Ben-Bassat, Yocheved
Dept. of Orthodontics Hebrew University - Hadassah Faculty of Dental Medicine P. O. Box 12272 Jerusalem, Israel Telephone: 972-2-677-6169 Fax: 972-2- 6427613
E-mail :Yochevedb@ekmd.huji.ac.il

Born 1947, Szczawno-Zdroj (Poland)
D.M.D. 1973, Hebrew University
Instructor 1977
Lecturer 1986
Clinical Senior Lecturer 1993
Other appointments:
Assistant Research Orthodontist, University of California, San Francisco, 1980
Visiting Professor, University of California, San Francisco, 1989.
Director of Undergraduate Studies, 2010

Research Interests:

• Dentofacial configuration in various ethnic groups.
• Dento-facial configuration under special conditions like trauma, multiple congenitally missing teeth, systemic diseases, scoliosis, ocular torticollis.
• Masticatory pattern of patients with unilateral posterior-cross-bite.
• Changes in the orthodontic undergraduate curriculum.
• Mandibular border remodeling .
• Asymmetries in craniofacial growth .

Research Projects:

•  Occlusal development of individuals with ocular torticollis.

•  Skeletal characteristics of individuals presenting multiple congenital absences of teeth. Funding: Hebrew University Hadassah SDM and Hadassah, Joint Research Fund (partial).

•  Mandibular border remodeling.

•  Optimizing Superimposition of Lateral Cephalograms on the Mandibular Symphysis.

Abstracts of current research:

