Department of Orthodontics

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https://hdl.handle.net/10566/406

The discipline of Orthodontics focuses on the growth and development of the craniofacial complex and dental occlusion, and the treatment of abnormalities related to these structures.

The Department of Paediatric Dentistry conducts an undergraduate and a postgraduate programme to enable students to manage the child dental patient. The postgraduate programmes consist of a postgraduate diploma in dentistry part-time and a masters programme full time.

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The accuracy of non-radiographic mixed dentition predictive methods used for the diagnosis of space discrepancies in orthodontic patients in the mixed dentition phase in Africa: A systematic review of diagnostic test accuracy
(University of Western Cape, 2021) Brijlall, Sarika; Harris, Angela
Orthodontic space analysis is a critical component into informing diagnosis and leading to targeted interceptive treatment planning in the mixed dentition stage of tooth development. Accurate and reliable space analysis methods - radiographic and non-radiographic - are beneficial for the early detection of imbalances between the mesiodistal diameter of unerupted permanent teeth and its alveolar bone support, which can contribute significantly in preventing severe malocclusions. Due to the ease and simplicity in its application, the non-radiographic mixed dentition space analysis methods; Moyers, and Tanaka and Johnston; were widely recommended. However, due to these space analysis methods derived from data of a Caucasian European population in the early 1970s, the external validation question, with dubious applicability of these methods in other populations, has been questioned. This has prompted researchers to seek newer, more context-specified prediction tables and equations for specific sample population groups.
Accuracy of Orthodontic bracket adaptation
(University of the Western Cape, 2019) Noordien, Naeemah; Hudson, Athol
Background: A close marginal adaptation between the tooth and the bracket base is important since it provides the space for the adhesive. In order to withstand and resist the orthodontic forces exerted as well as everyday forces like mastication and oral hygiene practices, the adhesive material to the bracket must have sufficient sheer bond strength. This means that no deformations, cracks, or fractures should occur within the bracket material and adhesive (Keizer et al., 1976). Aim: The aim of this study was to determine the accuracy of the marginal adaptation of the bracket bases of seven different brands of orthodontic brackets to the tooth surface of a right upper first premolar (ie. Abzil, Forestadent, GAC, Gemini, IMD, Ormco and Victory LP). Method: This research was an in vitro, descriptive comparison study. Fifteen caries and crack free intact human first premolars were used. The teeth were obtained from patients requiring extractions for orthodontic purposes and collected from Tygerberg Oral Health Centre. A convenience sample method was used, where whenever an upper caries free premolar was extracted, the parent was asked if the tooth could be used for this study and consent was obtained. The crowns of the 15 teeth were cleaned and polished with pumice and rubber cups for 10 seconds (as the clinician would do prior to bracket cementation). The same 15 teeth were used with the seven different brands of brackets in order to establish a comparison of the adaptability of the brackets. The brackets were placed at a set orthodontic prescription of 4mm (measured from the slot area of the bracket to the tip of the buccal cusp of the tooth) on the upper first premolars. After bracket placement, the dontrix gauge was applied to the bracket to engage the slot area. The brackets were held in place with a constant force of 0.70 Newton (N) by the dontrix gauge. This allowed for reproducibility for the seven brackets with all fifteen teeth. In order to assess the space between the brackets and the teeth no adhesive was used. The space between the margins of the bracket and tooth interface was viewed under the Stereomicroscope (Carl Zeiss microscope, Zeiss Stemi508) at 50 times magnification. A two way mixed measures ANOVA was run to determine whether there were differences between the seven brackets placed at six points on the tooth surface. Results: GAC had the smallest overall mean measurement between bracket base and tooth surface followed by Ormco and Gemini respectively. Abzil had the largest overall mean measurement for the six points around the bracket
Accuracy of orthodontic digital study models
(University of the Western Cape, 2012) Kriel, Earl Ari Mac; Harris, Angela Manbre Poulter; Johannes, K.C.
