Correlation between the atlas morphology and the maxillo-mandibular divergence pattern

Objective: To evaluate the correlation between atlas morphology and maxillo-mandibular divergence

Study Design: Cross-sectional, analytic study

Place and Duration of Study:Dental Clinics, The Aga Khan University Hospital, Karachi, Pakistan from February to August 2017

Methodology: Pretreatment lateral cephalograms of 208 subjects, aged 18 to 25 years, were evaluated. The atlas parameters were categorized into atlas dorsum, anteroposterior and ventrum, and measured on View Pro-X software.Various maxillary [FPPP, SNPP and FHPP angles] and mandibular [SNGoGn, saddle, articulare, gonial, sum of posterior and Y-axis angles] parameters were used to evaluate the divergence pattern of the individuals. Mann-Whitney U-test was used to compare atlas and maxillo-mandibular parameters between genders. Spearman correlation was used to correlate atlas and maxillo-mandibular parameters across genders. A p-value

Results: Statistically significant differences were found between various atlas and maxillo-mandibular parameters between genders. With atlas dorsum, the saddle angle [r = -0.3] in males; whereas gonial [r = -0.2], Y-axis [r = 0.1] and SNPP [r = -0.2] angles in females showed significant weak correlation. With atlas anteroposterior, saddle [r = -0.2], articulare [r = 0.2], SNPP [r = -0.2] and FHPP [r = -0.3] angles in males showed significant weak correlation. However, only the SNPP angle [r = -0.2] in females showed a significant weak correlation with atlas ventrum

Conclusion: A weak correlation was found between atlas parameters and various maxillo-mandibular angular parameters in both genders. Therefore, atlas morphology cannot be regarded as a good predictor of future maxillo-mandibular divergence pattern.

Dentoalveolar heights in vertical and sagittal facial patterns

Objective: To determine and compare the mean dentoalveolar heights [mm] in different vertical and sagittal facial patterns

Study Design: Cross-sectional study

Place and Duration of Study: Orthodontics Clinic, The Aga Khan University Hospital, Karachi, from September to November 2013

Methodology: Subjects, aged 15 - 20 years, having fully erupted first permanent molars and central incisors were included in the study from orthodontic records. The pretreatment cephalographs of subjects were traced manually over an illuminator. The various parameters like angles and dentoalveolar heights were measured and recorded on data collection form. Mean value +/- SD for the variables were generated. ANOVA was used to compare the means of dentoalveolar heights among the vertical and sagittal facial patterns. Post Hoc Bonferroni test was applied to show difference among the three vertical and three sagittal facial patterns. P-value equal to or less than 0.05 was taken as statistically significant

Results: The mean age of subjects was 15.8 +/-3.2 years in vertical group and 16.3 +/-2.9 years in sagittal group. There was statistically significant difference [p=0.008] for the upper anterior dentoalveolar height [UADH] among vertical groups, with statistically significant difference for UADH between hyperdivergent and normodivergent [p=0.04] and hyperdivergent and hypodivergent [p=0.01] facial patterns

Conclusion: The UADH were significantly greater in the hyperdivergent group as compared to both the normodivergent and hypodivergent groups. The sagittal groups showed no statistically significant difference for dentoalveolar heights

Plaque index in multi-bracket fixed appliances

To compare the plaque index in patients receiving multi-bracket fixed orthodontic treatment for various factors like age, gender, socio-economic status, brushing practices, meal habits, types of brackets, types of ligations, use of mouthwash and duration of treatment. Cross-sectional analytical study. Orthodontics Clinic, The Aga Khan University Hospital, from September to November 2011. Socio-demographic and clinical modalities were defined and recorded for 131 patients having multi-bracket fixed appliances. The plaque index of subjects were recorded according to the Silness and Loe plaque index method. Independent sample t-test was used to see difference in plaque index in factors having two variables. One way ANOVA and Post-Hoc Tukey tests were used to see difference in plaque index in factors having three variables. Kappa statistics was used to assess inter examiner reliability. P-value of

Inter-arch tooth size discrepancy among different sagittal malocclusion groups and its clinical implications

