Andrew Sandham

Orthodontic Treatment Need in Asian Adult Males

Orthodontic treatment in adults has gained social and professional acceptance in recent years. An assessment of orthodontic treatment need helps to identify individuals who will benefit from treatment and safeguard their interest. The purpose of this study was to assess the objective and subjective levels of orthodontic treatment need in a sample of orthodontically untreated adult Asian males. A sample of male army recruits (n = 339, age 17-22 years, Chinese = 258, Malay = 60, Indian = 21) with no history of orthodontic treatment or craniofacial anomalies participated in the study on a voluntary basis with informed consent. Impressions for study models were taken. Objective treatment need was assessed based on study model analysis using the Index of Orthodontic Treatment Need (IOTN). Questionnaires were used to assess subjective treatment need based on subjective esthetic component (EC) ratings. Fifty percentage of the sample had a definite need for orthodontic treatment (dental health component [DHC] grades 4 and 5), whereas 29.2% had a moderate need for treatment (DHC grades 3). The occlusal trait most commonly identified was dental crossbite. Malay males had the highest percentage with a definite need for treatment for both dental health and esthetic reasons in comparison with Chinese and Indian males. However, there was no difference in the level of treatment need among the ethnic groups (P > .05). No correlation between objective and subjective EC scores was found (P > .05). A high level of investigator-identified treatment need was not supported by a similar level of subject awareness among the adult sample.

Nasal Septal Deformity in Unilateral Cleft Lip and Palate

The present study is part of a larger rhinomanometric investigation to determine the type and extent of nasal septal deformity in subjects with repaired unilateral complete clefts of the lip and palate (UCLP). The cleft sample consisted of 21 subjects (mean age 16.4 years). A control group consisted of 30 subjects (mean age 13.1 years). The rhinomanometric measurements in this study have been previously reported (Sandham and Solow, 1987) and showed that bilateral nasal resistance did not differ significantly between the cleft sample and the controls. Unilateral measurements of nasal resistance showed higher valves for the cleft side than the noncleft side (p < .001). Nasal septal deformity was scored for anomaly type and severity, by direct visual observation of each nasal compartment. The results showed that nasal septal deviation occurs more frequently in subjects with cleft lip and palate than controls (p < .001). The cartilaginous nasal tip, like the maxillary nasal spine, deviated to the noncleft side because of its dependency for directional control on the maxillary crest, and it projected into the nasal aperture of the noncleft side. The most frequent deviation of the bony septum was to the cleft side, and this not only involved the valve area but also a broader area opposite the turbinates.

Evaluation of the linearity of soft- to hard-tissue movement after orthognathic surgery

INTRODUCTION Our aim in this study was to investigate whether a linear relationship exists between soft- to hard-tissue changes for both maxillary and mandibular landmarks over a wide range of skeletal changes. METHODS The sample consisted of 30 Chinese patients with Class III malocclusion treated with bilateral sagittal split osteotomy and LeFort I advancement. Lateral cephalograms were taken within 2 months before surgery and at least 6 months after surgery. Soft- and hard-tissue changes were recorded by computer-supported measurements of presurgical and postsurgical lateral cephalograms. To evaluate the linear association between soft- and hard-tissue movement, a quadratic function of hard-tissue movement adjusted for sex was initially fitted to the data. The residual plots were used to examine the appropriateness of the fitted quadratic function, and the lack of fit was examined by the F test. A linear function was fitted to the data when the quadratic term was not significant. RESULTS Visual inspection of the scatter plots of the 5 pairs of corresponding soft- and hard-tissue landmarks showed that relationships between the soft and hard tissues were reasonably linear for both male and female subjects, except for the Sn-ANS pair that showed a curvilinear relationship. Statistical tests confirmed that the association for the Sn-ANS pair was quadratic. CONCLUSIONS The results of this study provide evidence of a linear relationship between soft- to hard-tissue changes for mandibular landmarks over a wide range of skeletal changes. The nonlinear response of maxillary soft tissues to underlying hard-tissue change in the Sn-ANS pair supports the use of nonlinear ratios for selected maxillary soft- to hard-tissue movements in simulation software.

