Sunday, December 28, 2014

Lip Piercing: The Impact of Material on Microbiological Findings

Anna Abrahamian
January 7, 2014

Article Title: Lip Piercing: The Impact of Material on Microbiological Findings

Author: Ines Kapfere, DMD, et al.

Journal: Classic 100 Articles, #35

Major Topics: Adolescent Behavior, Body Piercing

Purpose: The purpose of this study was to assess microbiological findings in association with labial piercings made of different materials.
Methods: Study subjects were recruited via posters and flyers displayed on the Innsbruck Medical University campus (Switzerland) and other schools. The study cohort included 80 subjects with lip piercings that had to be in situ for at least 6 months. Participants completed a questionnaire to determine demographic data, smoking habits, characteristics of the piercing, and post-piercing complications.  A dental and periodontal exam were performed at which time the personal piercing of the subject was substituted with a sterile test piercing made of one of 4 commonly used piercing materials (titanium, stainless steel, polypropylene, and PTFE). These piercings were kept in situ for 2 weeks then removed so that microbiological testing could be performed
Results and Conclusions: There was no statistically significant differences between material groups in relation to baseline data. In samples from stainless steel piercings, the total microbial load was significantly higher than the other materials (P<.05). Ten periopathoenic species were found at significantly higher levels on steel than on the other materials.
Conclusions: Piercing studs made of stainless steel may promote the development of a pathogenic biofilm.

Assessment: This study was very thorough but does not make any recommendations for how to advise patients regarding lip or intra-oral piercings.

Wednesday, December 17, 2014

A Randomized Controlled Clinical Trial Comparing A Remineralizing Paste with an Anti- bacterial Gel to Prevent Early Childhood Caries

A Randomized Controlled Clinical Trial Comparing A Remineralizing Paste with an Anti- bacterial Gel to Prevent Early Childhood Caries
K.A. Plonka, BOralH, et al. 
Location: Queensland, Australia
Pediatric Dentristry Jan/Feb 2013
Resident: Maclin 

To compare twice daily tooth-brushing using 0.304% fluoride toothpaste alone with: (1) twice daily tooth-brushing plus once daily 10% casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) paste; and (2) twice daily tooth-brushing plus once daily 0.12% chlorhexidine gel (CHX) for reducing early childhood caries (ECC) and mutans streptococci (MS) colonization.

622 patients, recruited at birth were randomized to 1 of three groups. 1) to receive either CPP-ACP or 2) to receive CHX or or 3) to be the study control group with no product.  All children were examined at 6, 12, and 18 months old in their homes, and at 24 months old in a community dental clinic.

At 24 months old the caries incidence:
- 1% (2/163) in CPP-ACP
- 2% (4/180) in CHX
- 2% (3/188) in control groups. 

In children who were previously MS colonized at 12 and 18 months old, 
- 0% (0/11) and 5% (3/63), respectively, of the CPP-ACP group remained MS-positive 
- 22% (2/9) and 72% (18/25) in CHX 
- 16% (4/25) and 50% (7/14) in SC groups.

There is insufficient evidence to justify the daily use of casein phosphopeptide-amorphous calcium phosphate or chlorhexidine gel to control early childhood caries or mutans streptococci colonization.

Formulation and Characterization of Antibacterial Fluoride-releasing Sealants

Authors: Yuwei Fan, PhD, et al.

Publication: Pediatric Dentistry V35/NO1, Jan/Feb 2013

Purpose: To investigate the adhesion, fluoride release and recharge, and microleakage of experimental and commercial anti-bacterial fluoride-releasing sealant.

Background: According to the ADA, use of pit and fissure sealants is an effective way to prevent caries in children and adults, even in early incipient lesions. In the 1970’s, fluoride-releasing sealants were introduced to increase their caries-preventing effect. The method of adding soluble fluoride salt in sealants has been questioned because the dissolution of a soluble salt may weaken the sealant. In recent years, the authors of the study claim to have developed fluoride exchange monomers fluoride exchange monomers that have higher fluoride-releasing and recharging capacities than current commercial dental composites. They further claim to have developed antibacterial monomers (AM-2) containing fluoride that show higher antibacterial activity against S. mutans.

Experimental Summary: Five types of sealants were tested, three of them were commercial sealants and two of them were experimental sealants containing the AM-2 monomer. Experimental sealant 1 contained 15% NovaMin bioactive glass nanoparticles while the experimental sealant 2 did not contain it. Twenty extracted molar teeth were divided into 5 groups and tested with the five different sealants for microtensile bond strength and microleakage.