Background: Plaster study models are routinely used in an Orthodontic practice. With the recent introduction of digital models, an alternative is now available, whereby three dimensional images of models can be analyzed on a computer. Aims and objectives: The aim of this study was to compare the measurements taken on digital models created from scanning the impression, digital models created from scanning the plaster model, and measurements done on the plaster models. The objectives were: Measurement differences between those taken directly on plaster models compared with measurements on digital models created from scanned impressions and digital models created from scanned plaster models. Methods: The study sample was selected from the patient records of one Orthodontist. They consisted of 26 pre-treatment records of patients that were coming for orthodontic treatment. Alginate impressions were taken of the maxillary and the mandibular arches. Each impression was scanned using a 3Shape R700™ scanner. Ortho Analyzer software from 3Shape was used to take the measurements on the digital study models. Within 24 hours plaster study models were cast from the impressions, and were scanned using a 3Shape R700™ scanner. On the plaster models the measurements were done with a MAX-CAL electronic digital calliper. The mesiodistal width as well as intermolar and intercanine width for both the maxillary and mandibular models were recorded.Results and discussion: Box plots used to compare the variability in each of the three measurement methods, suggest that measurements are less variable for Plaster. Plaster measurements for tooth widths were significantly higher (mean 7.79) compared to a mean of 7.74 for Digital Plaster and 7.69 for Digital impression. A mixed model analysis showed no significant difference among methods for arch width. Conclusions: Digital models offer a highly accurate alternative to the plaster models with a high degree of accuracy. The differences between the measurements recorded from the plaster and digital models are likely to be clinically acceptable.
The accuracy of visualized treatment objectives in bimaxillary protrusion patients
(University of the Western Cape, 2008) Murphy, Desmond.; Murphy, Desmond; Harris, A.M.P.; Dept. of Orthodontics; Faculty of Dentistry
The aim of this research project was to assess the accuracy of four different types of VTO [Steyn (1979), Jacobson and Sadowsky (1980), Ricketts (1982) and Holdaway (1984)], in predicting the final result of the incisor and soft tissue response to orthodontic treatment in bimaxillary protrusive patients.
Allergic contact dermatitis from resin‑modified glass ionomers
(Wolters Kluwer, 2019) Buchanan, Glynn Dale; Tredoux, Sheree; Gamieldien, Mohamed Yasin
Monomers in a variety of dental materials may cause allergic contact dermatitis. While resin materials have been implicated in the onset of this condition, there is a paucity of evidence linking the condition to the resin‑modified glass ionomers (RMGIs). This report documents a rare case of a dentist who developed allergic contact dermatitis following exposure to a RMGI. Contact dermatitis occurred despite the use of latex gloves, which were worn during the procedure. Both the acute and chronic stages of the condition were clinically represented. Patch testing was conducted to confirm the diagnosis. A no‑touch technique and the routine use of nitrile gloves were subsequently adopted, which resulted in an overall decrease of the condition.Dentists, auxiliary personnel, and students should be aware of the possibility of sensitization to, and the development of allergic contact dermatitis not only from conventional resin materials, but also from the RMGIs.
Analysis of dental anomalies in patients with unilateral cleft lip and palate at academic hospitals in the western cape, South Africa
(University of the Western Cape, 2023) Gomba, Vuyisile Solomon; Bellardie, H
The aim of this study is to determine the type and frequency of dental anomalies associated with patients with non-syndromic complete unilateral cleft lip and palate receiving treatment at Academic hospitals (UWC Oral Health Centre and Red Cross War Memorial Children’s Hospital) in the Western Cape. To determine whether there is a relationship between gender and dental anomalies associated with unilateral cleft lip and palate. A retrospective cross-sectional study assessing the hospital records of patients diagnosed with unilateral cleft lip and palate. Panoramic radiographs of 93 patients with unilateral cleft lip and palate (UCLP) aged 8 to 14 years were evaluated. Missing and supernumerary teeth were also quantified on the cleft and noncleft side and in the maxilla and mandible. Ectopic teeth, peg shaped laterals, and Crown and root malformations were quantified. Statistical analysis first comprised description of the frequency and types of dental anomalies. Chi-square analysis was used for comparisons of dental anomalies, in addition to specific dental anomalies in relation to gender. There were no substantial differences in distribution by gender, of the 93 patients with UCLP, 47 (50.54%) were males and 46 (49.46%) were females. Regarding distribution by cleft side, the left side was more frequently affected (69.9%) in both male and female patients, compared with 30.1% found on the right side. The most affected tooth was the cleft lateral, which was missing in 35.48% of the participants, while the non-cleft lateral was absent in only 3.23% and bilateral laterals were missing in 10.75%. Supernumerary teeth were found in 7.53% of the participating individuals and the most affected tooth was the cleft lateral.
