Joseph Ghafari

Cephalometric superimposition on the cranial base: A review and a comparison of four methods

Spatial change in the jaws of growing persons is often evaluated by superimposing cephalometric tracings made at different points in time. Methods of superimposition vary according to structures used as references within the skull. This study compares four different superimposition methods. The sample consisted of 26 patients (13 boys, 13 girls) treated for Class II, Division 1 malocclusions with extraction of the four first premolars. Tracings of pretreatment (average age for boys, 12.5 years; for girls, 12.2 years) and posttreatment (average age for boys, 15.4 years; for girls, 14.9 years) cephalograms were superimposed according to the following methods: (1) best fit of anterior cranial base anatomy, (2) superimposition on SN line, registered at S, (3) superimposition on registration point R with Bolton-nasion planes parallel, and (4) superimposition on basion-nasion (Ricketts), registered at point CC (4) and point N (4a). Differences in amount of change among the superimposition methods were assessed independently for each of the following landmarks: PNS, ANS, A, B, Pog, Gon. On each patient and for each landmark, ten distances--the paired differences of five posttreatment positions obtained by methods 1, 2, 3, 4, and 4a--were evaluated. Two methods were compared at a time. A t test examined the average difference for each comparison. Because all differences between all paired methods were significant (P less than 0.01), t tests were then viewed under the hypothesis that a difference less than or equal to 1 mm was insignificant clinically. Clinically-statistically significant differences were found only for boys and for the total sample between methods 4a and each of methods 1, 2, and 3. As method 4a is advocated to assess changes of point A (Ricketts), this method gives, for the same person, an interpretation of anterior maxillary change in position different from the other methods. Conclusions about facial changes may be made only in reference to the superimposition method.

Transverse development of the jaws: Norms for the posteroanterior cephalometric analysis

Norms available for the posteroanterior (PA) cephalometric analysis yield different information. The material used to generate these standards is not clearly defined. The purpose of this study was to use data from the Bolton-Brush Growth Study to generate new norms for the PA analysis. The Bolton material is recognized as a controlled longitudinal record of growing children. The assumption that growth in the transverse dimension is the first to be completed is challenged by finding that increments in maxillary and mandibular width vary, like sagittal and vertical growth, according to gender and chronologic age.

Problems associated with ceramic brackets suggest limiting use to selected teeth

Ceramic brackets became popular as esthetic appliances which could withstand orthodontic forces and resist staining better than plastic brackets. Several clinical complications may arise from the use of ceramic brackets. They include the effects debonding can have on underlying enamel, attrition of teeth occluding with ceramic brackets and increased friction in the orthodontic appliance. Solutions to these problems are discussed which indicate the need for careful selection of teeth to be bonded with ceramic brackets.

Dental and occlusal characteristics of children with neuromuscular disease

Seventy-nine pediatric patients with neuromuscular diseases were examined for dental and occlusal characteristics. Fifty-six patients suffered from primary muscle disease (myopathies) including 43 with Duchennes muscular dystrophy. The neuromuscular disorders in 19 patients were of neuropathic origin, while four were caused by a fault in the neuromuscular junction. Posterior crossbites occurred more often in the myopathies (57%) as compared with the neurogenic dystrophies (14%) (P less than 0.003). Although not statistically significant, the prevalence of open bite was also higher in the combined myopathies (21%) as compared with neurogenic disorders (9%). The Duchenne patients exhibited a statistically significant delay in dental emergence (1.06 years), unlike the other myopathies (0.31 years) and the neurogenic disorders groups (-0.03 years). This study emphasizes the influence of muscular environment on dental development in general. The dentition may be more affected in muscular dystrophies stemming from degenerative or inflammatory muscle damage than in those originating from nerve malfunction or disorder of the neuromuscular junction.

