Safe sites for buccal shelf bone screw placement in various skeletal malocclusions: A CBCT study.

INTRODUCTION: The mandibular buccal shelf area is an extra-alveolar anchorage site that has high quality and quantity of bone, provides biomechanical benefits and has low failure rates. It is essential to place the implant in the region of bone with optimal thickness. The aim of this study was to determine the suitable site of the mandibular buccal shelf for bone screw insertion at 90 degrees and 30 degrees angles of insertion and various heights, angulations, areas of the buccal shelf in prognathic and retrognathic mandibles, and vertical and horizontal growth patterns. METHODS: In this retrospective study, we evaluated the cone-beam computed tomography (CBCT) images of 48 patients in the age range of 18-30 years, divided into four groups. Seven sectional sites were examined at 3, 5, and 7 mm from the alveolar crest at 90 degrees and 30 degrees. The angulation and area of the buccal shelf were examined. RESULTS: Cortical bone thickness increased distally from the first to the second molar in all four groups. CONCLUSIONS: The preferred site for buccal shelf implant placement was distal to the mandibular second molar. The maximum amount of cortical bone was observed distal to the second molar, 7 mm vertically from the alveolar crest, when the buccal shelf implant was placed at 30 degrees angulation to the long axis of the tooth.

Comparative evaluation of dermatoglyphic patterns between skeletal class I and skeletal class III malocclusion.

Background: Dermatoglyphics is the study of various dermal configurations on the fingers, palms, and soles. These appear during the 12th week of intrauterine life and develop completely by the 24th week. It is said that they remain constant thereafter. The aim of the present study was to compare and assess the association of dermatoglyphic patterns between skeletal class I and skeletal class III malocclusion. Methods: Finger and palm prints were collected using the ink and roller method from 604 subjects who were divided into skeletal class I, class III with maxillary retrognathism and class III with mandibular prognathism based on lateral cephalogram assessment. Results: Loop pattern was more predominant in skeletal class I malocclusion subjects and whorl pattern was more frequent in the other two groups. Total finger ridge count and atd angle also showed significant difference between the study groups. Conclusions: The present study attempted in assessing the association between dermatoglyphic patterns and skeletal malocclusion. Analysing dermal configurations may aid in indicating the type of developing malocclusion and thus help in interceptive and preventive orthodontics.

Association between dermatoglyphic patterns and growth patterns of subjects with skeletal class I relation: A cross sectional study.

Background: To assess the relationship between dermatoglyphic patterns and various growth patterns of the mandible. Methods: Patients with Class I Skeletal relation were selected after clinical diagnosis followed by digitally tracing the cephalogram. The patients were subdivided into three groups of mandibular divergence patterns ie Average, Horizontal and Vertical. 90 samples ie 30 in each group were selected for the study. The fingerprints of all the selected subjects were then extracted digitally and analysed for the most dominant pattern in each hand. Results: For the left hand, there was a statistically significant (P<0.05) association between fingerprint pattern and growth pattern when Horizontal growers were compared to Average and Vertical Growers. For the right hand, there was a statistically significant (P<0.05) association between fingerprint pattern and growth pattern when Horizontal growers were compared to Average Growers. A significant association (P<0.05) between fingerprint pattern and growth pattern was also found when average growers were compared to vertical growers. Conclusions: Horizontal growers had 80% frequency of appearance of whorls in their left hand and 67% in their right hand. Horizontal growers could easily be differentiated from the average and vertical growers because of the dominance of whorl pattern in their hands. Composite and arch pattern were more frequent in vertical growers when compared to horizontal and average growers.

'Comparison and correlation of the maxillary sinus dimensions in various craniofacial patterns: A CBCT Study'.

Background: To compare and correlate the maxillary sinus dimensions and basal bone height among various facial patterns using CBCT for advanced diagnosis and treatment planning in Orthodontics. Methods: 66 CBCT images within age group of 18-30 years were divided into horizontal (Group 1), average (Group 2) and vertical (Group 3) facial growth patterns. Maxillary sinus dimensions were compared and correlated in all three groups. The sinus height and basal bone height were recorded at 3 locations-between 1 st premolar and 2 nd premolar (PM1-PM2), between 2 nd premolar and 1 st Molar (PM2-M1) and between 1 st and 2 nd molar (M1-M2). Results: Overall reduction in sinus height and significantly reduced sinus volume was seen in Group-1. Longest maxillary sinus height in M1-M2 region and shortest in PM1-PM2 region was seen in Group-3. The basal bone height in PM1-PM2 region was significantly longer in Group-3 than in Group-1(p<.05).Shortest basal bone height in M1-M2 region was seen in Group-3. A significant negative correlation was seen between the maxillary sinus height and the basal bone height in Group-1 and Group-3(p<.05). Conclusion: There is a correlation between the maxillary sinus height and basal bone height with that of facial pattern which needs to be considered during orthodontic treatment planning and while carrying out facial growth modification procedures in younger patients.

