A New Orthodontic-Surgical Approach to Mandibular Retrognathia

(1) Background: Mandibular deficiency is one of the most common growth disorders of the facial skeleton. Recently, distraction osteogenesis has been suggested as the treatment of choice for overcoming the limitations of conventional orthognathic surgery; (2) Methods: A new custom-manufactured dental-anchored distractor was built and anchored in the first molar and lower canine. It consists of a stainless-steel disjunction screw, adapted and welded to the orthodontic bands through two 1.2 mm diameter connector bars with a universal silver-based and cadmium-free solder; (3) Results: The distractor described can be a useful tool to correct mandibular retrognathia and is better tolerated by patients, especially in severe cases; (4) Conclusions: The dental-anchored distractor increases the anterior mandibular bone segment without affecting the gonial angle or transverse angulation of the segments and avoids posterior mandibular rotation, overcoming the limitations of conventional surgical treatment.

Forensic age assessment using Kvaal’s method with digital orthopantomographs (OPG) and comparison with the actual age of the subjects

Background: Forensic Dentistry is one of the branch of Forensic Medicine which deals with the complete handling of dental evidence, estimation and examination and the evidence obtained would be used in the court for justice. Kvaal and Solheim given a method used on adults for calculation of age with the help of morphological and radiological methods, but extraction was still required. Hence to improve this procedure Kvaal et al made a method which is totally based on radiological analysis. Aims and Objective: The present study was designed to compare the forensic age assessment using Kvaal’s method and digital orthopantomographs with the actual age of the subjects. Materials and Methods: Present observational study was conducted in subjects with all the required complement of teeth on either right or left side, completely erupted clinical crown, without any morphological abnormalities for age estimation by Kvaal’s method with digital orthopantomograph as and compared with actual age of subjects. Results: In the present study out of 100 subjects, maximum number of subjects i.e. 61 were in the age group of 20 – 29 and minimum number of subjects i.e. 7 were in the age group of 50 –59. 43 were females and 57 were males. The regression equation was derived for all six studied teeth and coefficient of determination R2 was found for all the individual six teeth. Coefficient of determination was highest for lower first premolar (0.517) followed by upper central incisor (0.178), lower canine (0.134), lower lateral incisors, upper second premolar and upper lateral incisors. M & W-L were found significant predictors for lower first premolar, lower canine and upper central incisors. Similarly, coefficient of determination (R2) was significant higher for lower three teeth (0.478) than upper three teeth (0.069) with M & W-L were significant predictor. Regression equation derived for all six teeth together shows significant coefficient of determination R2(0.430) with M, W-L both are significant predictors. No statistically significant difference between the actual age and estimated age for all individual six teeth was noted. Mean difference lowest for lower first premolar (0.001) followed by lower canine (0.007). Conclusion: We noted that age assessment using Kvaal’s method with digital orthopantomographas and actual age of the subjects were comparable & no significant difference was noted. Kvaal’s method with digital orthopantomographas is a better option for age estimation without teeth removal.

Measurement of the lower canine pulp chamber through periapical radiography for age estimation

Objectives: The principle of measurement using the TCI (Tooth Coronal Index) method is to compare the pulp chamber height with a person's chronological age based on the formation of secondary dentin. The purpose of this study is to estimate age based on pulp chamber height in lower canines using periapical radiographs with TCI measurement. Materials and Methods: This study is an observational analytic study using 42 samples of periapical radiographs with the parallel technique of the lower canines. Samples were measured for CH and CPCH heights to determine TCI values and then linear regression was made to determine their biological age. Finally, the difference between biological and chronological age is calculated to determine the approximate age. Results: The mean difference between chronological age and biological age was ± 5.05 years and an average biological age of 29.38 years. Conclusion: TCI method based on pulp chamber height in lower canines using periapical radiographs can be used to estimate age with the difference between chronological age and biological age of ±5.05 years.

