An evaluation of changes in mandibular anterior alignment from 10 to 20 years postretention

Pretreatment, end of treatment, 10-year postretention, and 20-year postretention records of 31 four premolar extraction cases were assessed to evaluate stability and relapse of mandibular anterior alignment. Crowding continued to increase during the 10- to 20-year postretention phase but to a lesser degree than from the end of retention to 10 years postretention. Only 10% of the cases were judged to have clinically acceptable mandibular alignment at the last stage of diagnostic records. Cases responded in a diverse unpredictable manner with no apparent predictors of future success when considering pretreatment records or the treated results.     

Age changes in the human inferior alveolar artery--a histological study

The inferior alveolar artery was examined histologically in non-irradiated surgically resected mandibles. A total of 39 edentulous and 11 partially dentate specimens was studied. Narrowing of the lumen was most commonly due to arteriosclerosis which confirms previous reports. Stenosis was not found to be either commoner or more severe than that recorded in other arteries in the body. It is suggested that apparent narrowing of the inferior alveolar artery seen on angiography may represent a form of involutional atrophy of the artery associated with dental extraction and progressive resorption of the residual occlusal alveolar ridge.     

Age changes in the two-point discrimination threshold in human oral mucosa

Fifty young and fifty elderly subjects were tested by a two-point discrimination method applying an aesthesiometer to the mucous membrane of lips, cheeks and tongue. Two changes characteristic of ageing were disclosed: (1) higher threshold values were found in the older age group concomitant with (2) a greater range of variation in these values. The importance of the perception of tactile stimuli from the structures tested is discussed in relation to adaptation to full dentures. It is suggested that signals arising from lips, cheeks and tongue assist the process of adaptation, whereas signals from the denture foundation can, on occasion, prevent adaptation.     

Facial growth in females 14 to 20 years of age.

The objective of this study was to determine the magnitude and the direction of postpubertal mandibular and maxillary facial growth in females. The sample consisted of 37 untreated subjects who had Class I skeletal and dental characteristics and whose lateral cephalograms were taken at 14, 16, and 20 years of age. Mandibular growth was determined to be significant for the age periods of 14 to 16 years and 16 to 20 years. Overall mandibular growth as measured from Co-Gn was approximately twice that of the overall maxillary growth as measured from Co-A. Correlation analysis revealed a statistically significant relationship between the estimates of incremental mandibular growth from either articulare or condylion. The mandibular growth rate was found to be twice as large for age period 14 to 16 years as for age period 16 to 20 years. The increase in posterior vertical face height was slightly more than the increase in anterior vertical face height. The mandibular plane angle decreased 1.1 degrees during the age period of 14 to 20 years, suggesting a tendency for a closing rotation of the mandible. Mandibular incisors appeared to tip labially with advancing age. Although variable, the potential for significant maxillary and mandibular facial growth in females during late adolescent has been demonstrated.     

The areas of various surfaces in the human mouth from nine years to adulthood.

Surface area measurements of five regions of the oral cavity were made from study casts of 57 subjects with an age range from 9.3 to 19 years. While the longitudinal pattern of growth exhibited by the total of the five areas, when subgroups were compared, was characterized by a steady increase to around puberty (13 years), followed by a plateau, different areas showed different patterns of growth. Increase in the surface area of the teeth was associated with the eruption of the second and third molars, whereas the area of the buccal lingual mucosa continued to increase into adult life. The palate, buccal vestibular mucosa, and dorsum of the tongue demonstrated a typically skeletal pattern of growth, i.e., increase until puberty with a rapid cessation thereafter. The results of this study indicate the need for longitudinal data to further knowledge concerning growth of the oral cavity.     

Growth changes in the nasal profile from 7 to 18 years of age

Lateral head cephalograms of 17 male and 23 female subjects, aged 7 to 18 years, were evaluated for age changes in morphology and position of the nose with reference to the pterygomaxillary vertical plane. The study was confined to persons with normal facial profiles, normal overjets, and Class I molar relationships. Four linear and two angular dimensions were measured. Statistical analysis included the calculation of medians, Q ranges, proportion of growth completed at each age expressed as a percentage of the size of the variable at 18 years, and a pairwise correlation matrix. The results indicated that (1) increments in nose height, depth, and inclination are essentially complete in girls by 16 years of age, while continuing to increase in males up to and beyond 18 years; (2) the ratio of upper to lower nose heights remains at approximately 3:1 from 7 to 18 years in both sexes; (3) the ratio of nose depth to sagittal depth of the underlying skeleton changed from 1:2 at 7 years in both sexes to 1:1.5 in male subjects and 1:1.6 in female subjects at 18 years; (4) although upper nose inclination was similar for the two sexes, lower nose inclination was slightly larger in female subjects, especially after the age of 10 years; (5) persons with greater increments in nose depth than in nose height, or in nose depth than in the sagittal depth of the underlying skeleton, develop larger upper nose inclinations. The impact of nasal growth changes on orthodontic diagnosis and treatment planning was emphasized.     

Individual changes in malocclusion from adolescence to 35 years of age

It was the aim of this follow-up study to assess the extent of individual changes in the occurrence of specific pronounced traits of malocclusion in a sample of 176 subjects who were selected from a catchment population examined in adolescence in 1965-66 and who were re-examined in 1986-87 (mean age, 35.5 years). Orthodontic treatment had been received by 10% of the subjects, and extraction rates were low. Deep overbite and mandibular crowding, especially in the incisor segment, tended to increase in frequency. However, on the whole, the various malocclusion traits remained remarkably stable in the orthodontically untreated individuals.     

