Nihat Kiliç

Condylar asymmetry in unilateral posterior crossbite patients

INTRODUCTION Posterior crossbite is defined as an abnormal buccolingual relationship between opposing posterior teeth including the canines in centric occlusion. The most common form of posterior crossbite is unilateral with a functional shift of the mandible toward the crossbite side. Lateral shift of the mandible in functional crossbite patients results in mandibular skeletal deflection to the crossbite side. Thus, the asymmetrical position of the mandible in these patients can result in asymmetrical condylar heights. The purpose of this study was to investigate condylar and ramal asymmetries in unilateral crossbite patients as compared with normocclusive subjects. METHODS The study groups included 81 patients with unilateral posterior crossbite and a control group of 75 patients with normal occlusion. Condylar, ramal, and condylar-plus-ramal asymmetry values were computed for all subjects on panoramic radiographs. Data were analyzed statistically with ANOVA for repeated measures and univariate ANOVA. RESULTS The patients with unilateral posterior crossbite had more asymmetric condyles than did the controls. In addition, condylar, ramal, and condylar-plus-ramal heights on the crossbite side were smaller than those on the noncrossbite side. CONCLUSIONS Subjects with functional unilateral posterior crossbite have asymmetrical condyles.

Effects of rapid maxillary expansion on nasal breathing and some naso-respiratory and breathing problems in growing children: A literature review

OBJECTIVE Rapid maxillary expansion (RME) is a dentofacial orthopedic treatment procedure which has been routinely used in young patients. Main goal of RME is to correct the existing posterior crossbite and to widen the maxilla and maxillary dental arch. However, a concomitant and contributing benefit of this procedure is an improvement on nasal airway which facilitates nasal respiration. RME brings about not only an increase in nasopharyngeal airway dimensions and an improvement in nasal respiration but also a decrease in naso-respiratory problems of the patients having maxillary constriction and mouth breathing. The purpose of this article is to review the effects of RME on naso-respiratory and breathing problems caused by maxillary constriction and mouth breathing in growing children. CONCLUSION Although orthodontic treatment is carried out to correct dental and skeletal discrepancies, some authors showed that treatment outcomes of RME could also effective on naso-respiratory and sleep-disordered breathing problems of the growing children. However, it must be kept in mind that this respect of RME was evaluated in a little number of studies and had a low-level of evidence.

A comparison of dentoalveolar inclination treated by two palatal expanders.

The objective of the present study was to evaluate buccal dentoalveolar inclinations in subjects treated with a Hyrax (tooth-borne) or acrylic-bonded (tooth-tissue borne) palatal expander. The sample comprised 39 patients (10 males and 29 females) aged between 11 and 16 years randomly assigned to two groups. Rapid maxillary expansion (RME) was carried out with a Hyrax appliance in one group (n = 21) and with an acrylic-bonded appliance in the other (n = 18). Their mean ages were 13 years 9 months and 13 years 6 months, respectively. Orthodontic study models were obtained before RME (T1) and approximately 1 week after completion of maxillary expansion (T2). A line of barium sulphate solution was drawn between the upper first molars on the models, and radiographs were taken. The radiographic images of the models were transferred to digital medium, and buccal tipping of the molar crowns and alveolar processes were evaluated by means of a software program. The data were analysed by paired and Students t-tests. Both RME appliances produced significant (P < 0.001) dentoalveolar tipping during RME, but this was greater in the Hyrax group (P < 0.05).

Leptin levels in gingival crevicular fluid during orthodontic tooth movement.

OBJECTIVES To test if leptin can be detected in the gingival crevicular fluid (GCF) around moving teeth, and to determine whether any changes occur during orthodontic tooth movement. MATERIALS AND METHODS An upper canine requiring distal movement served as the test tooth; the contralateral canine was used as a control tooth. The control tooth was included in the orthodontic appliance, but was not subjected to the orthodontic force. GCF sampling from the distal sites of the test and control teeth was done at baseline, 1 hour, 24 hours, and 168 hours. RESULTS Leptin concentrations of the test teeth decreased in a time-dependent manner. When compared with the baseline measurement, the decrease was significant at 168 hours (P < .05). CONCLUSIONS The concentration of leptin in GCF is decreased by orthodontic tooth movement; the results of the present study also suggest that leptin may have been one of the mediators responsible for orthodontic tooth movement.

Condylar asymmetry in bilateral posterior crossbite patients.

OBJECTIVE To investigate whether patients with bilateral posterior crossbite have asymmetrically developed condyles. MATERIALS AND METHODS The study group consisted of 75 patients with bilateral posterior crossbite, and a control group of 75 subjects with normal occlusion. Condylar, ramal, and condylar plus ramal asymmetry values were computed for all of the subjects on orthopantomograms. Data were analyzed statistically by means of paired t-test and Students t-test. RESULTS The patients with bilateral posterior crossbite had more asymmetrical condyles relative to the controls. However, there were no statistically significant differences in condylar, ramal, or condylar plus ramal heights between left and right sides in both the control and crossbite groups. CONCLUSION Patients with bilateral posterior crossbite can have asymmetrical condyles and might be at risk for the development of future skeletal mandibular asymmetries.