Applicability of tooth size predictions in the mixed dentition analysis in a Kenyan sample
(University of the Western Cape, 2004) Ngesa, James Lwanga; Theunissen, E.T.L; Shaikh, A.B; Dept. of Orthodontics; Faculty of Dentistry
Mixed denticentition space analysis forms a critical aspect of early orthodo However, the applicability of these methods in other ethnic groups has been varied and questionable. The aim of this study is to evaluate the accuracy of the Tanaka and Johnston (1974) and the Moyers (1988) methods in a Kenyan sample. Mesio-distal tooth widths of 131 sets of dental casts obtained from randomly selected patients (50 males; 81 females) attending Kenyatta National Hospital were measured. The mean sum of the four mandibular incisors was used to determine the sum of canine and the two premolars in one quadrant. The predicted values of the mesio-distal widths were statistically compared with their respective actual sum of the canine and premolars of the same quadrants. The results of paired t tests and scatterplots indicated that there were highly significant differences (p<0.003) between actual measurements (Σ 3, 4 & 5) and their accurate among the non-radiographic prediction methods in the mixed dentition analysis in the Kenyan sample. treatment. The two most widely used non-radiographic tooth size prediction methods were derived from populations of Northern European ancestry. predicted values from Moyers (1988) prediction method except at 85% and/or 95% confidence levels. However, Tanaka and Johnston (1974) failed to show any statistically significant differences for either sex and combined sexes at p<0.05. The Tanaka and Johnston (1974) method was the most SAMPLE .
Application of lasers in orthodontics
(South African Dental Association, 2017) Mulder, Riaan; Melman, Geoffrey; Karic, Vesna
Laser is the acronym for Light Amplification by Stimulated Emission of Radiation, a usage that dates back to approximately 50 years ago. In 1960, the first functioning laser was built by the American physicist Maiman at the Hughes Research Laboratories by using a synthetic ruby crystal made of aluminum oxide and chromium oxide. In general, lasers are composed of the three principal parts: an energy source, an active medium and a set of two or more mirrors that form a resonator. Properties such as wavelength are determined primarily by the active medium, which can be a gas, crystal or a solid-state conductor.
Are fissure sealants still relevant as a caries preventive measure?
(South African Dental Association, 2016) Mulder, Riaan
The groundwork for fissure sealants was completed in 1955 and lead to the introduction in 1971 of the Nuva-Seal Fissure Sealant by L.D Caulk. Since caries predominantly affects the pits and fissures of the teeth of children, these sealants have been shown to be a valuable preventive procedure. FS are cost effective and provide an ideal preventive measure for children who have restricted access to dental services. However the advent of dental lasers, caries detection systems, fluoride varnishes and novel adhesive systems may have displaced FS as a preventive measure of choice. The aim of this investigation was to establish whether FS remain a relevant preventive measure for the anatomically vulnerable fissure system.
Assessment of Dental Arch Relationships in a sample of patients with Unilateral Cleft Lip and Palate in the Western Cape, South Africa
(University of the Western Cape, 2024) Galane, Mpatikana Leslie; Bellardie, Haydn
Unilateral cleft lip and palate (UCLP) is a specific form of orofacial cleft (OFC) that accounts for 23% of those born with clefts. In the Eastern Cape, Free State and Northern Cape provinces of South Africa (SA), the prevalence of OFCs is 0.1, 0.1, and 1.2 per 1000, respectively. UCLP is more common in males compared to females, with 2:1 gender distribution. In addition, UCLP has a strong predilection for the left side of the maxilla as compared to the right side. Individuals born with UCLP typically require several surgeries and/or other intricate procedures to rectify this anomaly. Individuals diagnosed with UCLP frequently exhibit a range of functional and aesthetic defects, in addition to the particular deformities associated with the condition. Complications related to UCLP include hypoplastic maxilla and a high incidence of Class III malocclusion. Children who are born with UCLP requires a complex management that starts with specialist nursing care, surgical repair on both the lip (which is generally done at three months of age) and the palate (at any time between six to 14 months of age). Several studies have verified that if the initial surgery is performed unskillfully, it can have a detrimental impact on the growth of the face, development of the dentition, and speech. Establishing a dependable approach for evaluating dental arch relationships is crucial in order to evaluate and contrast the outcomes of early management of UCLP in children.
