Diagnostic performance of dental maturity for identification of skeletal maturation phase.

The objective of this study is to analyse the diagnostic performance of the circumpubertal dental maturation phases for the identification of individual-specific skeletal maturation phases. A total of 354 healthy subjects, 208 females and 146 males (mean age, 11.1 ± 2.4 years; range, 6.8-17.1 years), were enrolled in the study. Dental maturity was assessed through the calcification stages from panoramic radiographs of the mandibular canine, the first and second premolars, and the second molar. Determination of skeletal maturity was according to the cervical vertebra maturation (CVM) method on lateral cephalograms. Diagnostic performances were evaluated according to the dental maturation stages for each tooth for the identification of the CVM stages and growth phases (as pre-pubertal, pubertal, and post-pubertal) using positive likelihood ratios (LHRs). A positive LHR threshold of 10 or more was considered for satisfactory reliability of any dental maturation stage for the identification of any of the CVM stages or growth phases. The positive LHRs were generally less than 2.0, with a few exceptions. These four teeth showed positive LHRs greater than 10 only for the identification of the pre-pubertal growth phase, with values from 10.8 for the second molar (stage E) to 39.3 for the first premolar (stage E). Dental maturation assessment is only useful for diagnosis of the pre-pubertal growth phase, and thus, precise information in relation to the timing of the onset of the growth spurt is not provided by these indices.

Surface corrosion and fracture resistance of two nickel-titanium-based archwires induced by fluoride, pH, and thermocycling. An in vitro comparative study.

The present comparative study aimed to evaluate the surface corrosion and fracture resistance of two commercially available nickel-titanium (NiTi)-based archwires, as induced by a combination of fluoride, pH, and thermocycling. One hundred and ten rectangular section NiTi-based archwires were used, 55 of each of the following: thermally activated Thermaloy® and super-elastic NeoSentalloy® 100 g. Each of these was divided into five equal subgroups. One of these five subgroups did not undergo any treatment and served as the control, while the other four were subjected to 30 days of incubation at 37°C under fluoridated artificial saliva (FS) at 1500 ppm fluoride treatment alone (two subgroups) or combined with a session of thermocycling (FS + Th) treatment at the end of incubation (two subgroups). Within each of the Thermaloy® and NeoSentalloy® groups, the FS and FS + Th treatments were performed under two different pH conditions: 5.5 and 3.5 (each with one subgroup per treatment). Analysis of the surface topography and tensile properties by means of scanning electron microscopy (a single sample per subgroup), atomic force microscopy, and a universal testing machine for ultimate tensile strength were carried out once in each of the control subgroups or immediately after the treatments in the other subgroups for 10 of the archwires. Non-parametric tests were used in the data analysis. Significant effects in terms of surface corrosion, but not fracture resistance, were seen mainly for the Thermaloy® group at the lowest pH, with no effects of Th irrespective of the group or pH condition. Different NiTi-based archwires can have different corrosion resistance, even though the effects of surface corrosion and fracture resistance appear not to be significant in clinical situations, especially considering that thermocycling had no effect on these parameters.

Gingival crevicular fluid alkaline phosphatase activity as a non-invasive biomarker of skeletal maturation.

OBJECTIVES: To evaluate the gingival crevicular fluid (GCF) alkaline phosphatase (ALP) activity in growing subjects in relation to the stages of individual skeletal maturation. SETTING AND SAMPLE POPULATION: The Department of Biomedicine, University of Trieste. Seventy-two healthy growing subjects (45 women and 27 men; range, 7.8-17.7 years). MATERIALS AND METHODS: Double-blind, prospective, cross-sectional design. Samples of GCF were collected from each subject at the mesial and distal sites of both of the central incisors, in the maxilla and mandible. Skeletal maturation phase was assessed through the cervical vertebral maturation (CVM) method. Enzymatic activity was determined spectrophotometrically. RESULTS: The relationship between GCF ALP activity and CVM stages was significant. In particular, a twofold peak in enzyme activity was seen at the CS3 and CS4 pubertal stages, compared to the pre-pubertal stages (CS1 and CS2) and post-pubertal stages (CS5 and CS6), at both the maxillary and mandibular sites. No differences were seen between the maxillary and mandibular sites, or between the sexes. CONCLUSIONS: As an adjunct to standard methods based upon radiographic parameters, the GCF ALP may be a candidate as a non-invasive clinical biomarker for the identification of the pubertal growth spurt in periodontally healthy subjects scheduled for orthodontic treatment.