The results showed that the experimental sealants had higher sustained fluoride release rates while the commercial sealants had much lower fluoride release rates after the first 3 days. The authors attribute this result to the fluoride-releasing monomer in both of the experimental sealants, which consists of a fluoride-exchange dimethacrylate monomer containing ternary zirconium fluoride chelate and an antibacterial monomer (AM-2). The fluoride-exchange monomer not only promotes the transport of the fluoride ion from the fluoride-releasing filler to the surface of the material, but also enhances the uptake of fluoride from high concentration fluoride sources, such as topical fluoride or fluoride-containing toothpaste. The authors anticipate that the combination of the fluoride-exchange monomer and antibacterial monomer will enhance the caries-inhibitive effect of the sealant and reduce secondary caries. Furthermore, the results showed that the experimental sealants showed very little to no microleakage and very similar bonding strengths to enamel as the commercial sealants.

Resorption of Incisors After Ectopic Eruption of Maxillary Canines: A CT Study

Title: Resorption of Incisors After Ectopic Eruption of Maxillary Canines: A CT Study
Authors: Ericson et al.
Journal: Angle Orthodontist Vol 70 2000

Purpose: Was to analyze the extent and prevalence of resorption of maxillary incisors after ectopic eruption of the maxillary canines in a sample of subjects referred to an orthodontic specialist.

Introduction: Resorption on permanent maxillary incisors are a rare complication of ectopically erupting maxillary canines, but when they occur they may lead to extractions, and/or orthodontic tx, Early detection of canine impaction and diagnosis and assessment of the extent of resportion is of great importance to prevent or reduce later complications.

Subjects and Methods: All subjects were referred to an orthodontic specialist for consultation because of the risks associated with ectopic eruption of the maxillary canines. The subjects consisted of 107 children, 39 boys and 68 girls, between 9 and 15 years of age (mean 12.5 years), with 156 ectopically and 58 normally erupting maxillary canines. After clinical investigation and primary intraoral radiographic examinations, the children demonstrating ectopic eruption maxillary canines difficult to assess on the panoramic or intraoral films due to overlapping were selected for CT imaging.  CT imaging of the upper alveolar bones were taken to evaluate the resorption of the incisor roots.

Results:  The results showed that relative to the roots of the adjacent incisors, the crowns of 21% ectopically positioned canines were located to the buccal, 18% to the disobuccal, 27% to the lingual, 23% to the distolingual, 5% apically and 6% between the central and lateral incisors. Ninety-three percent of the ectopically positioned canines were in contact with the roots of the adjacent lateral incisor and 19% were in contact with the central incisors. The corresponding figures for the normally erupting canines were 49%. Resorption on the roots of the incisors adjacent to the ectopically positioned canine occurred in 38% of the laterals and in 9% of the centrals. The resorptions were graded and tended to be extensive. Among the 58 resorbed lateral incisors, resorption was slight in 31%, moderate in 9% and severe with pulpal involvement in 60%. The corresponding figures for the 14 resorbed centrals were 36%, 21% and 43% respectively.

Discussion: About 60% of the resorptions involved the middle, and apical thirds. On the sides with normally erupting canines, 3 lateral maxillary incisors were slightly or moderately resorbed distally. In all, 51 of the 107 subjects with ectopically erupting maxillary canines (48%) had resorbed the maxillary incisors during the eruption of the maxillary canines. There were statistically significant correlations between ectopic eruption  of the maxillary canine, contacts between the teeth and resorptions on the adjacent incisors.

Conclusion: It was concluded that resorption on the maxillary after ectopic eruption of the maxillary canines is a more common phenomenon than previously reported and has to be considered in all cases with seriously diverging eruption of maxillary canines. It was also concluded that the resorptions of the roots of the incisors were caused by pressure during the eruption of the adjacent, aberrant canine. Finally, it was shown that CT scanning substantially increased the detection of root resorptions on incisors adjacent to ectopically erupting maxillary canines (~50%). The sensitivity of intra-oral films was low when diagnosing the resorptions, being calculated to 0.68. 

Dental Surgery and Anesthetic Precautions of a Patient with Down Syndrome and Juvenile Rheumatoid Arthritis: A Case Report

Author: Unkel et al
Journal: Pediatric Dentistry Vol 34 No 7
Year: Nov/Dec 2012

Type: Case Report

Purpose: The purpose of this case report was to demonstrate that Down syndrome and juvenile rheumatoid arthritis patients are at risk for cervical spine injury and should have the appropriate consultations and imaging completed before any dental surgery is undertaken.