Assessment of tooth movement in the maxilla during orthodontic treatment using digital recording of orthodontic study model surface contours
(University of the Western Cape, 2006) Harris, Angela Manbre Poulter; Nortje, C.J.; Wood, R.E.; Dept. of Orthodontics; Faculty of Dentistry
The aim of this project was to measure changes in dimension of the first three primary rugae and to evaluate tooth movement in the maxilla during orthodontic treatment in patients treated with and without premolar extractions.
Bio-active restorative materials as alternative pit and fissure sealants in pediatric and preventative dentistry: In vitro investigation
(MedCrave, 2017) Perchyonok, Tamara; Mulder, Riaan
BACKGROUND: It has been more than 40 years since the pit and fissure sealants were first used clinically. During this time, pit and fissure sealants have been shown to be effective in reducing the risk of occlusal caries. AIM: The aim of the investigation is to further develop and evaluate a versatile designed chitosan based bio-active materials on for use as bonding free fissure sealant/fissure protectors on permanent dentition and evaluate remineralization/demineralization capacity of the materials through pH cycling, as well as shear bond strength etch and no etch prototype as well as measurement of Vickers hardness of the newly designed materials and compare the property with the commercially available standard. RESULTS: In general there was an increase in bond strength of the enamel treated with the modified Premise containing nanodiamond: chitosan materials compared to the bond strength of the conventionally bonded teeth. It is seen that release of phosphorus into the dematerializing solution (i.e. loss of phosphorus from the samples) showed larger amplitude (from 600.2mg to 101.3 mg) than the uptake of phosphorus by the samples from the re-mineralizing solution (from 125.2 mg to 66.1 mg). Therefore, the treatment with chitosan seems to act more on the demineralization of tooth enamel with little effect on the remineralization process. Regarding the net phosphorus loss (net P loss), it can be seen that net demineralization occurs in all cases. However, the net amount of phosphorous released by the control group samples was significantly higher than those groups treated with chitosan. The net P loss for the control group was 475 mg of P, whereas the groups containing chitosan had a net P loss in the range of 30-182 mg. When a 1mm layer is assessed all the materials including the Premise control indicated a conversion of above 96%, which is the upper limit of the conventional fissure sealant material which makes the newly designed bioactive materials suitable for the application as fissure sealant materials. The important aspect of any newly designed/ developed restorative material is cytotoxicity as Grobler et. al [1] investigated the cytotoxic effect of nanodiamonds and also the effect of the incorporation in a dental material (Premise), who found a higher shear bond strength (p < 5%) after 3 months of Premise treated with nanodiamonds, chitosan, cyclodextrin (CD) and combinations thereof than for the control Premise. The sequence for the Vickers hardness was: CD (32.5) < nano (34.8) < CD Nano (38.8) < Premise (39) < Chitosan Nano (42.2). Nanodiamonds (92%) and the combination of chitosan + nanodiamonds (93%) showed little cytotoxicity. The shrinkage was lower for all the additions than for Premise alone. CONCLUSION: All modified Flowable bio-active materials can be further developed in effective fissure sealant material based on the acceptable in vitro results and cytotoxicity data.
