Arunachalam Sivakumar

Cephalometric assessment of dentofacial vertical changes in Class I subjects treated with and without extraction

INTRODUCTION There is disagreement concerning the effect of premolar extractions on the dentofacial vertical dimension. It has been suggested that orthodontic forward movement of the posterior teeth after first premolar extraction leads to reduction in vertical dimension. The purpose of this study was to examine cephalometrically the dentofacial vertical changes in Class I Indian subjects treated with and without extractions. METHODS The extraction group included 31 normodivergent patients (26 female, 5 male; pretreatment age, 17.19 +/- 3.89 years) with maxillary and mandibular first premolar extractions. The nonextraction group included 29 patients (18 female, 11 male; pretreatment age, 18.48 +/- 3.61 years). A coordinate system with the Frankfort horizontal plane and a mandibular fiduciary line was used for the cephalometric calibration. To determine vertical dimension changes due to treatment and to compare differences between the 2 groups, paired and unpaired t tests were performed, respectively. RESULTS Both groups had increases in linear vertical dimensions (P <0.05), but the change was comparatively greater in the extraction group (P <0.05). Mesial movement of the maxillary and mandibular posterior teeth was coincidental with the extrusion to such an extent that it increased the vertical dimension, although the mandibular plane angle remained unchanged during treatment. CONCLUSIONS Extraction of teeth only to increase the overbite or decrease the mandibular plane angle might not be justified.

Bimaxillary protrusion trait in the Indian population: A cephalometric study of the morphological features and treatment considerations

Abstract Purpose The orthodontic literature is discordant with the diagnosis of bimaxillary protrusion with no single anatomic answer and the anomaly has been referred in the literature with protean characteristics. The trait denotes a particular facial configuration and its cephalometric representation in certain ethnic and racial groups revealed a mixed pattern with individual variations. The present study was aimed at analyzing the dento-skeletal characteristics of bimaxillary protrusion in a sample of Indian men and women. Materials and methods Forty-six Indian subjects (28 women and 18 men; 19 ± 3.6 years of age) with Class I malocclusion and interincisal angle ≤110°, who attended orthodontic clinics for a comprehensive fixed orthodontic treatment were included for the study. The lateral films were hand traced and 27 parameters were measured. The data were imported to SPSS version 13 US package and statistical manipulation included means, standard deviation, and coefficient of variation (%). Male and female data were compared by Students t-test (unpaired). Correlation and regression analysis were performed to assess any relationship between different parameters. Results There was a marked increase in proclination of the maxillary incisors both to the maxillary plane (125.3 ± 5.7°), the NA line (35.1 ± 5.0°) and to sella–nasion (117.7 ± 5.5°). The positional relationship of the mandible to the maxilla with reference to the cranial base was within the normal limits (ANB = 3.1 ± 1.3°) and the skeletal pattern was Class I. The effective lengths of maxilla and mandible did not correlate significantly with sagittal skeletal discrepancy. Conclusion Unlike in other ethnic and racial groups, bimaxillary protrusion in Indian subjects is likely a bidental protrusion over normal dento-alveolar bases. The skeletal characteristics suggested a normal relationship of the functional components of the face. The condition could be treated successfully with orthodontic mechanotherapy alone.

Nucleotide variability of protamine genes influencing bull sperm motility variables

