Scanning electron microscopy of the epithelium-connective tissue interfacein human gingiva

The morphological characteristics of the interface between epithelium and connective tissue in normal human gingiva were examined by scanning electron microscogy after separation of epithelium and connective tissue by maceration in sodium bromide solution. Separated crevicular epithelium showed dispersed arcade-shaped pits corresponding to long conical connective tissue papillae. In the epithelium and connective tissue of the free gingiva, horizontal ridges ran parallel to the gingival margin. At the transition from free gingiva to attached gingiva, short conical connective tissue papillae arose from horizontal connective tissue ridges. Toward the alveolar mucosa these papillae increased in number, forming a honeycomb pattern on the separated epithelial surface.     

A method for the quantitation of the epithelium-connective tissue interface of the oral mucosa

abstract – A method has been developed for quantitating, on the basis of histologic serial sections, the contact area between the epithelium and connective tissue of oral mucosa. Magnified (200 ×) paper replicas are produced from histologic sections (20 microns) and two consecutive paper replicas are superimposed on an illuminated grid. By means of the grid lines the area between the two basement membranes is divided into trapezoids (T₁) which represent the projection of imaginary trapezoids (T₂) connecting the basement membranes of two adjacent sections. The area of these T₂-trapezoids may be calculated and is considered as representative for the epithelium-connective tissue interface. Depending on the appearance of the T₁ -trapezoids, a certain amount of discrepancy occurs between the calculated and actual area of the T₂-trapezoids. The significance of this is examined in thirty gingival specimens. It is concluded that without producing accurate values, the method offers the possibility to study quantitative differences in the epithelium-connective tissue interface.     

Three-dimensional analysis of labial morphology: effect of sex and age

Morphological changes in the lips during ageing, including labial volume, area and thickness were assessed in healthy individuals. 40 healthy volunteers (20 men and 20 women) were selected and divided into two groups according to age: 21-34 years (‘youthful’ group) and 45-65 years (‘aged’ group). Three-dimensional (3D) stone labial models were made, digitized, and 3D virtual reproductions obtained. Labial thickness, vermilion area, and volume of the upper and lower lips were measured from the digital reconstructions. The data were compared using three-way ANOVA. All data were significantly larger in men than in women (p < 0.05), the lower lip was thicker than the upper lip (p < 0.001). A significant effect of age for labial thickness and area were found (p < 0.001 and p = 0.014): the youthful group had higher values than the aged group. Upper to lower lip ratios were not significantly different between sexes or ages. Generally, young people have a larger lip area and thickness than aged ones and men had larger lips than women. The upper/lower lip ratios for area and volume were similar in the two genders.     

Infraposition of ankylosed permanent maxillary incisors after replantation related to age and sex

Abstract— The extent of infraposition of replanted and subsequently ankylosed permanent incisors was examined in a longitudinal study of 52 patients. Study cast models were made during the follow-up period. Infraposition was evaluated on frontal photos of the study cast models taken parallel with the occlusal plane. The extent of infraposition was defined as the difference between the position of the incisal edge of the replanted incisor and the adjacent non-injured incisor in apicocoronal direction, measured with a digital caliper at 50 X magnification of the negatives. The precision of this measuring procedure was 2.9% and the accuracy 2.0%. Marked infraposition was identified if the tooth was traumatized before the age of 16 in boys and before the age of 14 in girls. In addition, infraposition was observed when ankylosis developed in patients aged 20–30 years, with a yearly mean infraposition rate of 0.07 mm/year (range: 0.02–0.21 mmlyear) in males and 0.07 mm/year (range: 0.00–0.12 mmlyear) in females. The latter findings supported the concept of slow continuous eruption of the teeth. This phenomenon may have implications not only for the treatment of traumatized teeth but also for the treatment of tooth loss by osseointegrated implants, which represent an analogue to the ankylosed replanted tooth.     

The increase with age of the width of attached gingiva

The purpose of the study was to determine the variation with age of the width of attached gingiva and the location of the mucogingival junction. The material comprised orthopantomograms of 20 male and 20 female dental students aged 20–30 years and 20 male and 20 female adults aged 39–51 years. All the subjects had practically full dentitions and no supraerupted teeth. The mucogingival junctions were revealed with Schiller's iodine solution and marked with short pieces of metal wire, attached to the teeth and gingivae with Squibb's Orahesive Dental Bandage in the midline of the facial surface of each tooth. The orthopantomograms were taken with the X-ray beam passing the horizontally positioned occlusal level at a –5° angle. From the radiographs the distance from the cemento-enamel to the mucogingival junction was measured to the nearest millimeter separately for each tooth. In the mandible also the distance from the mucogingival junction to the lower border of the jaw was assessed accordingly. The results showed that the measured anatomical width of attached gingiva does not differ between sexes but also that it increases significantly with age. The distance between the mucogingival junction and the lower border of the mandible did not increase with age. It was concluded that the mucogingival junction remains at a probably genetically predetermined location while the teeth move in an occlusal direction through adult life. In the absence of concurrent retraction of the gingival margin this results in an increase of the width of attached gingiva with advancing age.     

