Total Anterior Facial Height Research Articles

The effects of extraction and nonextraction treatment on the mandibular position

Decisions on extraction of teeth as an aid in orthodontic treatment depend on dental and skeletal discrepancies concerning sagittal and vertical relationships. The purpose of this study was to assess the effects of extraction and nonextraction procedures on the posterior rotation of the mandible and the position of gnathion. Forty-eight nonextraction patients and seventy-three extraction patients treated in the orthodontic department were selected. The patients were from 11 to 15 years old, with a mean age of 12 years 2 months. The lateral cephalometric radiographs taken before and after treatment were traced and measured. Eleven variables reflecting the mandibular rotation were selected on the basis of factor analysis. Before treatment, total arch circumferential discrepancy and the 11 selected measurements showed significant differences between the extraction and nonextraction groups. In the extraction group, the lower anterior facial height was larger, ramus height was smaller, and the difference between vertical position of both maxillary and mandibular first molars and posterior facial height was greater than in the nonextraction group. Consequently, the mandible showed posterior rotation and was in retruded position in the extraction group. In the nonextraction group, the type of force application had no significant effect on the changes in skeletal and dental measurements. In the extraction group, however, the type of force application had a significant effect (p less than 0.05) on the changes in total anterior facial height, the horizontal distance of the maxillary first molar to a perpendicular line to the S-N plane passing through point S, the vertical distance of the maxillary molar to the S-N plane, the vertical distance of the maxillary and mandibular first molars to the S-N plane, the difference between the vertical position of the first molars and posterior facial height, and the difference between the vertical position of the first molar and vertical height of the ramus. In the group in which high-pull face-bow headgear was used, the extraction/nonextraction procedures had a significant effect (p less than 0.05) on the changes in angle ANB, total anterior facial height, anterior lower facial height, and the difference between anterior and posterior facial height.(ABSTRACT TRUNCATED AT 400 WORDS)

Face height and tooth eruption in adults-- a 20-year follow-up investigation

A longitudinal roentgen cephalometric investigation of vertical craniofacial and dentoalveolar changes during 20 years of adulthood, was performed in 15 men and 15 women. Two lateral cephalograms taken at the average ages 25 and 45 years, were available of each subject. Skeletal and dental changes were described by 13 linear and four angular cephalometric measurements. The analysis of the linear variables showed that total anterior face height increased by 1.60 mm on average. Approximately one-fifth of this increase occurred in the upper and four-fifths in the lower face. In the dentoalveolar region, significant increments of all dimensions except overjet and overbite were found, indicating an eruptive movement of the teeth and a vertical development of their investing tissues. The analysis of the angular measurements showed that posterior rotation of the mandible and uprighting of the upper incisors had occurred during the period of investigation.

The long face syndrome and impairment of the nasopharyngeal airway

Experimental evidence suggests that altered muscular function can influence craniofacial morphology. The switch from a nasal to an oronasal breathing pattern includes functional adaptations that include an increase in total anterior face height and vertical development of the lower anterior face. While some animal studies have suggested predictable growth pat­terns may occur, studies in human subjects have been much more controversial. Therefore, individual variations in response should be expected from the alteration of a long face syndrome patient's breathing mode. [Reprinted from The Angle Orthodontist, Fall 1990, vol. 60, pages 167-176]

The long face syndrome and impairment of the nasopharyngeal airway.

Experimental evidence suggests that altered muscular function can influence craniofacial morphology. The switch from a nasal to an oronasal breathing pattern induces functional adaptations that include an increase in total anterior face height and vertical development of the lower anterior face. While some animals studies have suggested predictable growth patterns may occur, studies in human subjects have been much more controversial. Therefore, individual variations in response should be expected from the alteration of a long face syndrome patient's breathing mode.

Patterns of vertical growth in the face

The purpose of this study was to examine the patterns of facial growth development in subjects with skeletal open-bite and skeletal deep-bite faces. Longitudinal data based on lateral cephalometric radiographs of 16 male and 16 female subjects, ages 3 through 18 years, were used. These subjects were selected on the basis of lower face height as a percentage of total face height. Persons exhibiting extreme values were selected to create four groups with eight subjects in each group. Curves of absolute and incremental growth for total anterior face height, upper anterior face height, lower anterior face height, posterior face height, and ramal length were analyzed statistically and graphically. It was established that the anterior dimensions of the face demonstrated typologically divergent patterns of development in open- and deep-bite faces. Further, the posterior dimensions of the face did not discriminate between these two typological groups. The female open-bite subjects were earliest in the timing of the adolescent growth spurt, followed in succession by deep-bite female subjects, open-bite male subjects, and finally the deep-bite male subjects. The clinical implications of these observations pertain to the timing of orthodontic treatment, the length of retention period, and the prediction of adult occlusal status during the mixed dentition.