Biomaterials and designer functional applications in oral cavity
(Nova Science Publishers, 2016-05-10) Perchyonok, Tamara; Mulder, Riaan
Dental biomaterials and natural products represent two growing research fields, revealing that plant¬derived compounds may play a role not only as nutraceuticals in affecting oral health but also in improving physicochemical properties of biomaterials used in dentistry. Recently, the role of free radicals in healthcare has attracted tremendous interest in the field of medicine, dentistry and molecular biology. Free radicals can be either harmful or helpful to the human body. When there is an imbalance between input and output of free radicals, a condition called “oxidative stress” develops. To counteract oxidative stress, the body has protective antioxidant mechanisms, which aid in lowering the incidence of various human morbidities and mortalities.
Bond strength of metal orthodontic brackets to all ceramic crowns
(University of the Western Cape, 2016) Ismail, Moosa; Shaikh, Amenah; Grobler, Sias
Aim: The aim of this study was to evaluate, in-vitro, the shear bond strength (SBS) and the resultant failure pattern after debonding of metal orthodontic brackets bonded with TransbondTM XT adhesive resin cement and RelyXTM Unicem 2 self-adhesive resin cement to pre-treated (35% ortho-phosphoric acid and silane coupling agent application) IPS eMax and porcelain veneered zirconia crowns. Material and methodology: A Typhodont maxillary lateral incisor was used and prepared in a conventional manner to receive a full ceramic crown. A CAD (computer aided design)/ CAM (computer aided manufacturing) machine was used to scan the prepared tooth and manufacture 40 IPS eMax crowns and 40 porcelain veneered zirconia crowns. Half the number of IPS eMax crown specimens (ie. 20) and half the number of porcelain veneered zirconia crown specimens (ie. 20) were thermocycled (ie. to mimic thermal changes which occur in the mouth), from 5 to 55o for 500 cycles as recommended by the International Organization for Standardization (ISO 6872, 2008). The remaining 20 IPS eMax crown specimens and 20 porcelain veneered zirconia crown specimens remained new and unexposed to thermal changes. The facial surfaces of all the thermocycled and non-thermocycled crown specimens were then etched. Etching of all the ceramic bonding surfaces was performed by the application of 35 per cent ortho-phosphoric acid liquid for 2 minutes, followed by a thin layer of a ceramic primer. A lateral incisor metal bracket with a bracket base area of 9mm2 (as confirmed by the manufacturer) was bonded to each of the etched and silane treated ceramic crown specimens and separated in the following manner: Group 1: (10 thermocycled, etched and silane treated IPS eMax and 10 thermocycled, etched and silane treated porcelain veneered zirconia crown specimens) RelyX™ Unicem 2 self-adhesive resin cement was used to bond the bracket to the ceramic crown specimens, Group 2: (10 thermocycled, etched and silane treated IPS eMax and 10 thermocycled, etched and silane treated porcelain veneered zirconia crown specimens) Transbond™ XT light cure adhesive primer was first applied onto the bonding surface of the crowns and then Transbond™ XT adhesive resin was used to bond the bracket to the ceramic crown specimens, Group 3: (10 non-thermocycled, etched and silane treated IPS eMax and 10 non-thermocycled, etched and silane treated porcelain veneered zirconia crown specimens) RelyX™ Unicem 2 self-adhesive resin cement was used to bond the bracket to the ceramic crown specimens, Group 4: (10 non-thermocycled, etched and silane treated IPS eMax and 10 non-thermocycled, etched and silane treated porcelain veneered zirconia crown specimens) Transbond™ XT light cure adhesive primer was first applied onto the bonding surface of the crowns and then Transbond™ XT adhesive resin cement was used to bond the bracket to the ceramic crown specimens. After bonding all samples were stored in distilled water for 24 hours before being submitted to the shear bond strength test. Debonding forces in Newtons (N) was determined by using a shear testing machine and converted into Mega Pascals (MPa). Results: The results after debonding were compared. The mean shear bond strength for RelyXTM Unicem 2 self-adhesive resin cement bonded to the all ceramic non-thermocycled crowns (Group 3) ranged from a low of 5.1 MPa (45.5 Newtons) when brackets were bonded to the IPS eMax crowns