Do malocclusion and Helkimo Index ≥ 5 correlate with body posture?

Whether there are correlations between the stomatognathic system and body posture remains controversial. Here, we have investigated whether malocclusal traits and having a Helkimo Index ≥ 5 show detectable correlations with body-posture alterations in children and young adults. A total of 1178 11- to 19-year-old subjects were divided into four groups: (i) controls; (ii) malocclusion; (iii) Helkimo Index ≥ 5 and (iv) malocclusion + Helkimo Index ≥ 5. Dental occlusion assessment included the following: overbite, overjet, posterior crossbite, scissorbite, mandibular crowding and dental class. Subsequently, body-posture assessments were performed through static analyses of body inclination and trunk asymmetry, and according to the dynamic Fukuda stepping test. Univariate and multivariate statistical analyses were performed. Although at the univariate level both the trunk asymmetry and Fukuda stepping test showed significant differences among the groups, the multivariate level revealed that age and gender were mostly responsible for this. The only significant correlation that was seen was for the malocclusion + Helkimo Index ≥ 5 group: these subjects had a positive (worse) trunk asymmetry and a negative (better) Fukuda stepping test performance. At the further multivariate analyses of each single malocclusal trait /Helkimo Index ≥ 5 (irrespective of the groups), only an increased overbite showed a statistically significant association with a slightly better Fukuda stepping test performance. Given the small number of significant associations seen and their limited entities, this study does not support the existence of clinically relevant correlations for malocclusal traits and Helkimo Index ≥ 5 with body posture in children and young adults.

Morphometric analysis of treatment effects of bone-anchored maxillary protraction in growing Class III patients.

The aim of the present morphometric investigation was to evaluate the effects of bone-anchored maxillary protraction (BAMP) in the treatment of growing patients with Class III malocclusion. The shape and size changes in the craniofacial configuration of a sample of 26 children with Class III malocclusions consecutively treated with the BAMP protocol were compared with a matched sample of 15 children with untreated Class III malocclusions. All subjects in the two groups were at a prepubertal stage of skeletal development at time of first observation. Average duration of treatment was 14 months. Significant treatment-induced modifications involved both the maxilla and the mandible. The most evident deformation consisted of marked forward displacement of the maxillary complex with more moderate favourable effects in the mandible. Deformations in the vertical dimension were not detected. The significant deformations were associated with significant differences in size in the group treated with the BAMP protocol.

Mucogingival interceptive surgery of buccally-erupted premolars in patients scheduled for orthodontic treatment. I. A 7-year longitudinal study.

BACKGROUND: Mucogingival interceptive therapy in patients with buccally erupting teeth is performed to prevent the ectopic permanent tooth from developing periodontal lesions. The keratinized tissue entrapped between the erupting tooth and the deciduous tooth is retained to maintain a satisfactory width of the gingiva for the permanent tooth. The aim of the present study on buccally-erupted premolars scheduled for orthodontics was to evaluate the keratinized tissue width 3 months, 2 years, and 7 years subsequent to mucogingival interceptive therapy and orthodontic treatment. METHODS: Twenty-nine patients participated. Three different surgical techniques were used according to specific indications. Eight patients were treated with double pedicle flaps (DPF), 10 patients with apically positioned flaps (APF), and 11 with free gingival grafts (FGG). RESULTS: The amount of keratinized tissue on the treated (test) sites was not significantly less than on the control (untreated) sites showing normally erupting premolars at all observation periods. All 3 surgical procedures appeared to be effective in saving the keratinized tissue for the permanent tooth. Preoperative periodontal parameters such as gingival width, probing depth, and bleeding on probing significantly influenced the outcome 3 months after surgery (P <0.01). CONCLUSIONS: Mucogingival interceptive surgery is an effective approach to conserve the keratinized buccal gingiva of ectopically erupting premolars.

