Testing causal mechanisms of nonsyndromic craniosynostosis using path analysis of cranial contents in rabbits with uncorrected craniosynostosis.

OBJECTIVE: Various causal mechanisms of familial nonsyndromic craniosynostosis have been presented. One hypothesis suggests that overproduction of bone at the suture is the primary origin of craniosynostosis, which affects brain and cranial growth secondarily through altered intracranial pressure (Primary Suture Fusion Model). Other hypotheses suggest that decreased cranial base growth or abnormal brain growth are the primary cause of craniosynostosis (Cranial Base, Brain Parenchyma Models, respectively). This study was designed to investigate which model best describes neurocranial changes associated with craniosynostosis in a rabbit model through multivariate path analysis. DESIGN: Serial magnetic resonance imaging scans and intracranial pressure measurements were obtained at 10, 25, and 42 days of age from 18 rabbits: six controls, six with delayed-onset synostosis, and six with early-onset synostosis. Five variables were collected from each rabbit: calvarial thickness at the affected suture, cranial base length, brain volume, cerebrospinal fluid volume, and intracranial pressure. This data set was used to test causal pathway relationships generated by the proposed models. Goodness of fit was measured by experimental group for each model. RESULTS: Primary Suture Fusion Model best explained the variables in both delayed-onset and early-onset synostotic rabbits (Goodness of fit = 93%, 97%, respectively). Cranial Base Model (Goodness of fit = 94%) best explained the data in control rabbits. CONCLUSION: Results suggest that the primary site of craniosynostosis in craniosynostotic rabbits is most likely the synostosed suture. Other cranial vault anomalies are most likely secondary compensatory changes. Results of the present study may provide insight regarding the causal pathway of craniosynostosis.     

An in vitro evaluation of the contents of root canals obturated with gutta percha and AH-26 sealer or Resilon and Epiphany sealer

The purpose of this study was to compare the contents of root canals obturated with gutta percha and AH-26 sealer (Dentsply, Tulsa, OK) to canals obturated with the Resilon and Epiphany (Pentron, Wallingford, CT) system. Canal contents were assessed by determining the percentage of canal space occupied by core material, sealer, voids, and debris. Forty extracted human maxillary anterior teeth were instrumented, and the teeth were randomly assigned to either the gutta percha/AH 26 group or the Epiphany/Resilon group. Canals were obturated, and the teeth were subsequently embedded in resin and sectioned horizontally at 2, 4, and 6 mm from the anatomic apex. Sections were photographed by using a low vacuum scanning electron microscope. Image-J (Wayne Rasband; National Institute of Health, Bethesda, MD) software was used to quantify the proportion of core material, sealer, voids, and debris in each canal. Percentages and statistical comparisons for each method were compared. There were no significant differences found among the two groups in terms of the percentage of core (p = 0.9), sealer (p = 0.58), debris (p = 0.999), or voids (p = 1.00). Additionally, there were no differences in the percentage of core material, sealer, debris, or voids at any of the examined levels (2, 4, or 6 mm).     

Hemodynamics and oxygen saturation during intravenous sedation for office-based laser-assisted uvuloplasty.

PURPOSE: Patients undergoing office-based laser-assisted uvuloplasty (LAUP) for snoring or mild obstructive sleep apnea are generally obese and have a high Mallampati score. Because avoidance of supplemental oxygen during laser procedures is generally mandated, the potential for intraoperative desaturation is high. This study was designed to look at intraoperative hemodynamic changes, respiration patterns, and oxygen saturations during intravenous sedation with midazolam and fentanyl during LAUP procedures. MATERIALS AND METHODS: This was a retrospective anesthesia chart review of 15 consecutive patients undergoing midazolam/fentanyl intravenous sedation for office-based LAUP treatment for snoring and/or mild obstructive sleep apnea. Data recorded were noninvasive baseline and intraoperative hemodynamic measurements at 5-minute intervals for systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), pulse pressure (PP), pulse (P), and rate-pressure product (RPP). Data collected were reported as mean values with standard deviation. Statistical analysis using the Student's t test was performed and found significant for P<.05. RESULTS: All changes from baseline were statistically insignificant, SBP (P=.4), DBP (P=.2), MAP (P=.2), P (P=.1), PP (P=.9), RPP (P=.5), RR (P=.9), and SpO2 (P=.4), and all within +/-20% of baseline (range, -5.0% to +7.5%). CONCLUSION: Midazolam and fentanyl intravenous sedation with local anesthesia maintained intraoperative hemodynamic and oxygenation variables close to baseline for office-based LAUP procedures.     