Porphyromonas gingivalis lipopolysaccharide inhibits the osteoblastic differentiation of preosteoblasts by activating Notch1 signaling

Although Porphyromonas gingivalis lipopolysaccharide (P‐LPS) is known to inhibit osteoblast differentiation, the exact molecular mechanisms underlying this phenomenon remain unclear. Here, we investigated the role of Notch signaling in the osteoblastic differentiation of both MC3T3E‐1 cells and primary mouse bone marrow stromal cells (BMSCs). P‐LPS stimulation activated the Notch1 signaling cascade and increased expression of the Notch target genes HES1 and HEY1. P‐LPS can also act as an inhibitor because it is capable of suppressing Wnt/β‐catenin signaling in preosteoblasts by decreasing both glycogen synthase kinase‐3β (GSK‐3β) phosphorylation and the expression of nuclear β‐catenin. These effects were rescued, however, by inhibiting Notch1 signaling. Furthermore, P‐LPS treatment inhibited osteoblast differentiation in preosteoblasts as demonstrated by reductions in alkaline phosphatase activity, osteoblast gene expression, and mineralization, all of which were rescued by suppression of Notch1 signaling. Moreover, inhibition of GSK‐3β, HES1, or HEY1 partially reversed the P‐LPS‐induced inhibition of osteoblast differentiation. Together, these findings suggest that P‐LPS inhibits osteoblast differentiation by promoting the expression of Notch target genes and suppressing canonical Wnt/β‐catenin signaling. J. Cell. Physiol. 225: 106–114, 2010.

Survival of flexible, braided, bonded stainless steel lingual retainers: a historic cohort study

The objectives of this study were to retrospectively evaluate the clinical survival rate of flexible, braided, rectangular bonded stainless steel lingual retainers, and to investigate the influence of gender, age of the patient, and operator experience on survival after orthodontic treatment at the Department of Orthodontics, University of Groningen, between the years 2002 and 2006. The study group comprised of 277 patients [162 females: median age 14.8 years, interquartile range (IQR) 13.6-16.5 years and 115 males: median age 15.3 years, IQR 14.2-16.7 years]. After acid etching the lingual surfaces of each tooth, an adhesive resin was applied and retainers were bonded using a flowable resin composite. Data concerning, failures, gender, age of the patient, and operator experience were retrieved from the patient files that were updated by chart entries every 6 months or when failure was reported by the patient. The maximum follow-up period was 41.7 months. All 277 patients received flexible, braided, bonded mandibular canine-to-canine retainers. Eighteen failures were observed in the maxilla. A failure was recorded when there was debonding, fracture, or both, occurring in one arch. Only first failures were used for statistical analysis. When failures occurred in both jaws, these were considered as two separate incidences. Ninety-nine debonding (35.7 per cent), two fractures (0.7 per cent), and four debonding and fracture (1.4 per cent) events were observed. No significant effect (P > 0.05) of gender (females: 41 per cent, males: 32 per cent) or patient age (<16 years: 37 per cent, > or =16 years 38.7 per cent) was observed. The failure rate did not differ due to operator experience (n = 15; less experienced: 38.0 per cent; moderately experienced: 28.9 per cent, professional: 46.7 per cent; P > 0.05; chi-square test). Kaplan-Meier survival curves showed a 63 per cent success rate for the bonded lingual retainers over a 41.7 month period.

Fluoride release and cariostatic potential of orthodontic adhesives with and without daily fluoride rinsing

INTRODUCTION In this study, we aimed to evaluate the fluoride-release profiles and caries lesion development in an enamel model with brackets cemented with 4 orthodontic adhesives with and without daily fluoride exposure. METHODS Four orthodontic adhesives (Ketac Cem mu, 3M ESPE, Seefeld, Germany; Fuji Ortho LC, GC Corporation, Tokyo, Japan; Light-Bond, Reliance Orthodontic Products, Itasca, Ill; and Transbond XT, 3M Unitek, Monrovia, Calif) were used. Brackets were bonded on bovine enamel with each adhesive (n = 10) and subjected to alternate cycles of demineralizing (pH 4.55) and remineralizing (pH 6.8) solutions. Unbracketed enamel samples served as a reference. Five samples from each group were immersed in a fluoride mouth rinse (250 ppm fluoride) for 1 minute each day (test groups). Fluoride release was measured at regular intervals over 28 days. The mineral distribution of peribracket enamel after 28 days was quantified by transversal microradiographs. RESULTS Fluoride-release profiles of Ketac Cem mu, Fuji Ortho LC, and Light-Bond were high for the first 24 hours and reached a constant level after 2 weeks. Fuji Ortho LC released significantly more fluoride than did the other adhesives in both the control and test groups (P <0.01, repeated measures ANOVA and Bonferroni test). Enamel bonded with Fuji Ortho LC had significantly shallower lesions and less mineral loss (P <0.01, 2-way ANOVA, and Tukey HSD). CONCLUSIONS Bonding of orthodontic brackets with Fuji Ortho LC resulted in less peribracket enamel demineralization with and without daily fluoride rinsing, mainly due to its better fluoride-release profile. In contrast, Transbond XT and Light-Bond offered few cariostatic effects to the enamel.