• Skeletal and functional effects of treatment for unilateral post cross-bite. This study examined in detail the morphologic, skeletal, and functional effects of the treatment for this malocclusion category. The experimental group consisted of 24 children in the mixed dentition stage with UPXB who were treated with removable expansion plates and a control group of 10 age-matched children with normal occlusion. Longitudinal follow-up revealed a stable dental maxillary arch expansion of at least 1.5 mm but a complete elimination of crossbite in only 50% of the cases. The frequent persistence of Class II subdivision relations and lower midline deviation that were not due to functional mandibular shift was striking. The pretreatment posteroanterior (P-A) cephalograms indicated reduced facial and maxillary widths. After treatment, the achieved maxillary width increase was greater than expected with normal growth. Longitudinal assessment of the mandibular movement response revealed by the electrognathograph showed a high prevalence of RS (reversed sequencing), which was reduced after treatment.
• Alveolar changes associated with mandibular border "remodeling": This study aimed to quantify the amount of alveolar modeling at the apices of the lower incisor and the lower first molar specifically associated with appositional and resorptive changes on the lower border of the mandible during growth. Cephalometric data from superimpositions on (1) anterior cranial base, (2) mandibular implants of the Bjork type, and (3) anatomical "Best fit" of mandibular border structures have been integrated. The average magnitudes of the changes at the root apices of the lower first molar and the lower central incisor associated with modeling/remodeling of the mandibular border and symphysis were surprisingly and unexpectedly small. The findings for mandibular alveolar change reported were only one fourth as large as the analogous changes in the maxilla which were reported for the same sample using the same method. They are consistent with the belief that dental displacements in association with surface modeling play a smaller role in final tooth position in the mandible than they do in the maxilla. It may also be reasonably inferred that anatomical "best fit" superimpositions made in the absence of implants give a more complete picture of total tissue turnover in the mandible than they do in the maxilla.
• Does secular trend exist in the distribution of occlusal patterns? The existence of secular trend in the distribution of occlusal patterns in two generations of the same ethnic group was studied. Study models and demographic data of a sample of 265 children of the previous generation and recordings of clinical examination of 988 children of the present generation served as the data base for this study. Children in whom caries affected occlusion and those in the deciduous dentition stage were excluded. Thus occlusal analysis was performed for 102 children in the previous generation (Group A) and 703 in the present generation (Group B). In addition to a dramatic decrease in the prevalence of caries affecting occlusion, no difference between the two groups in respect to molar and canine anteroposterior relationships was found. However, there was a decrease in the prevalence of normocclusion accompanied by an increase of class I malocclusion.
• Bone/tooth movement ratio during upper incisor retraction. The hypothesis that "bone follows tooth movement" was evaluated on cephalograms of 40 Angle Cl.II cases. It was hypothetized that a 1:1 cortical bone rmodeling (B)/tooth movement (T) ratio is maintained during upper incisor retraction. Pre- and post treatment cephalograms were analyzed. The results revealed a B/T ratio of 1:2 and 1:2.35 in two different orthodontic movements, indicating that "bone follows tooth movement" only to a limited extent.
• Profile of an orthodontic patient at risk of dental trauma. Increased overjet and inadequate lip coverage of the maxillary incisors are considered significant risk factors in many clinical studies. The purpose of the present study was to examine this issue of dental injury by actual cephalometric measurements in orthodontic patients, who experienced trauma to their maxillary incisors and compare them to patients with intact incisors. No statistically significant differences between boys and girls were found. Overjet or maxillary incisor exposure or interlabial gap, each as a single variable, could differentiate between the two groups. Logistic regression analysis indicated that only a small percentage (28.7%) of the dependent variable variation (trauma vs control) can be explained by interlabial gap, upper incisor long axis to facial plane (degree), upper incisor long axis to interlabial gap and overjet.
• Retrospective survey of cleft patients treated in a Dept. of Orthodontics. The cleft palate team was established in the Hadassah Medical Center about40 years ago, however, the treatment rendered by the orthodontic members ofthe team was never evaluated. To establish a database for further studiesof the 871 cleft patients treated by our team a questionnaire was sent to542 patients with known addresses. The questionnaire aimed at complementing the demographic, cleft related and treatment related data in the patients' files. The Access and Excel software's were used for data processing and x2test was applied. Out of the 152 respondents (28% out of the 542 patients with known addresses) 23.7% had cleft lip (CL), 48% a combined cleft of thelip and palate (CLP) and 28.3% cleft palate (CP). These as well as the gender distribution and association with additional anomalies were similar to those reported in the literature. Most patients were the 3rd child to their mothers and had normal birth weight. The percentage of parental "in family" marriages was 4 times that of the average in Israeli population and30% reported additional cleft in the family. Most of the CLP patient's were treated with presurgical orthopedic plates. Majority of the patients in all cleft categories underwent one lip and/or one palate operation. About a 1/4 of the patients had early orthodontic treatment while over 1/2 received comprehensive orthodontic treatment. This preliminary report shows similarities with cleft patients treated in other centers. It allows further in-depth evaluation of the orthodontic treatment of cleft patients.
• Optimizing Superimposition of Lateral Cephalograms on the Mandibular Symphysis. This study aims to identify the most stable cephalometric landmarks in the mandibular symphysis for use in cephalometric registration. Currently the displacement of selected landmarks on the mandibular symphysis is studied on cephalometric data of a sample with mandibular implants of the Bjork type.

  Key Words: Orthodontics, craniofacial morphology; craniofacial growth; cross-bite; electrognathograph; masticatory pattern; cephalometrics; implants; superimpositions; occlusal function, dental trauma, secular trend, cleft lip and palate; mandibular border remodeling; superimposition on symphysis;

Recent and selected publications:

Ben-Bassat Y, Brin I, Jarjoura R, Regev E. Morphological occlusal features following condylar fractures in children. Er J Orthod Advanced access published February 2011.

Ben-Bassat Y, Brin I. Maxillary canines in patients with multiple congenitally missing teeth – a roentenographic study. Seminars in Orthod. 2010;16:193-8.

Ben-Bassat Y, Brin I. Skeletal and dental pattern in patients with severe congenital absence of teeth. Am J Orthod Dentofacial Orthop. 2009;135:349-356.