A COMPREHENSIVE APPROACH TO THE TREATMENT OF PATIENTS WITH ALVEOLAR RIDGE ATROPHY IN PARODONTAL DISEASES: FROM THE USE OF BONE AUGMENTATION TO THE RESTORATION OF FUNCTIONAL OCCLUSION

The rate of atrophy is significantly lower with the included dentition defects than with the final ones, as the teeth that limit the newly formed defect are natural constraints for bone resorption. However, the comprised dentition defects are not able to prevent the pathological process in the inflammatory-destructive process and generalized diseases in parodontal tissues, which in the future will affect the choice of prosthetic restoration and patient’s aesthetic appearance. Therefore, in the complex treatment of parodontal diseases, functional occlusion plays a remarkable role, which is achieved by rational prosthetics with prosthetic restoration made in articulators customized for individual function by CAD/CAM technology to eliminate traumatic interference and evenly distribute the masticatory load on the dentition and parodontal tissues. The aim of the study is to increase the therapeutic efficacy for patients with alveolar ridge atrophy in generalized parodontal diseases due to the inflammatory-destructive process from the use of bone augmentation followed by prosthetic rehabilitation of such patients and the development of a treatment approach. Materials and methods: Preliminary examination of patients was carried out according to the generally accepted methods of subjective and objective examination. Spot-film radiography, computed tomography, diagnostics were performed in an individually adjusted articulator, orthopantomogram, Vita Easyshade Advance 4.0 device. A digital database has been created in Microsoft Excel for the calculations. Statistical processing of the results was performed by the "Statistica 6.0" software. The canine guide on the laterotrusion side causes the distal-buccal surface of the lower canine of the working side to slide along the palatal slope of the upper canine of the working side. According to the table, among 25 patients of female patients 15 patients dominate in the gender assessment of the results, including 11 patients who underwent a comprehensive treatment of parodontal diseases with apical complications from the use of bone augmentation, which estimated 73.3% (p<0.05). The other 4 patients, which estimated 26.7% (p<0.05) of the total number of female patients were treated without the use of bone augmentation. In the treatment of male patients, the distribution was as follows: 7 patients, which estimated 70% (p<0.05) of the total number of male patients, underwent comprehensive treatment of parodontal disease with bone augmentation, 3 patients (30% (p<0.05)) underwent comprehensive treatment of parodontal diseases without the use of bone augmentation. Therefore, there were 25 patients with generalized parodontal disease with apical complications, 18 patients (72% (p <0.05)) of all patients without gender distribution received comprehensive treatment with bone augmentation, 7 patients (28% (p<0.05)) without regard to gender, comprehensive treatment was performed without the use of bone augmentation. Destructive processes in generalized parodontal diseases with apical complications cause bone defects that have to be replaced to rebuild the implant site and areas of restoration. The directed or nondirectional bone augmentation was used for this purpose. However, the directed bone augmentation with bioresorbable membranes is not sufficient at considerable bone defects. A strong skeleton is required for this purpose, which will provide additional mechanical support to counteract the load from the upper tissues and external factors, increase the regenerative potential, be able to save the bone from resorption; it will not be resorbed by itself and will form the necessary pattern of the alveolar process. At the same time, the masticatory load on the parodontal tissues normalizes due to the restoration of the anatomical relief of the occlusal relations, which will ensure the durability of prosthetic restoration made by CAD/CAM technology and comfortable use.

Assessment of the quality of life of orthodontic and surgical patients. Analysis of the factors that motivate the initiation of treatment within the masticatory system