Early composite cranioplasty in infants with severe aplasia cutis congenita: a report of two cases.

OBJECTIVE: Severe cutis aplasia congenita has traditionally been treated with initial soft tissue coverage and delayed cranioplasty. We advocate the technique of early composite reconstruction of both bone and soft tissues. METHODS: Two cases of cutis aplasia congenita with large skull defects (6 x 10 cm, 8 x 8 cm) of superficial layers, skull, and dura are presented. In each case, composite reconstruction was undertaken before 2 weeks of age with restoration of bony and soft tissue coverage through autologous, full-thickness cranial bone grafts and scalp flaps. Both children have been followed up over 2 years with clinical examination and computed tomography (CT) scans. RESULTS: In both cases, defects were completely repaired postoperatively and remained closed 2 years later. Complete regeneration of calvarial bone graft donor sites were documented by CT scan. Head shape and circumference were normal at 2-year follow up.     

Predoctoral and postdoctoral students' perspectives about pediatric dental behavior guidance

This study compared acceptability scores of pediatric dental behavior guidance between predoctoral senior dental students and postdoctoral pediatric dentistry graduates. The scores were obtained with an anonymous survey that included twenty-five items related to behavior guidance techniques or situations, with the degree of acceptability of each being marked on a visual analog scale. Demographic data collected included year of graduation from the postdoctoral program, type of employment, being board-certified or not, gender, marital and parental status, previously receiving dental or medical treatment, and degree of unpleasantness from these treatments. Thirty-nine predoctoral and fifty-one postdoctoral surveys were compared. Analysis of variance (ANOVA) indicated that the predoctoral acceptability scores were statistically significantly higher than the postdoctoral scores for not allowing the child to speak during treatment, voice control, hand over mouth, active immobilization, and providing an exact explanation to the child. The predoctoral scores were lower than the postdoctoral scores for not using local anesthetic when the child does not want it, parent's presence in the operatory during treatment, or talking with the dentist during treatment. ANOVA of the predoctoral and postdoctoral scores combined indicated statistically significant differences between scores from male and females respondents for parent talking with the dentist during treatment; between married and not married respondents for hand over mouth, encouraging the child not to be a coward, the child being allowed to stop the treatment, and the parent being in the operatory during treatment; and between parents and not parents respondents for child not allowed to speak during the treatment, voice control, and hand over mouth. This study found that perspectives about pediatric dental behavior guidance are influenced by pre- and postdoctoral education and postgraduate experience.     

Oral health and dental attendance patterns of Pacific people in Christchurch, New Zealand