The relationship of the mesiodistal widths of the maxillary and mandibular teeth influences the optimal final occlusion, overbite and overjet. The aim of this study was to compare inter-arch tooth size ratios among different malocclusion groups and to determine the percentage of clinically significant cases [outside two SD from the Bolton's mean] in each malocclusion group. Pretreatment records of 110 patients belonging to different malocclusion groups [Class I = 40, Class II = 40, Class III = 30] were evaluated for Bolton's anterior, overall and posterior ratios. Angle's classification system was used to assign cases into different malocclusion groups. No significant difference was found in anterior, posterior and overall Bolton's ratios among the three malocclusion groups. Forty percent of the entire sample had clinically significant discrepancy in anterior ratio, while 14.54% patients had discrepancy in overall ratios. In Class I malocclusion group, 37.5% patients had anterior ratios and 20% had overall ratios discrepancy outside 2 SD from Bolton's mean. In Class II group, 35% patients had anterior ratios and 12.5% had overall ratios outside this range. In Class III malocclusion group, 50% patients had anterior and 10% patients had overall ratio discrepancies outside 2 SD from Bolton's means. No significant difference was found between males and females when the three ratios were compared between the two genders in individual malocclusion groups as well as in the entire sample

Applicability of Pont's index in orthodontics

To investigate the applicability of Pont's index in estimating the maxillary arch width depending on the sum of mesiodistal dimensions of maxillary incisors. Cross-sectional, comparative study. Dental Clinics, The Aga Khan University Hospital, Karachi, from January 2006 to December 2008. A total of 150 subjects were included. All measurements were taken on maxillary study casts by a digital caliper. The premolar arch width was taken from the first premolar of the left side to the right side at the distal end of its occlusal groove. The molar arch width was taken from the maxillary left permanent molar to the same of the right at its mesial pit on the occlusal surface. The combined width of the maxillary incisors was taken at their greatest mesiodistal widths. The predicted arch widths were estimated with the Pont's formula: Premolar width [P] = Sum of Incisor widths/80 x 100 Molar width [M] = Sum of Incisor widths/64 x 100 Incisor diameters and arch widths were described in terms of mean values, standard deviations, and coefficients of variation. Correlation coefficients were computed between observed arch widths and those predicted according to Pont's M and P indices. The mean age was 15.8 +/- 1.6 years. Low correlations existed between observed and Pont's predicted arch widths in both premolar [r = 0.364] and molar [r = 0.238] regions. Twenty two percent of interpremolar arch widths and 18% of intermolar arch widths showed differences between -1 mm to 1 mm. Low correlations were found between observed and Pont's predicted arch widths. Pont's index is unlikely to be clinically useful as a true predictor of arch width.

Bilateral maxillary canine-first premolar tansposition in permanent dentition

Transposition is a dental anomaly characterized by the exchange of position between two adjacent teeth, especially in relation to their roots, or development and eruption of a tooth in a position normally occupied by a nonadjacent tooth. Transposition of the maxillary canine and first premolar has a low prevalence in the population and it primarily affects maxillary canines and premolars. The aetiology of the transposition remains unclear, although it has been associated with genetic factors. It may also be related to a combination of localised factors such as malformation of adjacent teeth, tooth agenesis, retention of the deciduous canine and a history of local trauma. If uncorrected, the results are often both functionally and esthetically unsatisfactory. This case report presents treatment of a female patient with complete bilateral transposition of maxillary canine and premolar. The patient was treated orthodontically with non-extraction fixed mechanotherapy by simulation of maxillary first premolar as canine bilaterally

Perception - A comparison of professional assessments- A pilot study

Beauty and aesthetics are subjective phenomenon. In orthodontics, beauty is collaborated with function and a compromised function is known to lead towards detrimental effects in the long term. The measurement of aesthetics in orthodontics is through the Index of Orthodontic Treatment Need [IOTN]. This is a universal scale which is easy to use for all professionals dealing with child care. A cross-sectional validation study was conducted in the dental clinics of Karachi at Aga Khan University Hospital, Jinnah Medical and Dental College and Fatima Jinnah Dental College on a sample size of 17 professionals from July to August 2012. Each subject was shown a set of 32 pictures which they scored against the aesthetic component of the IOTN. The principal investigator assessed the normative score from the study casts using the IOTN-DHC. Data collected was analyzed using Kruskal- Wallis, Bland- Altmann, Paired sample t- test and Kappa Cohen's. Intra examiner reliability was assessed using Spearman's correlation. The sample size consisted of 24% males [mean age 28.25 +/- 2.06 years], and 76% females [[mean age 31.92 +/- 9.19 years]. A statistically significant difference was obtained between orthodontists', pedodontists' and restorative dentists perception for a single image [p- value 0.005]. Similarly a difference in perception of the three groups with normative need [p- value- 0.002 [orthodontists], 0.03 [pedodontists], 0.05 [restorative dentists]]; was also obtained.o There is no significant difference in perception between orthodontists, pedodontists and restorative dentists. Orthodontists, pedodontists and restorative dentists overestimate the patients' pretreatment condition as compared to normative treatment need