IntroductionAccording to Angle's classification, a correct bite should have, inter alia, the following regularities: the median line of the face should coincide with the line between the central incisors of the upper and lower arches, the lower incisors should be overlapped by the incisal edges of the upper incisors, the top of the canine in the upper arch is inserted between the lower canine and the tangent premolar, each tooth is in contact with two opposing teeth, adjacent teeth both in the upper and lower arch are in contact with each other. Any deviation from these rules may indicate the presence of a malocclusion. We can distinguish here, for example: posteroclusion, open bite, retrusive occlusion, protrusive occlusion, supraclusion bite. They seem to be important not only in terms of functionality, but also psychology. Research shows that the correction of mandibular prognathism increases the level of self-confidence and self-acceptance, which may improve the quality of life of patients.Purpose of researchThe aim of the study was to check the quality of life of orthodontic and surgical patients as well as what factors motivate these people to start treatment in the area of the masticatory system.Material and methods208 people aged 18 to 55 participated in the survey. They were both people with malocclusion and no malocclusion, who constituted the control group. The questionnaire was created on the basis of standardized OQLQ and OHIP-14 questionnaires. It also included questions about the factors that motivate to start treatment in the masticatory system.ResultsThe most common malocclusion among the respondents was progenia (58.8%), followed by retrogenia (34.3%), then open bite (4%) and posteroclusion (2.9%). According to the OHIP-14 form, statistically significant (p <.0001) higher quality of life was seen in people without a masticatory organ defect, compared to people with the malocclusion. A statistically significant difference (p <.0001) between people with present or recent malocclusion (M = 54.29, SD = 16.71) and people without malocclusion (M = 31.93, SD = 18.31) was also visible in the study with using the OQLQ questionnaire.ConclusionsA malocclusion worsens the comfort and quality of life.Incorrect bite, face and smile aesthetics as well as psychological aspects are the most important factors motivating to undertake surgical and orthodontic treatment.Bruxism and facial pain are not factors prompting the initiation of treatment of malocclusion.

Evaluation of Growth and Development of Adolescents’ Dental Arch Asymmetry with Normal Occlusion Using Three-Dimensional Digital Models

Objective. The purpose of this study was to observe the dental arch asymmetry in 12-year-olds with normal occlusion during the early permanent dentition stage. Methods. Ninety-two 12-year-old students (46 males and 46 females) who had normal occlusion during early permanent dentition were selected from a junior high school in Tangshan, China. Once per year for three consecutive years, a dental cast was obtained from each subject, and the cast was scanned with a 3D digital scanner (R700 3D). The median palatal plane (MPP) and transverse palatal plane (TPP) were used as the reference plane for the transverse and anteroposterior measurements, respectively. Results. Most of the dental arch asymmetry indicators decreased with age, but these differences were not statistically significant. The values of the midincisal edge of the upper central incisors (U1), midincisal edge of the upper lateral incisors (U2), upper canine cusp tip (U3), upper first premolar buccal cusp tip (U4), upper second premolar buccal cusp tip (U5), upper first molar mesiobuccal cusp tip (U6MB), and upper first molar distobuccal cusp tip (U6DB) to the TPP were 0.019 mm, 0.279 mm, 0.017 mm, 0.016 mm, 0.016 mm, 0.027 mm, and 0.200 mm, respectively; these values were larger in males than in females ( P < 0.05 ). The values of 2–5, 6MB, and 6DB-TPP were 0.154 mm, 0.102 mm, 0.119 mm, 0.259 mm, 0.206 mm, and 0.123 mm, respectively, larger in the mandibular than in the maxillary dental arch ( P < 0.05 ). The values of the midincisal edge of the lower central incisors (L1), midincisal edge of the lower lateral incisors (L2), lower canine cusp tip (L3), lower first premolar buccal cusp tip (L4), lower second premolar buccal cusp tip (L5), lower first molar mesiobuccal cusp tip (L6MB), and lower first molar distobuccal cusp tip (L6DB) to the MPP were 0.399 mm, 0.197 mm, 0.258 mm, 0.248 mm, 0.214 mm, 0.575 mm, and 0.531 mm, respectively, larger than L1-5, L6MB, and L6DB-TPP ( P < 0.05 ). Conclusion. The asymmetry of the dental arch in 12-to-15-year-olds with normal occlusion did not change significantly with age. The anteroposterior asymmetry of the maxillary dental arch is larger in males than in females. With the exception of the central incisor, the anteroposterior asymmetry of the mandibular dental arch is larger than that of the maxillary dental arch. The transverse asymmetry of the mandibular dental arch is larger than the anteroposterior asymmetry.

