Biomedical subjects

T Baccetti

Publications and source records attributed to T Baccetti.

At least 19 recordsLinked to original sources

PubMed2005

Transverse maxillary deficiency in Class II and Class III malocclusions: a cephalometric and morphometric study on postero-anterior films.

UNLABELLED: AUTHORS: Franchi L, Baccetti T. OBJECTIVES: The aim of the present study is to evaluate the dentoskeletal features of subjects with either Class II or Class III malocclusions in the mixed dentition using both conventional cephalometric analysis and TPS morphometric analysis applied to posteroanterior (PA) cephalograms. DESIGN: TPS analyses of PA cephalograms on 49 Cl-II, and 20 Cl-III subjects. Tracings were done by hand. SETTING AND SAMPLE POPULATION: The Department of Orthodontics, University of Florence. OUTCOME MEASURE: Size and shape differences between Cl-II and Cl-III malocclusions. RESULTS: Maxillary width was smaller in both Cl-II and Cl-III subjects compared with normal as measured conventionally. The TPS analysis revealed transverse plane compression and extension in the vertical plane. CONCLUSION: In Cl-II and Cl-III subjects the maxillary width was smaller 2.5 and 4 mm, respectively. TPS analyses corroborate these findings.

Case-Control Studies↗

PubMed2001

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.

Adolescent↗

PubMed2001

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.

Adolescent↗

PubMed2000

Treatment timing for Twin-block therapy.

This cephalometric study evaluated skeletal and dentoalveolar changes induced by the Twin-block appliance in 2 groups of subjects with Class II malocclusion treated at different skeletal maturation stages in order to define the optimal timing for this type of therapy. Skeletal maturity in individual patients was assessed on the basis of the stages of cervical vertebrae maturation. The early-treated group was composed of 21 subjects (11 females and 10 males). Mean age of these subjects at time 1 (immediately before treatment) was 9 years +/- 11 months, and at time 2 (immediately after discontinuation of the Twin-block appliance) was 10 years 2 months +/- 11 months. According to the cervical vertebrae maturation staging at times 1 and 2, the peak in growth velocity was not included in the treatment period for any of the subjects in the early group. The late-treated group consisted of 15 subjects (6 females and 9 males). Mean age of this group was 12 years 11 months +/- 1 year 2 months at time 1 and 14 years 4 months +/- 1 year 3 months at time 2. In the late group, treatment was performed during or slightly after the onset of the pubertal growth spurt. Both treated samples were compared with control samples consisting of subjects with untreated Class II malocclusions also selected on the basis of the stage in cervical vertebrae maturation. A modification of Pancherz's cephalometric analysis was applied to the lateral cephalograms of all examined groups at both time periods. Linear and angular measurements for mandibular dimensions, cranial base angulation, and vertical relationships were added to the original analysis. Annualized differences for all the variables from time 1 to time 2 were calculated for both treated groups and contrasted to the annualized differences in the corresponding untreated groups by means of nonparametric statistics. The findings of this short-term cephalometric study indicate that optimal timing for Twin-block therapy of Class II disharmony is during or slightly after the onset of the pubertal peak in growth velocity. When compared with treatment performed before the peak, late Twin-block treatment produces more favorable effects that include: (1) greater skeletal contribution to molar correction, (2) larger increments in total mandibular length and in ramus height, and (3) more posterior direction of condylar growth, leading to enhanced mandibular lengthening and to reduced forward displacement of the condyle in favor of effective skeletal changes. The importance of the biological evaluation of skeletal maturity in individual patients with Class II disharmony to be treated with functional appliances is emphasized.

Age Factors↗

PubMed2000

Mandibular growth as related to cervical vertebral maturation and body height.

The purpose of this study was to analyze the validity of 6 stages of cervical vertebral maturation (Cvs1 through Cvs6) as a biologic indicator for skeletal maturity in 24 subjects (15 females, 9 males). The method was able to detect the greatest increment in mandibular and craniofacial growth during the interval from vertebral stage 3 to vertebral stage 4 (Cvs3 to Cvs4), when the peak in statural height also occurred. The prevalence rate of examined subjects who presented with the peak in body height at this interval was 100% for boys and 87% for girls. Statural height and total mandibular length (Co-Gn) showed significant increments during the growth interval Cvs3 to Cvs4 when compared with the growth interval Cvs2 to Cvs3, and significant growth deceleration occurred during the interval Cvs4 to Cvs5 when compared with Cvs3 to Cvs4. Ramus height (Co-Goi) and S-Gn also showed significant deceleration of growth during the interval Cvs4 to Cvs5 when compared with Cvs3 to Cvs4. Cervical vertebral maturation appears to be an appropriate method for the appraisal of mandibular skeletal maturity in individual patients on the basis of a single cephalometric observation and without additional x-ray exposure. The accuracy of the cervical vertebral method in the detection of the onset of the pubertal spurt in mandibular growth provides helpful indications concerning treatment timing of mandibular deficiencies.

Adolescent↗

PubMed2000

Treatment and posttreatment craniofacial changes after rapid maxillary expansion and facemask therapy.