to a high of 5.8 MPa (51.9 Newtons) when brackets were bonded to the porcelain veneered zirconia crowns. The mean shear bond strength for Transbond XT adhesive resin cement bonded to the all ceramic non-thermocycled crowns (Group 4) ranged from a low of 6.4 MPa (57.3 Newtons) when brackets were bonded to the porcelain veneered zirconia crowns to a high of 8.1 MPa (72.7 Newtons) when brackets were bonded to the IPS eMax crowns. The side by side Box-and-Whisker plots of the shear bond strengths show wide and overlapping dispersions of the crown/adhesive resin combinations which consequently lessen the probability of significant differences between the crown/adhesive resin combinations in all 4 groups. According to the Kruskal-Wallis test (p < 0.05), and the Bonferroni Test the non-thermocycled crown/adhesive resin combinations do not differ significantly. Study of the mean ARI (Adhesive Remnant Index) values for the non-thermocycled crown/adhesive combinations shows that brackets bonded with Rely-XTM Unicem 2 to non-thermocycled porcelain veneered zirconia crowns failed entirely at the ceramic/adhesive interface and for all the other non-thermocycled ceramic/adhesive combinations most of the failures of the bond (70%) occurred at the bracket/adhesive interface, ie. cohesive fractures within the composite resin. No cohesive fractures of the porcelain crowns were noted. The results of the thermocycled groups (Group 1 and Group 2) show the TransbondTM XT/non-thermocycled IPS eMax crown combination yielded the highest overall mean shear bond strength of 8.1 MPa (72.7 Newtons) but dropped to a mean shear bond strength of 5.1 MPa (46.1 Newtons) (36.4% drop in shear bond strength) when the crowns were thermocycled prior to bonding. The TransbondTM XT/non-thermocycled porcelain veneerd zirconia crown combination yielded the second highest overall mean shear bond strength of 6.4 MPa (57.3 Newtons) and dropped to a mean shear bond strength of 5.1 MPa (45.8 Newtons) (19.3% drop in shear bond strength) when the crowns were thermocycled prior to bonding. The RelyXTM Unicem 2/non-thermocycled porcelain veneered zirconia crown combination yielded the third highest overall mean shear bond strength of 5.8 MPa (51.9 Newtons) but dropped significantly to a mean shear bond strength of 3.2 MPa (29.1 Newtons) (a significant 43.8% drop in shear bond strength) when the crowns were thermocycled prior to bonding. Lastly, the RelyXTM Unicem 2/non-thermocycled IPS eMax crown combination yielded the fourth highest mean shear bond strength of 5.1MPa (45.5 Newtons) but dropped to a mean shear bond strength of 4.9 MPa (44.5 Newtons) (a drop in shear bond strength of only 3%) when the crowns were thermocyled prior to bonding. Relaxing the significance level (p-value) somewhat demonstrates the negative influence of thermocycling on the shear bond strength of the crown/adhesive combinations. The non-thermocycled all ceramic crown/adhesive combinations showed mean ARI values of between 1.3 and 2.1 indicating cohesive fractures within the composite resin and efficient bonding of the adhesive material to the porcelain surface. However, all the thermocycled all ceramic crown/adhesive treatment combinations showed mean ARI values of between 0 and 0.8 indicating a bond failure between adhesive and porcelain and highlighting the negative influence of thermocycling on bond strength of both adhesive resin cements. Conclusion: Within the limitations of this study, it can be concluded that: 1.There was no significant difference in the shear bond strengths of metal orthodontic brackets bonded with RelyXTM Unicem 2 self-adhesive resin cement and metal orthodontic brackets bonded with TransbondTM XT adhesive resin cement to IPS eMax and porcelain-veneered zirconia crowns which were conditioned with 35 % phosphoric acid and a silane coupling agent. 2. Conditioning the porcelain surface with 35% phosphoric acid and a silane coupling agent (which is safer to use than Hydrofluoric acid) is sufficient for bonding metal orthodontic brackets to all ceramic crowns, and should make it simpler for clinicians to remove the remaining adhesive from the porcelain surface after debonding. 3. The negative influence of thermocycling prior to bonding can be seen on shear bond strength values. 4. Most of the failures of the bond occurred at the ceramic/adhesive interface and cohesive fractures within the composite resin. No cohesive fractures of the porcelain crowns were noted.