Primates from the Baynunah Formation

Fossil primates of the Baynunah Formation are represented by only two cercopithecoid specimens: AUH 35, a male lower canine of an indeterminate cercopithecid from site JDH-3, and AUH 1321, a lower molar of a guenon from site SHU 2-2. Although rare, these cercopithecoid primates are significant in terms of their age and biogeographic implications. AUH 1321 is the earliest known guenon in the fossil record, and at ~8 – 6.5 Ma, it is also one of the earliest cercopithecines known. The age and geographic position of both specimens in the Arabian Peninsula supports late Miocene Eurasian dispersal scenarios for cercopithecoid primates out of Africa and through Arabia before the Messinian Crisis. Whether or not this dispersal included both cercopithecines (macaques) and colobines is unclear, and it re- mains possible that both groups also dispersed across the Mediterranean Basin or Straits of Gibraltar during the Messinian as well. Among the potential Arabian dispersal routes, there is perhaps some support for the southern path over the Straits of Bab el Mandeb based on the presence of ~8 – 5.5 Ma cercopithecine and colobine fossils in the East African fossil record, geographically close to the Horn of Africa.

Transmigrated mandibular canines: clinical considerations and orthodontic biomechanics for the approach of orthodontic traction. A scoping review

This scoping review aims to identify the clinical considerations and orthodontics biomechanics of applying the orthodontic traction approach to transmigrated mandibular canines. The search strategy followed the PRISMA for scoping reviews and was based on six databases, Cochrane C.R.C. Trials, BVS, PubMed (NLM), Google Scholar, Web of Science, and SCOPUS, and included articles published as recently as February 2021. The records had to identify lower canines traction protocols and outcomes. The publications obtained had to meet criteria for the structure of the research and bibliography. The search included combinations of the keywords lower canine, cuspid, and transmigration, along with the terms biomechanics and scoping review in the databases. Only after a consensus of the three reviewers had been reached were the articles retrieved. When a transmigrated lower canine has already erupted, orthodontics biomechanics traction begins by bonding tooth buttons and/or bracket prescriptions: MBT 0.022” x 0.028”, Roth 0.018” x 0.022”, and/or Beggs rectangular arches, ligatures, and elastics. Surgical interventions may be added. The treatment time varied from 22 months to 3.6 years. The final occlusal relationships were satisfactory and did not cause damage to the surrounding tissues. Among the selected articles, the orthodontic biomechanics showed the complexity of the movements. An appropriate occlusion and stability were achieved. Failures in the approach were also found. The clinical considerations show this approach to be viable but to have inherent risks, which include the proximity of the canines to the lower incisor roots.

Universal Adhesive for Fixed Retainer Bonding: In Vitro Evaluation and Randomized Clinical Trial

This study aims to assess the efficacy of a universal adhesive (Scotchbond Universal, 3M ESPE) (SB) in total-etch mode, compared to a traditional orthodontic primer (Transbond XT Primer, 3M ESPE) (XT Primer), to perform bonding of orthodontic fixed retainers along with the Transbond XT Light Cure Adhesive Paste (3M ESPE). For the in vitro study, a round section wire (Ortosmail Krugg) was bonded using XT Primer for 20 bovine incisors (Group 1) and SB for other 20 (Group 2). Samples were debonded in a universal testing machine applying a tangential force to specimens (crosshead speed of 1 millimeter per minute). Shear bond strength (SBS) and adhesive remnant index (ARI) scores were calculated. For the in vivo study, 100 patients needing upper and lower canine-to-canine fixed retainers after orthodontic treatment were randomly assigned to two groups of 50 participants each, i.e., group 1 (retainer bonding with XT Primer) and group 2 (retainer bonding with SB). Over two years, examinations were carried out monthly, and detachments were registered by considering the teeth and arches affected. In vitro, no statistically significant differences in SBS and ARI scores were demonstrated between the two groups, both showing a mean bond strength of about 12 MPa and major frequency of ARI “2” (>50% remnant adhesive on the enamel). Conversely, a significantly lower failure rate over 2 years was assessed clinically for group 2 in both arches. Independently of the adhesive and arch, incisors reported a significantly higher failure rate than canines. Scotchbond Universal used in total-etch mode could be a valid alternative to the traditional orthodontic Transbond XT Primer.