New Posteroanterior Cephalometric Norms: A Comparison with Craniofacial Measures of Children Treated with Palatal Expansion

The aim of the study was to evaluate posteroanterior (PA) cephalometric characteristics in a normal longitudinal database and compare these measurements with corresponding measures in a group of patients treated with rapid maxillary expansion. Posteroanterior cephalographs of 16 girls and 14 boys from the Bolton-Brush growth study, taken at ages 10 and 18 years, were used to track growth in children with normal occlusion. Pretreatment PA cephalograms of 24 patients who had palatal distraction around age 10 were compared with the 10-year-old normal patients. Digitized landmarks included right and left jugale (J, at intersection of maxillary tuberosity and zygomatic buttress) and antegonion (AG, at notch of antegonial protuberance). Mandibular width (AG-AG) was similar in boys and girls at age 10 but not 18, when the difference between gender groups was statistically significant (P < .05). Maxillary width (J-J) was greater in boys than girls at both ages. The increase in AG-AG (5.5 mm, boys; 3.9 mm, girls) was more than twice that of J-J (2.4 mm, boys; 1.2 mm, girls). Arch width (at first molar) was nearly stable with age, indicating compensatory occlusal adaptation to differential changes between maxillary and mandibular widths. At age 18, the distance between the centers of the orbits, a surrogate measure of cranial width, was almost equal to J-J in girls and significantly correlated with AG-AG in boys (r = .71, P < .002) and girls (r = .77, P < .0001). The majority of treated children had both skeletal and dentoalveolar widths narrower than control values. Linear regressions between J-J and AG-AG revealed almost parallel slopes for control and treated groups in both genders, but the treated group was at a lower level, which is consistent with smaller maxillary widths.

Effect of film-object distance on posteroanterior cephalometric measurements: Suggestions for standardized cephalometric methods

Posteroanterior (PA) cephalographs are used for diagnosis of transverse skeletal and dentoalveolar relationships. Unlike lateral head films, the variability of the PA radiograph has not been assessed. The purpose of this study was to evaluate the effect of film-object distance (film-ear rod, or film-porionic axis distance: FPD) and head angulation on transverse measurements from PA cephalographs. Seventeen skulls were selected from a total of 45 on the basis of strict criteria, including a stable reproducible centric occlusion. Radiographs were taken of each skull at the FPD of 11, 12, 13, and 14 cm. At the FPD of 11 and 14 cm, additional radiographs were taken at the angulations of +5 degrees and -5 degrees from the Frankfort horizontal (FH). Distances between the following landmarks were measured on the radiographs with digital calipers accurate to 0.01 mm: J (on the lateral contour of the maxilla), Ag (at the antegonial notch), Go (Gonion), Mb (buccal surface of mandibular first molar), IR (inner ramal point at the intersection of mandibular ramus and body). No clinically significant difference existed between measurements at the different FPDs evaluated. For this reason, and because the majority of PA films taken of 59 human subjects were within a FPD range below and including 13 cm, regression analyses were computed only at FPD = 13 cm. Correlation coefficients r between the distance AG-AG and distances J-J, IR-IR, and Mb-Mb were 0.71, 0.75, and 0.68, respectively. Transverse measurements were not significantly affected by a head angulation within 10 degrees (FH -5 degrees to +5 degrees).(ABSTRACT TRUNCATED AT 250 WORDS)

Longitudinal evaluation of the Treatment Priority Index (TPI).

The Treatment Priority Index (TPI) is an epidemiologic tool used to rank malocclusions and assess the need for orthodontic treatment. The purpose of this study was to (1) evaluate the predictability of the TPI as an indicator of malocclusion severity, (2) evaluate the effect of orthodontic treatment on TPI values, and (3) compare the results with a national survey of American children aged 6 to 11 years and 12 to 17 years conducted by the United States Public Health Service. The TPI was recorded annually in a young student population of Juniata County, Pa., from 1975 to 1979, and later in 1985. The mean values of the TPI did not reflect the range of severity in the population. For this reason the Malocclusion Severity Scale (Burlington Growth Center) was used to identify four groups in 1985. Each group was tracked back to 1975. Further evaluation investigated the role of individual factors contributing to malocclusion over time (tooth displacement and occlusal factors). The conclusions are as follows: (1) the TPI is a valid epidemiologic indicator of malocclusion but does not predict the severity of individual malocclusions in the permanent dentition, (2) TPI values decrease with orthodontic treatment, and (3) the average TPI values for this population were higher than the national average between 6 and 11 years of age and slightly lower in late adolescence, but lie within a treatment-need range of slight to elective. A characterization of treatment need relative to malocclusion severity that is different from the available scale is suggested.