Age changes of the vascular pattern of the human dental pulp

A study is presented for the purpose of showing the change in vascular architecture of the human dental pulp with age. It is shown that as age increases, the number of vascular structures decreases, primarily at the expense of vessel reduction in the sub-odontoblastic layer of the pulp. It is demonstrated that the human pulp has a natural arterio-venous shunt system.     

Periapical changes following root-canal treatment observed 20-27 years postoperatively

AIM: The aim of the present study was to identify periapical changes 20-27 years after root-canal treatment. METHODOLOGY: The periapical condition of 265 roots filled by undergraduate students was evaluated in two series of intraoral radiographs taken 10-17 and 20-27 years after treatment. Roots (72) not recorded with a normal periapical situation on both occasions by two observers, were re-evaluated by other two examiners, separately and jointly. Final decisions about diagnoses were made by all four examiners. A strict definition was used for the identification of cases with an unfavourable outcome. RESULTS: Favourable outcomes were observed in 6.4% of the roots that had radiolucencies at the 10-17-year follow-up. Periapical radiolucencies after 20-27 years appeared in 1.5% of all other roots. The radiographic failure frequency for the total material was 4.9%. The percentage of cases with normal periapical findings at the final follow-up was 86.4%, whilst 8.7% were recorded with increased width of the apical periodontal space. Delayed healing owing to surplus root-filling material explained nearly all of the cases with favourable outcome assessed many years after treatment. CONCLUSIONS: Late periapical changes, with more successes than failures, were recorded when a 10-17-year follow-up period after root-canal treatment was extended for another 10 years.     

Reaction of the human gingival tissue to different suture materials used in periodontal surgery.

The gingival reaction to 4 different suture materials used in periodontal surgery was studied in 36 patients. The gingiva was sutured prior to surgery and biopsies were taken at 3, 7 and 14 days to observe the tissue reaction. The histological examination showed that silk caused the most intense and longest inflammatory response. Polyester and perlon provoked shorter, less intense tissue reactions than silk, and nylon caused the least inflammatory response, with earlier tissue repair.     

Radiographic follow-up of impacted third molars from age 20 to 32 years

Nineteen patients (13 male, six female) with 34 impacted third molars, 21 in the mandible and 13 in the maxilla were radiographically followed from age 20 to 32. All were examined clinically and panoramic radiographs were taken at baseline and at the end of the study. Radiographic analysis included resorption of teeth, enlargement of the follicle, development of the root, change in inclination of the third molar, state of impaction, relative depth of the third molar in bone and relation to the ramus of the mandible and to the second molar tooth. In the mandible, the mean change in inclination was 19 degrees and the percentage of teeth with changed angulation was 76%. In the maxilla, only 23% of the teeth changed their inclination. The state of impaction (soft tissue, partially in bone, completely in bone) had changed for 44% of the teeth. According to the questionnaire, no pain or symptoms in the region of the third molars were reported by 74% of the students during the 12-year period. It is concluded that considerable radiographic changes, without notable symptoms, may occur involving inclination of the tooth and state of impaction in impacted third molars after the usual age of eruption.     

Age-related changes in mucins from human whole saliva.

The predominant mucins in human whole saliva, MG1 and MG2, serve to protect and to lubricate the oral cavity. In this study, both unstimulated and stimulated whole salivas were collected from two groups of subjects: young (18-35 years of age) and aged (65-83 years of age). The subjects were in apparent good health. Saliva samples from each subject were analyzed by SDS-PAGE. The gels were stained with Stains-all, and both MG1 and MG2 were quantitated by video-image densitometry. The protocol gave reproducible values for each mucin. The stimulated and unstimulated salivas from aged subjects showed significant reductions in concentrations of both MG1 and MG2, as quantitated in mucin dye-binding units. Possible associations of these reductions with the aging process are discussed.     

Age changes in CT values of human major salivary glands]

OBJECTIVE: To investigate CT values ranges of normal major salivary gland in different age groups and regularity of age changes. METHODS: CT values of normal parotid and submandibular glands, comparing with those of masseter and sterocleidomastoid muscles, were measured and analyzed in 100 cases with 4 different age groups. RESULTS: CT values of parotid and submandibular gland decreased with aging, whereas no significant age change in CT values occurred in the masseter and sterocleidomastoid muscles. The CT values of parotid and submandibular gland showed big differences in different age groups. This difference, however, became smaller after the case were divided in 4 groups reference to age. CONCLUSION: CT value ranges of normal major salivary gland should be determined according to the age. It is possible to take the contralateral gland as the control gland for CT diagnosis.     

Glass embedded in labial mucosa for 20 years.

Foreign bodies may be deposited in the oral cavity either by traumatic injury or iatrogenically. Among the commonly encountered iatrogenic foreign bodies are restorative materials like amalgam, obturation materials, broken instruments, needles, etc. Few reports of glass pieces embedded in the soft tissues of the mouth have been published. We report a case where glass pieces had been lodged in the lower labial mucosa for 20 years, with consequent peripheral reactive bone formation.