The effects of perennial allergic rhinitis on dental and skeletal development: A comparison of sibling pairs

This study analyzed the effect of perennial allergic rhinitis on dental and facial skeletal characteristics. Twenty-five allergic children who were apparent mouth breathers, their 25 siblings who did not have the disease and were apparent nose breathers, and 14 nasal breathing control subjects were examined medically, dentally, and cephalometrically. Compared with their siblings, the allergic subjects had more nasal mucosal edema, a higher proportion of eosinophils in their nasal secretions, and greater nasal power. The allergic subjects were characterized by deeper palatal height, retroclined mandibular incisors, increased total anterior facial height and lower facial height, a larger gonial angle, and greater SN, palatal, and occlusal planes to mandibular plane angles. All of these measures except gonial angle were also significantly different between the allergic children and the nonconsanguineous controls. Also, the allergic subjects compared with controls had smaller SNB and SN-pogonion angles and an increased overjet. Both allergic and nonallergic sibling groups showed larger mean adenoid size on radiographs than controls. For most variables the nonallergic siblings fell between the allergic children and the control subjects. Overall, the allergic children had longer, more retrusive faces than controls. This retrusive characteristic was present in nonallergic siblings and cannot be ascribed to the apparent breathing mode at the time of the study. These results confirm earlier reports that allergic rhinitis may be associated with altered facial growth. Controlled longitudinal studies to analyze a possible cause-and-effect relationship and the effects of medical and surgical treatments should be undertaken.

Correction of anterior mandibular vertical excess: The functional genioplasty

The functional genioplasty is an osteotomy-ostectomy of the anterior mandible which reduces excessive lower anterior facial height to 55% of the total anterior facial height. The procedure is indicated particularly when one factor contributing to the long-face syndrome is vertical excess of the anterior mandible. The surgical technique involves creation of a tenon and mortise which not only preserves the insertions of both the labiomental muscles and at least some of the suprahyoid muscles but also improves the stability of transosseous fixation. Superior repositioning and advancement of the chin and myocutaneous structures produce both functional and esthetic benefits for the patient.

Components of adult Class II open-bite malocclusion

In an effort to identify the frequency and distribution of the dental and skeletal components of adult Class II malocclusion with and without open-bite, 124 adults, half of whom had an anterior open-bite, were evaluated. Significant differences ( P < 0.05) between the open-bite and non-open-bite groups were found for the following measurements: the posterior maxilla exhibited vertical excess in the open-bite group; the maxillary occlusal plane was less steep in the open-bite group; the mandibular occlusal plane was more steep in the open-bite group; the gonial angle was higher in the open-bite group; the mandibular plane angle was higher in the open-bite group; the mandibular ramus was positioned in a more downward and backward (clockwise) location in the open-bite group; the total and lower anterior facial height were increased in the open-bite group; and the mandible was less protrusive in the open-bite group. No significant intergroup differences were noted in the cranial base, the anteroposterior position of the maxilla or of the upper and lower incisors, the palatal plane, posterior facial height, mandibular ramus height, or mandibular body length. The results of this analysis indicate that the average Class II open-bite malocclusion is characterized by aberrations in both the maxilla and the mandible. Therapy, therefore, may frequently require surgical intervention in both jaws to successfully correct this deformity.

Facial pattern differences in long-faced children and adults

Vertical facial morphology has traditionally been studied by examining subjects chosen because of open bite/overbite or mandibular plane angle. The underlying skeletal and dental morphology associated with clinical facial appearance of normal and vertically dysplastic children and adults has not been well documented. The purposes of this study were to (1) describe vertical facial morphology in long-, normal-, and short-faced children and long-faced and normal adults, and (2) identify morphologic factors associated with the clinical evaluation of long-faced and normal subjects. Forty-two children, 6 to 12 years old, and forty-two young adults with varied vertical facial types were examined clinically and separated into three vertical classifications: long, normal, or short face. Lateral cephalometric radiographs were obtained in natural head position and seven angular, eighteen linear, and six ratio measurements were made. Descriptive statistics were used to characterize all groups, and intergroup differences were compared using analysis of variance for the three child groups and the t test for the two adult groups. For both long-faced children and adults, anterior total face height, mandibular plane angle, gonial angle, and mandibulopalatal plane angle were significantly greater than normal. Ramus height was not significantly different from normal in the children, but there was a tendency for long-faced adults to have short rami. Excessive dentoalveolar development was evident in long-faced children but not in adults. Factors associated with the clinical identification of vertical dysplastic subjects were identified by a principal component analysis. For each component, a variable highly correlated with that component was selected. These variables were then included in a stepwise discriminant analysis. The analysis selected three variables—SN/mandibular plane angle, anterior total face height, and the ratio of anterior upper to anterior total face height. Although related, multiple morphologic factors were most helpful in explaining the clinical vertical evaluation of facial patterns.

