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PubMed1989

Relationships of changes in craniofacial morphology, head posture, and nasopharyngeal airway size following mandibular osteotomy.

The aim of the present study was to illustrate a possible relationship between changes in craniofacial morphology after mandibular osteotomy and changes in head posture and nasopharyngeal airway size. The material comprised standardized profile cephalograms of 52 patients with mandibular prognathism, all of whom underwent orthodontic adjustment before mandibular osteotomy. Mean age of the patients was 24.3 years; 12 men and 40 women participated in the study. The first profile radiograph of each patient was taken 1 day before surgical treatment in the natural head (mirror) position. All patients underwent mandibular surgery with a bilateral vertical ramus osteotomy. The cephalometric investigation was repeated approximately 1 year after the surgical procedure (means = 1.12 years). Craniofacial morphology was evaluated by 12 parameters describing sagittal and vertical jaw relationship. Head posture was evaluated by the craniocervical angulation and airway as nasopharyngeal airway size. Pearson's correlation analysis was used to evaluate the relationship between morphology, posture, and airway size before surgery and changes in these parameters after surgery. Before surgical treatment statistically significant correlations were found between posture and many morphologic variables, mostly mandibular. Small correlations were observed between posture and airway size, and airway size and morphology. After the surgical procedure, changes in posture were still related to changes in mandibular morphology, while other correlations between posture and morphology had been eliminated. Changes in nasopharyngeal airway size were not correlated to any changes in morphology, apart from maxillary prognathism, nor to changes in posture. The results indicated that mandibular morphology and function play a significant role in determining head posture.

Adolescent↗

PubMed1992

Cervical and craniocervical posture as predictors of craniofacial growth.

The present study aimed to determine whether growth changes in craniofacial structure could be predicted by variables expressing the postural relations of the head and the cervical column. The sample comprised 34 children, 16 girls and 18 boys. Cephalometric radiographs obtained in natural head position (mirror position) were taken on two occasions before orthodontic treatment. Mean age was 9.9 years at time 1 and 12.7 years at time 2. Selection of the sample was based on skeletal maturity at time 2 indicating peak activity in pubertal growth. Forty-one reference points and four fiducial points were digitized on each film. Individual growth changes in craniofacial structure were determined by computerized structural superimposition of the digitized sets of points. Correlation coefficients were calculated between 11 postural variables at the first observation and the subsequent growth rate in 36 structural variables. Uniform fields of low to moderate correlation coefficients significant at the 5%, 1%, and 0.1% levels (0.3 to 0.6) were found for eight structural variables, indicating that a small craniocervical angle and a backward-inclined upper cervical column at time 1 was associated with horizontal facial development characterized by reduced backward displacement of the temporomandibular joint (TMJ), large maxillary growth in length, increased facial prognathism, and larger than average true forward rotation of the mandible; whereas, a large craniocervical angle and an upright position of the upper cervical column at time 1 was associated with vertical facial development characterized by large backward displacement of the TMJ, reduced growth in length of the maxilla, reduced facial prognathism, and less than average true forward rotation of the mandible. The findings are in agreement with a theoretical model for the developmental interaction between head posture and facial structure.

Cephalometry↗

PubMed1999

Temporomandibular joint remodeling in adolescents and young adults during Herbst treatment: A prospective longitudinal magnetic resonance imaging and cephalometric radiographic investigation.

The aim of this prospective study was to analyze and compare the temporomandibular joint adaptive mechanisms in 25 adolescent and 14 young adult Class II malocclusions treated with the Herbst appliance. Temporomandibular joint remodeling was analyzed by magnetic resonance imaging. In each subject, 4 magnetic resonance images of both temporomandibular joints were available: before treatment, at the start of treatment (when the Herbst appliance was placed), during treatment (6 to 12 weeks after appliance placement), and after treatment (when the appliance was removed). Furthermore, effective temporomandibular joint changes (the sum of condylar remodeling, fossa remodeling, and condyle-fossa relationship changes) were analyzed with the aid of lateral cephalometric radiographs from before and after treatment. All subjects were treated to Class I or overcorrected Class I dental arch relationships, and their mandibles became significantly (P <.001) more prognathic. After 6 to 12 weeks of Herbst treatment, signs of condylar remodeling were seen at the posterosuperior border in 48 of the 50 adolescent condyles and in 26 of the 28 young adult condyles. Bilateral remodeling of the mandibular ramus could be detected in 1 adolescent and 2 young adult patients. Signs of glenoid fossa remodeling at the anterior surface of the postglenoid spine were noted in 36 adolescent and 22 young adult temporomandibular joints. Effective temporomandibular joint changes during treatment were more horizontally directed and larger in both adolescents and young adult patients treated with the Herbst appliance than in an untreated group of subjects with ideal occlusion (Bolton standards). The increase in mandibular prognathism accomplished by Herbst therapy in both adolescents and young adults seems, in particular, to be a result of condylar and glenoid fossa remodeling. Because the Herbst appliance is most successful in Class II patients also at the end of the growth period, the treatment method could be an alternative to orthognathic surgery in borderline skeletal Class II cases. Magnetic resonance imaging renders an excellent opportunity to visualize the temporomandibular joint remodeling growth processes.