Monitoring growth during orthodontic treatment

The relationship between somatic growth and orthodontic treatment has been limited to the evaluation of body height and skeletal age relative to craniofacial development. The aim of this study was to evaluate the correlation of anthropometric and biochemical measures of general growth with facial and occlusal changes during the early treatment of Class II Division 1 malocclusion. Findings are reported from 46 children, ages 7.20 to 12.85 years (skeletal ages, 5.75 to 12.75 years), who are enrolled in a prospective clinical trial. Body and knee heights were measured monthly, with a Holtain stadiometer and a Knee Height Measuring Device, respectively. Every three months, serum levels were measured of the hormone dehydroepiandrosterone sulfate (DHEAS), an androgen associated with growth in midchildhood, and osteocalcin, an indicator of bone turnover. Significant correlations existed between knee height and various occlusal measurements, but mandibular length was not significantly correlated with knee height and DHEAS levels. Knee height correlated significantly (P < .05) with DHEAS and osteocalcin only in 46% and 37% of the children, respectively. The results indicate that the evaluated biochemical measures, at the time intervals considered, may not increase the accuracy of growth depiction by physical measures alone (height and skeletal maturation).

Palatal sutural response to buccal muscular displacement in the rat

Buccal shields inserted in the mouths of 30-day-old Sprague-Dawley rats displaced the buccal musculature away from the maxillary molar teeth. Intermolar distances increased significantly (P less than 0.02) 15 days following insertion of the appliance, thereafter decreasing with time. Histologically, at the level of the first molars, ossification of the sutural cartilage occurred earlier than in control sutures. While different interpretations are given to explain this result, the adaptive nature of secondary cartilage in the intermaxillary suture of the rat was demonstrated. This adaptation may be limited by the nature of mechanical stress exerted upon, and/or the growth potential, of the suture.

Correspondence Between Subjective and Linear Measurements of the Palatal Airway on Lateral Cephalometric Radiographs

OBJECTIVE To evaluate the correlation between and significance of 2 methods of palatal airway assessment on lateral cephalographs. DESIGN Diagnostic lateral cephalometric imaging study that took place from January 1, 2006, to December 31, 2007. SETTING American University of Beirut Medical Center. PATIENTS Children with chronic mouth breathing referred by a pediatric otolaryngologist for cephalometric evaluation by participating orthodontists. MAIN OUTCOME MEASURES Two distances were measured on the digitized lateral cephalographs between the adenoid and soft palate: the shortest adenoid distance (SAD) and the most convex adenoid distance (CAD). The palatal airway was assessed on a grade-1 to grade-3 scale independently by the referring otolaryngologist and an orthodontist. RESULTS A total of 200 children were included in the study (127 boys and 73 girls; mean age, 6 years; age range, 1.71-12.62 years). High correlations were observed between the airway ratings gathered by both examiners (r = 0.96) and between SAD and CAD (r = 0.92). Significant correlations were noted between the palatal airway grade and the SAD and CAD measurements (r = -0.73 and r = -0.79, respectively). Shortest adenoid distance measures of 2 mm or less corresponded mostly to grade 3 obstruction and were more prevalent in patients younger than 6 years. Age was inversely proportional to both the grade and SAD (P < .001). CONCLUSIONS Both methods are reliable for assessment of airway obstruction by the adenoid. Because SAD and CAD are highly correlated, we recommend the use of SAD as a more readily identifiable distance on cephalometric radiographs. Removal of adenoids when SAD is less than 2 mm may be indicated because this condition reflects a severe airway obstruction associated with potential changes in dentofacial structure.