The average three-dimensional face for different sex and age groups in a Dutch population

The increasing use of three-dimensional imaging calls for reference models representing large parts of the population. The aim of this prospective study was to create templates depicting facial maturation in the younger age groups. Healthy Dutch volunteers were captured, without selection of inclusions. Three-dimensional average faces were created using MATLAB, for both genders in four age groups (4–8 years, 8–12 years, 12–16 years, and ≥16 years). Variation within the groups was calculated and depicted on an average face with a green to red colour scale, corresponding to standard deviations between 0 and ≥ 3 mm, respectively. Measurements of the distances of eight peri-oral landmarks were provided as ratios. The statistical analysis was performed using ANOVA and Tukey’s test. Three-dimensional reconstructions of the average face and their first principal component were created for each gender and age group. The first principal component comprised the facial width for each group, and the variation of landmarks was low. All ratios showed an increasing trend with increasing age, except for the ratio of philtrum width to mouth width. This study is novel in comparing facial morphology by means of ratios and in creating average faces for the different young age groups. These data provide useful insights into facial maturation, which might be beneficial for facial surgeons.     

Sialic acid concentration in the attached gingival tissue of rates realted to age and sex

Determination of N-acetylneuraminic acid concentration in the attached gingival tissue of rats related to the age and sex of the animals was carried out. The concentration of the sialic acid decreased with increasing age. Differences between male and female animals were noted.     

Infraposition of ankylosed permanent maxillary incisors after replantation related to age and sex.

The extent of infraposition of replanted and subsequently ankylosed permanent incisors was examined in a longitudinal study of 52 patients. Study cast models were made during the follow-up period. Infraposition was evaluated on frontal photos of the study cast models taken parallel with the occlusal plane. The extent of infraposition was defined as the difference between the position of the incisal edge of the replanted incisor and the adjacent non-injured incisor in apico-coronal direction, measured with a digital caliper at 50x magnification of the negatives. The precision of this measuring procedure was 2.9% and the accuracy 2.0%. Marked infraposition was identified if the tooth was traumatized before the age of 16 in boys and before the age of 14 in girls. In addition, infraposition was observed when ankylosis developed in patients aged 20-30 years, with a yearly mean infraposition rate of 0.07 mm/year (range: 0.02-0.21 mm/year) in males and 0.07 mm/year (range: 0.00-0.12 mm/year) in females. The latter findings supported the concept of slow continuous eruption of the teeth. This phenomenon may have implications not only for the treatment of traumatized teeth but also for the treatment of tooth loss by osseointegrated implants, which represent an analogue to the ankylosed replanted tooth.     

The effect of age and sex on facial mimicry: a three-dimensional study in healthy adults

To assess sex- and age-related characteristics in standardized facial movements, 40 healthy adults (20 men, 20 women; aged 20–50 years) performed seven standardized facial movements (maximum smile; free smile; “surprise” with closed mouth; “surprise” with open mouth; eye closure; right- and left-side eye closures). The three-dimensional coordinates of 21 soft tissue facial landmarks were recorded by a motion analyser, their movements computed, and asymmetry indices calculated. Within each movement, total facial mobility was independent from sex and age (analysis of variance, p > 0.05). Asymmetry indices of the eyes and mouth were similar in both sexes (p > 0.05). Age significantly influenced eye and mouth asymmetries of the right-side eye closure, and eye asymmetry of the surprise movement. On average, the asymmetry indices of the symmetric movements were always lower than 8%, and most did not deviate from the expected value of 0 (Student's t). Larger asymmetries were found for the asymmetric eye closures (eyes, up to 50%, p < 0.05; mouth, up to 30%, p < 0.05 only in the 20–30-year-old subjects). In conclusion, sex and age had a limited influence on total facial motion and asymmetry in normal adult men and women.     

Traumatization of teeth and gingiva related to habitual tooth cleaning procedures

Abstract . Traumatization of oral hard and soft tissues connected with mechanical oral hygiene procedures has been reported in the dental literature. Definitions, classifications and localization of such lesions are listed, and in vivo and in vitro experiments within the field are reviewed. Existing literature suggests that hard tissue lesions are mainly due to abrasives in dentifrices, whereas gingival lesions may be caused by toothbrushing per se. Factual knowledge about the prevalence, severity and critical significance, as well as relevant and reliable experiments, is scarce and further research on these topics seems to be indicated.     

Stereophotogrammetric analysis of nasolabial morphology among asian malays: influence of age and sex

Objective : It is clear that population-specific norms should be used when planning plastic and reconstructive surgery for selected patients. In this study, we aimed to generate nasal and labial reference values by applying a stereophotogrammetric technique. A further aim was to investigate the effect of sexual dimorphism, age-related changes, and the interrelation between nasal and labial morphology. Design : Cross-sectional study. Setting : The data were collected from different locations on the Malaysian peninsula. Participants : A total of 276 Asian Malays (138 males and 138 females) were included in this study, and a three-dimensional system was used for capturing data. The sample was divided into three age groups: 13 to 14, 15 to 17, and 18 to 36?years. Main Outcome Measure(s) : Twenty-five dimensions of the nose and lips were measured and analyzed separately in males and females. Results : Significant differences between males and females were identified in 11 distances, and significant effects of age were found in most of the dimensions (p < .05). Significant correlations between the nasal and labial dimensions were recorded, particularly between lateral lip height and width of the ala insertion. A principal component analysis showed interrelationships between the nasal width distances and upper lip height. Conclusion : This study has provided a new three-dimensional database for nose and lip morphology in Malays and demonstrated patterns of variation that can be used by surgeons to make comparisons within and between different human populations and also to develop treatment plans for their patients.