Adaptation, Physiological↗

PubMed1978

A new approach to cephalometric analysis of the dental base relationship.

1. The Reference line, connecting the centres of area of the projected skull outline, the cranium and the face, is relatively easy to locate and forms a more stable base from which to measure changes in the face in profile including the dental base relationship, than are the sella-nasion, maxillary or mandibular planes. 2. The Reference-Profile angle is a reliable assessor of a bimaxillary prognathism or retrognathism. Its mean value is 44 degrees. Angles above this value are associated with a bimaxillary retrognathism, and angles below this value with a bimaxillary prognathism. 3. The Reference-Dental Base angle is the most consistent for assessing the anterior jaw relationship between the maxilla and mandible. Its mean value of 50 degrees indicates a Class I relationship. Angles of 53 degrees and above indicate clinical Class II cases and angles of 48 degrees and below indicate clinical Class III cases. 4. These two angles are potentially valuable diagnostic indices for use in orthodontic clinical assessment.

Adolescent↗

PubMed2003

Bialveolar protrusion in a Zimbabwean sample.

This study was undertaken to assess dentoalveolar relationships in a well-balanced sample of adult black Zimbabweans. Lateral cephalograms of 25 men and 25 women 18 to 38 years of age with Class I occlusions were obtained from the University of Zimbabwe. Twelve angular and 6 linear measurements were analyzed, and men and women were compared with the Student t test. No statistically significant difference was noted between the 2 sexes. The Zimbabwean sample had a low Frankfort-mandibular plane angle (19.6 degrees +/- 5.5 degrees ) with a receding chin as shown by the negative Pog-NB measurement (-0.7 +/- 1.5 mm). Both the maxilla (SNA = 88.5 degrees +/- 4.7 degrees ) and the mandible (SNB = 83.3 degrees +/- 4.4 degrees ) were prognathic, and the ANB difference was large (5.3 degrees +/- 2.7 degrees ). The maxillary incisors were more upright compared with those of white people as measured by the angle of the maxillary incisor to NA line (20.6 degrees +/- 7.7 degrees ), while the mandibular incisors were severely proclined (IMPA = 105.8 degrees +/- 6.0 degrees, L1-Apog = 6.9 degrees +/- 2.7 degrees, L1-NB = 37.6 degrees +/- 4.9 degrees ), and this proclination was considered to be compensatory to the prognathic maxilla.

Adolescent↗

PubMed1998

The use of the Jasper Jumper for the correction of Class II malocclusion in the young permanent dentition.

The effect of the Jasper Jumper in the treatment of Class II, division 1 malocclusions was studied in 26 consecutive 13-25-year-old patients. The median treatment time was 5 months, followed by a median period of observation or retention of 7 months. The effects of the treatment were evaluated from cephalograms taken before the treatment, at the removal of the Jumpers and at the end of the period of observation or retention. The Jumpers brought about a slight retrusion of the maxilla and markedly increased the mandibular prognathism. The maxillary incisors and molars were retruded, and the mandibular incisors and molars protruded. The median correction of the overjet was almost 5 mm and of the molar relationship 3 mm. The intrusive forces of the Jumper resulted in a transient intrusion of the maxillary molars and the mandibular incisors. After the period of retention and observation, the dento-alveolar effects had partially or totally relapsed. The remaining effect contributing most to the correction was the skeletal effect on the mandible, i.e. the increase in mandibular prognathism. The skeletal mandibular effect was the same in younger and older subjects. At the end of observation about 60 per cent of the overjet reduction and 75 per cent of the molar correction remained. The incidence of breakage of the Jumpers was 9 per cent.

