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Biomedical subjects

Dror Aizenbud

Publications and source records attributed to Dror Aizenbud.

9 recordsLinked to original sources

Comparison of second molar eruption patterns in patients with skeletal Class II and skeletal Class I malocclusions.

INTRODUCTION: The eruptive positions of the second molars in Class I and Class II malocclusions were studied. METHODS: Pretreatment records of 221 patients with a mean age of 11.3 years were evaluated. About 19% of them had skeletal Class I, 31% had skeletal maxillary Class II, and 50% had skeletal mandibular Class II malocclusions. RESULTS: The mean values of the dental and chronologic ages of the subjects were similar. The eruptive positions in relation to a reference line, the developmental stages of the patients' second molars and dental ages were recorded from the panoramic roentgenograms. The distribution of the various developmental stages in each malocclusion group was similar, and no association between skeletal malocclusion and dental developmental stage of the second molars was encountered. The eruptive position of the maxillary second molars was more occlusal only in the oldest maxillary Class II group, above 12 years of age (P = .02). CONCLUSIONS: These results support, in part, previous reports suggesting that the maxillary second molars may erupt earlier in patients with skeletal maxillary Class II malocclusions.

Analysis of Variance↗

Nasal airflow and olfactory function after the repair of cleft palate (with and without cleft lip).

OBJECTIVE: The objective of this study was to examine nasal airflow and olfactory functions in patients with repaired cleft palate compared with matching normal controls. STUDY DESIGN: The all-cleft group consisted of 25 patients with hard palate cleft comprising 15 patients with unilateral cleft palate and lip (UCLP); 2 with CP but no cleft lip (UCLP subgroup) and 8 patients with bilateral cleft lip and palate (BCLP subgroup). All had had surgical correction of the palate in infancy. The control group consisted of 20 nonaffected orthodontic patients. The median age of both groups was 14 years. The tests included the following: (1) nasal airflow measured by anterior rhinomanometry, (2) smell threshold for isoamyl-acetate determined using a 3-way forced choice method, (3) a self-administered questionnaire regarding the subjective perception of smell sense function, and (4) orthonasal and retronasal smell identification (correct/incorrect) and hedonics using visual analog scale (VAS). RESULTS: The respective test results follow. (1) When compared with the control group, the total airflow in the UCLP subgroup was significantly lower especially on the affected side; while in the BCLP subgroup it was lower than in the control group bilaterally. No significant difference was found between the cleft side of UCLP and BCLP subgroups. (2) The smell threshold of the UCLP subgroup was significantly higher than that of the control group and BCLP subgroup. No significant differences were found between right and left nostrils within the BCLP patients and between them and the control group. (3) No difference was found between the groups regarding the subjective perception of smell. (4) No significant differences were found between the UCLP and BCLP subgroups and between the all-cleft group and the control group, except for one item, regarding orthonasal and retronasal smell identification and hedonics. CONCLUSION: Although nasal airflow is significantly lower and the smell threshold higher on the cleft side, the day-to-day function of the sense of smell of cleft patients is similar to that of normal controls.

Adolescent↗

Congenitally missing teeth in the Israeli cleft population.

OBJECTIVE: The purpose of the study was to determine the prevalence of congenitally missing teeth in a group of Israeli children with various types of clefts. DESIGN: Prevalence of congenitally missing teeth was determined for 179 children with cleft lip, cleft lip and alveolar ridge, cleft lip and palate, and cleft palate. Subgroupings were assessed according to patient sex, origin, cleft type, tooth type, and the side of hypodontia. The diagnosis of congenitally missing teeth (CMT) was based on initial and follow-up panoramic roentgenograms. In case of doubt, occlusal or periapical roentgenograms as well as clinical dental photographs were also used. SETTING: Data collection was conducted at the Rambam Medical Center, Orthodontic and Craniofacial Unit, Haifa, Israel. RESULTS: In the total cleft group, 67.6% of the patients presented with hypodontia, totaling 246 missing teeth. A statistically significant difference was found in the distribution of patients with CMT of Jewish and minority origin according to sex. Cleft lip and palate was the most frequently affected group in which 195 teeth were missing. The most frequently missing tooth among the cleft population was the maxillary incisor. The order of frequency of the other missing teeth was the same as in the normal population. Hypodontia and malformations of permanent teeth were most common on the cleft side. CONCLUSION: The frequency of CMT in the Israeli cleft population studied was higher than in the intact population. This confirms findings in other populations worldwide.

Adolescent↗

Treatment of osseous cleft palate defects: a preliminary evaluation of novel treatment modalities.

OBJECTIVE: To compare the use of autogenous iliac bone graft (ABG) alone with nonresorbable expanded polytetrafluoroethylene Gore-Tex TR membrane (GTM) and with ABG plus resorbable Resolut XT membrane barriers for the secondary closure of alveolar cleft defects. STUDY DESIGN: Fifteen patients aged 9 to 17 years with unilateral cleft palate were included in this study. All patients had primary closure of the soft tissues at infancy. Presurgical orthodontics and scaling preceded the surgery. The patients were randomized to one of three surgical treatment groups: (1) ABG, (2) GTM, or (3) autogenous bone plus resorbable membrane (ABM). Periapical radiographs were taken pretreatment and 2 to 6 years later and were used to measure changes in size (linear and area) of the osseous defect. RESULTS: Significant decreases were observed in mean initial defect width (9.8 to 6.7 mm; p = .0263), mean initial defect height (20.7 to 15.1 mm), and overall mean defect size (223.6 to 143.9 mm2). Greater improvement in mean defect width was observed for the ABM group (6.42 mm) compared with the ABG (1.22 mm) and GTM (1.38 mm) groups. The reduction in overall mean defect size was significantly greater in the ABM group (177 mm2) compared with the GTM (20.51 mm2) and ABG (41.69 mm2) groups. CONCLUSION: Guided bone regeneration was found potentially useful for the treatment of osseous cleft palate defects. The combined approach yielded significantly greater defect fill. If further substantiated in larger independent studies, the adjunctive use of barrier membranes could improve the management of secondary closure of cleft palate defects.

