No abstract

It has been estimated that between 2% and 4% of the general adult population has radiographic evidence of an ossification of the stylohyoid chain. In an effort to prove that this is also the case in children and adolescents, 150 panoramic radiographs were examined at the Department of Pedodontics of St. Justine's Hospital in Montreal, Quebec, Canada. A total of 300 styloid processes and stylohyoid chains were evaluated and measured radiographically. The patients' mean age was 11 years. The mean length of the styloid processes was 10 mm. Forty percent of the population without symptoms studied showed some evidence of stylohyoid ligament ossification. Sixty percent of these were males; 40% were females. It was also found that 65.6% had no history of cervicopharyngeal trauma on review of the medical and dental histories.

Gla-protein or osteocalcin is one of the most abundant noncollagenous matrix proteins found in bone and dentin. The present study describes, with high resolution, the intracellular and extracellular distribution of Gla-protein in alveolar bone and incisor dentin. Sections of tissues embedded in Lowicryl K4M were incubated with rabbit antibodies to rat dentin Gla-protein. The site of the specific antigen-antibody reaction was revealed by the protein A-gold complex. Labeling was detected over bone and dentin while fewer gold particles were present over prebone and predentin. Gold particles were also seen over the protein synthetic organelles (rough endoplasmic reticulum, Golgi apparatus) of osteoblasts and odontoblasts. These findings confirm, with improved resolution, previous light immunohistochemical studies, and offer the possibility to examine the secretory pathway of the protein.

No abstract

Objectives Evaluate the effects of two different machined‐collar lengths and designs on peri‐implant healing. Material and Methods An implant with a microtextured surface and 3.6mm‐long internal‐connection machined collar was compared to two implants that had an identical 1.2mm‐long external‐connection machined collar, but one had the microtextured surface while the other's was machined. Participants received the three implants, with microgap at the crest, alternately at five sites between mental foramen, and a full‐arch prosthesis. Peri‐implant bone levels were measured after 23 to 26 years of function. Keratinized tissue height, plaque, probing depth, bleeding, and purulence were also evaluated. Descriptive and mixed models for repeated\measures analyses were used, with Bonferroni correction for pairwise comparisons. Results Twenty‐two participants (110 implants) were evaluated at the 25‐year examination. Microtextured implants with the longer machined collar had significantly greater mean marginal bone loss (−1.77mm ± 0.18, mean ± SE) than machined (−0.85mm ± 0.18, p < .001) and microtextured (−1.00 ± 0.18mm, p < .001) implants with the shorter machined collar. Keratinized tissue height was greater for internal‐connection (0.74mm ± 0.10) versus external‐connection (0.51 ± 0.08, p =  0.01) microtextured implants. No differences were observed for plaque (p = 0.78), probing depth (p = 0.42), bleeding (p  = 0.07), and purulence (p = 1.00). Implant survival rate was 99%. Conclusions Implants with the 1.2mm machined collar limited bone loss to 1mm, while those with the longer machined collar showed > 1.5mm loss after 25 years of function with microgap at the crest. Internal‐connection design and fixture surface microtexturing did not result in greater bone preservation. ClinicalTrials.gov Identifier: NCT03862482.