Mouth breathing in allergic children: Its relationship to dentofacial development

While there are many claims that abnormal breathing patterns alter facial growth, there are limited controlled data to confirm this. We evaluated forty-five North American Caucasians of both sexes, ranging in age from 6 to 12 years. Thirty chronically allergic mouth-breathing subjects were selected from a pediatric allergy practice, and fifteen nonallergic nose breathers were selected from a general pediatric practice. Each subject underwent an intraoral clinical examination and a cephalometric radiograph analysis. Various skeletal and dental relationships were evaluated for statistical differences related to mode of breathing and age. The upper anterior facial height and the total anterior facial height were significantly larger in the mouth breathers. Angular relationships of the sella-nasion, palatal, and occlusal planes to the mandibular plane were greater in the mouth breathers, and their gonial angles were larger. The mouth breathers' maxillae and mandibles were more retrognathic. Palatal height was higher, and overjet was greater in the mouth breathers. Maxillary intermolar width was narrower in the mouth breathers and was associated with a higher prevalence of posterior cross-bite. Over all, mouth breathers had longer faces with narrower maxillae and retrognathic jaws. This supports previous claims that nasal airway obstruction is associated with aberrant facial growth. Longitudinal studies are needed to evaluate the effectiveness of early intervention in preventing these growth alterations.

Early adult changes in the skeletal and soft-tissue profile

Early adult changes in the facial profile were studied longitudinally from 21 to 26 years of age in a Swedish Caucasian sample of 50 female and 101 male dental students. Lateral cephalometric radiographs were analysed by the conventional point-based method and by the structure-based method of superimposing serial films, adapted for computerized numerical analysis. Skeletal and soft tissue changes were described by 62 linear and angular variables. The magnitude of linear dimensional changes was similar in the two sexes. The largest changes were found in the vertical dimensions. Total anterior facial height increased by about 1.5 mm in the 5-year period, suggesting that the major part of the increase in vertical facial dimensions during the third decade of life takes place in the first half of this decade. Sagittal jaw relationship increased by about 0.5° in both sexes. Soft tissue changes reflected those of the vertical skeletal dimensions.

Varieties of anterior open-bite

Cephalograms of ninety-two male subjects with good occlusions, eighteen persons with Angle Class II anterior open-bite, and eighteen persons with open-bite mandibular prognathism (and Class III occlusion) were compared. On the average, persons with open-bite had a longer anterior lower face height, a shorter posterior face height, a shorter 1 to S-N distance, a smaller 6 to MP distance, a larger gonial angle, and a smaller UFH LFH ratio than did the normal control subjects. Total anterior face height was longer in the mandibular prognathism groups than in the control or Class II persons. The upper occlusal plane to S-N angle was similar in the three groups, but the lower occlusal plane to S-N angle was larger in the open-bite subjects. Facial polygons were used to show pattern differences between the groups.

The sagittal growth of the foetal cranial base.

There is an increase in the angular relationship between the anterior and posterior cranial components in foetal life. The angular changes taking place seem to occur in the region of the sphenoethmoidal junction. The spheno-occipital element of the cranial base showed stability during foetal life, whereas the spheno-ethmoidal part of the cranial base angles increased in the corresponding period. A large angle in any one of the cranial base angles is followed by large angles in the rest of the cranial angles. A large cranial base angle is followed by a large anterior total facial height and a relatively posterior rotation of the upper jaw, retrognathic lower face and a relatively posterior rotation of the lower jaw. The growth of the anterior cranial base is more active than the growth of the posterior cranial base. The ethmoidal and sphenoidal parts of the anterior cranial base contribute equally to the increase in length. A long anterior cranial base is followed by a large spheno-ethmoidal angle and rela...