Chaushu S, Bongart M, Askoy A, Ben-Bassat Y, Becker A. Buccal ectopia of maxillary canines with no crowding. Am J Orthod Dentofacial Orthop. 2009;136:218-223.

Chaushu S,Dykstein N, Ben-Bassat Y, Becker A. Periodontal status of impacted maxillary incisors uncovered by 2 different surgical techniques. Oral Max Surg. 2009;67:120-124.

Ben-Bassat Y, Yitschaky M, Kaplan L, Brin I. Occlusal patterns in patients with idiopathic scoliosis. Am J Orthod Dentofacial Orthop 2006;130:629-33.

Ben-Bassat Y, Huri M, Brin I. Orthodontic education for a changing professional environment. Orthodontic Forum 2006;2:145-53. 

Brin I, Ben-Bassat Y, Hirschfeld Z. Conservative adjunct to esthetic orthodontic treatment in young patients. Compend Cont Educ Dent. 2005;26:791-8.

Ben-Bassat Y, Brin I.. Skeleto-dental pattern in patients with multiple congenitally missing teeth. Am. J. Orthod. Dentofacial Orthop. 2003;124:521-5.

Brin I, Bar-Abudi R, Abed Y, Ben-Bassat Y, Harari D, Zilberman Y. A retrospective study of orthodontic treatment of children with clefts. Refuat Hapeh Vehashinayim. 2003;20:65-70 (Hebrew, with English summary).

Chaushu S, Brin I, Ben-Bassat Y, Zilberman Y, Becker A. Periodontal status following surgical-orthodontic alignment of impacted central incisors with an open-eruption technique. Eur. J.Orthod, 2003;25:579-84.

Becker A, Brin I, Ben-Bassat Y, Zilberman Y, Chaushu S. Closed-eruption surgical technique for impacted maxillary incisors: a postorthodontic periodontal evaluation. Am J Orthod Dentofacial Orthop, 2002;122:9-14.

Ben-Bassat, Y and Brin, I. The labio-gingival notch: an anatomical variation of clinical importance. J. Am. Dent. Assoc. 2001; 132:919-21.

Ben-Bassat Y, Brin I, Brezniak N. Can maxillary incisor trauma be predicted from cephalometric measurements? Am. J. Orthod Dentofacial Orthop. 2001; 120;186-9.

Brin, I, Ben-Bassat, Y, Heling, I, and Brezniak, N. Profile of an orthodontic patient at risk of dental trauma. Endod. Dent.Traumatol. 2000; 16:111-5.

Vardimon AD, Oren E, Ben-Bassat Y. Cortical Bone remodeling/tooth movement ratio during maxillary incisor retraction with tip versus torque movements. Am. J. Orthod. Dentofacial Orthop, 1998; 114:520-9.

Ben-Bassat Y, Brin I, Gilboa I, Koyoumdjisky-Kaye E. Dentofacial pattern of two Jewish ethnic groups compared with accepted norms. Int. J. Anthrop. 1996; 11:81-93. 

Baumrind S, Ben-Bassat Y, Bravo LA, Curry S, Korn EL. Partitioning the components of maxillary tooth displacement by the comparison of data from three cephalometric superimpositions. Angle Orthod.1996; 66:111-24.

Ben-Bassat Y, Yaffe A, Brin I, Freeman J, Ehrlich, J. Functional and morphological-occlusal aspects in children treated for unilateral posterior cross-bite. Europ. J. Orthod. 1993; 15:57-63.

Baumrind S , Ben-Bassat Y, Korn EL, Bravo LA, Curry S. Mandibular remodeling measured on cephalograms: 2. A comparison of information from implant and anatomic best-fit superimpositions. Am. J. Orthod. Dentofacial Orthop. 1992;102:227-38.

Ben-Bassat Y, Brin I, Fuks A, Zilberman Y. Effect of trauma to the primary incisors on permanent successors in different developmental stages. Pediatric Dentistry 1985; 7: 37-40.