Mucogingival interceptive surgery of buccally-erupted premolars in patients scheduled for orthodontic treatment. II. Surgically treated versus nonsurgically treated cases.

BACKGROUND: The aim of this 2-year longitudinal study was to compare the width of keratinized gingiva after orthodontic therapy for buccally erupting premolars that had been pretreated by extraction of deciduous teeth alone versus interceptive mucogingival surgery. METHODS: In 8 patients (aged 9 to 12 years) who presented with bilateral buccal eruption of homologous teeth (premolars), one side was randomly treated with extraction of the deciduous molar and mucogingival surgery (test site), while the other side was treated only by extraction of the deciduous molar (control site). All of the subjects underwent orthodontic treatment with fixed appliances. RESULTS: At the baseline visit prior to any treatment, there was no significant difference between the mean amount of keratinized gingiva at test sites (3.06 mm) and control sites (2.93 mm). Two years later, upon completion of orthodontic treatment, there was a significant difference between test (2.93 mm) and control (1.37 mm) sites in the mean width of keratinized tissue. In the control (untreated) group, 2 sites exhibited 1 mm of gingival recession after orthodontic treatment. CONCLUSIONS: Mucogingival interceptive surgery is an effective technique to maintain keratinized tissue in correspondence with buccally-erupted teeth.

A SEM study of in vivo accuracy of the Root ZX electronic apex locator.

Twenty-nine unprepared, vital teeth were used to evaluate the accuracy of the Root ZX in locating the root canal foramen. After extraction of the teeth, a scanning electron microscope analyzed the relation of the file tip to the foramen. The sample was divided into two groups (Group A and Group B) according to the presence of a normal apical foramen (along the root main axis) or of a lateral foramen (deviating from the root main axis). With a tolerance level of +/- 0.5 mm, a clinical accuracy rate of 82.75% was recorded in the total sample. With a +/- 1.0-mm tolerance level, an accuracy of 100% was found. The error in locating the apex was significantly smaller in cases with a normal apical foramen (Group A) than in cases with a lateral foramen (Group B) (p < 0.001). An accuracy of 100% at the +/- 0.5-mm tolerance level was registered in Group A.

A controlled study of associated dental anomalies.

The purpose of this study was to reveal patterns of association among seven types of dental anomalies (aplasia of second premolars, small size of maxillary lateral incisors, infraocclusion of primary molars, enamel hypoplasia, ectopic eruption of first molars, supernumerary teeth, and palatal displacement of maxillary canines) in an untreated orthodontic population, ages 7 to 14. The prevalence of associated tooth anomalies in seven groups of 100 subjects selected according to one primarily diagnosed dental anomaly was compared with the prevalence of the examined dental anomalies in a control group of 1,000 subjects. Significant reciprocal associations (p < 0.005) were found among five of the anomalies (aplasia of second premolars, small size of maxillary lateral incisors, infraocclusion of primary molars, enamel hypoplasia, and palatal displacement of maxillary canines), suggesting a common genetic origin for these conditions. Supernumerary teeth appeared to be a separate etiological entity with respect to all other examined tooth anomalies. The existence of associations between different tooth anomalies is clinically relevant, as the early diagnosis of one anomaly may indicate an increased risk for others.

Tooth rotation associated with aplasia of nonadjacent teeth.

