Lateral Cephalometry Research Articles

Osseous expansion of the cranial vault by craniotasis.

A study of cranial vault lengthening using a custom expandable fixation-distraction (craniotatic) appliance was performed in the young-adult rabbit model. Ten 24-week-old rabbits underwent circumferential suturectomy plus expansion (expanded group), 10 underwent circumferential suturectomy without expansion (sham control group), and 10 served as normal controls. The appliance was lengthened at a rate of 2.5 mm per week for 5 weeks. Serial lateral cephalometry, comparative dry-skull anthropometric measurements, and histologic examinations were performed. The expanded group demonstrated a significantly longer skull, cranial vault, anterior cranial base, posterior face, and orbit as compared with the control groups (p less than 0.05). Callus bone filled the distracted suturectomy and united the frontofacial complex to the posterior cranium. In conclusion, skull lengthening by distraction osteogenesis is possible in the rabbit model and offers a new technique for future investigation in the treatment of coronal synostosis.

The Effect of Posture on Upper Airway Dimensions in Normal Subjects and in Patients with the Sleep Apnea/Hypopnea Syndrome

The effect of posture on upper airway dimensions was assessed for two reasons. First, some patients with untreated sleep apnea/hypopnea syndrome (SAHS) report they sleep better sitting upright. Second, to allow comparison of the differing techniques used to determine the site of maximal airway narrowing in awake patients with SAHS, as some are carried out in the erect and others in the supine posture. Lateral cephalometry was therefore carried out in 33 nonsnoring normal subjects and in 29 patients with obstructive SAHS (mean apneas plus hypopneas, 46 per hour; range, 17 to 103). In both normal subjects and patients, uvular width was increased (p less than 0.05) in the supine posture, and this was associated with significant narrowing of the retropalatal airway in the patients with SAHS (erect, 5.0 +/- SD 2.6 mm; supine, 3.6 +/- 2.8 mm; p less than 0.01). In both normal subjects and patients, the retroglossal hypopharynx widened (p less than 0.05) in the supine posture (e.g., in patients with SAHS, posterior airway space was: erect, 11.5 +/- 4.5 mm; supine, 13.4 +/- 4.8 mm; p = 0.003). In the supine posture there was anterior movement of the hyoid and neck flexion in both groups. However, a study of the effect of neck flexion in the erect posture showed that neck flexion produced no changes in airway caliber. Thus, posture is an important determinant of upper airway dimensions.

Postnatal Craniofacial Skeleton Development Following a Pushback Operation of Patients with Cleft Palate

A longitudinal growth study of the craniofacial skeleton in 52 (19 males, 33 females) Danish individuals with cleft palates was performed. Thirty (13 males, 17 females) had clefts of the soft palate only or clefts extending into the posterior third of the hard palate. Twenty-two (6 males, 16 females) had more extensive clefts including up to two-thirds of the hard palate. The cleft was closed with a pushback operation at 22 months of age. Orthodontic treatment was included in the early mixed dentition. Lateral cephalometries were obtained at 5, 8, 12, 16, and 21 years of age. Twenty-four variables were digitized and analyzed. The results indicated that patients with more extensive clefts demonstrated significantly smaller anterior cranial base length (N-S), total cranial base length (N-Ba), maxillary dentoalveolar base length (A-PMP), mandibular length (Cd-Pgn), upper anterior and posterior facial heights (N-ANS and P-PMP), and total facial height (N-Gn). Patients with the more extensive clefts reached maximum growth spurt later than patients with less extensive clefts in all dimensions except the A-PMP and the lower and total facial heights.

Postnatal Craniofacial Skeleton Development following a Pushback Operation of Patients with Cleft Palate

A longitudinal growth study of the craniofacial skeleton in 52 (19 males, 33 females) Danish individuals with cleft palates was performed. Thirty (13 males, 17 females) had clefts of the soft palate only or clefts extending into the posterior third of the hard palate. Twenty-two (6 males, 16 females) had more extensive clefts including up to two-thirds of the hard palate. The cleft was closed with a pushback operation at 22 months of age. Orthodontic treatment was included in the early mixed dentition. Lateral cephalometries were obtained at 5, 8, 12, 16, and 21 years of age. Twenty-four variables were digitized and analyzed. The results indicated that patients with more extensive clefts demonstrated significantly smaller anterior cranial base length (N-S), total cranial base length (N-Ba), maxillary dentoalveolar base length (A-PMP), mandibular length (Cd-Pgn), upper anterior and posterior facial heights (N-ANS and P-PMP), and total facial height (N-Gn). Patients with the more extensive clefts reached maximum growth spurt later than patients with less extensive clefts in all dimensions except the A-PMP and the lower and total facial heights.

The Effect of Beam Collimation in Lateral Radiographic Cephalometry

A study was carried out to compare the image contrast of lateral cephalometric radiographs taken with and without the modified beam collimation and to evaluate the effect of this on the reliability of cephalometric measurements. The findings indicated that the cephalographs taken with modified beam collimation consistently showed a higher image contrast than the cephalographs taken with standard beam collimation. Despite this, however, there was no significant difference in the reliability of cephalometric measurements between the two groups of films.

Obstructive sleep apnoea in children undergoing routine tonsillectomy and adenoidectomy

Sleep screening was used to discover the incidence of sleep apnoea in 50 children undergoing routine adenotonsillectomy for recurrent upper respiratory tract infections, randomly selected from the waiting list. Preoperative assessment included a detailed parental history, physical examination, and lateral cephalometry, in order to identify factors that might alert the clinician to a diagnosis of obstructive sleep apnoea. There were 2 equal groups of snorers and non-snorers (grade 0); 1 patient was found to have the sleep apnoea syndrome (IV), 9 patients had obstructive snoring with apnoeic episodes (III), 3 patients had snoring with a disrupted sleep pattern (II), and 12 patients snored with no disruption of sleep (I). In identifying patients with apnoea, a history of snoring was unhelpful, whereas one of breathing irregularities was found to be highly specific. Nasal obstruction correlated poorly; however, there was a significant relationship between tonsillar position and size and sleep grade (Chi-squared P less than 0.01). Stepwise regression analysis showed a large contribution to the grading was made by the size of the oropharyngeal airway measured by lateral cephalometry. The children in grade II-IV were re-studied 3 months post-operatively and all reverted to grades 0 or I.

Dose reduction in lateral cephalometry using rare-earth screens.

Dose reduction in lateral cephalometry using rare-earth screens.

Mandibular atrophy and metabolic bone loss: Mandibular ridge augmentation by combined sandwich-visor osteotomy and resorption related to metabolic bone state. A 5-year follow-up

92 patients, 31 with and 61 without signs of metabolic bone loss, were treated with a combined sandwich-visor osteotomy. A 5-year follow-up showed a significantly higher rate of resorption in patients with radiographic signs of metabolic bone loss. The analysis was based upon lateral cephalometry.

Mandibular atrophy and metabolic bone loss: Mandibular ridge augmentation by combined sandwich-visor osteotomy and resorption related to metabolic bone state

22 edentulous women, 11 with and 11 without signs of metabolic bone loss were treated by a combined sandwich-visor osteotomy. Longitudinal studies showed a higher rate of resorption in women with radiographic signs of metabolic bone loss. The analysis was based upon lateral cephalometry.

Application of Lateral Skull Cephalometry to Prosthodontics

Application of Lateral Skull Cephalometry to Prosthodontics