Soft tissue profile changes following maxillary protraction in Class III subjects

SUMMARY The dentoskeletal effects of maxillary protraction (MP) therapy have been extensively investigated, while those relating to soft tissue profile changes are limited. Thus, the aim of this study was to determine the degree of soft tissue profile changes following MP therapy. The material consisted of the cephalometric films of 24 female subjects (12.69 +/- 1.08 years) with a Class III malocclusion who underwent MP therapy; these were compared with a control group of 15 females (12.13 +/- 0.63 years) with a Class I occlusion and matched for chronological age and observation period. Cephalometric films were available for all subjects before (T1) and after (T2) treatment/observation. The initial measurements and treatment/control changes were compared between the groups by means of a Students t-test. The subjects in the MP group had a concave facial profile when compared with the controls. Comparison of the changes induced by MP therapy showed that the maxilla and surrounding soft tissues showed significant anterior movement (P < 0.001), whereas the mandible and surrounding soft tissues showed a backward and downward rotation. The improvement in facial profile predominantly resulted from maxillary soft tissue changes and mandibular hard tissue changes. The concave soft tissue profiles of the Class III subjects were corrected by anterior movement of the maxilla and a concomitant increase in the fullness of the upper lip. The concave skeletal profiles were, however, corrected mainly by backward and downward rotation of the mandible.

Effects of early unilateral first molar extraction on skeletal asymmetry.

INTRODUCTION The purpose of this study was to investigate dental and skeletal asymmetry in patients who had unilateral first molar extractions. METHODS Two study groups were formed according to the location of the extracted first molars. Group I included 25 subjects who had a maxillary permanent first molar extracted (mean age, 18.25 years). Group II included 26 subjects who had a mandibular permanent first molar extracted (mean age, 17.75 years). The control group included 30 subjects with no missing teeth and normal occlusion (mean age, 18.50 years). Dental and skeletal asymmetry values were computed on posteroanterior radiographs for all subjects. Data were analyzed statistically with paired t tests to determine intragroup differences and with ANOVA and Scheffé tests to determine intergroup differences. RESULTS Unilateral first molar extractions caused dental midline deviations in both arches, but this was more prominent in the mandibular arch. Unilateral first molar extraction during growth and development can result in remarkable skeletal asymmetry, especially in the lower third of face. CONCLUSIONS Patients who had early unilateral first molar extraction can have skeletal and dental asymmetries.

Effects of rapid maxillary expansion with a memory palatal split screw on the morphology of the maxillary dental arch and nasal airway resistance

The purpose of this study was to investigate the effects of rapid maxillary expansion (RME) with a memory palatal split screw on the morphology of the maxillary dental arch and nasal airway resistance (NAR). The material consisted of the rhinomanometric records and study models of 15 patients (8 females and 7 males) with mean age of 12.89 ± 1.20 years. Data were collected before expansion (T1), immediately after expansion (T2), and after a retention period of 6 months (T3). Maxillary expansion was completed within 8 days in all subjects. The data were analysed by analysis of variance. The least significant difference test was also used to determine between which periods the changes in the measurements were significant. Statistical analyses showed that NAR decreased (P < 0.01) and intermolar and interpremolar distances increased (P < 0.001) significantly at all observation periods, except between T2 and T3. RME using a memory palatal split screw is effective for improvement of nasal respiration via a widening effect on the nasal cavity.

Effects of force magnitude on tooth movement: an experimental study in rabbits.

The aim of the present study was to investigate the effects of two different force levels on the amount of total and daily tooth movement in rabbits and to determine whether any increase in tooth movement is equal to the increase in force. Forces of approximately 20 (group I) and 60 (group II) g (19.6 and 58.8 cN) were applied to the upper central incisors of 25 young adult (14 weeks of age) New Zealand female rabbits. The distance between the incisors was measured daily from the mid-levels of the crowns using a digital calliper for 20 days. Analysis of variance and Bonferroni multiple range test were used for statistical analyses. The distance between the teeth in group II was significantly greater than that in group I during the first 3 days. Between days 4 and 14, no significant difference was observed. During the last 6 days, except for day 19, tooth movement in group II again increased, resulting in the distance between the teeth being greater in group II. The mean total opening was 3.98 +/- 0.59 mm in group I and 4.82 +/- 0.82 mm in group II, and the mean difference was approximately 0.8 mm. The results of this study show that there was a close relationship between tooth movement and force magnitude. However, higher forces did not produce force-equal tooth movements.

Temporomandibular joint osteoarthritis: cone beam computed tomography findings, clinical features, and correlations

The aim of this study was to determine the prevalence of and associations between clinical signs and symptoms and cone beam computed tomography (CBCT) findings of temporomandibular joint osteoarthritis (TMJ-OA). Seventy-six patients (total 117 TMJ) with osteoarthritis were included in this study. Clinical signs and symptoms and CBCT findings were reviewed retrospectively. A considerable decrease in mandibular motions and mastication efficiency, and considerable increase in joint sounds and general pain complaints were observed. The most frequent condylar bony changes were erosion (110 joints, 94.0%), followed by flattening (108 joints, 92.3%), osteophytes (93 joints, 79.5%), hypoplasia (22 joints, 18.8%), sclerosis (14 joints, 12.0%), and subchondral cyst (four joints, 3.4%). Flattening of the articular eminence and pneumatization were each observed in five joints. Forty-one patients had bilateral degeneration and 35 had unilateral degeneration. Hypermobility was detected in 47 degenerative joints. Masticatory efficiency was negatively correlated with both condylar flattening and sclerosis, and general pain complaints was positively correlated with condylar flattening. Condylar erosion, flattening, osteophytes, pain, joint sounds, reduced jaw movements, and worsened mastication were common findings in TMJ-OA in the present study. Poor correlations were found between osseous changes and clinical signs and symptoms of TMJ-OA. CBCT is a powerful diagnostic tool for the diagnosis of TMJ-OA.