OBJECTIVES: To determine levels of self-reported oral health, dental attendance patterns and barriers to seeking dental care among a Pacific community in New Zealand. DESIGN: Cross-sectional study using a self-completed questionnaire. SETTING: A Pacific Island Health Trust in Christchurch. PARTICIPANTS AND METHODS: Adults affiliated to the Pacific Trust Canterbury, who were in contact with any of the Trust's health services within a four-week period, were invited to complete a dental self-report questionnaire. RESULTS: One hundred and twenty-one Pacific adults took part in the study. The mean age of the sample was 38.7 years, with an age range of 17 to 77 years. Over half the respondents had not attended a dentist within the previous two years, and more than three-quarters had last attended a dentist because of pain. Most respondents had paid for their last treatment themselves, and over half had received an extraction because of infection. Participants who received a Government benefit were more likely to have used a public dental service than those in paid employment. Those who had not received education beyond secondary school were more likely to have used a public dental service than those who had achieved higher education levels. Males were more likely to have had a tooth removed due to infection than females; and Cook Island, Niuean and other Pacific groups were more likely to have had a tooth removed than Samoans. CONCLUSIONS: Most Pacific people among this sample were episodic dental attenders, usually presenting because of pain. Many depended on hospital dental departments, particularly beneficiaries, those with community services cards, and those in low socioeconomic occupations. Tooth loss was a common occurrence among this population. Further information on Pacific people's oral health in New Zealand would be beneficial.     

A new prosthodontic approach for craniofacial implant-retained maxillofacial prostheses

A newly fabricated prosthesis may need a complete remake if it does not match the patient's skin tone. Remakes of craniofacial implant-retained prostheses may require significant time and incur additional costs. An alternative procedure is presented to improve the predictability of such prostheses.     

A histomorphogenic analysis of bone grafts augmented with adult stem cells

PURPOSE: To evaluate the influence of bone marrow aspirate added to xenograft or alloplast graft matrix scaffold to produce bone. MATERIALS: A maximum of 4 cc bone marrow was aspirated from the anterior iliac crest of 5 patients to saturate the matrix scaffold prior to bone graft. Seven graft sites evaluated included sinus lift augmentation, particulate onlay graft of the maxilla via a tunneling procedure, and particulate onlay graft of the maxilla stabilized with titanium mesh. The xenograft scaffold was either PepGen Putty (DENTSPLY Friadent CeraMed, Lakewood, CO) or C-Graft resorbable algae material (Clinician's Preference, Golden, CO). The alloplast scaffold was beta-tricalcium phosphate (either Curasan AG, Kleinostheim, Germany, or Vitoss; Malvern, PA). RESULTS: Graft sites healed for 4-7 months. Core specimens of graft sites were taken with trephine drills, and submitted for standard histologic and histomorphogenic analysis. The percentage of graft material converted into bone, percentage of vital graft matrix, percentage of unresorbed matrix, and percentage of remaining interstitial tissue were measured. After a 4-month healing of sinus-lift augmentation with C-Graft, the biopsy showed 31% bone that was 100% vital. Unresorbed graft material was 26%, and remaining interstitial material constituted 43%. Using pure phase beta-tricalcium phosphate, a 4-month core biopsy showed 40% bone that was 100% vital. Residual graft was 3% and interstitial material 57%. A sinus grafted with PepGen P-15 (DENTSPLY Friadent CeraMed) was found to be 14% bone, with 100% of that bone vital. The non-bone within the core was 36%. After a 4 1/2-month healing of bilateral sinus grafts using a nonpure phase beta-tricalcium phosphate, the percentage of the biopsy that was bone was 23% on the right side and 16% on the left side. Vital bone was 89% (right side) and 86% (left side). The core taken after 4 months of healing from the anterior maxilla particulate onlay graft with PepGen P-15 showed 32% bone, with 100% found to be vital. Non-bone within the core was 15%, and 53% was interstitial material. After 7 months of healing, a biopsy core from the maxillary ridge augmented with C-Graft was 45% newly formed bone, with 100% of the bone vital. There was no residual graft material present. DISCUSSION: Bone regeneration by cell-based strategies depends upon an understanding of the biology and potential of adult stem cells as a method of regenerating bone. CONCLUSIONS: Bone marrow aspirate containing adult stem cells when mixed with bioengineered graft materials provide a scaffold to support the proliferation, differentiation, and maturation of the stem cells, as well as facilitating angiogenesis. This article presents histological evidence that stem cells aspirated from bone marrow and transplanted onto biocompatible scaffolds can successfully regenerate bone. This new standard for bone grafting may emerge as an alternative to autogenous bone grafts.