Evaluation of 3-dimensional tooth crown size in cleft lip and palate patients.

INTRODUCTION: The aims of this study were to evaluate 3-dimensional (3D) tooth crown sizes in patients with cleft lip and palate (CLP) and to compare them with those of a Class I control group. METHODS: Orthodontic dental casts were used of 72 subjects with CLP (20 bilateral [BCLP], 34 unilateral left [ULCLP], 18 unilateral right [URCLP]) and 53 adolescents in the permanent dentition stage with Class I occlusion. Mesiodistal (MD), labiolingual (LL), and occlusogingival (OG) measurements were recorded by the same examiner using a digital caliper. Statistical analyses were conducted, including repeatability, analysis of variance (ANOVA), and the Duncan tests. RESULTS: Maxillary and mandibular premolar MD dimensions were larger in the CLP groups than in the control group. The smallest MD dimensions were those of the maxillary right lateral incisors in the BCLP group (P <0.05). The maxillary left lateral incisor MD dimensions in the ULCLP group were smaller when compared with other CLP groups (P <0.001). In general, all LL and OG measurements were smaller in the CLP groups than in the Class I group in both dental arches. CONCLUSIONS: In general, MD, LL, and OG dimensions of CLP patients were smaller than those of the Class I subjects, not only in the affected maxillary dental arch, but also in the mandibular dental arch. Variations in 3D tooth dimensions were found among all CLP types. The lateral incisor in the cleft region was the smallest. A 3D tooth-size evaluation should be included in the diagnostic records to determine precise treatment planning and final occlusion in CLP patients.

Longitudinal investigation of soft palate and nasopharyngeal airway relations in different rotation types.

The relationship between the soft palate and the nasopharyngeal airway in different mandibular growth rotation models was investigated. A total of 72 lateral cephalograms were obtained three years longitudinally from 24 individuals. The subjects had a mean age of 10.7 +/- 1.2 years and showed a normal (n = 8), posterior (n = 8), and anterior (n = 8) mandibular rotation pattern. Linear and angular measurements of the soft palate and nasopharyngeal airway were recorded by using PORDIOS computer program and were examined by means of descriptive statistics and paired t-tests. A linear increase in the soft palate length (SPL) was observed in all groups, with the posterior mandibular rotation group showing the largest increase within the observation period (28.56 +/- 4.83 to 34.98 +/- 2.87; P < .01). According to the paired t-test, palatal plane (ANS-PNS)/soft palate tip (SPT) angle showed a statistically significant decrease in the posterior rotation group (P < .01). The ratio between SPL and superior nasopharyngeal space (SPS) did not show a statistically significant difference among the groups. Although various amounts of soft palate and nasopharyngeal airway growth occurred in the different mandibular rotation types, the ratio between SPL and SPS (SPL/SPS), which plays an indispensable role in velopharyngeal functions, did not show a statistically significant difference in the groups. This assured velopharyngeal closure throughout the active growth period.

Profile changes associated with different orthopedic treatment approaches in Class III malocclusions.

The aim of this study was to evaluate and compare the soft tissue effects of chincup (CC), chincup plus bite plate (CC+P), and reverse headgear (RHg) therapies with each other and with an untreated control group (C). The material consisted of lateral cephalometric and hand-wrist films of 59 Class III cases and 20 nontreated control subjects. Thirty-one cases were treated with CC, 14 with CC+P, and 14 with RHg, and Class I relation was achieved. The mean pretreatment ages were approximately 11 years and the observation period was one year. The cephalometric films were analyzed according to the structural superimposition method of Björk. All tracings were double digitized, and the measurements were calculated by a computer program (PORDIOS). Treatment and control changes within the groups and the differences between the groups were analyzed statistically. Forward positioning of the maxilla was significant in the RHg group, whereas the mandible was positioned backward significantly in all the treatment groups. Posterior rotation of the mandible was significant in the CC+P and RHg groups. The overjet increased and the overbite decreased significantly in all the treatment groups. Forward movement of soft tissue A and upper lip was significant in all groups, whereas more pronounced in the CC+P group. The soft tissue changes in the mandibular region were significant in the CC and CC+P groups, whereas in the maxillary region more significant and similar improvements were obtained by CC+P and RHg treatments. Longterm studies are required to confirm the stability of these changes.

Natural craniofacial changes in the third decade of life: a longitudinal study.

The aim of this study was to evaluate longitudinally the natural craniofacial and dentoalveolar changes that occur in the third decade of life. Natural head position lateral cephalometric films and dental casts of 30 people (14 women and 16 men) were evaluated. The mean age at the beginning of the observation period was 22.35 years for the women and 22.19 years for the men, and the observation period was approximately 10 years. Cephalometric films were superimposed by the structural method, and the measurements of the dental casts were made with a digital caliper. All tracings were digitized, and changes in the 65 cephalometric and 10 dental cast measurements were evaluated statistically. In this early adult period, small changes were found in the craniofacial and craniocervical parameters; the changes were more significant in the women. The most significant changes were found in the vertical dimension. The total anterior face height increased in both genders, while the lower anterior face height increased significantly in the female group. Soft tissue measurements reflected the vertical skeletal changes. The retrusion of the upper lip was significant in the women, and the upper lip thickness decreased in both genders. In the dentoalveolar region, the main movement was eruption of the teeth. The overbite amount increased significantly only in the female group. All dental arch measurements decreased in both sexes. The decrease in the mandibular arch length discrepancy was significant in the men. These findings have important clinical implications regarding the long-term stability and retention of orthodontic and orthognathic surgery treatment results.