Topographical relationship of the greater palatine artery and the palatal spine. Significance for periodontal surgery.

AIM: The aims of this study were to (1) identify the branching pattern and course of the greater palatine artery (GPA), (2) carry out a morphological analysis of the palatal bony prominence that divides the medial and lateral grooves and (3) characterize the topographical relationships between these two structures. METHODS: Thirty-six hemimaxillae were studied with the aid of a surgical microscope to elucidate the GPA. A further 25 dry skulls were examined to establish the morphology of the palatal spine. RESULTS: The most common GPA branching pattern was type I (41.7%, 15 sides), which gave off the medial and canine branches after the bony prominence. The distances from the CEJ to the lateral branch of the GPA were 9.04 ± 2.93 mm (canine), 11.12 ± 1.89 mm (first premolar), 13.51 ± 2.08 mm (second premolar), 13.76 ± 2.86 mm (first molar) and 13.91 ± 2.20 mm (second molar). The palatal spine was frequently observed as the bony prominence (66.3%, 57 sides), and was located at 6.49 ± 1.76 mm from the greater palatine foramen, with a length of 10.42 ± 2.45 mm. There was no a correlation between the bony prominence shape and the GPA branching pattern. CONCLUSIONS: These results could provide the reference data regarding the topography of the GPA for periodontal surgery.

Doppler ultrasound to detect pulpal blood flow changes during local anaesthesia.

AIM: To examine whether Doppler ultrasound can detect changes in pulpal blood flow after infiltration anaesthesia. METHODOLOGY: Changes in pulpal blood flow in maxillary central incisor teeth of 18 patients (mean age 26.7 years, 13 men, five women) after infiltration anaesthesia were examined. Before infiltration anaesthesia, the pulpal blood flow was measured using Doppler ultrasound. A local anaesthetic solution containing 2% lidocaine with 1:80,000 epinephrine was injected into the submucosa above the experimental tooth. The Doppler ultrasound test was carried out at 5, 10, 20, 30, 45 and 60 min after infiltration. The parameters were Vas (maximum linear velocity, cm s(-1) ), Vam (average linear velocity, cm s(-1) ) and Vakd (minimum linear velocity, cm s(-1) ), which are indicators of the level of blood flow. The mixed procedure at the 95% confidence interval was used to examine the changes in pulpal blood flow after the injection. RESULTS: The linear velocity profiles (Vas, Vam, and Vakd) decreased sharply 5 min after anaesthesia and then reduced continuously for 30 min. The maximum degree of blood flow reduction in Vas, Vam and Vakd was 58%, 83% and 82%, respectively. After 30 min, the linear velocities increased gradually. The Vam returned to the pre-anaesthesia state at 60 minutes but the Vas and Vakd did not recover completely. CONCLUSIONS: Doppler ultrasound can detect changes in pulpal blood flow after infiltration anaesthesia. In the future, Doppler ultrasound can be used as a tool for measuring pulpal blood flow.

The accuracy of identifying the greater palatine neurovascular bundle: a cadaver study.

BACKGROUND: The palate is a common site for harvesting subepithelial connective tissue grafts (SCTG). The size of SCTG that can be harvested is dictated by the position of the greater palatine neurovascular bundle (GPB). The aims of this cadaver study are to assess the accuracy of predicting the location of the GPB on study models and to evaluate anatomic factors that might influence the predictability. METHODS: Eleven fully dentate or partially edentulous maxillary cadavers were used. Study models were fabricated after the greater palatine foramen was identified. The GPB was recognized after dissection, from which the distance to the cemento-enamel junction of the first molar and premolar was measured. Eight periodontists and twelve periodontal residents were asked to estimate the location of the GPB on the study models and the same measurements were taken. Comparisons of the estimated and true GPB position were performed. The correlation between the palatal vault height and the variability of detecting the GPB was investigated. RESULTS: The most frequent greater palatine foramen location was between the second and third molars (66.6%). For most cases, there was an underestimation of the location of the GPB up to 4 mm. The interexaminer variability was positively correlated with the vault height. CONCLUSIONS: The estimated location of the GPB was commonly closer to the cemento-enamel junction of posterior teeth. Agreement on the location of the GPB was lowered with the presence of high palatal vaults. The results of this study could assist clinicians in planning the location for harvesting SCTG on the hard palate.

Clinical implications of the topography and distribution of the posterior superior alveolar artery.

The aim of this study was to clarify the arrangement of the anatomic courses and distribution of the intraosseous branch (IObr) of posterior superior alveolar artery. The anatomic variations in the topographic relationships were described to provide beneficial data to minimize injury to the IObr during surgical procedure of the buccal wall of the maxillary sinus. The IObrs in 42 hemifaces of embalmed Korean cadavers were examined. The courses of the IObr of the posterior superior alveolar artery were classified into 2 categories: the straight (type 1) and the U-shaped (type 2). The type 1 was the most common (78.1%), and the type 2 was observed in 21.9% of the specimens. The minimum mean height from the cervix to the IObr was 21.1 mm in the first molar region. The IObr ran at the lowest level from the maxillary sinus floor at the first premolar region. These anatomic findings in the current study could represent useful information for the various surgical procedures of the maxilla.

Tooth movement and vascularity of the dental pulp: a pilot study.

The effect of orthodontic tooth movement on the dental pulp was assessed histologically in twelve subjects. The participants in this study required the extraction of at least two maxillary first premolars for orthodontic treatment. They were asked to wear a maxillary removable appliance that acted to move a randomly determined premolar in a buccal direction. The appliance was designed to avoid contacting the contra-lateral tooth that was used as the matched control. The appliance was initially worn for a week to ensure patient comfort and cooperation. The appliance was then activated and the patient dismissed. After two weeks, the appliance was reactivated. Both the control and experimental teeth were extracted three weeks later, on the thirty-fifth day of activated appliance wear. The teeth were fixed, decalcified and sectioned. The sections were stained with haematoxylin and eosin for histological examination. This investigation demonstrated that orthodontic tooth movement did have an effect upon the dental pulp, causing vasodilation in the pulp of an orthodontically stressed tooth.