Absorbable Implants↗

Comparing the effects of V-Y advancement versus simple closure on upper lip aesthetics after Le Fort I advancement.

PURPOSE: The aim of this study was to compare upper lip movement and its dimensional changes after maxillary advancement via Le Fort I osteotomy, using V-Y advancement versus simple continuous closure. The study investigates dimensional changes in the superior and inferior portions of the upper lip, as well as changes in lip length, resulting from the procedure. PATIENTS AND METHODS: The study group consisted of 35 patients who had undergone 1-piece Le Fort I osteotomy for maxillary advancement of 3 to 6 mm with less than 3 mm of vertical changes. Fixation was performed by rigid monocortical plating. Closure of soft tissue was achieved using V-Y advancement in 17 patients and simple continuous suturing in 18 patients. Lateral cephalometric radiographs were taken and measured preoperatively and then 6 months after surgery. RESULTS: The magnitude of upper lip movement was 88.89% of the maxillary advancement in the simple continuous suturing group and 90.77% in the V-Y advancement group. The superior portion of the upper lip thickened by 2.08 mm and 2.35 mm in the 2 groups, respectively. The inferior portion of the upper lip thickened by -1.94 mm and -1.14 mm, respectively. The upper lip shortened by 0.79 mm in the simple continuous suturing group and lengthened by 1.10 mm in the V-Y advancement group. CONCLUSIONS: Upper lip movement and dimensional changes differ when simple continuous suturing and V-Y advancement closure are used.

Adolescent↗

Enhancement of bone formation by bone morphogenetic protein-2 during alveolar distraction: an experimental study in sheep.

BACKGROUND: The purpose of this study was to perform alveolar ridge augmentation by distraction osteogenesis (DO) and to enhance bone regeneration through the use of recombinant human bone morphogenetic protein-2 (rhBMP-2), followed by implant placement. METHODS: Alveolar segmental osteotomy was performed in the mandible of 10 sheep followed by placement of 1.5 mm alveolar distraction devices. The study group was injected on the fifth day of distraction with a single dose of 10 microg rhBMP-2. Only distraction was performed in the control group. RESULTS: A mean alveolar augmentation of 12 mm was achieved. After 12 weeks of consolidation, the distraction devices were removed and biopsies were taken for histological and immunohistochemical characterization and morphometry of the newly formed bone. Titanium threaded cylindrical implants were then placed in the newly augmented bone. Radiological evaluation showed lifting of the transport segment and integration of the implants within both the transport segment and the regenerated bone. The histological study demonstrated that the association of DO and BMP resulted in increased trabecular bone size and volume (32.2%+/-0.95% versus 18.6%+/-0.71%; P <1 x 10(-17) after 24 days of lengthening and 63.8%+/-1.89% versus 42.5%+/-1.33%; P<1 x 10(-15) after 12 weeks of consolidation) and increased numbers of proliferating cell nuclear antigen stained cells (0.7+/-0.04 versus 0.47+/-0.04; P<1 x 10(-10)) compared with the DO only group. CONCLUSIONS: Alveolar distraction augments atrophic alveolar ridge and creates new bone that permits implant placement. rhBMP-2 enhances bone quality and may shorten the consolidation period of distraction allowing for earlier implant placement.

Alveolar Bone Loss↗

[Application of Ilizarov method in maxillofacial treatment].

Distraction osteogenesis is becoming the treatment of choice for the surgical correction of hypoplasias of the maxillofacial skeleton. The mandible can be elongated by intraoral or extraoral devices. The intraoral devices are smaller, do not leave an external scar and do not cause social inconvenience to the patient. The main disadvantages are less control of vector and the need for a second operation for removal. The most important factors of mandibular distraction are planning of distraction, location of the osteotomy, control of vector of lengthening and type of distraction device. In the maxilla, our experience with three types of maxillary distraction is discussed: 1) the rigid extraoral distraction, 2) the surgically assisted protraction and 3) the intraoral method. In the last years, distraction osteogenesis was applied in the treatment of obstructive sleep apnea. The method has several advantages over other methods, mainly in treatment of young children in order to improve airway and to decannulate tracheostomy. Alveolar distraction osteogenesis poses a new challenge in reconstructing atrophic alveolar bone with no need to harvest bone graft or to use bone substitutes. The advantages and problematic issues of alveolar distraction such as vector control of distraction are described. The intraoral method should always be considered first. However, in severely hypoplastic patients, when three-dimensional correction is necessary, the extraoral device has an advantage over the intraoral device. In the future, the issues to consider will be improvement of osteotomies by endoscopy, development of smaller multidirectional devices, improvement of bone quality by cytokines and growth factors in order to shorten the time of device bearing by the patients.

Facial Bones↗