The prevalence of tooth rotation concomitant with aplasia of nonadjacent teeth in uncrowded, nonsyndromic subjects was assessed. The sample consisted of 1620 subjects (mean age 14 years 9 months). The findings were compared with the prevalence calculated for a matched control group of 1000 subjects. Rotation of maxillary lateral incisors in subjects with premolar aplasia and rotation of premolars in subjects presenting with maxillary lateral incisor aplasia were studied. Associations between both tooth position anomalies and tooth aplasia were significant (p < 0.01). In addition, the presence of rotated maxillary lateral incisors was also associated with aplasia of the homologous tooth on the opposite side of the dental arch; the same result was found for premolars. These data suggest a genetic component in the etiology of tooth malpositions, such as tooth rotation, which may be considered a covariable in a complex of genetically controlled dental disturbances, including tooth aplasia.

Cephalometric floating norms for North American adults.

Floating norms provide a method of analysis that uses the variability of the associations among suitable cephalometric measures, on the basis of a regression model combining both sagittal and vertical skeletal parameters. This study establishes floating norms for the description of the individual skeletal pattern in North American adults. The method is based on the correlations among the following craniofacial measurements: SNA, SNB, NL-NSL, ML-NSL, and NSBa. The results are given in a graphical box-like form. This easy, practical procedure allows for the identification of either individual harmonious craniofacial features or anomalous deviations from the individual norm. The use of cephalometric floating norms may be helpful for diagnosis and treatment planning in orthognathic surgery and dentofacial orthopedics.

Thin-plate spline analysis of mandibular growth.

The analysis of mandibular growth changes around the pubertal spurt in humans has several important implications for the diagnosis and orthopedic correction of skeletal disharmonies. The purpose of this study was to evaluate mandibular shape and size growth changes around the pubertal spurt in a longitudinal sample of subjects with normal occlusion by means of an appropriate morphometric technique (thin-plate spline analysis). Ten mandibular landmarks were identified on lateral cephalograms of 29 subjects at 6 different developmental phases. The 6 phases corresponded to 6 different maturational stages in cervical vertebrae during accelerative and decelerative phases of the pubertal growth curve of the mandible. Differences in shape between average mandibular configurations at the 6 developmental stages were visualized by means of thin-plate spline analysis and subjected to permutation test. Centroid size was used as the measure of the geometric size of each mandibular specimen. Differences in size at the 6 developmental phases were tested statistically. The results of graphical analysis indicated a statistically significant change in mandibular shape only for the growth interval from stage 3 to stage 4 in cervical vertebral maturation. Significant increases in centroid size were found at all developmental phases, with evidence of a prepubertal minimum and of a pubertal maximum. The existence of a pubertal peak in human mandibular growth, therefore, is confirmed by thin-plate spline analysis. Significant morphological changes in the mandible during the growth interval from stage 3 to stage 4 in cervical vertebral maturation may be described as an upward-forward direction of condylar growth determining an overall "shrinkage" of the mandibular configuration along the measurement of total mandibular length. This biological mechanism is particularly efficient in compensating for major increments in mandibular size at the adolescent spurt.

Treatment timing for rapid maxillary expansion.

The aim of this study was to evaluate the short-term and long-term treatment effects of rapid maxillary expansion in 2 groups of subjects treated with the Haas appliance. Treatment outcomes were evaluated before and after the peak in skeletal maturation, as assessed by the cervical vertebral maturation (CVM) method, in a sample of 42 patients compared to a control sample of 20 subjects. Posteroanterior cephalograms were analyzed for the treated subjects at T1 (pretreatment), T2 (immediate post-expansion) and T3 (long-term observation), and were available at T1 and at T3 for the controls. The mean age (years: months) at T1 was 11:10 for both the treated and the control groups. The mean ages at T3 also were comparable (20:6 for the treated group and 17:8 for the controls). Following expansion and retention (2 months on average), fixed standard edgewise appliances were placed. The study included transverse measurements on dentoalveolar structures, maxillary and mandibular bases and other craniofacial regions (nasal, zygomatic, orbital, and cranial). Treated and control samples were divided into 2 groups according to individual skeletal maturation. The early-treated and early-control groups had not reached the pubertal peak in skeletal growth velocity at T1 (CVM 1 to 3), whereas the late-treated and late-control groups were during or slightly after the peak at T1 (CVM 4 to 6). The group treated before the pubertal peak showed significantly greater short-term increases in the width of the nasal cavities. In the long-term, maxillary skeletal width, maxillary intermolar width, lateronasal width, and lateroorbitale width were significantly greater in the early-treated group. The late-treated group exhibited significant increases in lateronasal width and in maxillary and mandibular intermolar widths. Rapid Maxillary Expansion treatment before the peak in skeletal growth velocity is able to induce more pronounced transverse craniofacial changes at the skeletal level.