Can a new paediatric sub-specialty improve child health in South Africa?
(Health & Medical Publishing Group, 2012) Swingler, George; Hendricks, Michael; Hall, David; Hall, Susan; Sanders, David; McKerrow, Neil; Saloojee, Haroon; Reid, Steve
Compared with other middle-income countries, child health in South Africa is in a poor state, and should be addressed by focusing on the healthcare needs of all children across a system or region. Paediatricians have had little effect on this situation, partly because their training is not aligned with South African needs. The proposed re-engineering of primary healthcare will be limited by the skewed distribution of staff and the lack of suitable skills. A 'community' placement during specialist training, and the creation of a sub-specialty in Community Paediatrics and Child Health, could address the skills shortage and possibly attract health personnel to under-served areas through creating an appropriate career path. This proposal would also support the Department of Health's encouraging plans to re-engineer primary healthcare.
Cavity preparation using hard tissue lasers in operative dentistry
(South African Dental Association, 2017) Karic, Vesna; Mulder, Riaan; Melman, Geoffrey
A laser is a device that delivers coherent, monochromatic and collimated light as a form of energy. Most dental laser devices emit invisible light in the infrared portion of the electromagnetic spectrum. On May 7, 1997, the Food and Drug Administration (FDA) cleared for marketing in the United States the first erbium: yttrium - aluminum -garnet, or Er: YAG, laser for use in preparing cavities in the teeth of living human subjects.
A cephalometric and dental analysis of treatment outcomes of unilateral cleft lip and palate children treated at the Red Cross children's hospital
(University of the Western Cape, 2000) Kaskar, Salim; Bellardie, Haydn
This study was a cephalometric and dental investigation of the treatment outcomes of UCLP children treated at the Red Cross Children's Hospital (RCCH) with respect to craniofacial morphology and dental arch relationship. The quality of the outcome for the RCCH group was compared with the outcomes reported for the Six-Centre International Study (Melsted et al., 1992; Mars et al., 1992). The sample consisted of 20 (11 females, 9 males) consecutively treated UCLP children who had cephalometric and dental records taken between the ages of8 to 11years (mean 10.13 ± 1.2 years). The cephalometric analysis described by Melsted et al. (1992) was used to evaluate the skeletal and soft tissue morphology. The quality of the dental arch relationship was measured according to the Gosion Yardstick (Mars et al., 1987). The treatment outcome of children treated at the RCCH was evaluated with respect to craniofacial form and dental arch relationship. When comparing the mean cephalometric skeletal parameters of the RCCH to the six centres in the Eurocleft study, a significant difference was found between the RCCH group and centre D for most of the variables. A significant increase in the upper incisor inclination and maxillary inclination was found in the RCCH patients compared to the European centres. The difference in the soft tissue parameters was limited to the relative protrusion of the nose and the sagittal soft tissue variable sss-ns-pgs. The analysis of the Goslon scores showed a significant difference between the RCCH group and centres C, D, and F. According to the Goslon score, 85% of the RCCH patients had good to satisfactory dental arch relationship, which was comparable to that recorded for centres A(92%), B(89%) and C(94). In conclusion, the results of the cephalometric analysis and the Goslon Yardstick showed a significant difference between the RCCH group and centre D. The GosIon score indicated good quality of the dental arch relationship, which faired favourably with the better centres in the Six Centre Study.
A Cephalometric Comparison of Class II Extraction Cases Treated with Tip-Edge and Edgewise Techniques
(University of the Western Cape, 2012) Ngema, Maureen Nkosazana; Harris, A. M. P.