Comparison of nasal profiles in various skeletal patterns

The aim of this study was to determine any significant difference in nasal profiles amongst subjects in sagittal and vertical skeletal patterns in a sample Pakistani population, and to determine gender dimorphism if any. The sample was divided into three sagittal and groups, namely skeletal Class I, II, and III, and three vertical groups, namely, normo-divergent, hypo-divergent and hyper-divergent vertical skeletal patterns. On way ANOVA was used to find any difference in nasal profiles amongst vertical and sagittal skeletal patterns, and to assess gender dimorphism, respectively. Statistically significant differences were found between Skeletal Class I, II and III for naso-labial angle, naso-mental angle and soft tissue facial convexity. Furthermore, statistically significant differences were also obtained between males and females for nasal length, nasal depth, columella convexity and nasal bone length. Statistically significant differences were observed for nasal depth 2 and naso-labial angle in the vertical groups. Skeletal Class I, II, and III subjects have different nasal profiles. Nasal profiles are significantly different for males and females; hence it should be taken into consideration while planning ideal treatment for patients. Different vertical patterns are also associated with different nasal forms. It is recommended that further research be done to establish norms in our population for nasal profile

Assessment of fluctuating asymmetry in permanent dentition

Fluctuating asymmetry is the difference between the two sides of bilateral traits. The aim of this study was to assess fluctuating asymmetry of maxillary and mandibular arches in faciolingual and mesiodistal crown dimensions. This cross sectional study conducted from July to August' 2010, at the Aga Khan University Hospital, Karachi. Data was obtained from pre-treatment dental casts of 74 patients who visited the orthodontic clinic from June 2004 to August 2010. Antimeric pairs of the maxillary and mandibular permanent central incisors, canines and first molars were measured in mesiodistal and faciolingual crown dimensions. All measurements were done using digital vernier caliper. Paired sample t-test was used to depict the difference between the two sides of both jaws. Bland Altman test was used to assess the intra-examiner reliability for the measurements done in this study. Statistically significant differences were observed between right and left sides in the mesiodistal width of maxillary canines and buccolingual width of maxillary first molars. Fluctuating asymmetry was observed between right and left sides in the mesiodistal width of maxillary canines and faciolingual width of maxillary first molars. Assessment of asymmetry should be done for every patient before initiation of orthodontic treatment for its input in treatment planning

Comparison of tooth and arch dimensions in dental crowding and spacing

Any disproportion between tooth and arch dimensions predisposes to dental crowding and spacing, which are the most common forms of malocclusion. Hence, the objective of this study is to compare these elements between normal, crowded and spaced dental arches. A sample of 90 dental casts was collected and space analysis was performed by subtracting the sum of mesio-distal [MD] dimensions of all teeth [except the permanent molars] from the arch length. On the basis of this space analysis, the sample was divided into three groups, namely normal, crowded and spaced arches. ANOVA and Bonferroni post-hoc were performed for the comparison between the groups. A level of significance [p