Associated dental anomalies in an Etruscan adolescent.

Three fragments of the upper jaw of an Etruscan adolescent of the 6th century B.C. discovered at the necropolis of Cancellone 1 (Magliano in Tuscany, Grosseto, Italy) were examined. A triad of associated dental anomalies was found: congenitally missing second premolars, "peg-shaped" permanent lateral incisors, and ectopic (palatal) eruption of a permanent canine. These findings provided the opportunity to discuss etiopathogenetic aspects of the associations among different types of tooth abnormalities.

A clinical and statistical study of etiologic aspects related to associated tooth anomalies in number, size, and position.

BACKGROUND: The study was aimed to reveal patterns of association among five types of dental anomalies (aplasia of second premolars, small size of maxillary lateral incisors, infraocclusion of primary molars, ectopic eruption of first molars, and palatal displacement of maxillary canines) in an untreated orthodontic population, aged 7-14 years. METHODS: The prevalence of associated tooth anomalies in five groups of 100 subjects each and characterized by the constant presence of one primarily diagnosed dental anomaly was compared to the prevalence for the examined dental anomalies in a control group of 1,000 subjects, deriving from a common initial sample of 4,850 subjects. RESULTS: Significant reciprocal associations (p < 0.008) were found among four dental anomalies (aplasia of second premolars, small size of maxillary lateral incisors, infraocclusion of primary molars, and palatal displacement of maxillary canines), suggesting a common genetic origin for these conditions. Ectopic eruption of first molars appeared to be a rather separate pathological entity with respect to all other examined tooth anomalies. CONCLUSIONS: The statistically demonstrated existence of associations among different tooth anomalies is clinically relevant, since the diagnosis of those anomalies that appear earlier may indicate potential risk for later developing tooth and eruption disturbances.

[An analysis of the prevalence of isolated dental anomalies and of those associated with hereditary syndromes: a model for evaluating the genetic control of the dentition characteristics]. / Analisi della prevalenza di anomalie dentali isolate ed associate nelle sindromi ereditarie: modello per la valutazione del controllo genetico sulle caratteristiche della dentatura.

Tooth ontogenesis, morphogenesis, and eruption are under a multifactorial (genetic, epigenetic, environmental) control. The aim of this study has been a genetic appraisal of tooth developmental characteristics by means of the prevalence and patterns of association of tooth anomalies in a large sample of hereditary syndromes. MATERIALS AND METHODS. A sample of 169 hereditary syndromes exhibiting tooth abnormalities was collected from the literature: original articles were controlled in order to achieve uniformity of judgement about the definition of the dental defects. Tooth anomalies were classified according to anatomoclinical criteria: number (hypodontia/hyperdontia), shape, position, structure (enamel/dentin/cementum), size (micro-/macrodontism), eruption (precocious/delayed including unerupted teeth). Prevalence data were calculated for: 1) modes of syndrome inheritance; 2) syndromes exhibiting a single dental anomaly vs. syndromes exhibiting associated tooth abnormalities; 3) different types of tooth abnormalities; 4) isolated and associated tooth abnormalities.

[Autosomal chromosomes and anomalies of the oromaxillofacial area]. / I cromosomi autosomici e le anomalie del distretto oro-maxillo-facciale.