The Tip-Edge and edgewise techniques are the main techniques that are mostly used in orthodontics, and are applicable to the treatment of any type of malocclusion from the most simple to the most complex. The edgewise bracket wire combination produces bodily tooth movement simultaneously or separately in all three planes of space and hence permits correction of the most extreme tooth malpositions. On the other hand Tip-Edge offers a differential tooth movement (just like the previously used Begg technique) within an edgewise based bracket system (Parkhouse 2003). When treating patients using the Tip-Edge technique, it is recommended that a specialized archwire i.e. Australian stainless steel wire be used. This wire can be described as a round austenitic stainless steel wire that is heat-treated and cold-drawn to its proper diameter. This was done in order to produce its special and needed properties such as toughness, resiliency and tensile strength (Kesling, 1985). It is used in conjunction with light (2oz) class II elastics. The aim of this study was to compare cephalometric changes in skeletal and dento-alveolar parameters in cases treated by these two different orthodontic techniques. This was to be established by calculating and comparing the pre- and post-treatment cephalometric variables of cases treated with these techniques by looking at the skeletal and dento-alveolar measurements. Thirty Tip-Edge and thirty edgewise treated cases that had class II malocclusion, had extraction of four premolars and were treated with Class II elastics were selected. The gender distribution between the Tip-Edge and the edgewise techniques were 47% and 60% respectively for females. For males it was 53% in Tip-Edge and 40% in the edgewise techniques.
Changes in arch dimensions after extraction and non-extraction orthodontic treatment
(University of the Western Cape, 2008) MacKriel, Earl Ari.; Harris, A.M.P.; Dept. of Orthodontics; Faculty of Dentistry
The aim of this study was to determine whether there are changes in the interdental arch widths and arch lengths of the mandibular and maxillary arches during nonextraction and extraction orthodontic treatment. The records of 78 patients treated by one orthodontist were used for this study. Three treatment groups were selected: a nonextraction group (Group NE), a group treated with extraction of maxillary and mandibular first premolars (Group 44), and a group treated with extraction of maxillary first premolars and mandibular second premolars (Group 45). The arch width measurements were measured in the inter-canine, inter-premolar and inter-molar areas. The arch length was measured as the sum of the left and right distances from mesial anatomic contact points of the first permanent molars to the contact point of the central incisors or to the midpoint between the central incisor contacts, if spaced.Statistical analysis included descriptive statistics of the data, analysis of the correlation matrices, Wilcoxon Signed Rank tests and Kruskal-Wallis tests of the changes which occurred during treatment. The intercanine widths in the mandible and maxilla increased during treatment in all three groups, with the extraction groups showing a greater increase than Group NE (p<0.05). In Group NE the mandibular arch length increased (p>0.05), while the maxillary arch length remained essentially unchanged. Both extraction groups showed decreases in arch length in the dentitions (p<0.05), with greater decreases occurring in the maxilla. The difference in arch length change between the two extraction groups was not significant (p<0.05). The inter-canine arch width increased in all three treatment groups, more so in the two extraction groups. From this it is evident that extraction treatment does not necessarily lead to narrowing of the dental arches in the canine region. The inter-second premolar arch width decreased in both extraction groups. Non-extraction treatment resulted in an increase in the inter-premolar and inter-molar arch widths.
Characteristics of children under 6 years of age treated for Early Childhood Caries at Tygerberg Oral Health Centre, South Africa
(Tufts University, School of Dental Medicine, 2008) Mohamed, Nadia; Barnes, Jo
Objective: This retrospective survey highlighted the characteristics of children less than six years of age presenting with early childhood caries(ECC) who had two or more teeth extracted under intravenous sedation at the Tygerberg Oral Health Centre in Cape Town, South Africa. This survey was carried out in order to plan a community-appropriate intervention strategy. Methods: Records of 140 patients kept by the pediatric Dentistry Division met the inclusion criteria and were included in this survey. Most of the patients originate from economically disadvantaged areas. Results: Diet, feeding and oral hygiene habits were shown to be the most significant factors that contributed to the development of ECC in these patients. All the children were either breast- or bottle-fed past one year of age. 93.6% of the children went to sleep with the bottle or while on the breast and 90% of them were fed on demand during the night. On average, breastfeeding was stopped at 9 months of age compared to bottle-feeding that, on average, was stopped at a much later mean age of 23 months. Where oral hygiene practices were concerned, 52.6% of children brushed their own teeth without supervision. Frequency of brushing varied between subjects. Conclusion: The results of this study have demonstrated that there is a need for culturally appropriate education campaigns to inform parents (especially those in disadvantaged communities) about the importance of oral health and the prevention of oral disease.

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