Key Points:

  • Down syndrome and JRA both result in varying degrees of instability of the cervical spine 
  • Down syndrome - most of the pathology centers on the atlantoaxial joint
  • JRA - there is a more generalized pathologic process involving the posterior facets in combination with growth disturbances in the vertebral bodies
  • AAI incidence varies widely in Down syndrome (affects 10% to 20% of Down syndrome patients) 
  • Craniocervical instability, most commonly atlantoaxial instability (AAI), is the result of generalized ligamentous laxity involving the ligaments of the joint of the cervical first and second vertebra (C1 and C2). 
  • The joint is supported by the transverse atlantoaxial ligament, which maintains the odontoid process close to the anterior arch of the atlas, and a pair of alar ligaments. 
  • AAI is primarily caused by laxity of the transverse atlantal ligament.
  • Other risks involved with JRA 
    •  inflammatory synovitis that leads to cortical erosion of the odontoid process and may also lead to limited opening with TMJ involvement
  • ~ 40% of JRA patients exhibit clinical TMJ symptoms

  • 10-year-old Caucasian female with a history of Down syndrome and JRA
  • past medical history 
    • Down syndrome, JRA, Raynaud’s syndrome, spinal stenosis, and a laminectomy
  • physical examination - patient was nonambulatory and of short stature, with a rounded face and a prominent right side swelling, open mouth, high mandibular angle, protruding tongue, and a swelling on the right side of her face lateral to the nasolabial fold
  • Intraoral exam: mixed dentition, anterior open bite, normal TMJ range, retained primary teeth, and a parulis in her maxillary right buccal vestibule
  • radiographic examination: periapical radiolucencies superior to the primary maxillary right molars that encompassed the permanent dentition
  • parents were referred to a radiologist for imaging of the atlantoaxial joint and facial swelling

  • radiologist’s report of the CT scan:
    • 2 cystic lesions in the maxilla’s alveolar portion
    • Upon review of the cervical spine, the odontoid process was elevated to the level of foramen magnum, consistent with basilar invagination 
    • abnormal C1/C2 articulation with C2 rotated counterclockwise in relation to C1
  • Based on the imaging studies demonstrating the relationship of the odontoid process to the foramen magnum and brainstem, the child was placed in a supine position with bilateral fixation of the skull
  • Mayfield head holder was used to minimize risk of damage to the brainstem due to potential cervical manipulation during induction, intubation, and surgical manipulations.
  • General anesthesia was induced, and the patient was intubated using a fiberoptic technique to ensure minimal spinal movement. 
  • fluoroscopic image was obtained to ensure that the odontoid process was in a neutral position. 
  • maxillary cysts were enucleated
  • affected teeth were extracted
  • Upon completion of the procedure, 2 bite blocks were placed for stability (upon recommendation by the neurosurgeon) prior to transferring the patient to recovery 


Load Distribution in Fixed Space maintainers: A Strain-gauge Analysis

Article Title: Load Distribution in Fixed Space maintainers: A Strain-gauge Analysis
Author: Nihal Belduz Kara, DDS, PhD. et al.
Date: Pediatric Dentistry Vol. 35 No. 1, Jan/Feb 2013

Major Topic:  Load Distribution in fixed space maintainers   

Main Purpose:  Assess mechanically induced strain placed on the supporting teeth for band-and-loop, direct bonded, and fiber reinforced space maintainers (FRM).

Introduction:  Early loss of primary molars can lead to space loss, malocclusion and impaction of permanent teeth.  Some reasons for failure of space maintainers can be due to bond failure, cement failure, and breakage of solder joints.  However biomechnical forces placed on space maintainers and supporting teeth should be considered due to its influence on clinical complications. 