The morphology of sella turcica in cleft and non-cleft individuals.

AIMS AND OBJECTIVES: The aim of the study was to analyze the morphology and expedient the linear dimensions of Sella Turcica among cleft and non-cleft Indian individuals, and then to determine whether differences exist between different study groups. MATERIALS AND METHODS: The lateral cephalogram of 300 patients (150 cleft and 150 non-cleft), aged 18 to 30 years who reported for various treatments of malocclusions were studied. RESULT: The normal morphology of the sella turcica were seen in 85 of the 150 non-cleft individuals which was highest (56.66%) in the non-cleft group, however in the cleft group it was seen in only 16 of the 150 individuals (10.6%). Sella turcica bridge were seen in 10% of the non-cleft subjects, whereas in the cleft group it was seen in 38% of the individuals. A significant difference was seen in the linear measurements of the sella turcica of cleft and no-cleft individuals. CONCLUSION: The normal morphology of the sella turcica was seen in the majority of the non-cleft individuals. The cleft individuals showed an increased incidence of sella turcica bridging with reduced linear measurements of the sella as compared to the non-cleft individuals.

In vivo study on the release of nickel, chromium, and zinc in saliva and serum from patients treated with fixed orthodontic appliances.

BACKGROUND: Fixed orthodontic appliances can release metal ions such as nickel, chromium, and zinc into saliva and blood, which can cause contact dermatitis, hypersensitivity, and cytotoxicity. This study was undertaken to assess the release of nickel, chromium, and zinc in saliva and serum of patients undergoing fixed orthodontic treatment. MATERIALS AND METHODS: This in vivo study was conducted on 80 participants with an age range of 15-40 years. Thirty were included as controls and 50 participants were treated with fixed orthodontic appliances. Saliva and blood samples were collected at five different periods, before insertion of fixed orthodontic appliance and at 1 week, 3 months, 1 year, and 1.5 years after insertion of appliance, respectively. The metal ion content in the samples were analyzed by atomic absorption spectrophotometry. Mean levels of nickel, chromium, and zinc in saliva and serum were compared between groups using independent sample t-test and before and after results using paired t-test. P < 0.05 was considered as statistically significant. RESULTS: At the end of 1.5 years, the mean salivary levels of nickel, chromium, and zinc in controls were 5.02 ppb, 1.27 ppb, and 10.24 ppb, respectively, as compared to 67 ppb, 30.8 ppb, and 164.7 ppb at the end of 1.5 years. This was statistically significant with P < 0.001. A significant increase in the metal ion levels were seen in participants with before and after insertion of appliance (P < 0.001). CONCLUSION: Orthodontic appliances do release considerable amounts of metal ions such as nickel, chromium, and zinc in saliva and serum. However, it was within permissible levels and did not reach toxic levels.

Maxillomandibular plane angle bisector (MM) adjunctive to occlusal plane to evaluate anteroposterior measurement of dental base.

AIM: This study was undertaken to analyze the clinical usefulness of the maxillomandibular bisector, its reproducibility, its validity and its relationship to the functional occlusal plane, the bisecting occlusal plane and the nature of its cant. MATERIALS AND METHODS: Thirty pretreatment lateral cephalograms, each of adolescents (above 18 years of age) and children (10- 12 years), seeking orthodontic treatment were randomly selected and the Wits technique of anteroposterior measurement was used to compare A-B values measured to the new plane with those measured to the functional occlusal plane (FOP) and to the traditional or bisecting occlusal plane (BOP). RESULTS: Present study showed that MM bisector plane is more reproducible and valid reference plane, than the FOP and BOP. CONCLUSION: A new plane, geometrically derived from the dental base planes, has been tested as an occlusal plane substitute for the measurement of anteroposterior jaw relationships. It lies close to but at an angle and inferior to the traditional occlusal planes and is highly reproducible at all times. CLINICAL SIGNIFICANCE: Maxillomandibular planes angle bisector may be a useful adjunct for the cephalometric assessment of sagittal relationship of the patient.