Protamines (PRMs), important proteins of chromatin condensation in spermiogenesis, are promising candidate genes to explore markers of sperm motility. The coding and in-silico predicted promoter regions of these genes were investigated in 102 crossbred and 32 purebred cattle. Also, mRNA quantification was done to explore its possibility as diagnostic tool of infertility. The PCR-SSCP analysis indicated there were two band patterns only in fragment I of the PRM1 and fragment II of the PRM2 gene. The sequence analysis revealed A152G and G179A transitions in the PRM1 gene. Similarly, G35A, A49G and A64G transitions were identified in the PRM2 gene which resulted in altered amino acid sequences from arginine (R) to glutamine (Q), from arginine (R) to glycine (G) and from arginine (R) to glycine (G), respectively. This caused the reduction in molecular weight of PRM2 from 2157.66 to 1931.33 Da due to reduction in the number of basic amino acids. These altered properties of the PRM2 protein led to the reduction in Mass Motility (MM: P < 0.01), Initial Progressive Motility (IPM; P < 0.05) and Post Thaw Motility (PTM; P < 0.05) in crossbred bulls. The least squares analysis of variance indicated there was an effect of PRM2 haplotypes on MM (P = 0.0069), IPM (P = 0.0306) and PTM (P = 0.0500) in crossbred cattle and on PTM (P = 0.0408) in the overall cattle population. Based on the RT-qPCR analysis, however, there was not any significant variation of PRM1 and PRM2 gene expression among sperm of Vrindavani bulls with relatively lesser and greater sperm motility.

Treatment of 3-prong anterior crossbite and unilateral lingual posterior crossbite malocclusion in an adolescent boy

R. V, a 16-year-old boy, presented with Class III end-on molar relationship on Class III skeletal base with below average mandibular plane angle and normal maxillomandibular differential. The upper canines were erupting, and late mixed dentition development was evident. Minimal spaces were present in both the arches. Normal transverse dimension of the dental arches was evident, but with some asymmetry in the mandibular arch. Left buccal segment was in lingual crossbite relationship, and the maxillary anterior teeth were characteristically locked in crossbite position with mandibular anterior teeth (3-prong crossbite). Treatment involved establishment of adequate curve of Wilson in the mandibular arch and mesialization of the maxillary buccal segment teeth using orthodontic miniscrews.

Understanding masticatory function in unilateral crossbites

Dr. Maria Grazia Piancino is a researcher and Aggregate Professor in Orthognathodontics at University of Turin, Italy. She along with Dr. Stephanos Kyrkanides, Dean, University of Kentucky, Lexington, USA, has brought the first book of its type “Understanding Masticatory Function in Unilateral Crossbites.” Authors have studied the malocclusion from a gnathological viewpoint both in terms of diagnosis as well as treatment. The authoritative nature of the text is very evident from its composition and conforms to the vast knowledge and experience of the authors. The authors have emphasized the tenets of masticatory function and associated dentofacial and skeletal dysfunction in detail. The clinical attributes of masticatory function in unilateral crossbites enlighten us to understand the muscular Ingram in a better way before planning for orthodontic treatment.

‘enter safe zone’: a versatile radiographic and surgical guide for miniscrew-implant placement

The use of miniscrew-implants for enhancing orthodontic anchorage has become standard care in many orthodontic practices. The present article describes a 3-dimensional, user-friendly, radiographic and surgical guide for the placement of miniscrew-implants in the safe zone.

Secondary retention of permanent molars in otherwise healthy adults: Three case reports

Secondary retention of permanent molars is an uncommon condition with poorly understood causative factors. Data concerning the mechanism of secondary retention in the permanent molars are insuffici...

Accentuated and reversed curve of Spee.

latency period was presented as early as 1971 in an original article by Ilizarov. The requirements for a latency period longer than 5 days to ensure appropriate maturation of the distraction callus and allow bone formation during the distraction phase were reported in this article. Several other reports also described a latency period before 1987. Reports specific to SARPE are listed in Table II of our review article. It is still unclear whether Drs Alpern and Yurosko recommend a latency period. Our aim in the article was to highlight the significant variations in the protocols used for SARPE among various studies in the literature. Drs Alpern and Yurosko’s article described clearly and thoroughly their surgical procedure, but a consistent postoperative protocol was missing in the article. We thank them for clarifying the rate of postoperative expansion protocol. Lokesh Suri Parul Taneja Boston and Chelsea, Mass Am J Orthod Dentofacial Orthop 2008;133:786-7 0889-5406/

Report of a new syndrome: Focus on differential diagnosis and review of Ellis-van Creveld, Curry-Hall, acrofacial dysostosis, and orofacial digital syndromes

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