The study deals with genetic diseases due to anomalies in the number and structure of autosomal chromosomes associated with oro-facial malformations. Pertinent literature from 1980 and clinical cases for each defect were analyzed. By comparing clinical signs and symptoms with chromosome abnormalities it was possible to build an analytical diagram showing the prevalence of malformation exhibited by each anatomical oro-facial region (cranial, labial, palatal, nasal, ocular, dental, lingual region). A very high prevalence of malformation was assessed for lip-and-palate regions (78%). These region often shows "micro-signs" of cleft lip and/or palate (deep palatal vault, maxillary hypoplasia, congenitally missing upper central incisors) which may indicate the presence of a mildly expressed chromosome abnormality. The whole sample of autosomal chromosome abnormalities induce anomalies in structures lying along body and face mid-line. The phenotypic expression of such anomalies may be defective (cleft lip and/or palate), or excessive as well (excessive thickness of the lingual frenum, broadening of the nasal bridge).

Dentofacial characteristics associated with trauma to maxillary incisors in the mixed dentition.

The study investigated the dento-facial features of a group of 69 children with trauma to the maxillary central incisors in the mixed dentition compared to a control group of 100 children, in order to identify possible "anatomical" factors predisposing to this type of dental trauma. The group with dental trauma showed excessive proclination of upper incisors to the palatal plane (p < 0.001) and increased lower facial height (p < 0.001) as major characteristics associated to dental trauma. The role of early orthodontic treatment in the attenuation of these factors predisposing to traumatic injuries to frontal teeth is stressed.

Splint therapy for skeletal Class III malocclusion in the primary dentition.

An orthopedic appliance for the correction of skeletal Class III malocclusion in the primary dentition is described. The appliance consists of two resin splints with hooks for Class III elastic intraoral traction. Construction features and biomechanical aspects of the device are described along with the clinical evaluation of treatment effects in two case reports.

[Heredity and environment in the genesis, epigenesis and evolution of the orofacial area]. / Ereditarietà e ambiente nella genesi, epigenesi ed evoluzione del distretto oro-facciale.

Genetic and evolutionary aspects of the dento-facial complex are described according to the concept of heredity as a force of preservation for the human species, though ruled by natural selection and by mutational changes. Ontogenesis and growth of the oral structures reflect mutual regulations between genes and environmental factors. Therefore, the authors carry out an analysis of environmental and constitutional factors affecting dental and facial development. Three levels are identified: individual morphogenesis and growth; actual heredity of parietal dento-facial traits; role and meaning of teeth, jaws and temporo-mandibular joint during evolution leading to Homo sapiens sapiens. As far as individual development is concerned, genes provide only the input for initial cell proliferation and/or differentiation. Further on, growth and morphogenesis of oro-facial structures takes place by means of cell-to-cell and cell-to-substrate interactions. The final, structural result is due to reciprocal interactions among developing structures: muscles modify bone, teeth alignment influences bony bases alignment, ecc. Each structure is genetically determined (teeth, bones, muscles) and each structure carries out epigenetic regulations on other structures: no structure is secluded from biological function of the organism. The inheritance of oro-facial "traits", then, is hardly valuable. First of all, "traits" actually do not exist: they are the product of complex, multifactorial biological mechanisms. Moreover, facial characteristics are affected by polygenic regulation, each gene often showing pleiotropic effects. It has been calculated that 85-90% of facial dimensions in due to epigenetic modifications. Evolution and phylogenesis give evidence about the deep environmental influence on oro-facial morphology. Apart from certain molecular features regarding tooth structure (several dental proteins are today the same as those of the first Vertebrates who lived 500 millions of years ago), tooth number, form, and size depend upon environmental factors. Therefore, dentistry has the important task to preserve fundamental characteristics of dentition, and to intercept environmental pathogenetic factors, as dentition represents a precious instrument for the survival of the human species.