Microaesthetics of the smile: extraction vs. non-extraction

To compare microaesthetics in pre- and post-orthodontic cases, treated with non-extraction and extraction treatment and assessed whether the achieved microaesthetic parameters are comparable to the proposed norms. Quasi-experimental study. Orthodontic Clinic, the Aga Khan University Hospital, Karachi, from January 2005 to December 2009. Orthodontic records of 31 cases treated with non-extraction therapy and 26 cases treated with extraction of upper first premolars were selected. Patients were of Pakistani origin, aged between 12 to 30 years. Microaesthetics was assessed by measuring maxillary central incisor crown width-height ratio, connectors between the maxillary anterior sextant, gingival zenith level of the maxillary lateral incisor and golden percentage of the anterior teeth using the patients' plaster models and intraoral frontal photographs. Measurements of the golden percentage were made using the software Adobe Photoshop, whereas all other parameters were measured on the plaster casts using a digital vernier caliper. Paired t-test, independent t-test and one sample t-test were used to make comparisons within the groups, between the groups, and to compare the posttreatment values with the proposed norms, respectively. Statistical significance level was set at p

Lip line preference for variant face types

To determine the effect of altered lip line on attractiveness and to find preferred lip line for vertical face types in both genders. Cross-sectional analytical study. The Aga Khan University Hospital, Karachi, from May to July 2009. Photographs of two selected subjects were altered to produce three face types for the same individual with the aim of keeping the frame of the smile constant. Lip line was then altered for both the subjects as: both dentitions visible, upper incisors visible, upper incisors and 2 mm gum and 4 mm gum visible. The pictures were rated by different professionals for attractiveness. Descriptive statistics for the raters and multiple factor ANOVA was used to find the most attractive lip line. The total number of raters was 100 with the mean age of 30.3 +/- 8 years. The alterations in the smile parameters produced statistically significant difference in the attractiveness of faces, whereas the perception difference was found to be insignificant amongst raters of different professions. Preferred lip line was the one showing only the upper incisors in dolico and mesofacial male and female genders whereas 2 mm gum show was preferred in brachyfacial subjects. The variability in lip line showed significant difference in the perceived attractiveness. Preferred lip lines as the one showing only the upper incisors in dolico and mesofacial male and female genders whereas 2 mm gum show was preferred in brachyfacial subjects

Dentoalveolar heights in skeletal class I normodivergent facial patterns

To determine the dentoalveolar heights [mm] in skeletal class I normodivergent facial pattern and compare the same heights in male and female subjects. Cross-sectional observational study. Orthodontics Clinic, The Aga Khan University Hospital, Karachi, from July to October 2009. Eighty one subjects were selected from the orthodontic record at the Aga Khan University Hospital Karachi.The inclusion criteria were an age range of 12 to 30 years and skeletal class I normodivergent facial pattern with exclusion criteria of prior orthodontic treatment, restored teeth and craniofacial anomalies/syndromes. The pre-treatment cephalographs of the patients were traced manually on acetate paper by the principal investigator. The various land marks were marked and the parameters were recorded. Mean and standard deviations were determined. Independent sample t-test was used to find gender dimorphism. The mean age of the sample was 15.8 +/- 3.4 years. Mean ANB angle for the entire sample was 2.6° +/- 1.2° and for angle SN-MP was 31.5° +/- 2.5°. Descriptive analysis presented mean value of upper anterior, upper posterior, lower anterior and lower posterior dentoalveolar heights to be 28.5 +/- 2.7 mm, 22.9 +/- 2.6 mm, 41.3 +/- 2.9 mm and 31.5 +/- 3.2 mm respectively. Male subjects had significantly greater mean values for lower anterior and posterior dentoalveolar heights [p=0.02 and 0.05 respectively]. The mean dentoalveolar heights for the skeletal class I normodivergent sample were established. No gender dimorphism was found for upper dentoalveolar heights however, lower anterior and lower posterior were significantly greater in males as compared to females. All the values of dentoalveolar heights for male subjects were greater than female subjects

Orthodontic treatment outcome assessment using peer assessment rating [PAR] index

The crosssectional study was carried out to determine the degree of improvement in malocclusion after orthodontic treatment provided at the Aga Khan University Hospital [AKUH], Karachi, and to find out which malocclusion showed a marked reduction in PAR score after orthodontic treatment. It was conducted from March 2007 to April, 2007. This study evaluated the last 50 consecutively finished orthodontic cases using PAR index. The material consisted of pre- and post treatment casts and orthodontic files. Pre- and post-treatment PAR score was calculated for each patient. All patients who received complete orthodontic treatment at this hospital and whose good quality records were available were included in the study. Re-treatment cases and patients transferred out of hospital were excluded. Records of 50 patients [38 females and 12 males] were evaluated for PAR score. The mean reduction in the PAR score was 24 points [91.95%]. The number of patients in 'greatly improved' category was 30 [60%], in 'improved' category 19 [38%] and in 'worse/no different' category 1 [2%]. Statistically significant correlation was found between percentage PAR score reduction and pretreatment PAR score. A significantly higher orthodontic treatment standard was achieved. The mean reduction in PAR score was almost 92%. The percentage of patients in 'Greatly improved' category was 60%. A significant correlation [p<0.001] was found between pre-treatment PAR score and percentage reduction in PAR score