Activator Appliances↗

PubMed1999

Craniofacial morphology in 6-year-old Icelandic children.

The purpose of the study was to describe the craniofacial characteristics of 6-year-old Icelandic children, make a normative standard for children with an Angle Class I molar relationship, and compare them to those with an Angle Class II molar relationship. The material consisted of the radiographs of 363 children, 184 (50.7 per cent) boys and 179 (49.3 per cent) girls with a mean age of 6 years 7 months (range: 5 years 7 months-7 years 8 months). Twenty-two reference points were digitized and processed by standard methods with the Dentofacial Planner computer software program. The 33 variables calculated included both angular and linear. Two sample t-tests were used to study the differences between different groups. Only minimal differences could be noted between sexes in sagittal and vertical angular measurements. Linear measurements, on the other hand, were usually larger for the boys. When compared with Norwegian material of the same age group, similar trends were observed between sexes in both studies, but the Icelandic children showed slightly more mandibular prognathism and a lower mandibular plane angle. When compared with children with an Angle Class I molar relationship, children with an Angle Class II molar relationship did not have a different maxillary prognathism nor a different mandibular length. Cranial base dimensions were all significantly greater and the cranial base flexure was also significantly more obtuse in the distal group.

Case-Control Studies↗

PubMed1995

Treatment of the craniofacial complications of Beckwith-Wiedemann syndrome.

Variable degrees of macroglossia have been noted in patients with Beckwith-Wiedemann syndrome. Past studies have shown that a major effect of the macroglossia is protrusion of dentoalveolar structures, resulting in an anterior open bite and a prognathic mandibular appearance secondary to an abnormally obtuse gonial angle and increased effective mandibular length. In our series of 11 Beckwith-Wiedemann syndrome patients we have observed that early correction of the macroglossia by means of partial glossectomy has resulted in decreased anterior open bite and mandibular prognathism as compared with patients managed conservatively.

Beckwith-Wiedemann Syndrome↗

PubMed1993

Postnatal development of skull base, neuro- and viscerocranium in man and monkey: morphometric evaluation of CT scans and radiograms.

Postnatal development of the neuro- and viscerocranium with special reference to the maxillodental structures was studied morphometrically by analyzing computer tomograms and radiograms of human and monkey heads of different age groups. The following parameters were used: the prognathic angle, the clivus angle, the palate-incisivus angle, the interincisival angle and the viscerocranial quotient. In the newborn primates including man, all parameters measured were relatively similar; postnatally, however, characteristic differences in the growth pattern between man and monkey were developing. In monkey, a marked prognathic growth of the viscerocranium was found associated with characteristic positional changes of the frontal teeth, whereas the growth of the neurocranium was retarded. Here, unlike the human, a flattening of the skull base was observed. In contrast, the human skull showed no major proportional changes during its postnatal development compared with the original spherical skull form of the newborn.

Adolescent↗

PubMed1996

Geometric morphometrics in primatology: craniofacial variation in Homo sapiens and Pan troglodytes.

Traditionally, morphometric studies have relied on statistical analysis of distances, angles or ratios to investigate morphometric variation among taxa. Recently, geometric techniques have been developed for the direct analysis of landmark data. In this paper, we offer a summary (with examples) of three of these newer techniques, namely shape coordinate, thin-plate spline and relative warp analyses. Shape coordinate analysis detected significant craniofacial variation between 4 modern human populations, with African and Australian Aboriginal specimens being relatively prognathous compared with their Eurasian counterparts. In addition, the Australian specimens exhibited greater basicranial flexion than all other samples. The observed relationships between size and craniofacial shape were weak. The decomposition of shape variation into affine and non-affine components is illustrated via a thin-plate spline analysis of Homo and Pan cranial landmarks. We note differences between Homo and Pan in the degree of prognathism and basicranial flexion and the position and orientation of the foramen magnum. We compare these results with previous studies of these features in higher primates and discuss the utility of geometric morphometrics as a tool in primatology and physical anthropology. We conclude that many studies of morphological variation, both within and between taxa, would benefit from the graphical nature of these techniques.

Africa↗

PubMed1985

Bimaxillary protrusion in the Caucasian: a cephalometric study of the morphological features.