Occlusal status in Asian male adults: Prevalence and ethnic variation

The purpose of this study was to determine the occlusal status in young Asian male adults of three ethnic groups. Study models of a sample of male army recruits (N = 339, age 17-22 years) with no history of orthodontic treatment were assessed. The ethnic proportions of the sample were Chinese 76.1% (n = 258), Malay 17.7% (n = 60), and Indian 6.2% (n = 21). British Standard Institute (BSI) and Angles classification were used to determine incisor and molar relationships, respectively. Chi-square test or Fishers Exact test was performed to compare the occlusal traits between ethnic groups. The distribution of incisor relationships of the total sample consisted of Class I = 48.1%, Class II/1 = 26.3%, Class II/2 = 3.2%, and Class III = 22.4%. Right Angles molar relationships were 49.9%, 24.5%, and 24.2% whereas left Angles molar relationships were 53.1%, 25.1%, and 21.2% for Class I, II, and III, respectively. Comparison between ethnic groups found that Indian subjects were more likely to have Class II/1 malocclusions and clinically missing permanent teeth (P < .05). The study found that the overall prevalence of malocclusion (BSI) was Class I, Class II/1, Class III, and Class II/2 in descending order of proportions. Angles Class I molar was most prevalent followed by Class II and Class III relations. A significant difference in occlusal status between the ethnic groups was found regarding incisor relationship and missing permanent teeth (P < .05).

Outcome of orthognathic surgery in Chinese patients

Abstract Objective: To evaluate the outcome of orthognathic surgery by objective cephalometric measurement of posttreatment soft-tissue profile and by subjective evaluation of profile esthetics by laypersons and clinicians. Materials and Methods: The sample consisted of 30 Chinese patients who had completed combined orthodontic and orthognathic surgical treatment. The posttreatment cephalograms of these patients were analyzed with respect to profile convexity, facial height, and lip contours and these were compared to the previously established esthetic norms. Line drawings of the soft-tissue profile were displayed to a panel comprising six laypersons and six clinicians who scored the esthetics of each profile using a 7-point scale. Results: Complete normalization of cephalometric soft-tissue variables was not achieved with orthognathic surgery in most patients, with four of the six soft-tissue cephalometric measurements showing significant differences compared to the esthetic norms. There were good corre...

Cranial Base and Cleft Lip and Palate

Previous studies do not agree on relationships between cleft palate and the cranial base. This study comparing normal and cleft lip-and-palate samples finds no significant difference in cranial base angle, but significantly shorter clivus length in the cleft sample.

Mechanical tensile stress effects on the expression of bone sialoprotein in bovine cementoblasts

OBJECTIVE To develop a new cementoblast culture method and to detect bone sialoprotein (BSP) expression in response to high and low mechanical tensile stress in cementoblast in vitro. MATERIALS AND METHODS Cementoblasts were collected from the roots of newborn bovine teeth and were identified with cementum-derived attachment protein (CAP) antibody 3G9. Cell proliferation was evaluated by MTT [3-(4,5-dimethylthazol-2-yl)-2,5-diphenyl tetrazolium bromide] assay, and mineralization was confirmed by von Kossa staining. Mechanical tensile stress was applied in vitro to the cementoblast with the use of a uniaxial four-point bending system with 2000 or 4000 microstrains, at a frequency of 0.5 Hz for 3, 6, 12, 24, or 36 hours. BSP mRNA level was quantified by real-time quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR). RESULTS A large amount of cementoblast was observed to be expressing CAP. Cementoblasts had a proliferation tendency similar to that of osteoblasts but different from that of periodontal ligament (PDL) cells. Cementoblasts had the ability to become mineralized between osteoblasts and PDL cells. The mechanical tensile stress significantly up-regulated BSP mRNA expression, which reached a peak at 24 hours in both 2000 and 4000 microstrain groups (P < .01) and was tenfold and sixfold higher than that of controls, respectively. BSP expression dropped toward baseline levels at 36 hours in both groups. CONCLUSIONS Mechanical tensile stress up-regulated the expression of BSP. Low mechanical tensile stress induced earlier and more intensive up-regulation of BSP mRNA; this might represent the optimal stimuli for cementoblast activity.