Clinical applicability of variations in arch dimensions and arch forms among various vertical facial patterns

To compare dental arch dimensions and arch forms in various vertical facial patterns. Cross-sectional comparative study. The Aga Khan University Hospital, Karachi, from June 2007 to May 2008. Cases of age ranging 13-30 years were reviewed having full complement of teeth [upto second permanent molars] with less than 7 mm crowding. Exclusion criteria included presence of dental anomalies, previous dentoalveolar surgery, trauma or orthodontic treatment and craniofacial syndromes. One hundred cases including 40 normodivergent, 30 hypodivergent and 30 hyperdivergent facial patterns were selected. Occlusograms were made and various arch dimensions were measured. Arch forms were calculated according to ratios of three sagittal to three transverse dimensions. The mean age of the sample was 21 years and 5 months. Significant differences in arch dimensions were found only in maxillary total arch length [p=0.03] and mandibular posterior intermolar width [p=0.04]. Wide lower arches were predominant in all face types. Wide upper arches were predominant only in hypo- and hyperdivergent subjects. Statistically significant difference in arch dimensions was found only in maxillary total arch length and mandibular posterior intermolar width. A non-linear relationship was found between arch length and arch width. Wide lower arches were predominant in all face types whereas wide upper arches were predominant in hypo- and hyperdivergent subjects

White spot lesions in orthodontic patients part I: frequency and pattern of distribution

To determine the frequency and pattern of white spot lesions developed during orthodontic therapy in a sample of orthodontic patients. This cross-sectional study was designed to compare pre-treatment and post-treatment digital photographs of patients having undergone orthodontic therapy to determine the presence or absence of enamel decalcification in the form of white spot lesions. The distribution of the white spot lesions was also recorded with reference to the tooth type, as well as its location on a particular tooth. Data were analysed using SPSS [version 11.5] where the means and frequencies were computed. The study sample consisted of 60 orthodontic patients. Out of these, 14 [23.3%] were males and 46 [76.7%] were females with male to female ratio of 1:3.3. The mean age was 14 years and 5 months and the mean fixed appliance treatment duration was 2years and 9 months. The frequency of White Spot Sessions according to the total number of patients affected was 75%, whereas according to the number of total teeth affected was 19%. The upper lateral incisors were the most commonly affected teeth [78.3%], followed by the lower 1st permanent molars [55%], the upper central incisors [43%] and upper canines [40%]. According to the type, the chalky-white White Spot Lessions were more common [76.2%] as compared to the brown lesions and cavitations. According to the site, the upper anterior teeth showed a more central occurrence as compared to the upper posterior and lower teeth, which were mostly affected in the gingival third of the crown. Out of 60 patients, 75% were affected by White Spot Sessions while the overall number of teeth affected was 19%. The most commonly affected teeth were upper lateral incisors [78.3%] while chalky white type White Spot Lessions were more common [76.2%]. Middle third of the crown of upper anterior teeth was the most commonly affected site

Change in the position of hyoid bone with functional appliance treatment

The aim of this study was to delefmile change in the position of hyoid bone with functional appliance treatment. The present study was carried out using pre-functional and post-functional cephalographs of patients attending the Orthodontic Clinics at the Aga Khan University Hospital, Karachi, from 2003 to 2007. This study was conducted on 30 Pakistani subjects [12 males and 18 females] aged between 9 to 14 years, treated with removable or fixed functional appliances. Cephalometric points, linear and angular measurements assessing position of hyoid bone on pre-and-post functional cephalographs were recorded. Paired sample t-test was used to depict the change in the position of hyoid bone following functional appliance treatment. Linear and angular cephalometric measurements depicting the position of hyoid bone after functional appliance treatment were statistically insignificant. There was no statistically significant change observed in the position of hyoid bone with functional appliance treatment