The skeletal morphology of bimaxillary dental protrusion has been investigated in a comparative cephalometric study. Because this is considered a subset of Class I malocclusions, the null hypothesis is that there should be no significant skeletal differences between this group and a Class I control group. There were 30 Caucasians in each group with no bias for age and sex differences between them. Eighteen radiographic landmarks were identified from which 33 skeletal, dental and soft tissue parameters were computed. The bimaxillary group had an average interincisal angle of 115 degrees versus the controls 135 degrees, and showed the following morphological features which persisted over a 5-year growth period: A shorter posterior cranial base. A longer and more prognathic maxilla. Similar mandibular dimensions and prognathism. A mild Class II skeletal pattern. A smaller upper and posterior face height. Diverging facial planes. A procumbent soft tissue profile with a low lip line. These findings indicate that there is a distinctive difference between the underlying skeletal patterns found in the two groups.

Adolescent↗

PubMed1993

Maxillary protraction: different effects on facial morphology in unilateral and bilateral cleft lip and palate patients.

Since 1977 patients with anterior/posterior crossbites in the care of the Bergen CLP team have undergone an interceptive orthopedic protraction phase during the deciduous and mixed dentition period. Eighty-seven cases with complete clefts (63 unilateral and 24 bilateral) displaying anterior crossbite (negative overjet) were treated to normal occlusion. A fixed quad-helix appliance was used in combination with a facial mask. In the unilateral complete cleft lip and palate (UCLP) group, mean age at start of treatment was 6 years 10 months and mean duration was 12 months. In the bilateral complete cleft lip and palate (BCLP) group, mean age at start of treatment was 7 years and mean duration 15 months. The protraction force was 700 g. The sagittal changes during protraction in the UCLP and BCLP groups were compared, and related to the growth changes in a group of noncleft children at the same age. Dentofacial treatment effect was different in the UCLP and BCLP groups. Significant increase of maxillary prognathism (angle s-n-ss) was found only in the UCLP group, whereas the treatment effect in the BCLP group was mainly dentoalveolar. However, after protraction there was no longer a significant difference in maxillary prognathism between the two CLP groups, and the sagittal position of the upper molars was normalized in both groups. The upper incisors remained retroclined in both groups, significantly more in the BCLP group. Increase of the upper facial height (n-sp") and clockwise rotation of the occlusal line were significantly greater in the BCLP group. The computerized occlusal line was unsuitable as a reference standard for the evaluation of sagittal dentofacial treatment changes when the occlusal line was rotated during treatment.

Cephalometry↗

PubMed1994

Skeletal response to maxillary protraction in patients with cleft lip and palate before age 10 years.

Over the last 15 years, cleft lip and palate (CLP) patients with maxillary deficiency in the care of the Bergen CLP Team have received interceptive orthopedic treatment to correct anterior and posterior crossbites during the deciduous and mixed dentition periods. The present study comprises 72 subjects of various cleft types with anterior crossbite, treated to an acceptable positive overjet by maxillary protraction using a facial mask (Delaire). Lateral cephalograms were taken immediately before and after the active treatment periods. Individuals exhibiting a favorable (fair) skeletal response to the protraction were compared with those who revealed little, (poor) skeletal response. Two cephalometric variables were chosen for the evaluation of the sagittal skeletal treatment changes: (1) the sagittal maxillomandibular change (change of angle ss-n-sm [ANB]); and (2) the forward movement of the maxilla (change of distance NSP-maxp), where maxp (maxillary point) represents the anterior contour of maxilla and NSP is the perpendicular to the nasion-sella-line (NSL) through sella. A numerical change greater than or equal to the value 1.5 (degrees or mm, respectively) was classified as fair versus poor response revealing a change less than 1.5. Fair-response (favorable response) of sagittal maxillomandibular change was found in 63% of the cases (mean increase of angle ANB was 3.3 degrees), more often when protraction started early. The length of maxilla was increased, the skeletal maxilla was moved forward 1.8 mm, the upper dentition advanced 3.6 mm, the occlusal line was clockwise rotated, and the anterior face height was increased. Similarly, fair-response of forward movement of maxilla was found in 44% of the cases (mean increase of distance NSP-maxp was 2.4 mm), more often when protraction was started early and after long treatment duration. The maxillary prognathism increased 1.8 degrees, the angle ANB increased 3 degrees, the length of maxilla increased 1.5 mm, and the upper dentition was advanced 3.7 mm. The anterior face height increased with counterclockwise rotation of the nasal line, whereas the occlusal line was clockwise rotated. A paired fair-response of both skeletal maxillomandibular change and skeletal forward movement of maxilla was found in 35% of the cases. During protraction the mean increase of maxillary prognathism was 2.1 degrees, the maxilla moved forward 3.1 mm, the maxillary dentition advanced 4.3 mm, the maxillary length increased 1.9 mm, the ANB angle increased 3.7 degrees, and the lower anterior facial height increased 3.4 mm.