Methods:  Fabrication of test models and splints was completed using both primary and permanent teeth.  Primary teeth used: primary second molar and primary canine.  Permanent teeth used: First molar and first premolar (considered the anterior tooth in this model).  Teeth were arranged with spacing that mimicked that of the placement in an average arch.   Band and loop appliance was fabricated using 0.8mm-diameter stainless steel round wire adapted to an orthodontic band, wire was soldered, polished and cemented with glass ionomer cement.  Direct-bonded maintainers were made of 0.7 stainless steel round wires adapted to the buccal surfaces.  The FRM’s were fabricated using polyethylene fibers and boned to the approximal sides of the teeth.  Both direct and FRM space maintainers were bonded to teeth that were etched with 34.5% phosphoric acid using light-polymerized resin composite.  To measure the stain placed on the bone level during load application, linear strain-gauges were bonded to close proximity to the teeth and in the middle of the missing tooth space.  All gauges were “aged” by applying a cycling load of 50-200N, 100 times  to minimize hysteresis – a lagging or retardation of the effect that occurs when forces acting upon a body are changed.  Statistical analysis was completed using the Kruskal-Wallis and Mann-Whitney U test. 

Results:  Regardless of tooth receiving the space maintainer the microstrains on the molar teeth were comparable at the tested 50N and 100N, similar results were found for the space of the missing tooth.  At 50N there was no difference of the strain on the anterior tooth but at 100N the band and loop design had lower strain on the anterior tooth.  Strain amplitudes were comparable for the different space maintainers

Discussion:  Band and loop was used to due to its cantilever design, which was expected to have an influence on load partitioning.  This study was limited because it couldn’t mimic clinical situation were bond and cement failure are issues. 

Conclusions:  Load Distribution of the three space maintainers is comparable.  Direct-bonded maintainers, however, might be creating excessive loading of the bone on the buccal side due to bending of the load bearing system.

Tuesday, December 16, 2014

Development of human craniofacial morphology during the late embryonic and early fetal periods

Date: 12/17/14

Article Title: Development of human craniofacial morphology during the late embryonic and early fetal periods

Author: VM Diewert, DDS, M.Sc.
Journal: American Journal of Orthodontics. July 1985. 41-53.

Main Purpose: To review major changes in craniofacial dimensions and spatial relations during the late embryonic and early fetal periods. in order to understand the mechanisms of development of human facial morphology.

Methods: A quantitative morphometric evaluation of a large collection of staged embryos and fetuses in the Carnegie Embryological Collection.

Key Points:
-       After formation of the primary palate during the 5th and 6th week post-conception, the secondary palate develops during the late embryonic period (7-8 weeks) and early fetal period (9-10 weeks).  
-       Primary palate gives rise to the upper lip, alveolus and anterior palatal region.
-       Secondary palate gives` rise to hard and soft palatal region.
-     Between 7-10 weeks post-conception when crown-rump length increased from 18-49mm. Facial structures grew predominantly in the sagittal plane, with a four-fold increase in length, a two-fold increase in height, but little change in width. These changes altered relations of oronasal structures.
-    The sagittal position of the maxilla and the mandible to the anterior cranial base increased, and the mandible was prognathic during secondary palate closure in the first 2 weeks of fetal development.
- Both the mean cranial base angulation and the achieved maxillary position were similar to the angulations present later pre-natally and post-natally.
- Human patterns of cranial base angulation and maxillary position appear to develop during the late embryonic period when the chondrocranium and Meckel’s cartilage for the continuous craniofacial skeleton.
- Rapid directional growth of the primary cartilages is important to development of normal human facial morphology and interference with normal growth changes during this early critical period may produce irreversible effects on the face.

Lit Review

Title: Bilateral Parent-child interactions in School-age Children’s Tooth-Brushing behaviors
Authors: Goh, et al
Journal: Pediatric Dentistry, April 2012
Resident: Avani Khera, DMD

Purpose: The purpose of this study was to examine bilateral dynamics between parents and children in influencing children’s tooth-brushing behaviors.  The bilateral theory adopted in this study is the interaction between the parents and child.  Parents and children exercise power of influence over each other, and the nature of power Is asymmetrical and interdependent. 

Methods: In depth conversational interviews-a specific qualitative method-were conducted on 38 patients in urban Xiamen, China and Singapore to learn insights into parental strategies for encouraging tooth-brushing habits in 6-9 year old children.  The interviews also examined the range or responses from children toward these parental strategies. 

Results: Children usually do not comply with tooth-brushing instructions from parents without a process of negotiation. Children’s responses ranged from active resistant to compliant.  Parents in Xiamen tended to use softer strategies and were more prone to be emotionally and behaviorally influenced by the children’s effort to thwart these strategies.  Conversely, Singapore parents tended to demonstrate greater tenacity in negotiating with children. 

Conclusions: The process of developing children’s tooth brushing habits is not a unilateral parent-to-child process.  Instead, it should be conceptualized as an ongoing interaction with bilateral power of influence from both parties.