown mandible in the Malaysian population.
Materials and Methods: CBCT images which show MFPMs recorded in HUSM Dental Clinic between January 2015 and June 2016 was obtained and analyzed for their number of roots and canals. A total of 208 CBCT images of MFPMs were collected; 118 patients had unilateral molars and 90 patients had bilateral molars. The following observations were made: (1) root number; (2) number of canals per root; and (3) comparisons of number of roots and canals according to gender, ethnicity, and position.
Results: The majority of cases of bilateral MFPM had the same number of roots (95.6%, 95% confidence interval [CI]: 89.01%, 98.78%) on both the right and left side and only 4 cases (4.4%, 95% CI: 1.22%, 10.99%) had 3 roots on the right and 2 roots on the left sides. The majority of cases had the same number of canals on both sides (66.7%, 95% CI: 55.95, 76.26%) and 33.3% (95% CI: 23.74%, 44.05%) with unequal number of canals. The occurrence of the number of canals was not independent of the sides of the arch (P < 0.001) and there was statistically significantly greater proportion of cases who had greater number of canals on the right side than the left (P = 0.03). The prevalence of right single-rooted MFPM was very small at 0.3% (n = 1) in a Malay male (95% CI: 0.00, 1.83) and the most prevalent was two roots first molar (88.4%). The number of roots was not associated with sex or ethnic group (P > 0.05). The MFPM with a single root was found to have only one mesial canal. For two rooted MFPM, the most prevalent occurrence was two canals at the mesial and one canal at the distal roots (59%); followed by single canals in each mesial and distal (21%) and double canals per root (18%). Three roots MFPM have either single or double canals in the mesial root and double canals in the distal root.
Conclusions: The majority of population in the East Coast region of Malaysia has two roots and three root canals in their MFPMs. There was no difference in the number of roots between gender and ethnic and canals between ethnic.
Materials and Methods: This cross-sectional study was conducted among the GDPs of Karachi. A questionnaire was designed to collect data from 100 GDPs. The questionnaire included general/demographic information (practitioner's education, experience, and place of practice) and an average number of fixed prosthesis constructed by the GDP. The questionnaire was further categorized to evaluate the knowledge/practice of pontic design selection and latest recommendations.
Results: For the maxillary anterior segment, the ridge lap pontic was the most common (32%) followed by the modified ridge lap (28%). In the maxillary posterior segment, the ridge lap pontic was the most common (37%) followed by sanitary design (34%). For the mandibular anterior segment, the modified ridge lap (50%) was the most common followed by ridge lap pontic (17%). In case of the mandibular posterior segment, the sanitary design (34%) was the most common followed by ridge lap pontic (30%).
Conclusions: The pontic design selection for the fixed prosthesis is a neglected domain. The contemporary guidelines are not followed with full spirit by the GDPs leading to wide variations in the pontic design selection.
PURPOSE: The purpose of this observational study was to measure the prevalence of the presence of the anterior loop and to estimate sex and ethnicity-related variations in anterior loop length in the Malaysian population.
MATERIAL AND METHODS: A total of 100 cone beam computed tomography (CBCT) Digital Imaging and Communications in Medicine (DICOM) files were selected from a pool of 810 ongoing or completed patients in 3 different ethnic groups: Malay (33), Indian (33), and Chinese (34). The DICOM data were imported into commercial software. The IAN was traced with software along with the anterior loop and part of the incisive nerve. The vertical length of the nerve was estimated from the canal to the opening of the mental foramen from the cross-sectional view and translated to the panoramic view. Measurement was made from this point to the most anterior point of the anterior loop by following the trajectory of the nerve and was repeated on the opposite side. A 2-way mixed analysis of variance (ANOVA) test was carried out to evaluate the sex- and ethnicity-related variations (α=.05).
RESULTS: The anterior loop was present in 94% of the 100 participants. Overall anterior loop length (AnLL) ranged between 0.73 and 7.99 mm with a mean length of 3.69 ±1.75 mm on the left side and 3.85 ±1.73 mm on the right side. Among all participants, no statistically significant differences were found between the left and right sides of the mandible (P=.379). Overall, no significant main effect of ethnicity (P=.869) or sex (P=.576) was found on AnLL measurements. Also, with multiple comparisons, no significant effect was found between each pair of ethnic groups. Men in all 3 ethnic groups had greater AnLL than women.
CONCLUSIONS: The anterior loop was present in 94% of the 100 participants among the 3 major ethnic groups of Malaysia. Overall AnLL ranged between 0.73 and 7.99 mm and mean lengths of 3.69 ±1.75 mm on the left side and 3.85 ±1.73 mm on the right side, with no significant ethnicity- or sex-related variations.
METHODS: Forty direct impressions of a mandibular reference model fitted with six dental implants and multibase abutments were made using VPES and PE, and implant casts were poured (N = 20). The VPES and PE groups were split into four subgroups of five each, based on splinting type: (a) no splinting; (b) bite registration polyether; (c) bite registration addition silicone; and (d) autopolymerizing acrylic resin. The accuracy of implant-abutment replica positions was calculated on the experimental casts, in terms of interimplant distances in the x, y, and z-axes, using a coordinate measuring machine; values were compared with those measured on the reference model. Data were analyzed using non-parametrical Kruskal-Wallis and Mann-Whitney tests at α = .05.
RESULTS: The differences between the two impression materials, VPES and PE, regardless of splinting type, were not statistically significant (P>.05). Non-splinting and splinting groups were also not significantly different for both PE and VPES (P>.05).
CONCLUSIONS: The accuracy of VPES impression material seemed comparable with PE for multi-implant abutment-level impressions. Splinting had no effect on the accuracy of implant impressions.