Cephalometry↗

PubMed2002

Morphological evaluations in skeletal Class III malocclusion requiring maxillofacial surgery using orthognathic surgical analysis.

The purpose of this study was to establish a Japanese standard norm for orthognathic surgical analysis to be used in clinical applications and to clarify maxillofacial morphological characteristics in skeletal Class III malocclusions requiring orthognathic surgery. The materials were pretreatment lateral cephalometric radiographs in the relaxed lip posture from 50 subjects with skeletal Class III malocclusions diagnosed as requiring orthognathic surgery. The control group consisted of 50 subjects with normal occlusion and well-balanced faces. Detailed cephalometric measurements were recorded and analyzed statistically. The skeletal, dental, and soft tissue measurements from the normal group did not reveal any marked differences between the sexes. The Class III group exhibited a more retrognathic maxilla and prognathic mandible, a steeper mandibular plane, a more prominent chin, and a larger lower facial height in the skeletal measurements; a significant lingual inclination of the mandibular incisor in the dental measurement; and a more concave profile with prognathic mandible, a larger lower facial height, a more acute nasolabial angle and chin in the soft tissue measurements. We suggest that this analysis can be clinically useful in diagnosis, treatment planning, and posttreatment evaluation for orthognathic surgical cases who are Class III patients.

Case-Control Studies↗

PubMed1995

[The effect of sagittal split ramus osteotomy advancement and setback mandible on occlusal force and masticatory efficiency].

21 patients (mandibular prognathism = 11, mandibular retrognathism = 10) whose occlusal force and masticatory efficiency were measured and analysed preoperatively, three and six months following sagittal split ramus osteotomy. The result shows that, in individuals with mandibular retrognathism treated by lengthening of the mandible, the occlusal force and masticatory efficiency would decrease, in individuals with mandibular prognathism treated by reduction in mandibular length, the occlusal force and masticatory efficiency would increase. There is no linear correlation relationship between the change of the occlusal force and the movement of the angle and the distance of the mandible.

Adult↗

PubMed1981

The puppet-like syndrome of Angelman.

Five new cases are presented of a syndrome characterized mainly by severe mental retardation, epilepsy, puppet-like ataxic movements, microbrachycephaly, prognathism, tongue protrusion, and inappropriate paroxysms of laughter. The cases are analyzed with reference to personal and family histories, clinical findings, and results of special investigations (biochemical, chromosomal, dermatoglyphic, EEG, and radiologic). The findings are compared with those in the 22 patients described previously. Though clinically distinctive, there is as yet no clear-cut evidence as to cause.

Adolescent↗

PubMed2002

Confirmation of existence of a new syndrome: LAPS syndrome.

In l998, Hopkin et al. described a new disorder characterized by progressive laryngotracheal stenosis, short stature, and arthropathy. We provide extensive clinical information on two additional unrelated patients with this distinctive disorder and propose the name LAPS syndrome, to reflect the most consistently recognized features, namely, Laryngotracheal stenosis, Arthropathy, Prognathism, and Short stature.

Abnormalities, Multiple↗

PubMed1993

Gerodermia osteodysplastica: report on two patients and surgical correction of facial deformity.

We present four individuals with Gerodermia Osteodysplastica in a Jewish family from Morocco confirming the autosomal recessive inheritance of the disorder. Three previously unreported findings are described: a) enlarged funnel-shaped mandibular lingula; b) extension of the mandibular premolar and molar roots below the inferior dental canal, and of the second molars into the lower border of mandibular cortical bone; and c) hypercementosis of the maxillary incisors and mandibular molars surrounded by a radiolucent halo in several teeth. The facial deformity resulting from maxillary hypoplasia and mandibular prognathism was corrected by orthognathic surgery: Le Fort I maxillary osteotomy and vertical mandibular osteotomy.

Adult↗