Soft tissue profile response in extraction versus non-extraction orthodontic treatment

To compare changes occurring in the soft tissue profile with orthodontic treatment in extraction versus nonextraction cases, and to determine the hard and soft tissue parameters that show significant correlations to understand the factors influencing the response to tooth movement. Quasi-experimental. Dental Section, The Aga Khan University Hospital, Karachi, from 2005 to 2008. Pre-and post-treatment lateral cephalographs of 34 subjects were assessed. For half of the patients [n=17], treatment included the extraction of 4 premolars, whereas the other half were treated by the non-extraction approach. Incisal and soft tissue effects of treatment were analyzed and compared between both groups using the independent sample t-test to assess the degree of change with orthodontic treatment. Pearson's correlation test was used to determine correlation. The extraction group finished with a statistically significant reduction in upper and lower lip procumbency [p=0.004 and 0.021], while the non-extraction group finished with a slight increase in lower lip procumbency [p=0.009] due to significant increase in IMPA [p=0.046]. Although the premolar extraction group showed greater soft tissue changes with treatment, post-treatment comparisons showed that both groups finished within the same soft tissue parameters. Pearson's correlation revealed statistically significant correlations between the upper and lower lips and upper and lower incisors [p<0.01]. The effects of the two types of orthodontic treatment on the facial soft tissues were very similar, indicating that treatment, involving the extraction of premolars, does not have a detrimental effect on facial aesthetics provided the decision to extract is on sound basis and the mechanics are controlled

Comparison of three mixed dentition analysis methods in orthodontic patients at AKUH

To compare the actual sum of canine and premolars and that predicted from three mixed dentition prediction methods in orthodontic patients at the Aga Khan University Hospital [AKUH], Karachi. Cross-sectional comparative study. Orthodontic clinic at the Aga Khan University Hospital from June 2002 to December 2007. Data were collected using pretreatment records including orthodontic files and plaster casts of 121 orthodontic patients. Digital caliper was used to measure the mesiodistal widths of permanent teeth from 1st molar to 1st molar in mandibular arch, and central incisors and 1st molars in maxillary arch. The methods of Tanaka and Johnston, Moyers, and Bernabe and Flores-Mir were used to predict the mesiodistal widths of the canine and premolars. Comparison between the actual and predicted sum of the mesiodistal widths of canine and premolars was made for each prediction method, using paired sample t-test. There were 45 males and 76 females with average ages of 13.3 +/- 1.3 and 13.4 +/- 0.8 years respectively. For males statistically significant differences were found for Moyers at the 75th percentile and Bernabe and Flores-Mir method whereas for females only the Bernabe and Flores-Mir's method showed significant results. However, no significant difference was found in both genders for Tanaka and Johnston method. In the studied orthodontic patients for males Moyers 50th percentile and Tanaka and Johnston methods could be used; while for females Moyers 75th percentile and Tanaka and Johnston methods were applicable for mixed dentition analysis

Variability of arch forms in various vertical facial patterns

To compare arch forms in various vertical facial patterns and to make arch form guides based on posterior intermolar widths. Cross-sectional comparative study. The Aga Khan University Hospital, Karachi, from June 2007 to May 2008. Subjects with age range of 13-30 years were selected having full complement of teeth [upto second permanent molars] with absence of severe crowding [less than 7 mm]. Exclusion criteria were presence of dental anomalies, previous dentoalveolar surgery, trauma or orthodontic treatment and craniofacial syndromes. One hundred subjects including 40 normodivergent, 30 hypodivergent and 30 hyperdivergent cases were selected. Occlusograms were made and various arch dimensions were measured. Arch forms were calculated according to ratios of three sagittal to three transverse dimensions. The mean age of the sample was 21 years and 5 months. Differences in arch dimension were found only in maxillary total arch length [p=0.03] and mandibular posterior intermolar width [p=0.04]. Wide lower arches were predominant in all face types. Wide upper arches were predominant in only hypo- and hyperdivergent subjects. Wide lower arches were predominant in all face types whereas wide upper arches were predominant in both hype- and hyperdivergent subjects. A non-linear relationship was found between arch length and arch width; so arch form guides could not be made for specific face types