The aim of this study was to evaluate treatment and posttreatment dentoskeletal changes in 2 groups of subjects with Class III malocclusions. Subjects were treated with a bonded acrylic-splint expander and a face mask, and the optimal timing for this treatment protocol was assessed. The treated sample (29 subjects) was divided into 2 groups according to the stage of dental development. The early treatment group consisted of 16 subjects in the early mixed dentitional (erupting permanent incisors and/or first molars), whereas the late treatment group consisted of 13 subjects in the late mixed dentition (erupting permanent canines and premolars). Cephalograms were available at 3 time periods: T(1), pretreatment, T(2), end of active treatment, and T(3), posttreatment. The mean T(1)-T(2) interval (active treatment period) and the mean T(2)-T(3) interval (posttreatment period) were approximately 1 year each in both treatment groups. None of the patients wore any skeletal retention appliance during the posttreatment period (T(2)-T(3)). Groups of subjects with untreated Class III malocclusion were used as controls at both observation intervals. A significant increase in the sagittal growth of the maxilla was seen only when treatment was performed in the early mixed dentition. A restraining effect on mandibular growth rate associated with a more upward and forward direction of condylar growth was found in both treatment groups. An increase in vertical intermaxillary relationships was observed in Class III patients treated in the late mixed dentition. Posttreatment, the Class III craniofacial growth pattern was re-established in the absence of any skeletal retention appliance. Relapse tendency affects the sagittal growth of the maxilla in the early treated subjects and the sagittal position of the mandible in the late treated subjects. Orthopedic treatment of Class III malocclusion in the early mixed dentition is able to induce more favorable craniofacial adaptations than treatment in the late mixed dentition.

Age Factors↗

PubMed2000

Tooth anomalies associated with failure of eruption of first and second permanent molars.

The occurrence of tooth anomalies in association with failure of the first and second molars to erupt was assessed in a sample of 1520 nonsyndromic subjects with uncrowded dental arches (mean age, 14 years 4 months) and compared with the prevalence rate calculated in a matched control group of 1000 subjects. The tooth anomalies examined included infraocclusion of deciduous molars, palatal displacement of maxillary canines, rotation of maxillary lateral incisors, aplasia of second premolars, and small size of maxillary lateral incisors. Associations among arrested eruption of first and second permanent molars and anomalies in tooth eruption and position (infraoccluded deciduous molars, palatally displaced canines, rotated maxillary lateral incisors) were highly significant (P <. 001). No significant association was found among the occurrence of molar eruption disturbances, aplasia of premolars, and small-sized laterals. These findings point to a common biologic cause for the appearance of failure of eruption of molar teeth and other disturbances in tooth eruption and position, most likely under genetic influence.

Adolescent↗

PubMed2000

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.

Adolescent↗

PubMed2000

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.

Bicuspid↗

PubMed1999

Treatment and posttreatment effects of acrylic splint Herbst appliance therapy.

This study evaluated the skeletal and dentoalveolar changes induced by acrylic splint Herbst therapy of Class II malocclusion. The treated group comprised 55 subjects with Class II malocclusion treated with the acrylic splint Herbst appliance followed by comprehensive edgewise therapy. The mean age at Time 1 (immediately before treatment) was 12 years and 10 months +/- 1 year and 2 months. The mean age at Time 2 (immediately after debonding of the Herbst appliance) and Time 3 (posttreatment) was 13 years and 10 months +/- 1 year and 2 months and 15 years and 2 months +/- 1 year and 4 months, respectively. The two control groups were one group of 30 subjects with untreated Class II malocclusion and another group of 33 subjects with Class I occlusion. The three groups were homogeneous as to the stage of maturation of cervical vertebrae at all observation times. A modification of Pancherz's cephalometric analysis was applied to the lateral cephalograms of the three groups at Time 1, Time 2, and Time 3. Linear and angular measurements for mandibular dimensions, cranial base angulation, and vertical relationships were added to the original analysis. Differences for all the variables from Time 1 to Time 2 (active treatment effects), from Time 2 to Time 3 (posttreatment effects), and from Time 1 to Time 3 (overall treatment effects) were calculated for the treated group and contrasted to corresponding differences of both untreated groups by means of ANOVA (P <.05). The study showed that two thirds of the achieved occlusal correction was due to skeletal effects and only one third to dentoalveolar adaptations. Both skeletal and dentoalveolar effects were due mainly to changes in mandibular structures. A significant amount of relapse in molar relationship occurred during the posttreatment period, and this change could be ascribed to the mesial movement of the upper molars.

Acrylic Resins↗

PubMed1999

Thin-plate spline analysis of treatment effects of rapid maxillary expansion and face mask therapy in early Class III malocclusions.

An effective morphometric method (thin-plate spline analysis) was applied to evaluate shape changes in the craniofacial configuration of a sample of 23 children with Class III malocclusions in the early mixed dentition treated with rapid maxillary expansion and face mask therapy, and compared with a sample of 17 children with untreated Class III malocclusions. Significant treatment-induced changes involved both the maxilla and the mandible. Major deformations consisted of forward displacement of the maxillary complex from the pterygoid region and of anterior morphogenetic rotation of the mandible, due to a significant upward and forward direction of growth of the mandibular condyle. Significant differences in size changes due to reduced increments in mandibular dimensions were associated with significant shape changes in the treated group.

Case-Control Studies↗

PubMed1998

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.

Dental Instruments↗

PubMed1998

Shape-coordinate analysis of skeletal changes induced by rapid maxillary expansion and facial mask therapy.

The aim of this study was to evaluate maxillary and mandibular shape/size changes by means of Bookstein's shape-coordinate and tensor analysis in children with Class III malocclusions treated with rapid maxillary expansion and a facial mask in order to define optimum timing of intervention for this type of therapy. The treated group (46 subjects, 26 females and 20 males) was divided into two subgroups according to the stage of dentitional development. The early-treated group consisted of 23 subjects treated in the early mixed dentition (mean age at Time 1, 6 years 9 months +/- 7 months); the late-treated group included 23 subjects treated in the late mixed dentition (mean age at Time 1, 10 years 3 months +/- 1 year). The mean treatment period was about 11 months. The control group (32 subjects with untreated Class III malocclusion, 18 females and 14 males) also was divided into two subgroups (an early control group, 17 subjects in the early mixed dentition, and a late control group, 15 subjects in the late mixed dentition). Maxillary triangles (point T, the most superior point of the anterior wall of sella turcica, point FMN, the fronto-maxillary-nasal suture, and point A) and mandibular triangles (point Condylion, point Gonion, and point Pogonion) were digitized on cephalograms in both groups at Time 1 and Time 2. Combined facial mask and rapid maxillary expansion therapy produced a significant enhancement of the forward growth of the maxilla and significantly more upward and forward direction of growth of the mandibular condyle (leading to smaller increments in mandibular total length, Co-Pg) in the early-treated group when compared with controls and to the late-treated group. Both maxillary size and mandibular size were significantly affected by treatment in the early mixed dentition. The results of this study indicate that orthopedic treatment of Class III malocclusion induces favorable size and shape changes both in the maxilla and mandible, and that this combined treatment approach is more effective in the early mixed dentition than in the late mixed dentition.

Age Factors↗

PubMed1998

Skeletal effects of early treatment of Class III malocclusion with maxillary expansion and face-mask therapy.

The effectiveness of maxillary expansion and face-mask therapy in children with Class III malocclusion was studied in a sample of 46 subjects in mixed dentition and compared with a control sample of 32 subjects with untreated Class III malocclusion. Treated and untreated samples were divided into early and late mixed-dentition groups to aid identification of the optimum timing of the orthopedic treatment of the underlying skeletal disharmony. Cephalometric analysis was based on a stable basicranial reference system, appropriate for longitudinal studies started in the early developmental ages. The level of significance for intergroup comparisons was set at a p value of 0.01. Significant forward displacement of the maxillary complex was found in the early-treatment group. The region of the pterygomaxillary suture, in particular, showed significant changes in the subjects treated during early mixed dentition. No significant maxillary modifications were recorded in the late-treatment group. Both early and late groups exhibited smaller increments in mandibular protrusion and larger increments in the intermaxillary vertical relationship compared with their respective Class III control groups. Only children treated at an early age, however, showed a significant upward and forward direction of condylar growth, leading to smaller increments in total mandibular length. These results indicate that the combination of a bonded maxillary expander and face-mask therapy is more effective in early mixed dentition than in late mixed dentition, especially with regard to the magnitude of the protraction effects on maxillary structures.

Age Factors↗

PubMed1998

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.

Adolescent↗

PubMed1998

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.

Adolescent↗

PubMed1998

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.

Adult↗

PubMed1998

A retrospective comparison of functional appliance treatment of Class III malocclusions in the deciduous and mixed dentitions.

This retrospective study compared the effectiveness of treatment of Class III malocclusions with the removable mandibular retractor in the deciduous and mixed dentitions. A group of 20 children with Class III malocclusions started treatment at a mean age of 5 years 1 month +/- 7 months (deciduous dentition), while a group of 18 children with Class III malocclusions started treatment at a mean age of 8 years 2 months +/- 9 months (mixed dentition). The mean observation period was 2 years 3 months +/- 6 months for the first group, and 2 years 4 months +/- 7 months for the second group. Matched control groups of children with untreated Class III malocclusions in the deciduous and in the mixed dentition (16 subjects and 15 subjects, respectively) were used. The cephalometric analysis was based on a stable basicranial reference system appropriate for longitudinal studies that begin at early developmental ages. The results showed that treatment of Class III malocclusions in the deciduous dentition produced a more significant anterior morphogenetic rotation of the mandible, due to a more upward and forward direction of condylar growth (P < 0.01). This leads to significantly smaller increments in mandibular total length (Co-Pg) in children with Class III malocclusions under-going very early treatment (P < 0.01). On the contrary, maxillary dento-alveolar protrusion induced by therapy was greater in Class III subjects treated in the mixed dentition (P < 0.01). The optimum timing to improve skeletal relationships in Class III malocclusions by means of a functional appliance appears to be in the deciduous dentition.

Age Factors↗